Tag: battery

Battery research: visualisation of aging processes operando

Battery research: visualisation of aging processes operando

Lithium button cells with electrodes made of nickel-manganese-cobalt oxides (NMC) are very powerful. Unfortunately, their capacity decreases over time. Now, for the first time, a team has used a non-destructive method to observe how the elemental composition of the individual layers in a button cell changes during charging cycles. The study, now published in the journal Small, involved teams from the Physikalisch-Technische Bundesanstalt (PTB), the University of Münster, researchers from the SyncLab research group at HZB and the BLiX laboratory at the Technical University of Berlin. Measurements were carried out in the BLiX laboratory and at the BESSY II synchrotron radiation source.

Lithium-ion batteries have become increasingly better. The combination of layered nickel-manganese-cobalt oxides (NMC) with a graphite electrode (anode) has been well established as the cathode material in button cells and has been continuously improved. However, even the best batteries do not last forever; they ‘age’ and lose capacity over time.

‘A lot happens at the interfaces between the anode, separator and cathode while a battery is charging or discharging,’ explains Ioanna Mantouvalou, physicist at HZB and first author of the study. Typically, these changes are only studied after the battery has been disassembled, i.e. ex situ and at a specific point in the cycling process. But there is now another way: in situ and operando experiments allow to look inside the battery while the processes are taking place, using X-ray fluorescence (XRF) and X-ray absorption spectroscopy (XAS) in a so-called confocal geometry. This geometry permits 3D scanning of a sample with depth resolutions down to 10 µm. Such experimental setups are already possible at the synchrotron radiation source BESSY II. However, the measurement time at BESSY II is limited, so batteries cannot be studied over their entire lifetime.

Read more on HZB website

Image: Here is a selection of 3D element distributions of individual elements after 10,000 charge cycles, i.e. post mortem: On the top left, crystallised electrolyte can be seen, iron in the metal contacts and copper from the back contact have remained stable, while manganese from the NMC cathode (upper light blue stripe) has partially deposited on the bottom of the anode. The publication contains the full explanation.

Credit: BLiX/TU Berlin/HZB

Innovative battery electrode made from tin foam

Innovative battery electrode made from tin foam

Metal-based electrodes in lithium-ion batteries promise significantly higher capacities than conventional graphite electrodes. Unfortunately, they degrade due to mechanical stress during charging and discharging cycles. A team at HZB has now shown that a highly porous tin foam is much better at absorbing mechanical stress during charging cycles. This makes tin foam an interesting material for lithium batteries.

Modern lithium-ion batteries are typically based on a multilayer graphite electrode, with the counter electrode often made of cobalt oxide. During charging and discharging, lithium ions migrate into the graphite without causing significant volume changes in the material. However, the capacity of graphite is limited, making the search for alternative materials an exciting area of research. Metal-based electrodes, such as aluminium or tin, have the potential to offer higher capacity. However, they tend to expand significantly in volume when lithium is absorbed, which is associated with structural changes and material fatigue. Tin is particularly attractive because it’s capacity per kilogram is almost three times higher than graphite, and it is not a rare raw material but is available in abundance. One option for realising metal electrodes that ‘fatigue’ less quickly involves nanostructuring the thin metal foils. Another option is to use porous metal foams.

A team from the Helmholtz-Zentrum Berlin (HZB) has now studied various types of tin electrodes during the discharge and charging process using operando X-ray imaging, and developed an innovative approach to address this problem. Part of the experiments were carried out at the BAMline at BESSY II. The high-resolution radioscopic X-ray images were taken in collaboration with imaging experts Dr. Nikolai Kardjilov and Dr. André Hilger at HZB. ‘This allowed us to track the structural changes in the investigated Sn-metal-based electrodes during the charging/discharging processes,’ says Dr. Bouchra Bouabadi, first author of the study. With battery expert Dr. Sebastian Risse, she explored how the morphology of the tin electrodes changes during operation due to the inhomogeneous absorption of lithium ions.

Read more on HZB website

Image: Tin can be processed into a highly porous foam. An interdisciplinary team at HZB has investigated how this tin foam (pictured) behaves as a battery electrode.

