New chemistries for batteries, semiconductors and more could be easier to manufacture, thanks to a new approach to making chemically complex materials that researchers at the University of Michigan and Samsung’s Advanced Materials Lab have demonstrated.&nbsp;Their new recipes use unconventional ingredients to make battery materials with fewer impurities, requiring fewer costly refinement steps and increasing their economic viability.“Over the past two decades, many battery materials with enhanced capacity, charging speed and stability have been designed computationally, but have not made it to market,” said <a href="https://mse.engin.umich.edu/people/whsun" target="_blank" rel="noreferrer noopener">Wenhao Sun</a>, the Dow Early Career Professor of Materials Science and Engineering at U-M and the corresponding author of the study published in Nature Synthesis.<iframe width="640" height="360" src="https://www.youtube.com/embed/9WxUQoFuEWs?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe>“A lot of times, a simple material is a good starting point, but when you add a little bit of compound A and a little bit of compound B, magic happens and you get big improvements in capacity or charging rate. However, these chemically complex materials are often difficult to manufacture at scale with high purity.”Battery materials are typically made by mixing several different oxide powders and firing them in an oven. However, these powders react in a sequence rather than all at the same time. The first two ingredients to react are usually those that release the most energy upon reacting. The first reaction results in an intermediate compound that then reacts with the remaining powder, and so on, until no more reactions are possible.If the chemical bonds in the intermediate compounds are difficult to break, they might not fully react with the other ingredients. When they don’t fully react, the intermediates hang around as undesired impurities in the final material.“We designed a strategy to make impurity-free materials more reliably,” said <a href="https://mse.engin.umich.edu/people/jiadongc" target="_blank" rel="noreferrer noopener">Jiadong Chen</a>, the first author of the study and a U-M doctoral student in materials science and engineering and scientific computing. “The trick is to only work with two ingredients at a time, and deliberately make unstable intermediates that will react completely with the remaining ingredients.”To test this strategy, Sun’s team designed 224 different recipes to create 35 different known materials containing elements used in today’s batteries and next-generation ‘beyond-lithium’ batteries.&nbsp;The researchers then partnered with Samsung Semiconductor’s Advanced Materials Lab in Cambridge, Massachusetts, to test if their recipes produced these 35 materials with fewer impurities than conventional recipes. Samsung’s automated robotic lab can synthesize up to 24 different battery materials every 72 hours.Robotic arms handle the ingredients and operate the lab equipment that assesses the purity of the resulting materials. Meanwhile, computers automatically record the results of each experiment, creating a database that researchers can use to determine which recipes worked best.“With the automatic lab, we could broadly test our hypothesis on diverse battery chemistries,” Chen said.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1712996666658-battery-materials-featured-1920x1081+%281%29.jpg" style="width: 100%px;" class="fr-fic fr-dib">ASTRAL, Samsung’s robotic lab, uses automated robotic arms to manipulate lab equipment, reagents and samples. As the lab makes battery materials according to a pre-programmed recipe, it automatically records data on the quality of the materials along the way. The records allow researchers to evaluate a large number of recipes in a reproducible manner. Photo credit: Advanced Materials Lab, Samsung Advanced Institute of Technology-America, Samsung Semiconductor.The experiments confirmed that the new recipes with ingredients designed to be unstable tended to produce cleaner products. The new recipes improved the materials’ purity by up to 80%, and six of the target materials could only be made with new recipes.Blueprints for the robotic lab were detailed in the team’s report, which Sun hopes will enable more chemistry labs to adopt robotic labs for both science and materials manufacturing.“We need more data—not just from successful recipes but also the unsuccessful ones—to improve materials manufacturing strategies. More robotic labs will help generate the needed data,” Sun said.These labs are within reach for most research institutions and could significantly speed up materials development, the researchers say.“The startup cost for the robotic equipment is about $120,000—not as high as you might think. But the payoffs in throughput, reliability and data-management are invaluable,” said study co-author Yan Eric Wang, principal engineer and project manager of Samsung’s Advanced Materials Lab.

Mixing unconventional ingredients in just the right order can make complex materials with fewer impurities. The robotic lab that tested the idea could be widely adopted.

Better battery manufacturing: Robotic lab vets new reaction design strategy

As electric vehicle (EV) battery manufacturing expands, so too does the demand for the materials that are essential to their production. Today’s EVs employ several battery technologies with different combinations of materials. Around the world, governments are developing policies to ensure that these materials are readily available and to mitigate supply chain disruption risks.In a <a href="https://www.nature.com/articles/s41467-024-46418-1.epdf?sharing_token=4_W4TX-XN5hf4pPgys28ENRgN0jAjWel9jnR3ZoTv0PnOf5EcsU7quxpqwJX9Xvx1Kknep4kdCq_oWx29xEFTtXCjwgDK1nPtYAm1mMCWM14HjSs6N-aU6tNprpaHHnVJjkVY3-GfWzbWhoDa3vv-COI28ukJIlSa6QTFEIpTSQ%3D" rel="noopener" target="_blank">recent publication in Nature Communications</a>, a team of researchers from the Department of Engineering and Public Policy at Carnegie Mellon University provides analysis of the relationship between electric vehicle battery chemistry and supply chain vulnerability for four critical minerals—lithium, cobalt, nickel, and manganese—across particular countries that are key contributors to production. The primary lithium ion battery chemistries used in EVs today are lithium iron phosphate (LFP), nickel manganese cobalt (NMC), and nickel cobalt aluminum (NCA), which each depend on varying amounts of these minerals. The authors, Anthony Cheng, <a href="https://engineering.cmu.edu/directory/bios/fuchs-erica.html" target="_blank">Erica Fuchs</a>, <a href="https://engineering.cmu.edu/directory/bios/karplus-valerie.html" target="_blank">Valerie Karplus</a>, and <a href="https://engineering.cmu.edu/directory/bios/michalek-jeremy.html" target="_blank">Jeremy Michalek</a>, find that effectively reducing vulnerabilities to disruption related to any particular country may require addressing multiple layers of upstream supply relationships.<blockquote>We need to anticipate new potential supply chain vulnerabilities so that we can act strategically to mitigate risk.<cite>Jeremy Michalek, Professor, Mechanical Engineering and Engineering and Public Policy</cite></blockquote>“In the 1970s, several global oil supply disruptions sent shock waves through the economy, with motorists waiting in long lines to fill up,” says Michalek, a professor of engineering and public policy and mechanical engineering and who also serves as director of <a href="https://www.cmu.edu/cit/veg/" rel="noopener" target="_blank">Carnegie Mellon’s Vehicle Electrification Group</a>. “As we shift away from gasoline toward electric vehicles, we need to anticipate new potential supply chain vulnerabilities so that we can act strategically to mitigate risk.”By mapping the supply chains of the four critical materials, calculating a vulnerability index, and using a network flow optimization to bound uncertainties, the study finds that production at multiple supply chain steps is highly concentrated in single countries. In particular, production at multiple stages of the supply chain across battery technologies occurs in China, primarily due to its role in materials refining and cathode production.“Our approach provides a new measure of energy security as we move beyond fossil fuels,” says Karplus, a professor of engineering and public policy and associate director of the <a href="https://www.cmu.edu/energy/" rel="noopener" target="_blank">Wilton E. Scott Institute for Energy Innovation</a>.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1712184833930-0319-em-ev-supply-chain.png" style="width: 100%px;" class="fr-fic fr-dib">A Sankey diagram for global flows of lithium that available data suggest are involved in battery material supply chains.&nbsp;Source:&nbsp;Nature CommunicationsA supply chain disruption centered in one country could occur for any number of reasons, ranging from geopolitical strategy to political or economic instability, a natural disaster, or another pandemic. Last year, China restricted exports of graphite, another key material used in batteries. Countries that make EVs, like the U.S., have an interest in diversifying supply chains to reduce disruption risks such as this.Additionally, the research finds that the levels of vulnerability vary based on the lithium-ion battery chemistry. For example, the LFP chemistry may currently be more vulnerable to supply disruptions in China, but NMC chemistries depend on more critical materials, resulting in more pathways for disruptions from other countries to affect the supply chain, such as the Democratic Republic of Congo or South Africa.As efforts are made to diversify the supply chain and incentivize domestic production, the authors note that a comprehensive approach must be considered beyond battery cell and pack production, including minerals extraction, processing, and component production.“The U.S. Inflation Reduction Act provides major incentives to diversify the supply chain and build more batteries in the U.S.,” says Michalek. “We’re actively working to analyze how this policy may incentivize changes in different parts of the supply chain and in battery technology.”The findings in this research can be useful to policymakers as they seek to identify specific bottlenecks, key relationships, and potential levers for reduction of supply chain vulnerabilities.

