tag:theconversation.com,2011:/africa/topics/the-future-of-batteries-40687/articlesThe future of batteries – The Conversation2019-07-15T12:03:29Ztag:theconversation.com,2011:article/991642019-07-15T12:03:29Z2019-07-15T12:03:29ZHow do lithium-ion batteries work?<figure><img src="https://images.theconversation.com/files/278151/original/file-20190605-40743-d27krz.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C927%2C679&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lithium-ion batteries power lots of different kinds of devices.</span> <span class="attribution"><a class="source" href="http://www.tc.gc.ca/eng/tdg/lithium-batteries-are-dangerous-goods-1162.html">Transport Canada</a></span></figcaption></figure><p>Three researchers who developed a technology at the heart of the smartphone era – and its resulting societal transformation – have won the <a href="https://www.nobelprize.org/prizes/chemistry/2019/summary/">2019 Nobel Prize in Chemistry</a>. The work of John B. Goodenough, M. Stanley Whittingham and Akira Yoshino made crucial advances in lithium-ion batteries, which store large amounts of power in small battery cells and are quick and easy to recharge.</p>
<p>First sold commercially <a href="http://www.kyria.co.uk/blog-the-25th-anniversary-of-the-lithium-ion-battery/">in 1991 by Sony</a> for its camcorders, these types of batteries are good for much more than portable consumer electronics. They’re at the center of two other technological revolutions with the power to transform society: the transition from internal combustion engines to electric vehicles, and the shift from an electric grid powered by fossil fuels to renewable energy generators that store surplus electricity in batteries for future use.</p>
<p>So how do these batteries work? Scientists and engineers have spent entire careers trying to build better batteries and there are still mysteries that we don’t fully understand. Improving batteries requires chemists and physicists to look at changes on the atomic level, as well as mechanical and electrical engineers who can design and assemble the battery packs that power devices. As a materials scientist at the University of Washington and Pacific Northwest National Lab, <a href="https://scholar.google.com/citations?hl=en&user=AlYxAVEAAAAJ">my work</a> has helped explore new materials for lithium-air batteries, magnesium batteries and of course lithium-ion batteries. </p>
<p>Let’s consider a day in the life of two electrons. We’ll name one of them <a href="https://en.wikipedia.org/wiki/Alessandro_Volta">Alex</a> and he has a friend named <a href="https://en.wikipedia.org/wiki/George_Johnstone_Stoney">George</a>. </p>
<h2>Battery anatomy</h2>
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<a href="https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=496&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=496&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=496&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278145/original/file-20190605-40731-14aq0oy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">What a standard AA alkaline battery looks like on the inside.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Alkaline-battery-english.svg">Lead holder/Wikimedia Commons</a></span>
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<p>Alex lives inside a standard alkaline AA battery, like in your flashlight or remote control. Inside a AA battery, there is a compartment filled with zinc and another filled with manganese oxide. At one end, the zinc only <a href="https://www.khanacademy.org/science/biology/chemistry--of-life/chemical-bonds-and-reactions/v/electronegativity-trends">weakly hangs onto electrons</a> like Alex. On the other end, the manganese oxide <a href="https://blogs.scientificamerican.com/degrees-of-freedom/the-periodic-table-and-batteries/">powerfully pulls</a> electrons toward itself. In between, stopping the electrons from going directly from one side to another, is a piece of paper soaked in a solution of potassium and water, which coexist as positive potassium ions and negative hydroxide ions.</p>
<p>When the battery is put into a device and switched on, the device’s internal circuit is completed. Alex gets pulled out of the zinc, through the circuit and into the manganese oxide. Along the way, his movement powers the device, or light bulb or whatever is connected to the battery. When Alex leaves, he can’t come back: The zinc that has lost an electron bonds with the hydroxide to form zinc oxide. This compound is extremely stable and cannot easily be converted back into zinc. </p>
<p>On the other side of the battery, the manganese oxide gains an oxygen atom from the water and leaves hydroxide ions behind to balance out the hydroxide being consumed by the zinc. Once all of Alex’s neighbors have left the zinc and moved to the manganese oxide, the <a href="https://www.nytimes.com/2017/08/01/technology/alkaline-batteries-replace-lithium-ion.html">battery is exhausted</a> and needs to be recycled. </p>
<h2>Lithium-ion advantages</h2>
<p>Let’s compare this to George, who lives in a lithium-ion battery. Lithium-ion batteries have the same basic building blocks as alkaline AA cells, with a few differences that confer major advantages. </p>
<p>George lives in graphite, which is even weaker than zinc at holding onto electrons. And the other part of his battery is lithium cobalt oxide, which pulls electrons much more powerfully than manganese oxide – which gives his battery the ability to store much more energy in the same amount of space than an alkaline battery. The solution separating the graphite and lithium cobalt oxide contains positively charged lithium ions, which easily form and break chemical bonds as the battery is discharged and recharged.</p>
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<a href="https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=618&fit=crop&dpr=1 600w, https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=618&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=618&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=776&fit=crop&dpr=1 754w, https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=776&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/278147/original/file-20190605-40738-hwlbkk.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=776&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">As electrons move outside the battery, lithium ions move inside it to keep the electrical equilibrium.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1039/C3CS60199D">Islam and Fisher, Chemical Society Reviews, 2014.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<p>Those chemical reactions are reversible, unlike the formation of zinc oxide, which is what lets the electrons and the lithium ions flow back and forth over many cycles of charging and discharging. </p>
<p>This process <a href="https://theconversation.com/why-does-my-phone-battery-die-so-fast-98367">isn’t 100% efficient</a>, though – all batteries eventually lose their ability to hold energy. Nevertheless, the family of Li-ion chemistries have been powerful enough to dominate battery technology today.</p>
<p><em>Editor’s note: This is an updated version of an article originally published July 15, 2019.</em></p>
<p>[ <em><a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=thanksforreading">Thanks for reading! We can send you The Conversation’s stories every day in an informative email. Sign up today.</a></em> ]</p><img src="https://counter.theconversation.com/content/99164/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Masse is a Ph.D. candidate at the University of Washington in Seattle, as well as the founder of Astrolabe Analytics, Inc. He has received funding from the National Science Foundation, and Astrolabe has received funding from the United States Air Force. </span></em></p>The 2019 Nobel Prize in Chemistry rewarded crucial advances in these small, powerful, easy to charge batteries.Robert Masse, Ph.D. Student in Materials Science and Engineering, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1039552018-11-27T11:41:24Z2018-11-27T11:41:24ZWhy aren’t there electric airplanes yet?<figure><img src="https://images.theconversation.com/files/246328/original/file-20181119-119943-169t93l.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Building an electric airplane is very different from building an electric car or truck.</span> <span class="attribution"><span class="source">Venkat Viswanathan</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>As electric cars and trucks appear increasingly on U.S. highways, it raises the question: When will commercially viable electric vehicles take to the skies? There are a number of <a href="https://theconversation.com/inspired-by-sci-fi-an-airplane-with-no-moving-parts-and-a-blue-ionic-glow-107233">ambitious efforts</a> to build electric-powered airplanes, including <a href="https://zunum.aero/">regional jets</a> and planes that can cover <a href="https://www.airbus.com/innovation/The-future-is-electric.html">longer distances</a>. Electrification is starting to enable a type of air travel that <a href="https://arstechnica.com/tech-policy/2018/10/scotlands-orkney-islands-may-see-electric-plane-service-by-2021/">many have been hoping for</a>, but haven’t seen yet – <a href="https://www.theverge.com/2017/4/20/15369850/lilium-jet-flying-car-first-flight-vtol-aviation-munich">a flying car</a>.</p>
