Tag: batteries

What drives ions through polymer membranes

What drives ions through polymer membranes

Ion exchange membranes are needed in (photo)electrolysers, fuel cells and batteries to separate ions and enable the desired processes. Polymeric membranes such as synthetically produced compounds like NAFION are particularly efficient, but they cannot be degraded. A ban on the use of these “eternal chemicals” is currently under discussion in the European Union, and the development of suitable alternatives will be a major challenge. So, it is crucial to understand why NAFION and other established polymeric membranes work so well.

A team led by Dr. Marco Favaro of the HZB Institute for Solar Fuels has now investigated this using a special type of electrolysis cell. Here, the membrane sits on the outer wall and is in contact with both the liquid electrolyte and a gaseous external environment. It can act either as an anode or a cathode, depending on the polarity of the applied potential. This hybrid liquid-gas electrolyzer is considered particularly favorable for the electrochemical conversion of CO2 thanks to the higher CO2 concentrations that can be achieved in the gas phase, thereby overcoming the poor solubility of CO2 in aqueous solutions.

For the study, Favaro and his team used commercially available ion-exchange membranes in contact with a model electrolyte like sodium chloride (NaCl) in water. Water vapor was fed to the gas phase, with the partial pressure of water close to its vapor pressure at room temperature. To analyze the migration of sodium and chloride ions through the membrane, they used in situ ambient pressure hard X-ray photoelectron spectroscopy (AP-HAXPES) at the SpAnTeX end-station at the KMC-1 beamline of BESSY II.

“Indeed, we were expecting that the ion dynamics was determined, under applied potentials, by the electric fields generated between the anode and cathode of the electrolyzer, and that electromigration was therefore the main driver,” says Marco Favaro.

However, analysis of the data showed otherwise: electromigration hardly plays a role; the ions simply diffuse across the membrane. The data could be perfectly simulated numerically with a diffusion model. “Our conclusion is that ions move through the polymer membranes in these types of electrolyzers due to hopping mediated by the ionized functional groups present in the membranes. In addition, since water diffuses as well through the polymer, the ions are “dragged” as well” explains Favaro.

These results are exciting for a number of reasons: These types of electrolyzers are a way to convert CO2 into valuable chemicals that can otherwise only be obtained from fossil fuels. Understanding how these devices work helps on the way to decarbonize the economy. On the other hand, the ion-exchange membranes that are a key component of these cells are themselves problematic: the European Union may soon ban the use of persistent chemicals. Understanding the relevant drivers of such transport processes will help to develop new membrane materials that are both efficient, durable, and environmentally friendly. Favaro now intends to take this project forward at HIPOLE, the new Helmholtz Institute in Jena, which will focus on polymer materials for new energy technologies.

Read more in the Journal of Materials Chemistry A

Image: Membrane

Credit: HZB

New study could help unlock ‘game-changing’ batteries for electric vehicles and aviation

New study could help unlock ‘game-changing’ batteries for electric vehicles and aviation

Significantly improved electric vehicle (EV) batteries could be a step closer thanks to a new study led by University of Oxford researchers, published today in Nature. Using advanced imaging techniques, this revealed mechanisms which cause lithium metal solid-state batteries (Li-SSBs) to fail. If these can be overcome, solid-state batteries using lithium metal anodes could deliver a step-change improvement in EV battery range, safety and performance, and help advance electrically powered aviation.

One of the co-lead authors of the study Dominic Melvin, a PhD student in the University of Oxford’s Department of Materials, said:

Progressing solid-state batteries with lithium metal anodes is one of the most important challenges facing the advancement of battery technologies. While lithium-ion batteries of today will continue to improve, research into solid-state batteries has the potential to be high-reward and a gamechanger technology.

Li-SSBs are distinct from other batteries because they replace the flammable liquid electrolyte in conventional batteries with a solid electrolyte and use lithium metal as the anode (negative electrode). The use of the solid electrolyte improves the safety, and the use of lithium metal means more energy can be stored. A critical challenge with Li-SSBs, however, is that they are prone to short circuit when charging due to the growth of ‘dendrites’: filaments of lithium metal that crack through the ceramic electrolyte. As part of the Faraday Institution’s SOLBAT project, which Diamond is a partner, researchers have led a series of in-depth investigations to understand more about how this short-circuiting happens.