A recent study analyzes the relationship between electric vehicle battery chemistry and supply chain vulnerability for four critical minerals—lithium, cobalt, nickel, and manganese—across particular countries that are key contributors to production.

Anticipating and reducing EV battery supply disruptions

Powerful, safe and environmentally friendly – sodium-ion batteries have many advantages over conventional batteries. Since they do not contain critical raw materials such as lithium or cobalt, they could also make applications such as stationary energy storage and electromobility much cheaper. However, there is currently a lack of the necessary energy storage materials for production. The start-up Litona, founded at the Karlsruhe Institute of Technology (KIT), wants to produce them on an industrial scale. From April 22nd to 26th, 2024, Litona will be presenting itself at the KIT stand at “Energy Solutions” (Hall 13, Stand C76) at the Hannover Messe.&nbsp;Prussian White, a “chemical relative” of the well-known dye Prussian Blue, is essentially based on sodium, iron and manganese. “As an energy storage material, it can be used on the cathode, i.e. the positive pole of a sodium-ion battery,” says Sebastian Büchele from the Institute for Applied Materials at KIT and founder of Litona. “Such batteries are cheap and all the raw materials they contain are widely available. I am convinced that we will soon be able to use them on a mass scale in electric vehicles and grid storage.” The question, however, is who produces them. The European industry is facing a major problem here. “It is currently difficult even for research institutions to obtain Prussian White in sufficient quantities. Hardly any company in Europe produces it,” reports the scientist. “Research and transfer of future-oriented sodium-ion technology will be extremely slowed down.”<h2 id="isPasted">Prussian White for mass production</h2>Since Büchele also wanted to research sodium ion technology, he decided to synthesize Prussian white himself. This work at KIT not only resulted in a high-quality cathode material, but also an innovative process for its production. With the aim of serving a larger market, he founded the start-up Litona together with the chemist Tom Bötticher. “Competitors had problems scaling the production of Prussian White analogues,” says Büchele. “We believe we have solved this. We have also developed methods to further enhance our material.”<h2>Opportunity for European industry</h2>To validate the scaling steps and optimize the material for use in next-generation batteries, Litona used KIT's infrastructure. In the meantime, the two founders are already working on setting up their own state-of-the-art production facility. “We consciously chose Germany as a location,” emphasizes co-founder Bötticher. “We believe in the potential of European battery production. When it comes to lithium-ion batteries, Asia has been ahead in recent years. Sodium-ion technology is now a huge opportunity for a new beginning in Europe. We don’t just want to watch.”<h2>Litona at the Hannover Messe 2024</h2>The start-up Litona will be presenting itself at this year's Hannover Messe from April 22nd to 26th at the KIT stand at “Energy Solutions” (Hall 13, Stand C76).<hr><h2>About Litona</h2>Litona was founded in August 2023 with the aim of supplying the European industry with sodium-ion energy storage materials. However, the young company does not want to rule out developing its own sodium-ion batteries in the future. The founders are currently in discussions with well-known investors from the deep tech scene.&nbsp;Further information:&nbsp;<a href="https://www.litona-batteries.de/" target="_blank">https://www.litona-batteries.de/</a>

Litona founder Sebastian Büchele shows a bottle of the energy storage material Preußisch Weiß for sodium-ion batteries. (Photo: Markus Breig, KIT)

Litona, a spin-off from KIT, produces the cathode material Prussian White for next-generation batteries

Battery material for the sodium-ion revolution

In this episode, we discuss a breakthrough from an EPFL researcher which promises to finally make hydrogen a feasible source of energy by extracting it efficiently from ammonia. 

Podcast: How Hydrogen Will Replace Batteries

Battery Type: Electrochemistry, Capacity, and Energy DensityConsider the application and device form factor when choosing the battery. Coin cell batteries are compact and suitable for low-power devices with minimal energy needs but have limited capacity and are non-rechargeable. Lithium-ion (Li-ion) or lithium-polymer (Li-poly) batteries offer higher capacity, rechargability, and longer lifespans, making them suitable for devices with higher power demands and longer lifecycles. Customized batteries may be necessary for devices with unconventional form factors.Capacity, measured in mAh or Wh, refers to the amount of charge a battery can store, while energy density relates to the amount of energy stored per unit volume or weight. Selecting a battery with sufficient capacity and energy density ensures extended device operation without frequent battery replacements.Voltage and Discharge CharacteristicsEnsure the battery voltage aligns with the device's voltage requirements over its entire lifespan. Understand the discharge rate influenced by the application's use, such as data transmission frequency, intensity, and duration. These factors impact battery characteristics, including discharge rate and voltage drop over time, ultimately affecting power consumption and runtime.TemperatureTemperature significantly affects battery performance. Extreme temperatures can impact capacity, discharge rate, and lifespan. Select a battery with an operating temperature range suitable for the device's environmental conditions.Battery and Device Shelf LifeConsider battery conditions, such as self-discharge, both before integration into the IoT device and once integrated. Aging and self-discharge affect performance, so understanding these parameters during product development and post-market deployment is crucial.Cost and LifespanEvaluate upfront cost and total cost of ownership over the battery's lifespan. Assess the battery's expected lifespan and balance it with the device's operational duration to optimize cost-effectiveness.By considering these factors, developers can choose the right battery for their IoT devices, ensuring optimal performance, longevity, and cost-effectiveness. Relying solely on data sheets is not sufficient. Further tests need to be done due to the device-specific conditions and batteries. This will be adressed in the following blogpost. If you can’t wait, download the&nbsp;<a href="https://www.qoitech.com/whitepaper/powering-iot-devices/" target="_blank">white paper</a>.

Choosing the appropriate battery for IoT devices is critical to ensure optimal performance and longevity. There are several factors to consider when selecting a battery that aligns with the specific requirements of the application, allowing for reliable and long-lasting power supply.