Credit: B. Bouabadi / HZB

Why Your Headphone Battery Doesn’t Last

Why Your Headphone Battery Doesn’t Last

Editor’s Note: The following article was originally issued by the University of Texas at Austin. The research team performed nano-diffraction measurements on battery particles extracted from a commercial wireless earbud at the Hard X-ray Nanoprobe (HXN) at the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Brookhaven National Laboratory. Their findings indicate that there are tiny, coexisting regions within the battery that behave differently. These regions show signs of changing phases, which adds to the bigger picture of how the material behaves across different parts of the battery cell. For more information on Brookhaven’s role in this research, contact Denise Yazak (dyazak@bnl.gov, 631-344-6371).

AUSTIN, Texas — Ever notice that batteries in electronics don’t last as long as they did when they were brand new?

An international research team led by The University of Texas at Austin took on this well-known battery challenge, called degradation, with a twist. They’re focusing their work on real-world technology that many of us use daily: wireless earbuds. They deployed X-ray, infrared and other imaging technologies to understand the complexities of all the technology packed in these tiny devices and learn why their battery lives erode over time.

“This started with my personal headphones. I only wear the right one, and I found that after two years, the left earbud had a much longer battery life,” said Yijin Liu, an associate professor in the Cockrell School of Engineering’s Walker Department of Mechanical Engineering, who led the new research published in Advanced Materials. “So, we decided to look into it and see what we could find.”

They found that other critical components in the compact device, like the Bluetooth antenna, microphones and circuits, clashed with the battery, creating a challenging microenvironment. This dynamic led to a temperature gradient — different temperatures at the top and bottom portions of the battery — that damaged the battery.

Exposure to the real world, with many different temperatures, degrees of air quality and other wildcard factors, also plays a role. Batteries are often designed to withstand harsh environments, but frequent environmental changes are challenging in their own way.

These findings, the researchers say, illustrate the need to think more about how batteries fit into real-world devices such as phones, laptops and vehicles. How can they be packaged to mitigate interactions with potentially damaging components, and how can they be adjusted for different user behaviors?

Read more on BNL website

Lithium-sulphur pouch cells investigated at BESSY II

Lithium-sulphur pouch cells investigated at BESSY II

A team from HZB and the Fraunhofer Institute for Material and Beam Technology (IWS) in Dresden has gained new insights into lithium-sulphur pouch cells at the BAMline of BESSY II. Supplemented by analyses in the HZB imaging laboratory and further measurements, a new picture emerges of processes that limit the performance and lifespan of this industrially relevant battery type. The study has been published in the prestigious journal Advanced Energy Materials.

Lithium-sulphur batteries have a number of advantages over conventional lithium batteries: they use the abundant raw material sulphur, do not require the critical elements cobalt or nickel, and can achieve extremely high specific energy densities. Prototype cells are already achieving up to 500 Wh/kg, almost twice as much as current lithium-ion batteries.

Degradation processes examined

However, lithium-sulphur batteries have so far been much more susceptible to degradation processes: during charging and discharging, dissolved polysulphides and sulphur phases form on the lithium electrode, gradually reducing the performance and lifetime of the battery. ‘Our research aims to elucidate these processes in order to improve this type of battery,’ says HZB physicist Dr. Sebastian Risse, who leads a team at HZB working on operando analysis of batteries.

The pouch cell lab at HZB

He is focusing on pouch cells, a battery format widely used in industry. HZB’s Institute for Electrochemical Energy Storage (CE-IEES), headed by Prof. Yan Lu, has therefore set up a laboratory specialising in the production of lithium-sulphur batteries in the required pocket format. Here, scientists can produce and investigate a wide variety of lithium-sulphur pouch cells. As part of the BMBF-funded ‘SkaLiS’ project, coordinated by Sebastian Risse, a team from the Fraunhofer Institute for Material and Beam Technology (IWS) in Dresden has now published a comprehensive study of lithium-sulphur pouch cells in the prestigious journal Advanced Energy Materials.

Multimodal setup

The battery cells were studied in a setup developed at HZB using various methods such as impedance spectroscopy, temperature distribution, force measurement and X-ray imaging (synchrotron and laboratory source) during charging and discharging. For the first time, we were able to observe and document both the formation of lithium dendrites and the dissolution and formation of sulphur crystallites during multi-layer battery operation,’ says Dr Rafael Müller, HZB chemist and first author of the study.