<p>A key challenge in building electric aircraft involves how much energy can be stored in a given amount of weight of the on-board energy source. Although the best batteries store about 40 times less energy per unit of weight than jet fuel, a greater share of their energy is available to drive motion. Ultimately, for a given weight, jet fuel contains about <a href="https://www.wired.com/2017/05/electric-airplanes-2/">14 times more usable energy</a> than a state-of-the-art lithium-ion battery. </p>
<p>That makes batteries relatively heavy for aviation. Airline companies are already <a href="http://www.abc.net.au/news/2018-09-15/airlines-and-carry-on-bag-weight-why-it-matters/10236612">worried about weight</a> – imposing <a href="https://www.nytimes.com/2013/04/09/business/airlines-weigh-costs-and-passenger-pounds-on-the-road.html">fees on luggage</a> in part to limit how much planes have to carry. Road vehicles can handle heavier batteries, but there are similar concerns. Our research group has <a href="https://doi.org/10.1149/2.0671711jes">analyzed the weight-energy tradeoff</a> in <a href="https://doi.org/10.1149/2.0671711jes">electric pickup trucks</a> and <a href="https://doi.org/10.1021/acsenergylett.7b00432">tractor-trailer</a> or <a href="https://www.wired.com/2017/06/elon-musk-tesla-semi-truck-battery/">semi-trucks</a>. </p>
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<figcaption>
<span class="caption">This artist’s concept of NASA’s experimental electric plane design shows 14 motors along the wings.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:X57-Maxwell-CGI_(cropped).jpg">NASA</a></span>
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<h2>From electric trucks to flying vehicles</h2>
<p>We based our research on a very accurate description of the energy required to move the vehicle along with details of the underlying chemical processes involved in Li-ion batteries. We found that an electric semi-truck similar to today’s diesel-powered ones could be designed to travel up to 500 miles on a single charge while being able to carry the cargo of about 93 percent of all freight trips. </p>
<p>Batteries will need to get cheaper before it makes economic sense to begin the process of converting the U.S. trucking fleet to electric power. That seems <a href="https://www.bloomberg.com/news/articles/2017-12-05/latest-bull-case-for-electric-cars-the-cheapest-batteries-ever">likely to happen</a> by the <a href="https://arxiv.org/abs/1804.05974v1">early 2020s</a>.</p>
<p>Flying vehicles are a bit further away, because they have different power needs, especially during taking off and landing.</p>
<h2>What is an e-VTOL?</h2>
<p>Unlike passenger planes, <a href="https://www.businessinsider.com/amazon-and-ups-are-betting-big-on-drone-delivery-2018-3">small battery-powered drones that carry personal packages</a> over short distances, while flying below 400 feet, are already coming into use. But carrying people and luggage requires 10 times as much energy – or more.</p>
<p>We looked at how much energy a small battery-powered aircraft capable of <a href="http://evtol.news/evtol-timeline/">vertical takeoff and landing</a> would need. These are typically designed to <a href="https://www.wired.co.uk/article/vtol-vertical-take-off-landing-explained">launch straight up like helicopters</a>, shift to a more efficient airplane mode by rotating their propellers or entire wings during flight, then transition back to helicopter mode for landing. They could be an efficient and economic way to navigate busy urban areas, avoiding clogged roads.</p>
<h2>Energy requirements of e-VTOL aircraft</h2>
<p>Our research group has built a computer model that calculates the power needed for a single-passenger e-VTOL along the lines of designs that are <a href="https://www.digitaltrends.com/cool-tech/all-the-flying-cars-and-taxis-currently-in-development/">already under development</a>. One such example is an e-VTOL that weighs 1,000 kilograms, including the passenger.</p>
<p>The longest part of the trip, cruising in airplane mode, needs the least energy per mile. Our sample e-VTOL would need about 400 to 500 watt-hours per mile, around the same amount of energy an <a href="https://doi.org/10.1149/2.0671711jes">electric pickup truck</a> would need – and about twice the energy consumption of an <a href="https://arxiv.org/abs/1711.04822">electric passenger sedan</a>.</p>
<p>However, takeoff and landing require much more power. Regardless of how far an e-VTOL travels, our analysis predicts takeoff and landing combined will require between 8,000 and 10,000 watt-hours per trip. This is about half the energy available in most compact electric cars, like a Nissan Leaf. </p>
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<p>For an entire flight, with the best batteries available today, we calculated that a single-passenger e-VTOL designed to carry a person 20 miles or less would require about <a href="https://pubs.acs.org/doi/abs/10.1021/acsenergylett.8b02195">800 to 900 watt-hours per mile</a>. That’s about half the amount of energy as a semi-truck, which is not very efficient: If you needed to make a quick visit to shop in a nearby town, you wouldn’t hop into the cab of a fully loaded tractor-trailer to get there.</p>
<p>As batteries improve over the next few years, they may be able to pack in about <a href="https://doi.org/10.1149/2.1571707jes">50 percent more energy</a> for the same battery weight. That would help make e-VTOLS more viable for short- and medium-range trips. But, there are a few more things needed before people can really start using e-VTOLS regularly.</p>
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<figcaption><span class="caption">Slide the ‘specific energy’ slider side to side to see how making batteries better can change vehicles’ energy needs.</span>
<span class="attribution"><a class="source" href="https://www.andrew.cmu.edu/user/venkatv/">Venkat Viswanathan</a></span>
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<h2>It’s not just energy</h2>
<p>For ground vehicles, determining the useful range of travel is enough – but not for planes and helicopters. Aircraft designers also need to closely examine the power – or how quickly the stored energy is available. This is important because ramping up to take off in a jet or pushing down against gravity in a helicopter takes much more power than turning the wheels of a car or truck.</p>
<p>Therefore, e-VTOL batteries must be able to discharge at rates roughly 10 times faster than the batteries in electric road vehicles. When batteries discharge more quickly, they get a lot hotter. Just as your laptop fan spins up to full speed when you try to stream a TV show while playing a game and downloading a large file, a vehicle battery pack needs to be cooled down even faster whenever it is asked to produce more power. </p>
<p>Road vehicles’ batteries don’t heat up nearly as much while driving, so they can be cooled by the air passing by or with simple coolants. An e-VTOL taxi, however, would generate an enormous amount of heat on takeoff that would take a long time to cool – and on short trips might not even fully cool down before heating up again on landing. Relative to the battery pack size, for the same distance traveled, the amount of heat generated by an e-VTOL battery during takeoff and landing is <a href="http://dx.doi.org/10.1021/acsenergylett.8b02195">far more than electric cars</a> and semi-trucks.</p>
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<p>That extra heat will shorten e-VTOL batteries’ useful lives, and possibly make them more susceptible to catching fire. To preserve both reliability and safety, electric aircraft will need specialized cooling systems – which would require more energy and weight.</p>
<p>This is a crucial difference between electric road vehicles and electric aircraft: Designers of trucks and cars don’t have any need to radically improve either their power output or their cooling systems, because that would add cost without helping performance. Only specialized research will find these vital advances for electric aircraft.</p>
<p>Our next research topic will continue to explore ways to improve e-VTOL battery and cooling system requirements to provide enough energy for useful range and enough power for takeoff and landing – all without overheating.</p>
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<span class="caption">An experimental electric aircraft for two passengers.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/-France-Paris-Air-Show/9ad563eef56745a3aaff6b3b8a72eb36/15/0">AP Photo/Remy de la Mauviniere</a></span>