Choosing the Right IoT Battery

With the U.S. government’s goal to reduce emissions from transportation as part of a net-zero climate goal by 2050, efficient and reliable batteries are a necessity. A collaborative team of researchers led by the McKelvey School of Engineering at Washington University in St. Louis is working toward that goal by developing an energy storage system that would have a much higher energy density than existing systems.With $1.5 million from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), Xianglin Li, associate professor of mechanical engineering &amp; materials science, will lead a multi-institutional team to develop a lithium-air (Li-air) battery with ionic liquids to deliver efficient, reliable and durable performance for high-energy and high-power applications. The Phase I, 18-month funding is part of $15 million ARPA-E awarded to 12 projects across 11 states to advance next-generation, high-energy storage solutions to speed electrifying the aviation, railroad and maritime transportation sectors.Funded through the Pioneering Railroad, Oceanic and Plane ELectrification with 1K energy storage systems (<a href="https://arpa-e.energy.gov/technologies/programs/propel-1k" target="_blank">PROPEL-1K</a>) program, projects aim to develop emission-free energy storage systems with “1K” technologies capable of achieving or exceeding 1,000-Watt-hour per kilogram (Wh/kg) and 1,000 Watt-hour per liter (Wh/L).“The current commercially available lithium-ion batteries have the specific energy of around 200 watt-hour per kilogram, and those would not work because 1,000 watt-hour per kilogram is beyond their thermodynamic limit,” Li said. “We need to increase that specific energy density by four to five times, so this is a very aggressive goal.”If successful, PROPEL-1K technologies would electrify regional flights traveling as far as 1,000 miles with up to 100 people, all North American railroads, and all vessels operating exclusively in U.S. territorial waters, the agency said.&nbsp;Li’s team’s concept would use pure lithium in the anode because it has the highest energy density. They will use a very thin separator with unique properties to transfer the lithium ion back and forth. The cathode must contain catalysts that make the electrochemical reaction of oxygen reduction and evolution reactions happen quickly and efficiently.“All of these components must be put together almost perfectly, because that 1,000 watt-hour per kilogram is near the limit of any energy storage technology,” Li said. “That's why we have a large team with complementary experts on different parts of this whole system. My team will lead the overall design of the system and focus on the cathode where the oxygen reaction would occur.”For the proposed Li-air flow battery, the team will use a unique electrolyte: ionic liquids with high oxygen solubility, low viscosity, ultra-low volatility and high ionic conductivity. The team will also customize catalysts and lithium metal protection membranes to enhance battery performance while reducing power consumption during electrolyte circulation. Preliminary experimental results have shown a tenfold increase in capacity by using a circulating electrolyte.“Commercial batteries use organic electrolytes, but because our Li-air cell is an open system, that electrolyte would evaporate over time,” Li said. “Ionic liquid is a salt that acts like a liquid but does not evaporate and can flow at room temperature.”Co-principal investigators on the project include Peng Bai, associate professor, and Vijay Ramani, the Roma B. &amp; Raymond H. Wittcoff Distinguished University Professor, both in the Department of Energy, Environmental &amp; Chemical Engineering in McKelvey Engineering; Mark Shiflett, Foundation Distinguished Professor at the University of Kansas; Ivan Vlassiouk, senior research staff at the Oak Ridge National Laboratory; James Saraidaridis, principal research engineer at Raytheon Technologies Research Center; and Sherry Quinn, electrochemist at Powerit. Together, they will work to develop a prototype that may be further developed and taken to market.The team also will conduct an economic analysis of its Li-air flow battery systems to the aviation, railroad and maritime transportation sectors to highlight the importance of advancing energy storage technologies beyond the current Li-ion battery technology.

With $1.5 million from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), Xianglin Li, associate professor of mechanical engineering & materials science, will lead a multi-institutional team to develop a lithium-air (Li-Air) battery with ionic liquids to deliver efficient, reliable and durable performance for high-energy and high-power applications. (Credit: iStock photo)

With the U.S. government’s goal to reduce emissions from transportation as part of a net-zero climate goal by 2050, efficient and reliable batteries are a necessity.

Efficient lithium-air battery under development to speed electrification of vehicles

According to the Global EV Outlook from IEA, the EV stock reaches 145 million in 2030, accounting for 7% of the road vehicle fleet. However, one of the main challenges facing EVs is the battery, which determines the performance, range, safety, and cost of the vehicle. The battery enclosure is the protective structure that houses the battery cells and modules. The article explores different materials and design considerations for enclosures to optimize and supercharge EV performance. &nbsp;<h2 dir="ltr">Steel vs. Aluminium vs. Carbon Fiber</h2>Steel is a traditional material that offers high strength and durability. However, steel is heavy and prone to corrosion, which can reduce the energy efficiency and lifespan of the battery. In addition, steel has high thermal conductivity, which affects the battery performance and safety. Aluminum, in contrast, is preferred due to its lightweight and high strength-to-weight ratio. It is also more resistant to corrosion than steel.Sounds like aluminum wins in every way, no material is without its challenges, however. There is also the poor impact performance of metal materials. Carbon fiber reinforced polymer (CFRP), a newer and more innovative composite material, offers lightweight, anti-impact, durable and flexible performance. However, it is also more expansive. Moreover,<a href="https://www.sae.org/news/2021/01/novel-materials-approach-to-ev-battery-box-design" target="_blank">&nbsp;its thermal expansion mismatch with the battery cells</a>, which makes it still a cautious choice.<h2 dir="ltr">Design to Improve Cooling Efficiency</h2>Other than material selection, the factors such as structure optimization, thermal management system, etc., are also crucial. The modular design with multiple cooling channels and the use of cooling fins and heat sinks can enhance the cooling efficiency of the battery pack. Therefore, the surface area for heat transfer increased, allowing air or liquid to flow through the channels. If the heat, generated by battery cells during operation, is not dissipated properly, can reduce the lifespan of the battery, and even cause safety hazards.<h2 dir="ltr">Multi-layered Housing Structure</h2>Another important aspect of the battery pack housing design is the protection against mechanical and thermal shocks. A multi-layered housing structure consisting of an outer layer of aluminum or steel, a middle layer of insulation material, and an inner layer of polymer film can balance the pros and cons of different materials.This structure protects against physical damage to the battery cells from external impacts or vibrations, and protects against thermal runaway, which can occur when the battery overheats and triggers a chain reaction leading to a fire or explosion. The insulation layer prevents heat from spreading to adjacent cells and absorbs impact energy, while the polymer film acts as a barrier to prevent oxygen from entering the battery and fueling the combustion.<h2 dir="ltr">On-demand Manufacturing Accelerates Your Enclosure Development</h2>Before launching battery packs to the market, you need to conduct many prototyping verifications. RPWORLD is happy to support alongside your auto part development with 20-years’ experience and expertise. Choose RPWORLD, you will get:<ul><li dir="ltr">Fast delivery in as little as 7 days to help you ahead of competitions.</li><li dir="ltr">One-stop manufacturing including CNC machining, injection molding and more to bring your design to life under one roof.</li><li dir="ltr">Design optimization and manufacturability advice to mitigate production risks.</li><li>00+ high-performance engineering materials to suite your different needs.</li></ul>

According to the Global EV Outlook from IEA, the EV stock reaches 145 million in 2030, accounting for 7% of the road vehicle fleet. However, one of the main challenges facing EVs is the battery, which determines the performance, range, safety, and cost of the vehicle.