Read more on HZB website

Image: Photomontage: the diagonal line divides the image into a photo of the lithium-sulfur pouch cell (left) and the corresponding X-ray image (right) during the multimodal measurement with force sensor (golden) and temperature sensors. The perforated honeycomb structure of the current collector can be clearly seen on the X-ray image. This new design approach reduces the weight of the cell without compromising performance.

Credit: R. Müller/ HZB

New protective coating can improve battery performance

New protective coating can improve battery performance

A research team at the Paul Scherrer Institute PSI has developed a new sustainable process that can be used to improve the electrochemical performance of lithium-ion batteries. Initial tests of high-voltage batteries modified in this way have been successful. This method could be used to make lithium-ion batteries, for example those for electric vehicles, significantly more efficient.

Lithium-ion batteries are considered a key technology for decarbonisation. Therefore, researchers around the world are working to continuously improve their performance, for example by increasing their energy density. “One way to achieve this is to increase the operating voltage,” says Mario El Kazzi from the Center for Energy and Environmental Sciences at Paul Scherrer Institute PSI. “If the voltage increases, the energy density also increases.”

However, there is a problem: At operating voltages above 4.3 volts, strong chemical and electrochemical degradation processes take place at the transition between the cathode, the positive pole, and the electrolyte, the conductive medium. The surface of the cathode materials gets severely damaged by the release of oxygen, dissolution of transition metals, and structural reconstruction – which in turn results in a continuous increase in cell resistance and a decrease in capacity. This is why commercial battery cells, such as those used in electric cars, have so far only run at a maximum of 4.3 volts.

To solve this problem, El Kazzi and his team have developed a new method to stabilise the surface of the cathode by coating it with a thin, uniform protective layer. The researchers report on their discovery in a study published in the scientific journal ChemSusChem (Wiley).

Read more on PSI website

Image: Mario El Kazzi and his team have developed a cathode surface coating that enables operating voltages of up to 4.8 volts.

Credit: Paul Scherrer Institute PSI/Mahir Dzambegovic

New type of battery could outlast EVs

New type of battery could outlast EVs

There’s a big push underway to increase the lifespan of lithium-ion batteries powering EVs on the road today. By law, in the US, these cells must be able to hold 80% of their original full charge after eight years of operation.

However, many industry experts believe we need batteries that last decades – so that once they’re no longer robust enough for use in EVs, we can put them to use in “second-life applications” – such as bundling them together to store wind and solar energy to power the electrical grid.

Researchers from Dalhousie University used the Canadian Light Source (CLS) at the University of Saskatchewan to analyze a new type of lithium-ion battery material – called a single-crystal electrode – that’s been charging and discharging non-stop in a Halifax lab for more than six years. It lasted more than 20,000 cycles before it hit the 80% capacity cutoff. That translates to driving a jaw-dropping 8 million kms.  As part of the study, the researchers compared the new type of battery – which has only recently come to market – to a regular lithium-ion battery that lasted 2,400 cycles before it reached the 80% cutoff.

“The main focus of our research was to understand how damage and fatigue inside a battery progresses over time, and how we can prevent it,” says Toby Bond, a senior scientist at the CLS, who conducted the research for his PhD, under the supervision of Professor Jeff Dahn, Professor Emeritus and Principal Investigator (NSERC/Tesla Canada/Dalhousie Alliance Grant) at Dalhousie University. The study was funded by Tesla Canada and NSERC under the Alliance grant program.

Things got very interesting, he says, when the scientists used the ultrabright synchrotron light to peer inside the two batteries. When they looked at the inner workings of the regular lithium-ion battery, they saw an extensive amount of microscopic cracking in the electrode material, caused by repeated charging and discharging. The lithium, he explains, actually forces the atoms in the battery material apart and causes expansion and contraction of the material.

“Eventually, there were so many cracks that the electrode was essentially pulverized.”

However, when the researchers looked at the single crystal electrode battery, they saw next to no evidence of this mechanical stress. “In our images, it looked very much like a brand-new cell. We could almost not tell the difference.”