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</figure><img src="https://counter.theconversation.com/content/103955/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Venkat Viswanathan is a consultant for Pratt & Whitney. He is a technical consultant, owns stock options and a member of Advisory Board at Zunum Aero. He is a technical consultant for Quantumscape. His research group receives funding from Airbus A^3, Quantumscape and Zunum Aero. </span></em></p><p class="fine-print"><em><span>Shashank Sripad receives funding from Zunum Aero and Airbus A^3 to undertake research as a Ph.D. Student at Carnegie Mellon University. </span></em></p><p class="fine-print"><em><span>William Leif Fredericks receives funding from Airbus A^3 to undertake research as a Research Assistant at Carnegie Mellon University. </span></em></p>The battery technology and cooling systems needed for electric aircraft to lift people and cargo are getting closer to reality, but they’re still very different from electric cars and trucks.Venkat Viswanathan, Assistant Professor of Mechanical Engineering, Carnegie Mellon UniversityShashank Sripad, Ph.D. Candidate in Mechanical Engineering, Carnegie Mellon UniversityWilliam Leif Fredericks, Research Assistant in Mechanical Engineering, Carnegie Mellon UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/907282018-10-04T10:28:10Z2018-10-04T10:28:10ZNew materials are powering the battery revolution<figure><img src="https://images.theconversation.com/files/238736/original/file-20181001-195256-1e68x0s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research is finding better ways to make batteries both big and small.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/charging-batteries-elecric-motor-disassembling-battery-753568081">Romaset/Shutterstock.com</a></span></figcaption></figure><p>There are <a href="https://www.independent.co.uk/life-style/gadgets-and-tech/news/there-are-officially-more-mobile-devices-than-people-in-the-world-9780518.html">more mobile phones in the world</a> than there are people. Nearly all of them are powered by <a href="https://doi.org/10.1038/s41928-018-0048-6">rechargeable lithium-ion batteries</a>, which are the single most important component enabling the portable electronics revolution of the past few decades. None of those devices would be attractive to users if they didn’t have enough power to last at least several hours, without being particularly heavy.</p>
<p>Lithium-ion batteries are also useful in larger applications, like electric vehicles and <a href="http://doi.org/10.1126/science.1212741">smart-grid energy storage systems</a>. And <a href="https://doi.org/10.1038/s41928-018-0048-6">researchers’ innovations in materials science</a>, seeking to improve lithium-ion batteries, are paving the way for even more batteries with even better performance. There is already demand forming for <a href="http://doi.org/10.1126/science.aak9991">high-capacity batteries that won’t catch fire or explode</a>. And many people have dreamed of smaller, lighter batteries that charge in minutes – or even seconds – yet store <a href="http://doi.org/10.1038/ncomms12647">enough energy to power a device for days</a>.</p>
<p><a href="https://scholar.google.com/citations?user=boDNTDwAAAAJ&hl=en">Researchers like me</a>, though, are thinking even more adventurously. Cars and grid-storage systems would be even better if they could be <a href="https://theconversation.com/why-does-my-phone-battery-die-so-fast-98367">discharged and recharged tens of thousands of times</a> over many years, or even decades. Maintenance crews and customers would love batteries that could monitor themselves and send alerts if they were damaged or no longer functioning at peak performance – or even were able to fix themselves. And it can’t be too much to dream of dual-purpose batteries integrated into the structure of an item, helping to shape the form of a smartphone, car or building while also powering its functions.</p>
<p>All that may become possible as my research and others’ help scientists and engineers become ever more adept at controlling and handling matter at the scale of individual atoms.</p>
<h2>Emerging materials</h2>
<p>For the most part, advances in energy storage will rely on the continuing development of materials science, pushing the limits of performance of existing battery materials and developing entirely new battery structures and compositions. </p>
<p>The battery industry is already working to reduce the cost of lithium-ion batteries, including by removing expensive cobalt from their positive electrodes, called cathodes. This would also reduce the <a href="https://www.wired.com/story/alternatives-to-cobalt-the-blood-diamond-of-batteries/">human cost of these batteries</a>, because many mines in Congo, the world’s leading source of cobalt, <a href="http://money.cnn.com/2018/05/01/technology/cobalt-congo-child-labor-car-smartphone-batteries/index.html">use children to do difficult manual labor</a>.</p>
<p>Researchers are finding ways to replace the cobalt-containing materials with cathodes made mostly of nickel. Eventually they may be able to <a href="https://www.wired.com/story/alternatives-to-cobalt-the-blood-diamond-of-batteries/">replace the nickel with manganese</a>. Each of those metals is cheaper, more abundant and safer to work with than its predecessor. But they come with a trade-off, because they have <a href="https://www.ft.com/content/3b72645a-91cc-11e8-bb8f-a6a2f7bca546">chemical properties that shorten their batteries’ lifetimes</a>.</p>
<p>Researchers are also looking at <a href="https://phys.org/news/2018-09-high-capacity-sodium-ion-lithium-rechargeable-batteries.html">replacing the lithium ions that shuttle between the two electrodes</a> with ions and electrolytes that may be cheaper and potentially safer, like those based on sodium, magnesium, zinc or aluminum.</p>
<p><a href="https://research.mse.ncsu.edu/augustyn/">My research group</a> looks at the possibilities of using two-dimensional materials, essentially extremely thin sheets of substances with useful electronic properties. <a href="https://news.mit.edu/2018/graphene-insulator-superconductor-0305">Graphene</a> is perhaps the best-known of these – a sheet of carbon just one atom thick. We want to see whether stacking up layers of various two-dimensional materials and then <a href="https://doi.org/10.1016/j.joule.2017.09.008">infiltrating the stack with water</a> or other conductive liquids could be key components of batteries that recharge very quickly.</p>
<h2>Looking inside the battery</h2>
<p>It’s not just new materials expanding the world of battery innovation: New equipment and methods also let researchers see what’s happening inside batteries much more easily than was once possible. </p>
<p>In the past, researchers ran a battery through a particular charge-discharge process or number of cycles, and then removed the material from the battery and examined it after the fact. Only then could scholars learn what chemical changes had happened during the process and infer how the battery actually worked and what affected its performance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238731/original/file-20181001-195260-rjw9jj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">X-rays generated by a synchotron can illuminate the inner workings of a battery.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/60066150@N04/5718398619">CLS Research Office/flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But now, researchers can watch battery materials as they undergo the energy storage process, analyzing even their atomic structure and composition in real time. We can use sophisticated spectroscopy techniques, such as X-ray techniques available with a type of particle accelerator called a <a href="https://www.esrf.eu/about/synchrotron-science/synchrotron">synchrotron</a> – as well as electron microscopes and scanning probes – to <a href="https://doi.org/10.1021/acsnano.8b02273">watch ions move and physical structures change</a> as energy is stored in and released from materials in a battery.</p>
<p>Those methods let researchers like me imagine new battery structures and materials, make them and see how well – or not – they work. That way, we’ll be able to keep the battery materials revolution going.</p><img src="https://counter.theconversation.com/content/90728/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Veronica Augustyn receives funding from the National Science Foundation, Department of Energy, and Research Corporation for Science Advancement. </span></em></p>Is it too much to dream of batteries that are part of the structure of an item, helping to shape the form of a smartphone, car or building while also powering its functions?Veronica Augustyn, Assistant Professor of Materials Science and Engineering, North Carolina State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1027592018-09-21T10:42:35Z2018-09-21T10:42:35ZPaper-based electronics could fold, biodegrade and be the basis for the next generation of devices<figure><img src="https://images.theconversation.com/files/235661/original/file-20180910-123119-wxtsn3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A foldable, biodegradable battery based on paper and bacteria opens a new opportunity in electronics.</span> <span class="attribution"><span class="source">Seokheun Choi/Binghamton University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>It seems like every few months there’s a new cellphone, laptop or tablet that is so exciting people line up around the block to get their hands on it. While the perpetual introduction of new, <a href="https://slate.com/technology/2018/09/new-iphone-rumors-how-apple-could-improve-battery-life.html">slightly more advanced electronics</a> has made businesses like Apple hugely successful, the short shelf life of these electronics is bad for the environment.</p>