Supercharge EV's Performance with Optimized Battery Enclosures

By leveraging the inherent energy storage properties of an emerging technology known as enhanced geothermal, the research team found that flexible geothermal power combined with cost declines in drilling technology could lead to over 100 gigawatts’ worth of geothermal projects in the western U.S. — a capacity greater than that of the existing U.S. nuclear fleet. Such an innovation would transform geothermal energy from its niche status on the grid today into a major component of a decarbonized future. The researchers <a href="https://www.nature.com/articles/s41560-023-01437-y" target="_blank">published their analysis</a> January 15 in Nature Energy.“People generally think of geothermal as this always-on, baseload energy source, but we’ve shown that there’s a lot of extra value to be had in operating these plants in a different way,” said research leader <a href="https://engineering.princeton.edu/faculty/jesse-jenkins" target="_blank">Jesse Jenkins</a>, assistant professor of <a href="https://mae.princeton.edu/" target="_blank">mechanical and aerospace engineering</a> and the <a href="https://acee.princeton.edu/" target="_blank">Andlinger Center for Energy and the Environment</a>.Since the early 20th century, people have been harnessing the earth’s heat to produce electricity, but these conventional geothermal power plants require a specific set of conditions: hot, permeable rocks close to the earth’s surface, and some sort of fluid to transport heat up from underground. These requirements have limited traditional geothermal energy to only a handful of favorable locations in the western United States and Hawaii — places with naturally occurring geysers, volcanoes, and hot springs. Consequently, geothermal plants generated only <a href="https://www.eia.gov/energyexplained/geothermal/use-of-geothermal-energy.php" target="_blank">0.4% of the total electricity</a> in the U.S. in 2022.Yet advances in drilling and hydraulic fracturing technologies have unlocked the enhanced geothermal approach, which removes the need for permeable rocks and greatly expands access to the heat that already exists far beneath our feet.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709337323262-fervo_horizontal-drilling_crop.png" style="width: 100%px;" class="fr-fic fr-dib">A diagram illustrating the enhanced geothermal approach employed by Fervo Energy. Fluid is first injected at the injection well, flows through engineered fractures in subsurface rock, picking up heat along the way, and then returns to the surface via production wells to generate electricity. The process creates a self-contained underground radiator that can function as a type of energy storage system (courtesy of Fervo Energy).In the approach, engineers dig two or more boreholes into impermeable rock that extend thousands of feet below the earth’s surface, then drill similar distances horizontally, and subsequently create fracture networks in the horizontal sections to connect those holes deep underground. Afterward, they inject a fluid into one borehole, which heats up as it travels through the fractures. That heated fluid can be pulled up through the other wells and subsequently used to generate electricity.“Enhanced geothermal is much less geographically dependent than conventional geothermal, which is really only possible in a small number of ideal spots,” said Wilson Ricks, first author of the study and a graduate student in mechanical and aerospace engineering. “With enhanced geothermal, you can open up wide swathes of the country — wherever you can dig down and find hot rocks close to the earth’s surface.”<h3>Adding value through flexibility</h3>Efforts to develop and scale enhanced geothermal energy have historically focused on lowering the costs associated with drilling and other equipment. The U.S. Department of Energy unveiled an&nbsp;<a href="https://www.energy.gov/eere/geothermal/enhanced-geothermal-shot" target="_blank">Enhanced Geothermal Shot</a> in 2022, for example, which calls for a 90% cost reduction of enhanced geothermal technologies by 2035.But in their research, the team found an alternate avenue to make geothermal power more market-competitive: flexibility.By operating enhanced geothermal power plants flexibly — using the inherent energy storage capabilities offered by enhanced geothermal reservoirs to generate more or less energy as needed — the team found that the value of geothermal energy dramatically increased because it could complement and compensate for intermittent energy sources such as solar and wind.“Wind and solar are now the cheapest sources of clean energy, but their downfall is their variability and weather dependency,” said Jenkins. “You can earn a lot of additional revenue if you can find a way to shift your clean energy generation to times without wind and solar.”Fortunately for enhanced geothermal, it can do just that.As Ricks explained, the impermeable rock required for enhanced geothermal also functions as a self-contained underground reservoir for heated fluid that acts like a giant energy storage system.Analogous to how a conventional battery can be charged and discharged to store and release energy, operators can change how fast they inject and extract fluid into the enhanced geothermal system to shift between energy production and energy storage. To “charge” the system, engineers would simply inject more fluid underground than they pull out, filling up the reservoir with heated fluid and building up pressure. And when clean energy is most needed, this heated, pressurized fluid can be discharged to the earth’s surface to generate electricity.“Because enhanced geothermal comes with its own variation of energy storage, you’re able to shift how you operate the plant to generate as much power as possible at the times when it’s most valuable to the grid,” said Ricks. “That added flexibility allows enhanced geothermal to avoid generating energy when wind and solar are active and electricity prices are extremely low, something many alternative energy sources struggle to do.”<h3>Flexibility in practice</h3>Adding flexible operations to enhanced geothermal made the technology more valuable and increased its optimal installed capacity in every scenario, even without further cost declines in drilling technologies. In fact, scenarios that assumed flexible operations were similarly impactful to the deployment of geothermal as scenarios that only assumed lower drilling costs. Combining flexible operations&nbsp;and&nbsp;cost declines, the team found that geothermal energy could add up to over a third of the installed clean energy capacity in the western U.S.Moreover, adding flexibility to an otherwise baseload geothermal plant would only require a few changes at the aboveground facility. Engineers would have to overbuild the capacity of the power station to accommodate for the times when the plant is discharging as much heated fluid to the surface as possible, and they would need infrastructure to store additional fluid for the “charging” periods, when more fluid is being injected than produced.But below ground, the baseload and flexible systems would look nearly identical.“That’s one of the real advantages here: the core technology — in terms of the wells and the subsurface engineering — doesn’t change. Once you’ve built the wells, the subsurface system is inherently flexible,” said co-author Jack Norbeck, chief technology officer and co-founder of Fervo Energy, a startup focused on developing enhanced geothermal resources.In field testing at its commercial&nbsp;<a href="https://www.technologyreview.com/2023/03/07/1069437/this-geothermal-startup-showed-its-wells-can-be-used-like-a-giant-underground-battery/" target="_blank">Project Red</a> plant in Nevada, Fervo Energy has demonstrated energy storage capabilities exceeding five days. When translating that field data into physical models, Norbeck said there were scenarios in which the system could achieve over 10 days of energy storage.“When you consider that many people are currently quantifying long-duration energy storage as anything over eight to ten hours, that’s very exciting to be already demonstrating something above five days,” Norbeck said.While initial field tests have validated many projections, Norbeck said work is still needed to demonstrate the robustness of flexible operations over many charge/discharge cycles and to characterize certain system properties like roundtrip efficiency. He added that flexible geothermal power will also require innovations to contract structures, since purchasing agreements for geothermal energy often assume that plants will operate as a baseload energy source.With support from the&nbsp;<a href="https://www.arpa-e.energy.gov/technologies/projects/fervoflex-long-duration-reservoir-energy-storage-and-load-following" target="_blank">Advanced Research Projects Agency for Energy (ARPA-E)</a>, Fervo Energy and Princeton’s ZERO Lab will continue their collaboration to explore these advanced geothermal techniques in the field and in computer models, answering key questions about the potential role of geothermal energy, as well as the necessary steps for achieving that role.“In <a href="https://www.sciencedirect.com/science/article/abs/pii/S0306261922002537" target="_blank">earlier work</a>, we’ve looked at the value of adding flexible operations to a single, first-of-its-kind enhanced geothermal plant, and in this work, we’ve answered the broader question of how flexible geothermal might fit into a future decarbonized energy system,” Ricks said. “The next step is to look at the intermediate timescale to understand how enhanced geothermal can get from the nascent technology it is today to become the clean energy heavy hitter we’ve shown it can be.”<hr>The paper, “<a href="https://www.nature.com/articles/s41560-023-01437-y" target="_blank">The role of flexible geothermal power in decarbonized electricity systems</a>,” was published January 15 in Nature Energy. In addition to Jenkins, Ricks, and Norbeck, co-authors include Katharine Voller and Gerame Galban of Fervo Energy. The work was supported by the U.S. Department of Energy Office of Science Small Business Innovation Research program, ARPA-E, and Princeton University’s Zero-carbon Technology Consortium.

A drilling rig at Fervo Energy's Project Red enhanced geothermal pilot project in Nevada (photograph courtesy of Fervo Energy).

Many consider geothermal to be an around-the-clock clean energy resource, but according to a Princeton-led study in collaboration with startup Fervo Energy, operating new geothermal plants flexibly could provide the best value for the grid.