Bond attributes the near absence of degradation in the new style battery to the difference in the shape and behaviour of the particles that make up the battery electrodes. In the regular battery, the battery electrodes are made up of tiny particles up to 50 times smaller than the width of a hair. If you zoom in on these particles, they are composed of even tinier crystals that are bunched together like snowflakes in a snowball. The single crystal is, as its name implies, one big crystal: it’s more like an ice cube. “If you have a snowball in one hand, and an ice cube in the other, it’s a lot easier to crush the snowball,” says Bond. “The ice cube is much more resistant to mechanical stress and strain.”

Read more on CLS website

Battery research with the HZB X-ray microscope

Battery research with the HZB X-ray microscope

New cathode materials are being developed to further increase the capacity of lithium batteries. Multilayer lithium-rich transition metal oxides (LRTMOs) offer particularly high energy density. However, their capacity decreases with each charging cycle due to structural and chemical changes. Using X-ray methods at BESSY II, teams from several Chinese research institutions have now investigated these changes for the first time with highest precision: at the unique X-ray microscope, they were able to observe morphological and structural developments on the nanometre scale and also clarify chemical changes.

Lithium-ion batteries are set to become even more powerful with new materials for the cathodes. For example, layered lithium-rich transition metal (LRTMO) cathodes could further increase the charge capacity and be used in high-performance lithium batteries. However, so far it has been observed that these cathode materials ‘age’ rapidly: the cathode material degrades as a result to the back-and-forth migration of lithium ions during charging and discharging. Until now it was unclear what specific changes these would involve.

Teams from Chinese research institutions have therefore applied for beam time at the world’s only transmission X-ray microscope (TXM) at an undulator beamline at the BESSY II storage ring to investigate their samples using 3D tomography and nanospectroscopy. The HZB-TXM measurements were performed by Dr. Peter Guttmann, HZB, back in 2019, before the coronavirus pandemic. The X-ray microscopic analysis was then supplemented by further spectroscopic and microscopic examinations. After careful evaluation of the extensive data, the results are now available: they provide detailed information on changes in the morphology and structure of the material, but also on chemical processes during discharge.

‘Soft X-ray transmission microscopy allows us to visualise chemical states in LRTMO particles in three dimensions with high spatial resolution and to gain insights into chemical reactions during the electrochemical cycle,’ explains Dr Stephan Werner, who is responsible for the scientific supervision and further development of the instrument.

Read more on HZB website

Image: The left side of the figure shows nanotomography images of an LRTMO particle taken at the TXM of BESSY II before the first charging cycle (top) and after 10 charging cycles (bottom). In the simulation (right side), the isolated pores are highlighted in light blue. After 10 charging cycles, the number of pores and cracks has significantly increased.

Credit: HZB

Synchrotron light impact on battery materials during real-time analysis

Synchrotron light impact on battery materials during real-time analysis

A multi-centre study carried out by ALBA Synchrotron, ICMAB-CSIC, CIC energiGUNE and BRTA researchers has uncovered critical beam-induced effects in battery materials studied using synchrotron light. The team demonstrated that X-ray radiation can inhibit electrochemical activity in common lithium-ion battery electrodes during characterization studies.

The study identifies radiation dose thresholds and proposes new strategies to mitigate beam-induced effects to ensure more accurate operando battery characterization.

Efficient energy storage is critical to achieving a clean energy future, since large-scale batteries will enable the storage and distribution of renewable energy sources like solar and wind power. Global efforts to optimize battery performance include the development of new materials, which are often characterized using synchrotron-based operando techniques. These real-time measurements examine the performance of the battery as it charges and discharges. However, the potential impact of high-intensity X-ray beams on the materials under study had not been fully understood until now, raising concerns about the accuracy of results from these powerful techniques.

A new study, published in Chemistry of Materials, sheds light on this issue by systematically investigating how synchrotron radiation affects two widely used battery electrode materials based on lithium: LiNi0.33Mn0.33Co0.33O2 (NMC111) and LiFePO₄ (LFP). The research reveals that the X-ray beams produced at synchrotron facilities and used in these experiments can alter the electrochemical activity of these materials, and in extreme cases, this may lead to incorrect conclusions about the performance of the materials.