<p>Modern electronics are filled with circuit boards on which <a href="http://www.appropedia.org/Metal_reclamation_and_recycling_of_electronic_waste">various metals and plastics are soldered</a> together. Some of these <a href="http://www.appropedia.org/Metal_reclamation_and_recycling_of_electronic_waste">materials are toxic</a> – or <a href="https://symbiosisonlinepublishing.com/biotechnology/biotechnology03.pdf">break down into toxic substances</a>. There are efforts underway to <a href="https://doi.org/10.1016/j.aogh.2014.10.001">boost recycling of e-waste</a>, <a href="https://doi.org/10.1016/j.mex.2015.02.010">recovering materials that can be reused</a> and properly disposing of the rest. But <a href="https://www.theverge.com/2016/6/22/11991440/eri-e-waste-electronics-recycling-nyc-gadget-trash">most devices</a> end up added to the <a href="https://motherboard.vice.com/en_us/article/z4gv73/americas-television-graveyards">growing piles</a> of <a href="https://www.epa.gov/international-cooperation/cleaning-electronic-waste-e-waste">e-waste in landfills</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/235416/original/file-20180907-90549-50j1jk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Circuit boards and other electronics can really pile up.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Electronic-Waste-Recycling/7e979f106b7748a6a607b7f645265388/30/0">AP Photo/Michael Conroy</a></span>
</figcaption>
</figure>
<p>Instead of adding more trash to these ever-growing piles, there is an opportunity to create electronics that are biodegradable. That’s why <a href="https://scholar.google.com/citations?user=2H01tqsAAAAJ&hl=en&oi=ao">other researchers and I</a> are looking to the emerging field of paper-based electronics – known as “<a href="http://nsf-papertronics.rutgers.edu/">papertronics</a>.” They’re flexible – even foldable – sustainable, friendly to the environment and low-cost. </p>
<p>But to be truly eco-friendly, papertronics can’t use traditional batteries, which are made of metals and caustic acids, to store and discharge electricity. Recently, my chemist colleague <a href="https://www.binghamton.edu/chemistry/people/sadik/sadik.html">Omowunmi Sadik</a> and I developed a <a href="https://doi.org/10.1002/adsu.201800041">paper battery that’s recyclable and biodegradable</a>, as well as reliable enough to actually use. The key is bacteria.</p>
<h2>Flexible bio-batteries</h2>
<p>I’ve developed flexible batteries, <a href="https://doi.org/10.1002/admt.201700127">batteries powered by saliva</a> and more. I figured that when seeking to power paper-based electronics, it made sense to try to make a battery out of paper. Fortunately, paper is a good potential battery material: It’s flexible, a good insulator – which makes it a good platform for mounting electronic components on – and absorbs and releases fluids easily. We added polymers – <a href="https://doi.org/10.1002/adsu.201800041">poly (amic) acid and poly(pyromellitic dianhydride-p-phenylenediamine)</a> – to improve those electrical characteristics.</p>
<p>Then, to store energy in the battery, in place of the metals and acids that react chemically to generate electrons, we added bacteria. When these batteries are eventually commercialized, they’ll use bacteria that are safe for humans and the environment and well-contained to reduce any other contamination.</p>
<p>Because the paper is rough and porous, the bacteria stick to it, and generate their own energy by breaking down almost any available organic material, including plant material or wastewater. At the moment, we’re prepackaging source material, but it could also come from the environment. This chemical reaction produces electrons. Normally in a bacterial reaction, those electrons would bond with oxygen, but we’ve built our battery to limit oxygen and substitute an electrode, meaning we can capture the electron flow and use it to power devices. </p>
<p>We were concerned that oxygen could get into the paper and interrupt the electron flow between the bacteria, decreasing the battery’s efficiency. We found that while that does happen, it has minimal effects. That’s because so many bacterial cells are so tightly attached to the paper fibers; they form a multi-layer biofilm that shields the chemical reaction from most oxygen.</p>
<p>We also wanted a battery that could biodegrade. The bacteria in the battery itself, once they’re done releasing energy, can break down the paper and polymers into harmless components. In water, our battery easily biodegraded, without any special equipment or other microorganisms to aid in the breakdown.</p>
<p>The polymer-paper structures are lightweight, low-cost and flexible. That flexibility also allows for the batteries to fold like a normal piece of paper, or be stacked on top of each other. That lets more battery power fit into smaller spaces.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=537&fit=crop&dpr=1 600w, https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=537&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=537&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=674&fit=crop&dpr=1 754w, https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=674&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/235453/original/file-20180907-90581-1tk49v5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=674&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A group of folded batteries can power a paper-based electronic device.</span>
<span class="attribution"><span class="source">Seokheun Choi/Binghamton University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Promises and opportunities</h2>
<p>Papertronics can be particularly useful in remote areas with limited resources because they’re powered by bacteria that can inhabit even the most extreme of conditions and break down nearly any material to produce electrons. They don’t need a well-established power grid, either. In addition, though paper batteries are designed to be disposable after they’re used, their materials are recyclable – and new batteries can be created from recycled paper.</p>
<p>As revolutionary as paper-based bio-batteries are for future electronic devices, they’re fairly straightforward to make. The polymers and bacteria can be blended with paper in traditional manufacturing processes, including roll-to-roll printing and <a href="https://doi.org/10.1039/C4RA04946B">screen printing</a> – or even be painted or poured right onto paper.</p>
<p>Other materials can also be added to the paper batteries – like metals, semiconductors, insulators and nanoparticles. These and other substances can add more properties and capabilities to paper-based devices, opening new doors for the next generation of electronics.</p><img src="https://counter.theconversation.com/content/102759/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Seokheun Choi receives funding from the National Science Foundation and the Office of Naval Research. </span></em></p>Paper-based devices with foldable, biodegradable batteries provide a new way to reduce electronic waste. But how would these new gadgets work?Seokheun Choi, Associate Professor of Electrical and Computer Engineering, Binghamton University, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/791802017-07-27T20:16:06Z2017-07-27T20:16:06ZA guide to deconstructing the battery hype cycle<figure><img src="https://images.theconversation.com/files/177811/original/file-20170712-9330-882ntf.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A share of the Edison Storage Battery Company, issued 19 Oct. 1903.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Edison_Storage_Battery_Company_1903.JPG">Wikimedia/Sammlung eines Mitglieds des Ersten Deutschen Historic-Actien-Clubs e.V</a></span></figcaption></figure><p><em>This article is part of a series on building the future of batteries. How can we create the batteries we’ll need to power our electronics, transport and industry, and what’s standing in the way? You can read the rest of the series <a href="https://theconversation.com/au/topics/the-future-of-batteries-40687">here</a>.</em></p>
<hr>
<blockquote>
<p>“The storage battery is, in my opinion, a catchpenny, a sensation, a mechanism for swindling the public by stock companies.”