Flexible geothermal power approach combines clean energy with a built-in "battery"

<h2 id="isPasted">How Nanotechnology Is Inspiring the Next Generation of Batteries</h2>Rechargeable batteries are an important part of many modern-day technologies. Researchers, manufacturers and end-user companies are always looking to improve the efficiencies of batteries, making them safer, smaller, and more lightweight to fit in the requirements of new technologies—that is, the consumer desire to have higher-powered, smaller, and more lightweight electronic devices. Conventional fabrication methods, electrochemistries, and materials will take batteries technologies only so far, so a lot of interest in recent years has been around using nanomaterials within the electrodes.Nothing is wrong with current battery technologies—as showcased by the 2019 Nobel Prize in Chemistry, which honored the scientists behind the Li-ion battery—but change is inevitable. Without an ever-changing electronics industry, technological advances made in the past few decades would not have been possible.While lithium-ion (Li-ion) batteries are ubiquitous nowadays, their efficiencies aren’t overly impressive. They are much safer than other batteries while still having a good energy density, so there is room for improvement. Other types of batteries are gaining traction at both fundamental and commercial levels, but a drive to improve the already-established Li-ion batteries by incorporating nanomaterials into them has begun.<h2>Why Nanomaterials?</h2>The switch to trialing nanomaterials over bulkier materials is for many of the same reasons that other industries have made the switch (or have looked to make the switch). A number of properties can be harvested for a small amount of nanomaterials being included in a device (or within another material).Not all nanomaterials are suitable for batteries, as some nanomaterials are inherently insulating in nature. Rather, it is the conductive nanomaterials that are of use in battery systems, such as those of solid-state nature, or those which are incredibly thin (for example, some 2D materials). Luckily, the use of nanomaterials in electrodes is not a completely new invention. It is merely a natural progression to make systems more effective without altering the internal workings of the technology. While the inclusion of nanomaterials might slightly alter the specific mechanisms of how the ions move into the electrodes (because of different-sized/geometry atomic holes) via different architectures, the general operational mechanism of the batteries remains the same. This means that any safety or efficiency issues that arise can be pinpointed much easier than trying to develop a new type of battery from scratch. Sometimes, improving the status quo is better than trying to develop something completely novel.Many of the nanomaterials trialed have high electrical conductivity, and with this comes a high charge carrier mobility. These properties stem from nanomaterials having a very active surface–and a very high surface area–compared to bulkier materials. In some cases, the active surface is the whole nanomaterial (2D materials). Given that nanomaterials are inherently thin, they are a lot more flexible–even the inorganic materials–than bulk materials, meaning that they are more useful for the batteries used in flexible and wearable technologies (Figure 1).<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709117096314-Flexible+Graphene+Image.webp" style="width: 100%px;" class="fr-fic fr-dib">Figure 1: The inherently thin nature of nanomaterials, as shown in this graphene sheet, means they are more flexible than bulk materials and thereby more suitable for batteries used in flexible and wearable technologies. (Source: BONNINSTUDIO/Shutterstock.com)Despite their small size, a lot of nanomaterials are very stable and are resistant to high temperatures, harsh chemicals, and high physical stresses. While this can’t be said for all nanomaterials, enough of them are stable and conductive enough for battery electrodes. One disadvantage of nanomaterials is their higher cost because of the more complex fabrication methods required to make them. However, because only a small amount is needed for the same (or better) properties than bulkier materials, the cost is a lot less than many people believe. The small addition of nanomaterials also means that less waste is often produced, and the batteries are more lightweight than when bulk materials are used.<h2>Graphene is the Front-Runner</h2>Of all the nanomaterials being trialed, graphene is the front-runner and is found in more prototypes than any other type of nanomaterial. A number of companies now commercially manufacture graphene batteries for different industrial sectors. Reportedly, some big cellphone manufacturers might use graphene batteries in some next-generation phones in the near future (graphene is already used in the cooling systems of some phones).Graphene exhibits some of the best recorded-values of almost all the properties that nanomaterials can exhibit, meaning that making compromises between the beneficial properties of different materials can often be negated by using graphene. Additionally, given that many batteries already use graphite—many graphene layers stacked on top of each other—it is a much more natural progression than other materials, and systems have been developed that use graphite-graphene electrodes.Graphene has one of the highest electrical conductivity and charge carrier mobilities known in the materials world. Moreover, it has an incredibly high tensile strength and flexibility (more than most nanomaterials and bulk materials), as well as being stable to high temperatures and harsh chemicals. The culmination of properties means that it can be used in a number of environments without its performance being affected, which is important when the batteries and the technologies they are in can get very hot internally, never mind the external heat they can be exposed to. Single-layer graphene is optically transparent, so it has the potential for being used to create transparent electrodes and transparent conductive films that could be used in batteries of the future that need to be invisible to the user.Aside from the properties being more suited to batteries than most other nanomaterials, the industry is in a much better place to cope with huge demands should it arrive. Because the properties and potential for graphene is well-understood, the industry has been preparing and growing in size around the world and graphene can now be produced at scale in a number of different forms. The raw material side is more scalable than other nanomaterials, making it a much more viable commercial option.<h2>Conclusion</h2>There is a drive in modern-day society for more efficient and smaller batteries, regardless of whether the application is consumer phones or remote monitoring equipment. Companies are starting to trial nanomaterials in battery systems because they bring about performance benefits and can make the batteries smaller, while not significantly increasing cost because only a small amount is required. A number of companies manufacture graphene batteries, but while graphene batteries are available for the industrial markets, it might take some time for the high-tech consumer markets (phones, tablets, etc.) to adopt graphene (or other nanomaterials) on a large-scale because the status quo is well-tested and any changes in these markets can take a long time to come to fruition.

Rechargeable batteries are an important part of many modern-day technologies. Researchers, manufacturers and end-user companies are always looking to improve the efficiencies of batteries, making them safer, smaller, and more lightweight to fit in the requirements of new technologies

Nanotechnology Is Inspiring Next-Gen Batteries

LPWAN networks aim to conserve energy by operating devices with minimal power consumption. However, battery utilization efficiency depends on factors such as device power consumption, network connectivity, transmission power, and data rate. Understanding and optimizing these factors are key to achieving desired battery performance and ensuring reliable and uninterrupted device functionality.Efficient battery management not only reduces the frequency of battery replacements but also enhances the sustainability of IoT deployments. This is especially important for applications that require long-term monitoring, such as environmental sensing, asset tracking, and smart agriculture. By extending battery life, organizations can reduce operational costs, minimize environmental impact, and improve the overall viability and scalability of their IoT solutions.<h3>Optimizing Battery Life of LPWAN IoT Devices</h3>Battery life is a critical consideration for the successful deployment of IoT devices with limited power resources. Understanding and managing factors that influence battery life are essential for optimizing power consumption and maximizing operational efficiency.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA4NTA0NDAxMjM1LW90aWktYmF0dGVyeS1wZXJmb3JtYW5jZS0xMDI0eDc2OC5wbmciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 300px;" class="fr-fic fr-dib"><h3 id="isPasted">Device Power Consumption&nbsp;<iframe id="645c016f1f67f100087c4425" width="250" class="specs-iframe" height="440" src="https://wevolver.com/iframe/specs/otii-arc-pro?iframe=true" frameborder="0" scrolling="no" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true">&nbsp;</iframe></h3>IoT device power consumption significantly affects battery life. Factors such as hardware architecture, sensor configurations, and firmware optimization play a crucial role. Leakage current from various components can cause energy loss. Firmware and software optimization are vital for enhancing battery efficiency. By employing efficient algorithms, minimizing unnecessary background tasks, and optimizing code execution, developers can reduce power consumption in the device's software stack.Implementing power management techniques can have a significant impact on battery life. These techniques may involve dynamically adjusting power levels based on network conditions, reducing power to peripheral components during idle periods, or optimizing data processing and filtering algorithms to minimize power consumption.<h3>Data Rate and Duty Cycle</h3>Data rate and duty cycle determine the frequency and duration of data transmission in LPWAN devices. Lower data rates and duty cycles reduce power consumption but result in longer transmission times. Striking the right balance between data rate, duty cycle, and application requirements is crucial for optimizing battery life while ensuring sufficient data throughput.<h3>Network Connectivity and Protocols</h3>The frequency of network connectivity and the size of message payloads transmitted by LPWAN IoT devices affect power consumption. Low power capabilities of the network, such as power save modes, spreading factor, and adaptive data rate mechanics of cellular and non-cellular LPWAN networks, can further enhance battery life. The choice of messaging protocol can have a negative impact on device longevity due to the level of transmission overhead and required quality of service (QoS). By finding the right balance between power efficiency and communication requirements, developers can maximize battery performance and extend the operational lifespan of their IoT devices.<h3>Sleep Mode and Wake-Up Interval</h3>Effectively utilizing sleep mode is a key strategy for conserving power in IoT devices. By defining appropriate wake-up intervals and adjusting sleep durations based on application requirements, developers can minimize power consumption during idle periods, leading to significant battery savings.<h3>Transmission Power and Range</h3>The transmission power level required for reliable communication affects battery life. Higher transmission power increases range but consumes more power. By optimizing transmission power settings based on the deployment environment and required range, battery life can be prolonged without compromising communication reliability.By considering and fine-tuning these factors, developers can make informed decisions to optimize power consumption and extend the battery life of IoT devices. In the following blogposts, we will delve deeper into strategies and techniques to choose the right battery and implement optimization measures for maximizing battery performance in LPWAN IoT deployments. If you can’t wait, download the <a href="https://www.qoitech.com/whitepaper/powering-iot-devices/" target="_blank">white paper</a>.