Researchers from the Institute of Materials Science of Barcelona (ICMAB-CSIC), the Centre for Cooperative Research on Alternative Energies (CIC energiGUNE), the Basque Research and Technology Alliance (BRTA) and the ALBA Synchrotron collaborated to investigate the electrochemical behavior of NMC111 and LFP—two key components of commercial lithium-ion batteries—under X-ray radiation. Using X-ray Diffraction (XRD) and X-ray Absorption Spectroscopy (XAS) at the MSPD and NOTOS beamlines of ALBA, they observed how the materials reacted to different radiation intensities while undergoing charge and discharge cycles.

The results showed that at high doses, the synchrotron radiation caused a localized inhibition of the electrochemical reactivity at the irradiated areas. In other words, the X-ray beam interfered with the normal functioning of the battery material, slowing down or halting the expected chemical reactions. The effects were found to be dose-dependent, with higher radiation doses leading to more significant inhibition. Importantly, the study demonstrated that these effects were reversible. Once the beam was moved to a different area or when the radiation intensity was reduced, the materials returned to their normal activity. This suggests that the materials were not permanently damaged by the beam, but rather their activity was temporarily “paused” due to X-ray exposure.

These findings corroborate already known beam-induced effects in operando measurements with synchrotron light. Nevertheless, thanks to the systematic investigation they also enable researchers to propose several strategies to mitigate them. For example, reducing the intensity of the synchrotron beam by using attenuators, such as aluminum foils to lower the photon flux reaching the sample. The researchers also found that thinner battery electrodes were less affected by the beam, suggesting that the thickness of the materials being studied influences their radiation tolerance. Additionally, they observed that controlling the exposure time and introducing rest periods between measurements could help prevent the build-up of beam effects.

This study, the first to use the NOTOS beamline for advancing battery research, not only provided a first systematic analysis of the beam-induced effects when using synchrotron light to study materials under actual working conditions, but also has broader implications for improving the accuracy of synchrotron-based characterization techniques across many fields of materials science. As scientists work to develop new and more efficient battery materials—especially for applications like electric vehicles and renewable energy storage—synchrotron specialists around the world will continue refining high-brilliance X-ray techniques to provide accurate, real-time data for understanding the complex chemical processes that take place during battery operation.

Read more on ALBA website

Battery Scientist Honored by DOE’s Vehicle Technologies Office

Battery Scientist Honored by DOE’s Vehicle Technologies Office

UPTON, N.Y. — Longer lasting batteries would allow electric vehicles (EVs) to drive farther and perhaps inspire more people to make the switch from fossil fuels. One key to better EV batteries is understanding the intricate details of how they work — and stop working.

Xiao-Qing Yang, a physicist who leads the Electrochemical Energy Storage group within the Chemistry Division at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, has spent a good deal of his professional career doing just that. DOE’s Vehicle Technologies Office (VTO) recently recognized his contributions with a Distinguished Achievement Award presented during its 2024 Annual Merit Review. Each year, VTO presents awards to individuals from partner institutions for contributions to overall program efforts and to recognize research, development, demonstration, and deployment achievements in specific areas. 

Yang was honored “for pioneering [the use of] advanced characterization tools, such as in situ X-ray diffraction and absorption, to analyze battery materials under operational and extreme conditions in support of VTO battery research and development (R&D) at Brookhaven National Laboratory over the last 38 years.”

Read more on BNL website

Image: Battery chemist Xiao-Qing Yang (left) with colleagues Enyuan Hu and Eli Stavitski at the Inner-Shell Spectroscopy (ISS) beamline of the National Synchrotron Light Source-II at Brookhaven National Laboratory

Credit: Brookhaven National Laboratory

New versatile spectro-electrochemical cell

New versatile spectro-electrochemical cell

Equipment improves the investigation of materials for fuel cells, batteries and electrolysers

Fossil fuels are the main source of energy in the world. However, the search for clean, renewable, and cheap energy sources has intensified recently, especially with the growing consensus that the rise in the average temperature of the planet is caused by human action. In this context, electrochemical devices, which involve reactions for the transformation of chemical energy into electrical energy, appear as a viable option to fossil fuels.