- Thomas Edison, 1883 </p>
</blockquote>
<p>When American inventor Thomas Edison <a href="https://books.google.com.au/books?id=LMbzAwAAQBAJ&pg=PT32&lpg=PT32&dq=The+storage+battery+is,+in+my+opinion,+a+catchpenny,+a+sensation,+a+mechanism+for+swindling+the+public+by+stock+companies&source=bl&ots=yU3nsgxIy1&sig=8-QabvJgQSq2rA1nhtQ7En0fj04&hl=en&sa=X&ved=0ahUKEwiL0cXFmKjVAhXCvLwKHcnbC-sQ6AEITzAH#v=onepage&q=The%20storage%20battery%20is%2C%20in%20my%20opinion%2C%20a%20catchpenny%2C%20a%20sensation%2C%20a%20mechanism%20for%20swindling%20the%20public%20by%20stock%20companies&f=false">made this statement</a>, he was working on the nickel-iron battery. It became the backbone of the electric vehicle fleet of the day, before petrol took over. At the time, the lead-acid battery was in its infancy and went on to outperform Edison’s nickel-iron technology.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=779&fit=crop&dpr=1 600w, https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=779&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=779&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=979&fit=crop&dpr=1 754w, https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=979&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/177810/original/file-20170712-9330-19n1g12.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=979&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Thomas Alva Edison with his nickel-iron battery in 1910.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Edison-ni-fe.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>Today lead-acid batteries are still used heavily in the automotive industry, while lithium-ion batteries power our electronics and newer cars. Emerging battery technologies continue to generate interest and serious hype; there are breathless promises of longer cycle life, more energy and more power. </p>
<p>A team at Carnegie Mellon University has even attempted <a href="http://iopscience.iop.org/article/10.1088/2053-1613/2/4/045002/meta">to quantify</a> the hype cycle for batteries that scientists hope will surpass lithium-ion. </p>
<p>How do we wade through the fact and fiction to avoid being – as Edison put it – swindled?</p>
<h2>Not all batteries are the same</h2>
<p>In batteries, the positive and negative electrodes are separated by an electrolyte. Charged molecules (such as the lithium ions in lithium-ion batteries) move between the two electrodes, delivering energy.</p>
<p>There are two ways to improve the energy of a battery cell:</p>
<ul>
<li>increase the amount of charge that can be stored, or</li>
<li>increase the voltage between the negative and positive electrodes.</li>
</ul>
<p>But when it comes to measuring how they work, the numbers can be confusing.</p>
<p>Researchers generally describe energy as either watt-hour per kilogram or watt-hour per litre, which mean two different things:</p>
<ul>
<li>watt-hour per kilogram measures the energy density of a battery – it tells us how much energy is stored per unit of mass.</li>
<li>watt-hour per litre refers to specific density – how much energy is stored per unit of volume.</li>
</ul>
<p>Either of these two measurements can be important depending on the application. </p>
<p>Mass or weight matters in different situations. A bus, for example, can handle a heavy battery. Sometimes size is paramount – a battery with small volume is important for smartphones so the device can fit in your pocket.</p>
<h2>High energy versus high power</h2>
<p>Watch out for claims that a new battery is high-energy <em>and</em> high-power.</p>
<p>Researchers and engineers can design battery materials and electrodes to be suitable for either high-energy or high-power uses, but generally not both.</p>
<p>For example, a battery can deliver large amounts of energy over a long period of time for a wildlife-tracking sensor. Or, for applications such as a hand drill, it can provide a large amount of power in a short burst.</p>
<p>This is largely governed by the process of how fast lithium ions can be stored in the electrode and released.</p>
<p>For high-energy batteries, lithium metal is the holy grail, because it’s the material with the highest energy per unit of mass. When it comes to power, researchers are looking at things like lithium iron phosphate, which can charge and discharge quickly.</p>
<h2>How super are super materials?</h2>
<p>In some papers, you may read about the use of additives in either the battery’s electrode or the electrolyte that lead to better performance. These new materials have a lot of potential for the promised effects, but significant limitations remain.</p>
<p>Let’s consider graphene. A 2D material made from a single layer of carbon atoms, it’s a good electrical conductor. Some researchers are looking at it as a possible electrode material.</p>
<p>But like the internal combustion engine, a battery has the highest efficiency when it delivers energy under a constant and steady load. Graphene has no physical sites where ions can be stored. Since it doesn’t “store” ions, the material doesn’t add to the energy of the device. </p>
<p>Graphene could be used <a href="https://theconversation.com/graphene-is-missing-ingredient-to-help-supercharge-batteries-for-life-on-the-move-44867">in supercapitators</a>, however, which use static electricity rather than a battery’s chemical reaction to produce energy.</p>
<p>Not to mention, graphene and other 2D materials are generally expensive and hard to process on a large scale.</p>
<h2>Overstating cycle life</h2>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=975&fit=crop&dpr=1 600w, https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=975&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=975&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1225&fit=crop&dpr=1 754w, https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1225&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/177812/original/file-20170712-14233-12u47h1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1225&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A diagram from the United States patents granted to Thomas Edison.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Collection_of_United_States_patents_granted_to_Thomas_A._Edison,_1869-1884_(1869)_(14776765513).jpg">USPTO/Wikimedia</a></span>
</figcaption>
</figure>
<p>And then there are the bold claims made about a battery’s cycle life. </p>
<p>This is the number of times you can charge and discharge a battery before it dies. Many companies define this cycle life for themselves, which means they could create a self-serving test that effectively allows their battery to last forever.</p>
<p>Often new battery testing is done with coin cell batteries, which are similar to the batteries you might find in a watch. In other words, they’re great for research but don’t resemble batteries you’d actually use to run an electric car.</p>
<p>Depending on how it’s used, more than 1,000 cycles – each cycle is one charge and discharge – are typically required for a battery to come to market. </p>
<p>In order to provide clarity on this issue, many industry groups, such as the <a href="http://www.uscar.org/guest/article_view.php?articles_id=74">United States Council for Automotive Research</a>, have adopted standard test cycles to evaluate and compare batteries.</p>
<h2>Obstacles to commercialisation</h2>
<p>The reality is, not all batteries are created equal. Not all batteries will serve every market. </p>
<p>When you read “our battery is targeting automotive applications”, there is more to consider than just energy and power – there is safety, cost and cycle life to consider, among other issues.</p>
<p>It’s also important to recognise that it’s tremendously difficult to get a new battery into a car. Automotive companies demand tried and true solutions, and it can be a challenge for new technologies to get a foothold in the market.</p>
<p>We have come a long way from when Edison invented the nickel-iron battery, but it’s important to check the detail and understand the lingo to make sure that you aren’t being swindled.</p><img src="https://counter.theconversation.com/content/79180/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>As a CSIRO employee, Adam Best receives funding from the Commonwealth Government and companies working in the energy storage domain. </span></em></p>High energy, high power and endless life cycles: not all batteries are created equal.Adam Best, Research Group Leader & Senior Research Scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/808862017-07-26T20:15:34Z2017-07-26T20:15:34ZPolitically charged: do you know where your batteries come from?<p><em>This article is part of a series on building the future of batteries. How can we create the batteries we’ll need to power our electronics, transport and industry, and what’s standing in the way? You can read the rest of the series <a href="https://theconversation.com/au/topics/the-future-of-batteries-40687">here</a>.</em></p>
<hr>
<p>People are excited about batteries, from electric cars to Tesla’s <a href="https://theconversation.com/explainer-what-can-teslas-giant-south-australian-battery-achieve-80738">129 megawatt-hour energy storage project </a> in South Australia. But one important issue is often overlooked: the raw materials needed to build this technology – where they come from and their environmental cost.</p>