Battery performance is crucial for the successful operation of IoT devices, particularly in remote or inaccessible locations. They rely on battery power to sustain their operation over extended periods, and maximizing battery life directly impacts longevity, maintenance costs, and user experience.

Importance of IoT Battery Performance

As augmented and mixed reality experiences become more popular through various devices, advancements in battery technologies are needed to ensure that these crucial components are made smaller, yet maintain their functionality. One <a href="https://www.mse.engineering.cmu.edu/index.html" rel="noopener" target="_blank">Department of Materials Science and Engineering</a> alumnus is involved with developing the technologies needed to bring these products to market at Meta.As a battery system engineer, Ankur Gupta, BS’10, MS’10, takes an interdisciplinary approach rooted in his studies at CMU to working with the multiple teams of engineers involved in the development of devices such as the Quest 3 and Ray-Ban | Meta smart glasses.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA4MDk3Njk5MzE2LTAyMDktZW0tZnV0dXJlLXZpc2lvbi5wbmciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 300px;" class="fr-fic fr-dib">At one end of the spectrum, he works with cell engineers, often chemical and materials science engineers, who design the chemistry inside the cell. &nbsp;At the other end, Gupta coordinates with the product design team, typically mechanical engineers, who are creating the physical design of what the actual active material has to fit into. Gupta bridges the work of these two groups, drawing on the experiences he had as a student, taking their outputs and designing the battery management unit (BMU). The BMU in the Ray-Ban | Meta smart glasses is now the world’s smallest and has all the circuitry for protection, gauging, and charging.Gupta’s interest in electronic materials was nurtured through his work with <a href="https://engineering.cmu.edu/directory/bios/whitacre-jay.html" target="_blank">Jay Whitacre</a>, professor of materials science and engineering, on batteries and energy technologies. When Gupta first enrolled as a student in the College of Engineering at Carnegie Mellon, he had no idea what materials science was. His initial interest was in electrical engineering, though he was also curious about nanotechnology. In his first year, he took the introduction to materials science and engineering course, and he was immediately drawn in. Later in his studies, Whitacre encouraged Gupta to think through bringing concepts to mass production, taking into account the economic influences and incremental changes in materials technologies.“The idea of taking a concept and actually bringing it to mass production has stuck with me, both in my past role at Apple and now at Meta,” says Gupta, as he reflects on projects involving batteries for devices such as iPhones, Airpods, Apple Watches, and now the Quest 3 and Ray-Ban | Meta smart glasses.While he did eventually go on to pursue a graduate degree in electrical engineering, he attributes his continued education to his background in materials science.“The reason why I went back to electric engineering was because of my foundation in materials science, especially in batteries,” says Gupta. “I knew how batteries were made and how they worked, but I wanted to go beyond that.”Gupta credits Carnegie Mellon’s emphasis on interdisciplinary studies focused on next generation problems to fostering his interest in batteries, as well as his approach to his work.“Batteries in particular are extremely interdisciplinary. There’s the chemistry side with materials science, the mechanical side of physically making the cell, the electrical side of what to do with the energy that comes out of the cell, and the economic side of building a supply chain.”<blockquote>The idea of taking a concept and actually bringing it to mass production has stuck with me.<cite>Ankur Gupta<cite id="isPasted">, MSE'10</cite> </cite></blockquote>Gupta draws on his materials science foundation still in his career today, recalling insights from Professor <a href="https://engineering.cmu.edu/directory/bios/heard-robert.html" target="_blank">Robert Heard</a>, who encouraged students to dive deep into a problem and think about it “at an atomic scale.”“For battery packs, we have to really dive into the printed circuit board (PCB) materials. Even though it’s electrical engineering, it’s also materials science getting into what’s going on at the atomic level.”Gupta draws on his own personal experiences of using the smart glasses to capture a photo, rather than trying to find his phone, to illustrate the ability that AR could have for users to experience the world, rather than looking down at phones. As Meta moves forward with developments for the Quest line of products with the goal of eventually functioning as a replacement to a traditional laptop, refining batteries to meet product design and functionality needs will be imperative.“Some of the key steps involve being able to have a battery that can power all that a laptop can do, but in the size of a phone,” he says. “It takes a lot of engineering and innovation to compact all these features into a very small product.’The pathway to a career in industry was not always clear, as the role of materials science in similar companies is not always immediately recognized, but Gupta encourages current students to think outside traditional career pathways.“If you think that there’s a way for materials to impact a certain industry, there probably is,” he says. “Make connections, and you can find a way to show there is an avenue.”

Ankur Gupta (MSE’10) is working to develop the battery technologies needed to bring augmented and mixed reality products to market at Meta.