In this latest study, the group used an advanced imaging technique called X-ray Computed Tomography (X-ray CT) at the I13-2 beamline of Diamond Light Source to visualise dendrite failure in unprecedented detail during the charging process.

Read more on the Diamond website

A first step to designing better solid-state batteries

A first step to designing better solid-state batteries

Electrifying transportation is an essential step towards mitigating climate change. To improve the power, efficiency and safety of electric vehicles, researchers must continue to develop better batteries. All-solid-state lithium batteries (SSBs), which have a solid electrolyte instead of a liquid, are safer than traditional lithium-ion batteries because they are less flammable and more stable at higher temperatures. They could also have higher energy densities than lithium-ion batteries, allowing for longer lasting batteries in smaller sizes for portable electronics and other applications.

A research team led by Joshua Gallaway of Northeastern University in Boston and scientists at the Department of Energy’s (DOE) Argonne National Laboratory recently tested how the composition of thick cathodes affected electrochemical reactions in SSBs. The team used the resources of the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne. Their discoveries were published in the journal ACS Energy Letters.

“How all-solid-state batteries are designed will determine what their applications will be and how they will be optimized moving forward,” — Josh Gallaway, Northeastern University

Gallaway relates batteries to sandwiches — they are comprised of an anode on one side, a cathode on the other, a separator in the middle, and electrolyte solution throughout. When batteries provide power, lithium ions flow from the anode to cathode through the electrolyte. While SSBs don’t require traditional separators because the electrolyte separates the anode and cathode, they do require thick cathodes.

In this study, Gallaway and his colleagues evaluated batteries with thick cathodes that were comprised of two materials: a sulfide solid electrolyte called LPSC and an NMC (nickel, manganese, cobalt) cathode active material (CAM). They altered the composition of these two materials, so some batteries were 80% CAM, 20% LPSC, while others were 70% CAM, 30% LPSC and 40% CAM, 60% LPSC. Then, they used X-ray imaging and scattering at APS beamline 6-BM-A to measure six slices within the cathode and solid-state electrolyte.

Read more on the Argonne website

Image: An all-solid-state battery on an experimental stage used in the study. The battery is compressed in a vise and has a laser shining on it to align the X-ray beam.

Credit: Josh Gallaway/Northeastern University, Boston.

The APS prepares for its renewal

The APS prepares for its renewal

The facility’s ultrabright X-ray beams will turn off for a year to enable a comprehensive upgrade, one that will light the way to new breakthroughs

With the start of the construction period, the Advanced Photon Source is now only a year away from re-emerging as a world-leading X-ray light source. Its brighter beams will lead to new discoveries in energy storage, materials science, medicine and more.

Today, a year-long effort to renew the Advanced Photon Source (APS), a U.S. Department of Energy (DOE) Office of Science user facility at DOE’s Argonne National Laboratory, officially begins.

After years of planning and preparation, the team behind the APS Upgrade project will now spend the next 12 months removing the old electron storage ring at the heart of the facility, replacing it with a brand new, state-of-the-art storage ring and testing the new ring once it is in place. The team will also build seven new experiment stations, construct the needed infrastructure for two more and update nearly every existing experiment station around the APS ring.

This is an extensive project, representing an $815 million investment from DOE. When complete, the APS will re-emerge as a world leader in global hard X-ray synchrotron science, enabling unimaginable new discoveries. Science conducted at the APS will lead to longer-lasting, faster-charging batteries, more durable airplane engines and better treatments for infectious diseases, among many other discoveries.

“The APS Upgrade is not only an investment in the facility’s future, but in the next 25 years of advancements that will change the way we power our vehicles, harness renewable energy and learn more about the fundamental science that underpins our future technologies.” — Linda Horton, associate director of science for Basic Energy Sciences, U.S. Department of Energy.

“This is a significant day for Argonne,” said Argonne Director Paul Kearns. ​“The APS Upgrade will transform the future of science for America and the world. Once we safely complete construction, the APS will shed new light on how the brain works, develop materials to decarbonize our economy, refine quantum technologies that can power the internet of the future and answer many other questions in numerous other disciplines.”