<p>New types of batteries such as vanadium “flow batteries” still <a href="https://theconversation.com/when-will-we-have-better-batteries-than-lithium-ion-for-gadgets-and-electric-vehicles-41341">lag in comparison</a> with the performance of lithium-ion ones (as used by Tesla). Other technologies <a href="http://www.abc.net.au/news/2017-07-22/lithium-ion-battery-tech-where-is-our-next-gen-energy-storage/8722670">face significant hurdles</a> before they can be commercially available. </p>
<p>This means that, for now, demand for lithium-ion batteries <a href="https://minerals.usgs.gov/minerals/pubs/commodity/lithium/mcs-2017-lithi.pdf">for use in</a> portable electronics, hybrid vehicles and electric tools will only grow. Lithium demand for batteries is forecast to <a href="http://www.metalstech.net/market-outlook/">increase dramatically</a>, driving more than a doubling in total lithium demand by 2025. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=574&fit=crop&dpr=1 600w, https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=574&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=574&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=722&fit=crop&dpr=1 754w, https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=722&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/179753/original/file-20170726-30149-1lho6e8.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=722&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This demand has led to enthusiastic investment, <a href="http://www.abc.net.au/news/2017-07-07/explainer-why-is-lithium-such-a-hot-item-right-now/8443646">first in lithium</a> and more recently in the electrode materials required for these batteries, including graphite, nickel and cobalt.</p>
<p>We need to think carefully about the security of the sources of lithium-ion battery materials, as well as the environmental impact of their extraction.</p>
<h2>Where can we find lithium?</h2>
<p>Getting lithium into a battery is not simply a matter of digging it up.</p>
<p>The current major producers of lithium are Australia, Chile, Argentina and China, with Australia and Chile accounting for about <a href="https://minerals.usgs.gov/minerals/pubs/commodity/lithium/mcs-2017-lithi.pdf">75% of the total</a>. </p>
<p>These four countries also have the largest reserves of lithium. Chile, in particular, is thought to have more than 50% of known economic reserves (the portion of mineral resources <a href="http://www.nordicmining.com/artikler-ikke-synlig-i-meny-mineral/mineral-resource-classification-article75-171.html">expected to be minable at a profit</a>). </p>
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<p>However, Argentina and Bolivia have so far identified more than <a href="https://minerals.usgs.gov/minerals/pubs/commodity/lithium/mcs-2017-lithi.pdf">9 million tonnes each</a> in lithium resources (a classification for minerals with more uncertainty about if and at what cost they can be extracted). </p>
<p>Because of the concentration of reserves in South America, the regions of highest lithium potential are often referred to as the “<a href="http://www.bbc.com/news/magazine-26993915">lithium triangle</a>”. If battery power replaced oil, some <a href="http://www.meridian-int-res.com/Projects/Lithium_Problem_2.pdf">analysts predict</a> that South America would become the “new Middle East”.</p>
<h2>The environmental impact of lithium mining</h2>
<p>Lithium mining has different ecological impacts depending on how it’s extracted.</p>
<p>Australia, for example, mostly produces lithium from <a href="http://www.ga.gov.au/data-pubs/data-and-publications-search/publications/aimr/lithium">hard rock ores</a>. Other countries, including those in South America, more often produce it from brines. </p>
<p>To produce lithium from ore, the ore is typically crushed. Then <a href="http://www.meridian-int-res.com/Projects/Lithium_Problem_2.pdf">chemicals and high temperatures</a> are used to separate the lithium from the rest of the rock. </p>
<p>Producing lithium this way requires land use changes – clearing land, digging mines and storing waste rock. Significant energy and chemical use are also needed to obtain to the final product. </p>
<p>For brines, a naturally occurring concentrated solution of lithium (mixed with other salts containing sodium, magnesium and potassium when it is found naturally) is pumped out of the ground. It is put in large ponds <a href="http://library.eawag-empa.ch/empa_publications_2009_open_access/EMPA20090698.pdf">to evaporate excess water</a> and separate the other salts for many months. The remaining lithium compound is then purified and processed. </p>
<p>For brines, the main environmental concern, especially in Chile, is that the extraction can <a href="http://www.meridian-int-res.com/Projects/Lithium_Problem_2.pdf">impact water supply</a> in desert areas. It also uses some chemicals for purification. </p>
<p>Many analysts consider that lithium from brines <a href="http://www.miningfeeds.com/2015/06/11/brine-harvesting-of-lithium-vs-hard-rock-mining/">is preferable</a> environmentally because the impacts are lower using present methods.</p>
<p>Of course, increasing demand might change this and increase the environmental cost: the brines could be evaporated more quickly using heat (possibly from fossil fuels or from concentrated solar energy). The size of the pond could also be expanded.</p>
<h2>Where do we find the rest of the battery?</h2>
<p><strong>Graphite</strong></p>
<p>Graphite reserves are dominated by three countries: <a href="https://minerals.usgs.gov/minerals/pubs/commodity/graphite/mcs-2017-graph.pdf">Turkey (36%), Brazil (29%) and China (22%)</a>, but production is presently dominated by China. An estimate of 2015 production reported that China produced <a href="http://www.bgs.ac.uk/mineralsuk/statistics/worldStatistics.html">up to 82% of the world’s total</a>, but there are often discrepancies in reporting.</p>
<p>Graphite can also be <a href="https://minerals.usgs.gov/minerals/pubs/commodity/graphite/mcs-2017-graph.pdf">synthetically derived</a>, but only natural graphite is considered here, as it is currently easier to produce. </p>
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<p><strong>Cobalt</strong></p>
<p>Some materials needed for batteries are not extracted and refined in the same place. This is particularly true for cobalt: in 2015, Democratic Republic of Congo produced most of the <a href="http://www.bgs.ac.uk/mineralsuk/statistics/worldStatistics.html">mined cobalt</a>, but China was <a href="http://www.bgs.ac.uk/mineralsuk/statistics/worldStatistics.html">the largest producer</a> of the refined metal.</p>
<p>After these two major players, Canada and Australia play moderately important roles in both mining and refining. Australia is second on the list of reserves of cobalt, with around <a href="https://minerals.usgs.gov/minerals/pubs/commodity/cobalt/mcs-2017-cobal.pdf">14% of global reserves</a>. </p>
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<p><strong>Nickel</strong></p>
<p>Nickel is the least centralised of the metals considered here. It is found widely, mined widely, and in 2015, the dominant producers only held estimated shares of up to <a href="http://www.bgs.ac.uk/mineralsuk/statistics/worldStatistics.html">20% (Philippines, mining)</a> and <a href="http://www.bgs.ac.uk/mineralsuk/statistics/worldStatistics.html">30% (China, refining)</a>. Australia <a href="https://minerals.usgs.gov/minerals/pubs/commodity/nickel/mcs-2017-nicke.pdf">is thought to have</a> 24% of global reserves.</p>
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<p>Environmentally, the extraction of cobalt and nickel is driven by the type and grade of ores, and their location. </p>
<p>Typically, ores that are easier to mine and extract are already being exploited, leaving deeper, more complex deposits for the future. </p>
<p>For this reason, unlike lithium, the ecological impact of these minerals <a href="http://users.monash.edu.au/%7Egmudd/files/SustMining-Aust-Report-2009-Master.pdf">is likely to increase</a>. Deeper mines and lower grades lead to more waste rock, greater energy use tied to greenhouse gas emissions, and more chemicals used per tonne.</p>
<h2>The supply chain risks</h2>
<p>Turning minerals into batteries takes a supply chain, and each stage – mining, processing, refining, manufacturing – could present a bottleneck. </p>
<p>Manufacturers such as electric vehicle makers should be concerned that the supply of one of the key mineral components, or the processing and refining infrastructure, could become too centralised in a single country.</p>
<p>Without diverse source options, the possibility of supply restriction becomes more likely. </p>
<p>Consider the rare earths price peak between 2009 and 2012, which was caused by highly centralised supply. The majority of rare earths were produced <a href="http://www.mdpi.com/2075-163X/3/3/304/htm#B58-minerals-03-00304">in China at the time</a> and the <a href="https://www.uni-frankfurt.de/43866701/WP_6-2011_Lackner_and_McEwen_Rare_earth_China.pdf">restriction of exports</a> for ostensibly political reasons caused concern that there would be insufficient supply for components such as the magnets used in <a href="https://www.technologyreview.com/s/423730/the-rare-earth-crisis/">wind turbines and electric vehicle motors</a>.</p>
<p>Currently, graphite is quite centralised because fewer countries produce it, but reserves are more diversified. With almost half of the world’s cobalt ore <a href="https://minerals.usgs.gov/minerals/pubs/commodity/cobalt/">reserves concentrated in Democratic Republic of Congo</a> for the foreseeable future, and with a large proportion of refining capacity located in China, the supply chain could be more vulnerable.</p>