Powering a vision for the future

Sensors that monitor infrastructure, such as bridges or buildings, or are used in medical devices, such as prostheses for the deaf, require a constant supply of power. The energy for this usually comes from batteries, which are replaced as soon as they are empty. This creates a huge waste problem. An EU study forecasts that in 2025, 78 million batteries will end up in the rubbish every day.A new type of mechanical sensor, developed by researchers led by Marc Serra-Garcia and ETH geophysics professor Johan Robertsson, could now provide a remedy. Its creators have already applied for a patent for their invention and have now presented the principle in the journal Advanced Functional Materials.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1706923590408-image0.imageformat.lightbox.847766885.jpg" style="width: 300px;" class="fr-fic fr-dib">Newer models of the sensor are highly miniaturised and fit on a fingertip. (all images: courtesy of Marc Serra-Garcia / Amolf)<h2>Certain sound waves cause the sensor to vibrate</h2>“The sensor works purely mechanically and doesn’t require an external energy source. It simply utilises the vibrational energy contained in sound waves,” Robertsson says.Whenever a certain word is spoken or a particular tone or noise is generated, the sound waves emitted – and only these – cause the sensor to vibrate. This energy is then sufficient to generate a tiny electrical pulse that switches on an electronic device that has been switched off.The prototype that the researchers developed in Robertsson’s lab at the Switzerland Innovation Park Zurich in Dübendorf has already been patented. It can distinguish between the spoken words “three” and “four”. Because the word “four” has more sound energy that resonates with the sensor compared to the word “three”, it causes the sensor to vibrate, whereas “three” does not. That means the word “four” could switch on a device or trigger further processes. Nothing would happen with “three”.Newer variants of the sensor should be able to distinguish between up to twelve different words, such as standard machine commands like “on”, “off”, “up” and “down”. Compared to the palm-sized prototype, the new versions are also much smaller – about the size of a thumbnail – and the researchers are aiming to miniaturise them further.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1706923608776-image1.imageformat.lightbox.523155445.jpg" style="width: 300px;" class="fr-fic fr-dib">High miniaturisation: 100 sound-sensitive elements fit into just 1x1 mm.<h2>Metamaterial without problematic substances</h2>The sensor is what is known as a metamaterial: it’s not the material used that gives the sensor its special properties, but rather the structure. “Our sensor consists purely of silicone and contains neither toxic heavy metals nor any rare earths, as conventional electronic sensors do,” Serra-Garcia says.The sensor comprises dozens of identical or similarly structured plates that are connected to each other via tiny bars. These connecting bars act like springs. The researchers used computer modelling and algorithms to develop the special design of these microstructured plates and work out how to attach them to each other. It is the springs that determine whether or not a particular sound source sets the sensor in motion.<h2>Monitoring infrastructure</h2>Potential use cases for these battery-free sensors include earthquake or building monitoring. They could, for example, register when a building develops a crack that has the right sound or wave energy.There is also interest in battery-free sensors for monitoring decommissioned oil wells. Gas can escape from leaks in boreholes, producing a characteristic hissing sound. Such a mechanical sensor could detect this hissing and trigger an alarm without constantly consuming electricity – making it far cheaper and requiring much less maintenance.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1706923630751-image2.imageformat.lightbox.1424652832.jpg" style="width: 300px;" class="fr-fic fr-dib">Vergrösserter Ausschnitt des schallempfindlichen Sensors neuerer Bauart: Die einzelnen Elemente sind nur wenige Mikrometer gross.<h2>Sensor for medical implants</h2>Serra-Garcia also sees applications in medical devices, such as cochlear implants. These prostheses for the deaf require a permanent power supply for signal processing from batteries. Their power supply is located behind the ear, where there is no room for large battery packs. That means the wearers of such devices must replace the batteries every twelve hours. The novel sensors could also be used for the continuous measurement of eye pressure. “There isn’t enough space in the eye for a sensor with a battery,” he says.“There’s a great deal of interest in zero-energy sensors in industry, too,” Serra-Garcia adds. He no longer works at ETH but at AMOLF, a public research institute in the Netherlands, where he and his team are refining the mechanical sensors. Their aim is to launch a solid prototype by 2027. “If we haven’t managed to attract anyone’s interest by then, we might found our own start-up.”<hr><h2 id="isPasted">Reference</h2>Dubček T, Moreno-Garcia D, Haag T, et al. In-Sensor Passive Speech Classification with Phononic Metamaterials. Adv. Funct. Mater. 2024, 2311877. DOI: <a href="https://doi.org/10.1002/adfm.202311877" target="_blank">external page10.1002/adfm.202311877</a>

prototype of the sound sensor is relatively large. (Photograph: Astrid Robertsson / ETH Zurich)

Researchers at ETH Zurich have developed a sensor that utilises energy from sound waves to control electronic devices. This could one day save millions of batteries.

Sound-powered sensors stand to save millions of batteries

<section id="isPasted">Polymer-air batteries often face challenges related to stability, kinetics and conductivity. In response, Dr. Jodie Lutkenhaus has developed a method to use a polymer as an anode in these batteries.In a recent article published by<a href="https://www.cell.com/joule/pdf/S2542-4351(23)00355-0.pdf" rel="noopener" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">&nbsp;Joule</a>, Lutkenhaus, associate department head of internal engagement and chemical engineering professor at Texas A&amp;M University,&nbsp;&nbsp;collaborated with chemical engineering professor Dr. Abdoulaye Djire to reveal how these polymers store and exchange charge with the electrolyte.“The cathode reacts with oxygen from air to complete the circuit. We specifically targeted the use of a conjugated polymer with a rigid backbone structure for the anode,” Lutkenhaus said.These features make the polymer both conductive and stable, enabling the necessary reversible reactions required for repeated charging and discharging, she said.Despite the benefits of aqueous polymer-air batteries, including improved safety, reduced cost, higher ionic conductivity and sustainability, their electrochemical performance is limited, the article stated.</section><blockquote>By using a polymer as an electrode, we could change the electrolyte to prevent the formation of carbonates.<cite>Dr. Jodie Lutkenhaus</cite></blockquote><section>“To overcome these limitations, researchers have explored alternative polymer anodes, which have several advantages over metal anodes, including low cost, ease of functionalization and high stability,” according to the article.The battery’s rigid ladder structure, fast kinetics and high electrical conductivity allowed it to undergo 500 cycles with minimal performance loss. Additionally, the article revealed the real-time charge transfer mechanism, demonstrating a fast hydronium ion charge compensation process.The article notes that metal-air batteries have a higher energy density compared to conventional lithium-ion batteries. This is attributed to the oxygen cathode, which offers a much higher capacity than conventional metal oxide cathodes. However, the article highlights limitations in using metal anodes in air batteries due to the stability, cost, and environmental impact of extracting and processing metal resources.Issues like dendrites, passivation and corrosion on the metal anode lead to low utilization and inferior cycling stability in metal-air batteries. Despite the adoption of interfacial modification and electrolyte formulation, these issues can be severe in the presence of oxygen from the air.“The polymer-air battery provides an alternative means of storing energy versus the metal-air battery,” Lutkenhaus said. “The polymer-air battery has a high capacity for energy storage and a very long cycle life.”She explained that having a long cycle life means that people can use their batteries longer before having to recharge them or replace them.&nbsp;&nbsp;“Air-based batteries are promising for high-energy batteries because they have a lower mass than conventional batteries,” Lutkenhaus said. “However, long-term operation of air-based batteries often results in the generation of carbonate deposits that clog the battery and prevent long-term operation. By using a polymer as an electrode, we could change the electrolyte to prevent the formation of carbonates.”</section>

Polymer-air batteries often face challenges related to stability, kinetics and conductivity. In response, Dr. Jodie Lutkenhaus has developed a method to use a polymer as an anode in these batteries.