Read more on the Argonne National Laboratory website

Image: The Advanced Photon Source is undergoing a comprehensive upgrade that will result in X-ray beams that are up to 500 times brighter than the current facility can create. After a year-long shutdown, the upgraded APS will open the door to discoveries we can barely imagine today

Credit: Argonne National Laboratory/JJ Starr

New SLAC-Stanford Battery Center targets roadblocks to a sustainable energy transition

New SLAC-Stanford Battery Center targets roadblocks to a sustainable energy transition

The center at SLAC aims to bridge the gaps between discovering, manufacturing and deploying innovative energy storage solutions. 

The Department of Energy’s SLAC National Accelerator Laboratory and Stanford University today announced the launch of a new joint battery center at SLAC. It will bring together the resources and expertise of the national lab, the university and Silicon Valley to accelerate the deployment of batteries and other energy storage solutions as part of the energy transition that’s essential for addressing climate change.

A key part of this transition will be to decarbonize the world’s transportation systems and electric grids ­– to power them without fossil fuels. To do so, society will need to develop the capacity to store several hundred terawatt-hours of sustainably generated energy. Only about 1% of that capacity is in place today.

Filling the enormous gap between what we have and what we need is one of the biggest challenges in energy research and development. It will require that experts in chemistry, materials science, engineering and a host of other fields join forces to make batteries safer, more efficient and less costly and manufacture them more sustainably from earth-abundant materials, all on a global scale. 

The SLAC-Stanford Battery Center will address that challenge. It will serve as the nexus for battery research at the lab and the university, bringing together large numbers of faculty, staff scientists, students and postdoctoral researchers from SLAC and Stanford for research, education and workforce training. 

 “We’re excited to launch this center and to work with our partners on tackling one of today’s most pressing global issues,” said interim SLAC Director Stephen Streiffer. “The center will leverage the combined strengths of Stanford and SLAC, including experts and industry partners from a wide variety of disciplines, and provide access to the lab’s world-class scientific facilities. All of these are important to move novel energy storage technologies out of the lab and into widespread use.”

Expert research with unique tools

Research and development at the center will span a vast range of systems – from understanding chemical reactions that store energy in electrodes to designing battery materials at the nanoscale, making and testing devices, improving manufacturing processes and finding ways to scale up those processes so they can become part of everyday life. 

“It’s not enough to make a game-changing battery material in small amounts,” said Jagjit Nanda, a SLAC distinguished scientist, Stanford adjunct professor and executive director of the new center, whose background includes decades of battery research at DOE’s Oak Ridge National Laboratory. “We have to understand the manufacturing science needed to make it in larger quantities on a massive scale without compromising on performance.”

Longstanding collaborations between SLAC and Stanford researchers have already produced many important insights into how batteries work and how to make them smaller, lighter, safer and more powerful. These studies have used machine learning to quickly identify the most promising battery materials from hundreds made in the lab, and measured the properties of those materials and the nanoscale details of battery operation at the lab’s synchrotron X-ray facility. SLAC’s X-ray free-electron laser is available, as well, for fundamental studies of energy-related materials and processes. 

SLAC and Stanford also pioneered the use of cryogenic electron microscopy (cryo-EM), a technique developed to image biology in atomic detail, to get the first clear look at finger-like growths that can degrade lithium-ion batteries and set them on fire. This technique has also been used to probe squishy layers that build up on electrodes and must be carefully managed, in research performed at the Stanford Institute for Materials and Energy Sciences (SIMES).

Nanda said the center will also focus on making energy storage more sustainable, for instance by choosing materials that are abundant, easy to recycle and can be extracted in a way that’s less costly and produces fewer emissions.

Read more on the SLAC website

Improving the production of batteries for electric vehicles

Improving the production of batteries for electric vehicles

A research lead by the company BASF has characterized a new methodology to produce nickel-rich cathode materials used in lithium-ion batteries that optimizes the conventional production process. The proposed model leads to an increase in throughput by a factor of three, representing a considerable increase in the efficiency of future cathode active materials production for battery electric vehicles. The contributions of the MSPD beamline at ALBA have been key in these findings.

Batteries of electric vehicles still have not reached full cost competitiveness with respect to cars powered by combustion engines. This is mainly due to the increase in the cost of the raw materials used to produce the cathode of the batteries. In the search for low-cost materials for cathodes, the research on efficient manufacturing is of utmost importance.