<p>After all, it’s possible governments might again restrict supply.</p>
<p>In this scenario, Democratic Republic of Congo is not high on the list of preferred suppliers. It rates poorly on most <a href="http://info.worldbank.org/governance/wgi/#reports">World Bank indicators</a> thanks to its tenuous political situation, while China rates better. But as China has shown in the case of rare earth elements, there is still uncertainty about its reliability as a supplier. </p>
<h2>Where does that leave the lithium battery?</h2>
<p>The supply of major materials for lithium batteries is not under threat any time soon, but demand is likely to open up new areas for extraction, bringing new risks.</p>
<p>The political situations of countries with large reserve shares and large shares in the processing of these metals can quickly become uncertain. Will countries like Bolivia allow unrestricted export of lithium? Will Democratic Republic of Congo or China restrict cobalt supply?</p>
<p>Environmentally, the lithium-ion battery’s future is also worrying. The production of electrode materials may become more environmentally damaging. On the other hand, the impact of the lithium supply itself is likely to improve.</p>
<p>Ultimately, <a href="https://theconversation.com/lithium-australia-needs-to-recycle-and-lease-to-be-part-of-the-boom-54037">recycling lithium</a> should play a part in mitigating political, environmental and economic risks in the future, but high rates of lithium battery recycling are yet to be seen.</p><img src="https://counter.theconversation.com/content/80886/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ben McLellan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We need to think about the raw materials of batteries – where they come from and their environmental cost.Ben McLellan, Honorary Senior Research Fellow, Kyoto UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/797502017-07-25T20:09:03Z2017-07-25T20:09:03ZHow to make batteries that last (almost) forever<p><em>This article is part of a series on building the future of batteries. How can we create the batteries we’ll need to power our electronics, transport and industry, and what’s standing in the way? You can read the rest of the series <a href="https://theconversation.com/au/topics/the-future-of-batteries-40687">here</a>.</em></p>
<hr>
<p>When a battery runs low it usually needs to be manually recharged, but new approaches are being developed to help this energy source last indefinitely.</p>
<p>Self-sustaining batteries are needed for activities that use sensors. These include long-term tracking of <a href="https://research.csiro.au/dss/research/long-term-tracking/">wildlife</a> like flying foxes, multi-year biodiversity assessments in <a href="https://research.csiro.au/dss/rainforest-regeneration/">Australian rainforests</a> and <a href="https://www.moore.org/article-detail?newsUrlName=revolutionizing-biodiversity-monitoring-in-the-amazon">the Amazon</a>, and studying the health of the Great Barrier Reef. </p>
<p>This is where energy harvesting comes in handy. </p>
<p>Energy harvesting allows energy to be collected from the environment – through the sun or vibration, for instance. But just like wind and solar energy used for the electricity grid, energy harvesting for mobile technology provides an intermittent and unpredictable energy supply. </p>
<p>This raises the challenge of how to continuously power these devices when it matters most. </p>
<p>To address the issue, we have designed <a href="http://dl.acm.org/citation.cfm?id=2893738">a software framework</a> that can adapt a device’s sensing and computation tasks based on a forecast of harvested energy. This ensures that the sensor can collect and dispatch the necessary data without running out of power.</p>
<h2>Energy neutral operation</h2>
<p>Our software aims to help devices operate in an energy-neutral way, so that the battery can last indefinitely or until its recharge cycles are exhausted.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=554&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=554&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=554&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=696&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=696&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178002/original/file-20170713-19681-bsx15v.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=696&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A heat map in Springbrook National Park.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>One example is our <a href="https://research.csiro.au/dss/camazotz-smart-tech-keeping-track-bats/">Camazotz tracking device</a> that we use for researching flying foxes. This device is attached to the animals using collars and collects GPS data to understand their movements. It also has a tiny battery and solar panel to recharge each day. </p>
<p>Our software can predict the likely movement of the animal and energy availability, and use this data to determine suitable schedules for the use of on-board sensors. This ensures that the energy needed for obtaining the GPS samples does not exceed the energy we expect to have available through the solar panels. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178003/original/file-20170713-11517-8vbrxc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A sensing node in Springbrook National Park.</span>
<span class="attribution"><span class="source">CSIRO</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This software framework can also be used for consumer devices such as smartphones and wearables. But while there is no hard battery lifetime for this approach, how long the battery lasts will still depend on the maximum number of times the battery can be recharged before dying.</p>
<p>Other researchers are exploring <a href="http://ieeexplore.ieee.org/document/7146512/">energy-positive sensing</a>. Energy can be harvested from human motion, which can in turn can power a wearable device. But in addition to providing some amount of power, information about human activity, such as whether the wearer walking or running, can be reconstructed from the harvested energy signal. </p>
<h2>Protecting the environment from batteries</h2>
<p>Of course, there are challenges to having battery-powered devices that operate indefinitely in the wild.</p>
<p>Over time, batteries may leak damaging chemicals such as nickel, cadmium or hydrofluoric acid into the environment, or even catch fire under extreme heat. </p>
<p>When monitoring <a href="https://research.csiro.au/aim/home/aims-research-test-beds/great-barrier-reef-monitoring-response/">the health</a> of the Great Barrier Reef with a battery-powered sensor, for instance, any battery-powered device must be fully sealed and insulated from the water.</p>
<p>The development of batteries that biodegrade is an interesting direction that could reduce the environmental impact of large sensing systems. Some researchers are experimenting with dissolvable batteries <a href="http://cen.acs.org/articles/95/web/2017/04/Dissolvable-batteries-made-silk.html">using silk</a>, skin pigment melanin and salt water solutions for electrolytes. </p>
<p>Animal welfare must also be considered: devices for long-term wildlife tracking must either be light and small enough so that animals can move normally, or have a drop-off mechanism at a set time.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178011/original/file-20170713-18558-11uiew8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sensors in the Great Barrier Reef shouldn’t damage the environment.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/magnificent-colours-great-barrier-reef-154199480?src=lTgVwHDFl7_APayP4EE3yQ-1-3">JC Photo/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The ethics of batteries that last forever</h2>
<p>From a philosophical perspective, creating indefinitely powered devices that can sense, think, and act moves us closer to creating artificial life forms. </p>
<p>Couple that with an ability to reproduce through 3D printing, for example, and to learn their own program code, and you get most of the essential components for creating a self-sustaining species of machines. </p>
<p>Self-sustaining battery-powered devices can also continue to gather data from their environment beyond their intended mission. This could lead to the collection of unintended data that might have privacy or political implications. </p>
<h2>No battery is sometimes better</h2>
<p>Motivated by the risks of battery-powered devices, some manufacturers <a href="http://www.ti.com/tool/tidm-rf430-tempsense">have created</a> <a href="http://www.evigia.com/batteryless-wireless-sensors/">battery-less sensing devices</a> to eliminate the need for battery recharging and environmental risk altogether. </p>
<p>This opens up new applications, such as placing sensors in human and animal bodies for physiological sensing.</p>
<p>Rather than having a continuous storage of energy, these devices can use near-field radio waves or other nearby energy sources to gather enough power to conduct a limited set of sensing or computing operations on-demand. They are similar in concept to passive radio-frequency identification (RFID), but may provide more information than simply the identity of a tag. </p>