Researchers Investigate Advanced Energy Storage Solutions

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new lithium metal battery that can be charged and discharged at least 6,000 times — more than any other pouch battery cell — and can be recharged in a matter of minutes.The research not only describes a new way to make solid state batteries with a lithium metal anode but also offers new understanding into the materials used for these potentially revolutionary batteries.&nbsp;The research is published in&nbsp;<a href="https://www.nature.com/articles/s41563-023-01722-x" target="_blank">Nature Materials</a>.&nbsp;“Lithium metal anode batteries are considered the holy grail of batteries because they have ten times the capacity of commercial graphite anodes and could drastically increase the driving distance of electric vehicles,” said&nbsp;<a href="https://seas.harvard.edu/person/xin-li" target="_blank">Xin Li</a>, Associate Professor of Materials Science at SEAS and senior author of the paper. “Our research is an important step toward more practical solid state batteries for industrial and commercial applications.”&nbsp;One of the biggest challenges in the design of these batteries is the formation of dendrites on the surface of the anode. These structures grow like roots into the electrolyte and pierce the barrier separating the anode and cathode, causing the battery to short or even catch fire.&nbsp;These dendrites form when lithium ions move from the cathode to the anode during charging, attaching to the surface of the anode in a process called plating. Plating on the anode creates an uneven, non-homogeneous surface, like plaque on teeth, and allows dendrites to take root. When discharged, that plaque-like coating needs to be stripped from the anode and when plating is uneven, the stripping process can be slow and result in potholes that induce even more uneven plating in the next charge.In 2021, Li and his team<a href="https://seas.harvard.edu/news/2021/05/long-lasting-stable-solid-state-lithium-battery" target="_blank">&nbsp;offered one way to deal with dendrites&nbsp;</a>by designing a multilayer battery that sandwiched different materials of varying stabilities between the anode and cathode. This multilayer, multi-material design prevented the penetration of lithium dendrites not by stopping them altogether, but rather by controlling and containing them.&nbsp;In this new research, Li and his team stop dendrites from forming by using micron-sized silicon particles in the anode to constrict the lithiation reaction and facilitate homogeneous plating of a thick layer of lithium metal.&nbsp;In this design, when lithium ions move from the cathode to the anode during charging, the lithiation reaction is constricted at the shallow surface and the ions attach to the surface of the silicon particle but don’t penetrate further. This is markedly different from the chemistry of liquid lithium ion batteries in which the lithium ions penetrate through deep lithiation reaction and ultimately destroy silicon particles in the anode.&nbsp;But, in a solid state battery, the ions on the surface of the silicon are constricted and undergo the dynamic process of lithiation to form lithium metal plating around the core of silicon. &nbsp;&nbsp;“In our design, lithium metal gets wrapped around the silicon particle, like a hard chocolate shell around a hazelnut core in a chocolate truffle,” said Li.&nbsp;These coated particles create a homogenous surface across which the current density is evenly distributed, preventing the growth of dendrites. And, because plating and stripping can happen quickly on an even surface, the battery can recharge in only about 10 minutes.&nbsp;The researchers built a postage stamp-sized pouch cell version of the battery, which is 10 to 20 times larger than the coin cell made in most university labs. The battery retained 80% of its capacity after 6,000 cycles, outperforming other pouch cell batteries on the market today.&nbsp;The technology has been licensed through&nbsp;<a href="https://otd.harvard.edu/" target="_blank">Harvard Office of Technology Development</a> to Adden Energy, a Harvard spinoff company cofounded by Li and three Harvard alumni. The company has scaled up the technology to build a smart phone-sized pouch cell battery.&nbsp;Li and his team also characterized the properties that allow silicon to constrict the diffusion of lithium to facilitate the dynamic process favoring homogeneous plating of thick lithium. They then defined a unique property descriptor to describe such a process and computed it for all known inorganic materials. In doing so, the team revealed dozens of other materials that could potentially yield similar performance.&nbsp;“Previous research had found that other materials, including silver, could serve as good materials at the anode for solid state batteries,” said Li. “Our research explains one possible underlying mechanism of the process and provides a pathway to identify new materials for battery design.”&nbsp;The research is co-authored by Luhan Ye, Yang Lu, Yichao Wang, and Jianyuan Li. It was supported by the Department of Energy Vehicle Technology Office, the Harvard Climate Change Solutions Fund, and Harvard Data Science Initiative Fund.

Research paves the way for better lithium metal batteries

Solid state battery design charges in minutes, lasts for thousands of cycles

From powering electronic devices, to electric vehicles and renewable energy systems, the use of batteries as an energy storage solution has been prevalent. However, batteries have limitations like slow charging, limited lifespan, and restricted power output. This is where supercapacitors, also known as ultracapacitors or electric double-layer capacitors (EDLCs), step in.Supercapacitor CharacteristicsTo understand how supercapacitors can enhance batteries, it helps to understand what they do and how they work. There are several factors that need to be taken into consideration, including the application requirements.&nbsp;<h4>Considerations Based on Application Requirements</h4>First, determine the required capacitance for the application. The capacitance of the supercapacitors needed to complement the batteries will depend on the specific application requirements, such as the required power output, charge/discharge times, and energy density. This can be calculated using the formula:C = (I x t) / ΔVWhere C is the capacitance in Farads, I is the current in amps, t is the time in seconds, and ΔV is the voltage drop during discharge.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703774887395-Screenshot%2B2023-11-06%2B151847.png" style="width: 300px;" class="fr-fic fr-dib"> Then, choose the appropriate supercapacitor voltage rating. The voltage rating of the supercapacitor should be chosen to be at least as high as the maximum battery voltage. This must be done to avoid overvoltage conditions that can damage the supercapacitor.&nbsp;Finally, consider the equivalent series resistance (ESR). The ESR of the supercapacitor can affect the overall system efficiency and power delivery. Lower ESR values generally provide better performance, but at a higher cost.&nbsp;<h4>External Component Considerations</h4>It is necessary to include high power balancing circuits. Balancing circuits can be added to ensure that each supercapacitor is charged and discharged evenly, preventing overvoltage or undervoltage conditions that can damage the supercapacitor or decrease its performance. Since supercapacitors operate at high current levels compared to batteries, it is important the balancing system can operate (correct voltage imbalances) at high current levels too.&nbsp;It is important to note that the electrical sizing and connection of supercapacitors and batteries will vary depending on the specific application and system requirements. It is recommended to consult with an expert or refer to the manufacturer's guidelines to ensure the best performance and safety of the system.<h4>Why Can Supercapacitors Complement Batteries?</h4>Supercapacitors can supply or absorb high current peaks. This allows the supercapacitor to take some of the load off the battery, improving its performance and reducing its wear and tear.Supercapacitors can also store and release energy much faster than conventional batteries. They function by storing electrical charge on the surface of specialized electrodes, typically made of materials like activated carbon. This design enables supercapacitors to deliver rapid bursts of high-power output, making them well-suited for applications requiring quick energy delivery, like regenerative braking in electric vehicles.This is a key advantage of supercapacitors. While batteries can take hours to charge fully, supercapacitors can achieve this in just seconds to minutes. This swift charging ability enables supercapacitors to provide a rapid energy boost to batteries, reducing overall charging time. &nbsp;Moreover, supercapacitors can extend the lifespan of batteries. Since batteries have a finite number of charge-discharge cycles before deterioration, supercapacitors can absorb some excess energy during high-power cycles. This reduces stress on the battery, prolonging its lifespan and reducing the need for frequent replacements.While not every application requires the use of supercapacitors they can be a valuable addition, particularly in scenarios where battery system performance needs optimization. This includes a variety of applications include e-mobility (bikes, cars, trucks, boats, and planes), renewable energy, telecom, and robotics.<h4>Renewable Application: Microgrids</h4><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703774927601-microgrid%2Bgraphic%2B-%2BAdobeStock_540991784.jpeg" style="width: 300px;" class="fr-fic fr-dib"><div data-block-type="2" id="isPasted">Renewable energy microgrids have rapidly gained interest as the demand for resilient energy systems have increased. These microgrids have typically included battery energy storage systems which are great for long duration storage, but they have a difficult time with dynamic situations. For example, the transient inrush currents from connecting a transformer, which could cause circuit breakers or protection circuits to trip. Another example is the instantaneous power draw of many electric vehicles plugging into the microgrid at once may be more power than a battery system alone can handle, potentially causing a brownout. What these microgrids need is a hybrid system, where long duration is handled by batteries, and short bursts of power are provided by power dense technologies, like supercapacitors.A supercapacitor’s ability to rapidly charge and discharge is beneficial in instances where renewables on the microgrid experience short fluctuations due to weather conditions (clouds passing over solar panels, for example). &nbsp;By having the supercapacitor provide the short bursts of power necessary to ride through these fluctuations, the batteries are protected from unnecessary cycling. This not only enhances the lifespan of the battery, but also contributes to long-term cost savings by minimizing the need for frequent battery replacements.&nbsp;</div><div data-block-type="2"><h4>Conclusion</h4></div><div data-block-type="2">Supercapacitors are a valuable complement to batteries, enhancing their performance by providing high-power output, rapid charging, and extended lifespan, making them particularly useful in applications like renewable energy systems. In applications with dynamic power fluctuations, a battery-supercapacitor hybrid energy storage system is recommended to optimize performance and efficiency.&nbsp;</div>

Batteries have limitations like slow charging, limited lifespan, and restricted power output. This is where supercapacitors, also known as ultracapacitors or electric double-layer capacitors (EDLCs), step in.

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