A research led by the company BASF, in collaboration with different German universities and research centers, has studied how to optimize the conventional production process of nickel-rich cathode materials for lithium-ion batteries. This process is a thermal treatment called calcination. More specifically, researchers wanted to obtain a deeper understanding of the lithiation mechanism itself. And also, whether a two-stage calcination process, including a partial-lithiation step, can be used to synthesize cathode active materials with similar properties to those of a conventional one-stage calcination protocol.

The proposed calcination concept leads to an increase in throughput by a factor of three, increasing the efficiency of future cathode active materials production without modifying their physico-chemical properties and electrochemical behavior. Moreover, further advantages of the partial-lithiation process regarding homogeneity of the composition and crystallite size of the cathode active materials are believed to come into view as soon as large-scale sample amounts are investigated, which will be part of future work.

To further characterize the samples after the partial-lithiation step, synchrotron X-ray powder diffraction (XRD) measurements were performed at the MSPD beamline of the ALBA Synchrotron. This is the first report on the composition of the lithium-containing residual needles, which are indicative of an incomplete reaction. By combination of XRD, and other characterization techniques, the presence of Lithium hydroxide was confirmed in the samples prepared with the conventional method but not on the samples obtained with the novel two-stage methodology.

Read more on the ALBA website

NSLS-II Researchers Win 2022 Microscopy Today Innovation Award

NSLS-II Researchers Win 2022 Microscopy Today Innovation Award

The team developed a set of bonded x-ray lenses to overcome a long-standing alignment issue, making nanometer resolution more accessible than ever before.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory received the 2022 Microscopy Today Innovation Award for their development of a system with bonded x-ray lenses that make nanoscale resolution more accessible than ever before. When the team at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science user facility, tested the new lens system, they achieved a resolution down to approx. 10 nanometers.

“We need technologies of the future to tackle some of society’s biggest challenges — from microelectronics to tiny qubits for quantum computers to longer-lasting batteries,” said John Hill, NSLS-II Director. “However, to develop these new devices, researchers need to study materials at the nanoscale. And this where these new lenses really come into their own. They make focusing hard x-ray beams down to a few nanometers much easier than ever before. By using the very focused x-ray beams that these lenses produce, we can reveal the function, structure, and chemistry of next-generation materials on the nanoscale. This crucial breakthrough was only made possible through years of intense work by experts—who are world-leaders in their respective fields—working together. I am delighted that their work has been recognized by this award and very proud to have this new lens system at NSLS-II.”

Read more on the Brookhaven National Laboratory website

Image: The members of the development team in front of NSLS-II. From left to right: Yong Chu, Hanfei Yan, Weihe Xu, Wei Xu, Xiaojing Huang, Ming Lu, Natalie Bouet, Evgeny Nazaretski. Not pictured: Juan Zhou and Maxim Zalalutdinov.

Copper doping improves sodium-ion battery performance

Copper doping improves sodium-ion battery performance

Although lithium-ion batteries currently drive the electronic world, sodium-ion batteries are gaining ground. A big plus is that sodium is more earth-abundant than lithium, which lowers costs and eases environmental and supply-chain concerns. As a result, enormous research efforts are underway to improve the energy density and cycling longevity of sodium-ion batteries.

One promising strategy to enhance energy density is to exploit additional sources of a key chemical reaction—oxidation reduction (redox)—in the battery’s cathode. In cathodes made of layered transition-metal oxides (the sodium ions move in and out from between the layers), it turns out that the oxygen component in the layers unexpectedly contributes to redox activity. Unfortunately, oxygen redox is frequently accompanied by irreversible oxygen behavior, resulting in both voltage and capacity decays.

To enhance oxygen redox reversibility, researchers doped a sodium-ion cathode material (Na0.6Mg0.3Mn0.7O2, or NMMO) with copper ions (Na0.6Mg0.15Mn0.7Cu0.15O2, or NMMCO). To understand how this affects the oxygen redox activity, they used a technique developed at Beamline 8.0.1 of the Advanced Light Source (ALS), called mapping of resonant inelastic x-ray scattering (mRIXS), to measure the effect of the copper doping at different states of charge.

“The mRIXS technique is one of the most powerful characterization tools available for detecting oxygen redox activities in battery electrodes,” said Liang Zhang, a professor at Soochow University and co-corresponding author of the published work. “With mRIXS, it’s also possible to quantify the reversibility of the oxygen redox reaction, which could greatly help us understand the oxygen evolution process during electrochemical cycling.”