<p>The drawback is that it only works under specific conditions. In particular, it requires that the energy source be within a very short distance of the passive device.</p>
<p>Energy-sustainability will be vital for applications from animal detection and tracking to shipping and logistics. Companies have already started to introduce value-added services such as <a href="http://www.inboundlogistics.com/cms/article/sensor-based-logistics-monitoring-shipment-vital-signs-in-real-time/">sensor-based logistics</a> to deliver real-time information on high-value shipments. Sustainable operation of the sensors will only encourage this trend.</p><img src="https://counter.theconversation.com/content/79750/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Raja Jurdak receives funding from QLD Government, Department of Environment, Gordon Moore and Betty Foundation. </span></em></p><p class="fine-print"><em><span>Brano Kusy has received funding from Australian Coal Association Research Program (ACARP), Queensland Government, Department of Environment, Gorden and Betty Moore Foundation. </span></em></p>Batteries that can self-sustain are needed for long-term animal tracking as well as shipping and logistics.Raja Jurdak, Research Group Leader, Distributed Sensing Systems, CSIROBrano Kusy, Research Scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/796642017-07-24T20:11:18Z2017-07-24T20:11:18ZTo build better batteries, you need to catch them in the act<figure><img src="https://images.theconversation.com/files/179141/original/file-20170721-14719-zvitda.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">We need to look at batteries in-action to understand them better. </span> <span class="attribution"><span class="source">Ruth Knibbe</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em>This article is part of a series on building the future of batteries. How can we create the batteries we’ll need to power our electronics, transport and industry, and what’s standing in the way? You can read the rest of the series <a href="https://theconversation.com/au/topics/the-future-of-batteries-40687">here</a>.</em></p>
<hr>
<p>Emerging industries, from large-scale energy storage to electric cars, will need longer lasting batteries. But to build them, we need to know a lot more about what is limiting battery life. </p>
<p>New tools let researchers examine, at the <a href="https://www.nano.gov/nanotech-101/what/nano-size">nanometer scale</a>, batteries while they’re in operation. This helps them identify internal faults that can trigger battery failure.</p>
<p>Advanced tools, such as electron microscopes and <a href="https://theconversation.com/the-australian-synchrotron-is-great-but-what-does-it-do-5704">synchrotrons</a> – a very powerful light source – let us look at batteries while they’re in use. High speed cameras and detectors, chip technology and the ability to process large amounts of data also play a role. </p>
<p>This emerging field still has its obstacles: the high energy x-rays or electron beams used by these tools can interfere with battery operation, and typically the sample size is limited because it needs to fit into a relatively small instrument space. </p>
<p>Despite the technical challenges, these tools can provide us with important insights into the current limitations of battery technology. </p>
<h2>How can we look at batteries while they are in operation?</h2>
<p>To understand how we look at batteries in action, it’s important to first understand their parts.</p>
<p><a href="https://engineering.mit.edu/engage/ask-an-engineer/how-does-a-battery-work/">Each lithium-ion battery</a>, for example, has a positive and negative electrode, and an electrolyte that separates them. This electrolyte, typically a liquid chemical mixture, allows an electrical charge (in the form of lithium ions) to flow. Lithium ions diffuse through the electrolyte between the electrodes depending on whether the cell is being charged or discharged. </p>
<p>When imaging batteries that are operating, it’s possible to see these nanoscale processes and pinpoint problems with the materials used. In the lab, a <a href="https://www.sparkfun.com/products/338">coin cell battery</a> is often used for testing.</p>
<p>A range of tools can be used to look at batteries in this way, but x-ray and <a href="http://smeng.ucsd.edu/wp-content/uploads/Advanced-analytical-electron-microscopy-for-lithium-ion-batteries.pdf">electron microscopy techniques</a> are particularly promising.</p>
<p>For researchers to be able to see what’s inside a battery, the imaging beam, whether light, x-ray or electron beam, needs to pass through the sample. Just think about light hitting a wall rather than a window: if the battery is too thick, the x-ray or electron beam cannot penetrate.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/179143/original/file-20170721-14743-1c43wc3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The author with a coin cell battery used for testing.</span>
<span class="attribution"><span class="source">Ruth Knibbe</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Conventional lab x-rays have a low energy and intensity, and so cannot penetrate very deeply into a material. However, an x-ray beam from a synchrotron has a <a href="http://www.esrf.eu/about/synchrotron-science/synchrotron-light">considerably higher energy</a> and allows for deeper penetration. </p>
<p>However synchrotrons are typically very large facilities that are difficult to operate and access. </p>
<p>A more common instrument is the <a href="http://ammrf.org.au/myscope/tem/introduction/">transmission electron microscope (TEM)</a>. A TEM is a microscope that uses an electron beam instead a light beam, unlike a conventional microscope. The electron beam can allow for magnification of more than <a href="http://web.pdx.edu/%7Epmoeck/pdf/all%20you%20wanted%20to%20know%20about%20electron%20microscopy.pdf">one million times</a>. </p>
<p>However, if an electron beam was passed through air, it would scatter considerably and you would not be able to see anything. For this reason, operation of a TEM requires a very high vacuum which allows the electron beam to easily pass. </p>
<p>Unfortunately, this presents another challenge for researchers: the vacuum makes the inclusion of a liquid electrolyte (present in many standard batteries) impossible, as the liquid would likely evaporate. </p>
<p>Recently, <a href="http://www.protochips.com/products/poseidon/">new TEM holders</a> have been designed that allow the battery material and the liquid electrolyte to be encased between two electron transparent windows, as well as the current to be passed through the battery material. </p>
<p>This makes it possible to create an image at very high magnifications while operating the battery.</p>
<h2>What battery problems are we looking for?</h2>
<p>This emerging type of battery research is needed to address the faults in batteries.</p>
<p>Of particular importance are the conditions that allow for lithium dendrite growth. </p>
<p>Lithium dendrites are microscopic tree-like structures that can grow from a lithium electrode, potentially short-circuiting the cell. This process can <a href="http://newscenter.lbl.gov/2013/12/17/roots-of-the-lithium-battery/">even cause a battery fire</a>, and the issue is hampering the use of powerful lithium electrodes.</p>
<p>Preliminary work has shown that it is possible to image the <a href="http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b00175">dynamic growth of lithium dendrites</a> in a TEM.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=295&fit=crop&dpr=1 600w, https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=295&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=295&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=371&fit=crop&dpr=1 754w, https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=371&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/178573/original/file-20170718-22017-m99hyg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=371&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Two scanning electron microscope images that illustrate how a traditional electrolyte can cause dendrite growth (left), while a new electrolyte instead causes the growth of smooth nodules that don’t short-circuit batteries (right).</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pnnl/16446719694/in/photolist-WaTTNN-W3zEB9-r4kJLE-L8EqSf-rY3NgU-xYsc3P">Pacific Northwest National Laboratory/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Degradation can also occur in lithium-ion batteries through stresses introduced by large volume changes as lithium ions are absorbed and released, electrode components dissolving in the electrolyte and long-term corrosion issues. </p>
<p>These problems are only loosely understood currently, but nanoscale imaging will help us improve battery design. </p>
<p>Our vision is to make it easier to observe new battery systems under different operating conditions. This way we can understand the challenges holding back long-life battery systems.</p><img src="https://counter.theconversation.com/content/79664/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ruth Knibbe does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Emerging industries, from energy storage to electric cars, will need longer lasting batteries. Watching batteries in action will help us build them.Ruth Knibbe, Lecturer, School of Mechanical and Mining Engineering, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.