Among those available are fuel cells and batteries, capable of converting the chemical energy of molecules into electrical energy and storing it, and electrolysers capable of converting low-cost molecules into more economically attractive molecules. Thus, to improve the performance of these electrochemical devices, it is essential to understand the processes that occur between their components, more precisely in the interaction between the electrodes and the electrolyte.

For this reason, researchers from the State University of Campinas (UNICAMP), in collaboration with researchers from the Brazilian Center for Research in Energy and Materials (CNPEM) and the Federal University of São Carlos (UFSCar), developed an electrochemical cell [1] with the objective to perform various types of in situ experiments. These experiments allow direct access to the dynamics of electrochemical reactions in real time and make it possible to understand the processes that occur in the system from an atomic and molecular point of view. Hence, it is possible to optimize the materials that are part of fuel cells, batteries and electrolysers mentioned, and also of devices such as supercapacitors and electrochemical sensors, among others.

Read more on the LNLS website

Image: Figure 1: A, B) Schematic drawings of the SEC: threaded lip (1); aperture for passing the radiation beam and, in the case of a photoelectrochemical experiment, to illuminate the electrode with a solar simulator or LEDs (2); window (3); O-rings (4, 5, 17); CE (6 16); SEC body – part 1 (7); chamber for the electrolyte, the CE and the RE (8); electrolyte inlet and outlet (9, 11, 13), WE inlet (10); RE inlet (12); RE (14); CE inlet (15); bolt (18); SEC body – part 2 (19); WE (20).

NSRRC users and scientists develop novel materials for high-rate vehicle batteries

NSRRC users and scientists develop novel materials for high-rate vehicle batteries

An international team coordinated by the user of National Synchrotron Radiation Research Center (NSRRC), Professor Cheng-Hao Chuang from the Tamkang University, has developed novel materials for high-rate lithium (Li) ion batteries that can be charged in minutes. Prof. Chuang discovered that the use of black phosphorus (BP) as the active anode for high-capacity Li storage could realize ultra-fast and convenient charging for e-mobility. It takes less than two minutes to recharge the battery for an incredible energy storage with a driving range of 560 kilometers, surpassing gasoline-powered cars’ long-standing advantages of quick-refueling and long driving ranges. The outstanding research result was published in the world’s top journal Science on October 9th, 2020.

Read more on the National Synchrotron Radiation Research Centre website

Image: Schematic of BP-graphite particles/polyaniline. Credit: NSRRC

New discovery will have huge impact on the development of future battery cathodes

New discovery will have huge impact on the development of future battery cathodes

A new paper published today in Nature Energy reveals how a collaborative team of researchers have been able to fully identify the nature of oxidised oxygen in the important battery material – Li-rich NMC – using RIXS (Resonant Inelastic X-ray Scattering) at Diamond. This compound is being closely considered for implementation in next generation Li-ion batteries because it can deliver a higher energy density than the current state-of-the-art materials, which could translate to longer driving ranges for electric vehicles. They expect that their work will enable scientists to tackle issues like battery longevity and voltage fade with Li-rich materials.

The paper, ‘First cycle voltage hysteresis in Li-rich 3d cathodes associated with molecular O2 trapped in the bulk’ by a joint team from the University of Oxford, the Henry Royce and Faraday Institutions and Diamond, examines the results of their investigations to better understand the important compound known in the battery industry as Li-rich NMC (or Li1.2Ni0.13Co0.13Mn0.54O2).   

Principal Beamline Scientist on I21 RIXS at Diamond, Kejin Zhou,said:

Our work is much about understanding the mysterious first cycle voltage hysteresis in which the O-redox process cannot be fully recovered resulting in the loss of the voltage hence the energy density.

Read more on the Diamond website

Image: A previous study (Nature 577, 502–508 (2020)) into this process made by the same research team, at the I21 beamline at Diamond, reported that, in Na-ion battery cathodes, the voltage hysteresis is related to the formation of molecular O2 trapped inside of the particles due to the migration of transition metal ions during the charging process.