Read more on the ALS website

Image: The partial substitution of Mg ions in the cathode with Cu ions, which possess similar ionic radii but distinct electronic states, led to strong Cu–O bonds (i.e., modulated transition metal (TM)–O covalency), which helped stabilize the lattice during repeated cycles. Light blue = Cu, dark green = Na, red = O, dark yellow = Mn, blue = Mg

X-rays capture ageing process in EV batteries

X-rays capture ageing process in EV batteries

CLS researcher Toby Bond uses x-rays to help engineer powerful electric vehicle batteries with longer lifetimes. His research, published in The Journal of the Electrochemical Society, shows how the charge/discharge cycles of batteries cause physical damage eventually leading to reduced energy storage. This new work points to a link between cracks that form in the battery material and depletion of vital liquids that carry charge.

Bond uses the BMIT facility at the Canadian Light Source at the University of Saskatchewan to produce detailed CT scans of the inside of batteries. Working with Dr. Jeff Dahn at Dalhousie University, he specializes in batteries for electric vehicles, where the research imperative is to pack in as much energy as possible into a lightweight device.

“A big drawback to packing in more energy is that generally, the more energy you pack in, the faster the battery will degrade,” says Bond.

In lithium-ion batteries, this is because charging physically forces lithium ions between other atoms in the electrode material, pushing them apart. Adding more charge causes more growth in the materials, which shrink back down when the lithium ions leave. Over many cycles of this growing and shrinking, micro-cracks begin to form in the material, slowly reducing its ability to hold a charge.

Read more on the CLS website

Image: Toby Bond adjusts a battery sample on the BMIT beamline

Science’s great strength is the universal language

Science’s great strength is the universal language

SSRL’s #LightSourceSelfie

Forrest Hyler is a PhD student at the University of California Davis and regular user of the Stanford Synchrotron Lightsource (SSRL). Forrest’s research involves exploring the structural and electronic properties of materials that are used as catalysts for carbon dioxide reduction in the lab. In his #LightSourceSelfie, Forrest describes his work as all encompassing as it involves studying materials related to a broad range of applications such as batteries, catalysis and the storage of radioactive materials. Forrest’s journey has involved a large range of scientists and he says, “The greatest part about science is that it’s kind of that universal language. You get to interact with people around the globe working together for a common goal to push science beyond the boundaries that we’ve ever been at before.”

Probing the Structure of a Promising NASICON Material

Probing the Structure of a Promising NASICON Material

As physicists, materials scientists, and engineers continue striving to enhance and improve batteries and other energy storage technologies, a key focus is on finding or designing new ways to make electrodes and electrolytes.  One promising avenue of research involves solid-state materials, making possible batteries free of liquid electrolytes, which can pose fire and corrosion hazards.  An international group of researchers joined with scientists at Argonne National Laboratory to investigate the structure of crystalline and amorphous compounds based on the NASICON system, or sodium super-ion conductors. The work (using research carried out at the U.S. Department of Energy’s Advanced Photon Source [APS] and published in the Journal of Chemical Physics) reveals some substantial differences between the crystalline and glass phases of the NAGP system, which affect the ionic conductivity of the various materials.  The investigators note that the fraction of non-bridging oxygen (NBO) atoms appears to play a significant role, possibly altering the Na+ ion mobility, and suggest this as an area of further study.  The work provides fresh insights into the process of homogeneous nucleation and identifying superstructural units in glass ― a necessary step in engineering effective solid-state electrolytes with enhanced ionic conductivity. 

Because of their high ionic conductivity, materials with a NASICON structure are prime candidates for a solid electrolyte in sodium-ion batteries.  They can be prepared by a glass-ceramic route, which involves the crystallization of a precursor glass, giving them the usefulness of moldable bulk materials.  In this work, the research team specifically studied the NAGP system [Na1+xAlxGe2-x(PO4)3] with x = 0, 0.4 and 0.8 in both crystalline and glassy forms. Working at several different facilities, they used a combination of techniques, including neutron and x-ray diffraction, along with 27Al and 31P magic angle spinning and 31P/23Na double-resonance nuclear magnetic resonance spectroscopy.  The glassy form of NAGP materials was examined both in its as-prepared state and after thermal annealing, so that the changes on crystal nucleation could be studied.

Neutron powder diffraction measurements were performed at the BER II reactor source, Helmholtz-Zentrum Berlin, using the fine resolution powder diffractometer E9 (FIREPOD), followed by Rietveld analysis.  Further neutron diffraction observations were conducted at the Institut Laue-Langevin using the D4c diffractometer and at the ISIS pulsed neutron source using the GEM diffractometer.  X-ray diffraction studies were performed at X-ray Science Division Magnetic Materials Group’s beamline 6-ID-D of the APS, an Office of Science user facility at Argonne National Laboratory. 

Read more on the APS website

Image: Fig. 1. NASICON crystal structure showing the tetrahedral P(4) phosphate motifs (purple), octahedral GeO6 motifs (cyan) and Na+ ions (green). Oxygen atoms are depicted in red.

Tiny Chip-Based Device Performs Ultrafast Manipulation of X-Rays

Tiny Chip-Based Device Performs Ultrafast Manipulation of X-Rays

Researchers from the U.S. Department of Energy’s Advanced Photon Source (APS) and Center for Nanoscale Materials at Argonne National Laboratory have developed and demonstrated new x-ray optics that can be used to harness extremely fast pulses in a package that is significantly smaller and lighter than conventional devices used to manipulate x-rays. The new optics are based on microscopic chip-based devices known as microelectromechanical systems (MEMS).

“Our new ultrafast optics-on-a-chip is poised to enable x-ray research and applications that could have a broad impact on understanding fast-evolving chemical, material and biological processes,” said research team leader Jin Wang from the X-ray Science Division Time Resolved Research (TRR) Group at the APS. “This could aid in the development of more efficient solar cells and batteries, advanced computer storage materials and devices, and more effective drugs for fighting diseases.”

In new results published in The Optical Society OSA) journal Optics Express, the researchers demonstrated their new x-ray optics-on-a-chip device (Fig. 1), which measures about 250 micrometers and weighs just 3 micrograms, using the TRR Group’s 7-ID-C x-ray beamline at the APS. The tiny device performed 100 to 1,000 times faster than conventional x-ray optics, which that tend to be bulky.

Read more on the APS website

Image: Fig. 1. The photograph shows two MEMS elements on a single chip (A), with the active elements of 250 µm × 250 µm, and the micrograph (B) highlighting the size of the diffractive element, as compared to a section of human hair (C).

Researchers identify lithium hydride and a new form of lithium fluoride in the interphase of lithium metal anodes

Researchers identify lithium hydride and a new form of lithium fluoride in the interphase of lithium metal anodes

A team of researchers led by chemists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory has identified new details of the reaction mechanism that takes place in batteries with lithium metal anodes. The findings, published today in Nature Nanotechnology, are a major step towards developing smaller, lighter, and less expensive batteries for electric vehicles.

Recreating lithium metal anodes

Conventional lithium-ion batteries can be found in a variety of electronics, from smartphones to electric vehicles. While lithium-ion batteries have enabled the widespread use of many technologies, they still face challenges in powering electric vehicles over long distances.

To build a battery better suited for electric vehicles, researchers across several national laboratories and DOE-sponsored universities have formed a consortium called Battery500, led by DOE’s Pacific Northwest National Laboratory (PNNL). Their goal is to make battery cells with an energy density of 500 watt-hours per kilogram, which is more than double the energy density of today’s state-of-the-art batteries. To do so, the consortium is focusing on batteries made with lithium metal anodes.

Read more on the BNL website

Image: Brookhaven chemists Enyuan Hu (left, lead author) and Zulipiya Shadike (right, first author) are shown holding a model of 1,2-dimethoxyethane, a solvent for lithium metal battery electrolytes.

Graphite electrodes for rechargeable batteries investigated

Graphite electrodes for rechargeable batteries investigated

Rechargeable graphite dual ion batteries are inexpensive and powerful.

A team of the Technical University of Berlin has investigated at the EDDI Beamline of BESSY II how the morphology of the graphite electrodes changes reversibly during cycling (operando).

The 3D X-ray tomography images combined with simultaneous diffraction now allow a precise evaluation of the processes, especially of changes in the volume of the electrodes. This can help to further optimise graphite electrodes.

Read more on the HZB website

Image: The tomogram during the charging process shows the spatially resolved changes in the graphite electrode thickness of a rechargeable aluminium ion battery in a discharged and charged state.

Credit: © HZB