High-pressure study advances understanding of promising battery materials

High-pressure study advances understanding of promising battery materials

X-ray investigation shows systematic distortion of the crystal lattice of high-entropy oxides

In a high-pressure X-ray study, scientists have gained new insights into the characteristics of a promising new class of materials for batteries and other applications. The team led by Qiaoshi Zeng from the Center for High Pressure Science in China used the brilliant X-rays from DESY’s research light source PETRA III to analyse a so-called high-entropy oxide (HEO) under increasing pressure. The study, published in the journal Materials Today Advances is a first, but very important step paving a way for a broader picture and solid understanding of HEO materials.

Modern society requires industry to manufacture efficiently sustainable products for everyday life, for example batteries for smart phones. About five years ago, a new class of materials emerged that appears to be very promising for the design of new applications, especially batteries. These high-entropy oxides consist of at least five metals that are distributed randomly in a common simple crystal lattice, while their crystal structure can be different from each metal’s generic lattice. A popular example of a HEO material consists of 20 per cent each of cobalt, copper, magnesium, nickel and zinc for every oxygen atom, or (Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O.

Read more on the DESY website

Image: Example of a high-entropy oxide between the anvils of a diamond anvil cell used to exert increasing pressure on the sample. Credit: Center of High Pressure Science, Qiaoshi Zeng

Scientists probe the chemistry of a single battery electrode particle both inside and out

Scientists probe the chemistry of a single battery electrode particle both inside and out

The results show how a particle’s surface and interior influence each other, an important thing to know when developing more robust batteries.

The particles that make up lithium-ion battery electrodes are microscopic but mighty: They determine how much charge the battery can store, how fast it charges and discharges and how it holds up over time – all crucial for high performance in an electric vehicle or electronic device.

Cracks and chemical reactions on a particle’s surface can degrade performance, and the whole particle’s ability to absorb and release lithium ions also changes over time. Scientists have studied both, but until now they had never looked at both the surface and the interior of an individual particle to see how what happens in one affects the other.

Read more on the SSRL (SLAC National Accelerator Laboratory) website

Image: Images made with an X-ray microscope show particles within a nickel-rich layered oxide battery electrode (left). In a SLAC study, scientists welded a single charged particle to the tip of a tungsten needle (right) so they could probe its surface and interior with two X-ray instruments. The particle is about the size of a red blood cell. (S. Li et al., Nature Communications, 2020)

Longer-lasting cell phone batteries

Longer-lasting cell phone batteries

Studies demonstrate the promise of phosphorene in electronics

Phosphorene is attracting a lot of attention lately in the energy and electronics industries, and for good reason. The theoretical capacity of the two-dimensional material—which consists of a single layer of black phosphorus—is almost seven times that of anode materials currently used in lithium-ion batteries. That could translate into real-world benefits such as significantly greater range for electric vehicles and longer battery life for cell phones.

There are a couple of strikes against phosphorene though. Commercially available black phosphorus is costly, at roughly $1000 per gram, and it breaks down quickly when it’s exposed to air. Researchers from Western University teamed up with scientists from the Canadian Light Source (CLS) at the University of Saskatchewan on a pair of studies to determine if they could address both issues.

Read more on the Canadian Light Source website

Image: Dr. Andy Sun at the Canadian Light Source.

Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live

Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live

Using silicon as a material for electrodes in lithium-ion batteries promises a significant increase in battery amp-hour capacity.The shortcoming of this material is that it is easily damaged by the stress caused by charging and discharging.Scientists at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) have now succeeded for the first time in observing this process directly on crystalline silicon electrodes in detail.Operando experiments using the BESSY II synchrotronprovided new insights into how fractures occur in silicon – and also how the material can nevertheless be utilised advantageously.

Whether in smartphones or electric cars – wherever mobile electric power needs to be available, it usually comes from rechargeable lithium-ion batteries. One of the two electrodes inside these batteries consists of graphite in which lithium ions are lodged, thereby storing electrical energy. The disadvantage of this carbon material is that its energy storage capacity is quite small – which makes frequent recharging of the battery necessary. For this reason, researchers worldwide are searching for alternative electrode materials to lengthen the battery charge/discharge cycles.

Read more on the Helmholtz Zentrum Berlin website

Image: The design of the experimental set-up shows how the structure of the silicon electrode periodically changes during charging and discharging on the basis of voltage measurements. © HZB