Imaging dendrite growth in zinc-air batteries

SXCT captures unprecedented detail of dendrite formation, growth and dissolution

Modern life runs on rechargeable batteries, which power all of our mobile devices and are increasingly used to power vehicles and to store energy from renewable sources. We are approaching the limits of lithium-ion battery technology in terms of maximum energy capacity, and new technologies will be needed to develop higher capacity rechargeable batteries for the future. One class of promising candidates is metal-air batteries, in particular zinc-air batteries that have a high theoretical energy density and low estimated production costs. However, zinc-air batteries present certain challenges, in key areas such as cycle life, reversibility and power density. The formation of metal dendrites as the battery charges is a common cause of failure, as dendrites can cause internal short circuits and even thermal runaway. (Thermal runaway is a sequence of exothermic reactions that take place within the battery, leading to overheating and potentially resulting in fire or an explosion. It is also a problem in lithium-ion batteries, and the subject of ongoing research.) In work recently published in Joule, a team of researchers from Imperial College, London, University College London, the University of Manchester and the Research Complex at Harwell carried out in situ experiments investigating how dendritic growth can cause irreversible capacity loss, battery degradation and eventually failure.
>Read more on the Diamond Light Source website

Image: (extract, see full image here) Single dendrite and dendritic deposits inside and on top of the separator (FIB-SEM)

Reversible lattice-oxygen reactions in batteries

The results open up new ways to explore how to pack more energy into batteries with electrodes made out of low-cost, common materials.

For a wide range of applications, from mobile phones to electric vehicles, the reversibility and cyclability of the chemical reactions occurring inside a rechargeable battery are key to commercial viability. Conventional wisdom had held that involving oxygen in a battery’s electrochemical operation spontaneously triggers irreversible oxygen losses and parasitic surface reactions, reducing reversibility and safety. Recently however, the idea emerged that reactions involving lattice oxygen (i.e., oxygen that’s part of the crystal-lattice structure vs oxygen on the surface) could be useful for improving battery capacity. Here, researchers report the first direct quantification of a strong, beneficial, and highly reversible chemical reaction involving lattice oxygen in electrodes made with low-cost elements.

>Read more on the Advanced Light Source

Image: Advanced spectroscopy at the ALS clearly resolves the activities of cations and anions (known in Chinese as “yin” and “yang” ions) in battery electrodes.

Cause of cathode degradation identified for nickel-rich materials

Combination of research methods reveals causes of capacity fading, giving scientists better insight to design advanced batteries for electric vehicles

A team of scientists including researchers at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and SLAC National Accelerator Laboratory have identified the causes of degradation in a cathode material for lithium-ion batteries, as well as possible remedies. Their findings, published on Mar. 7 in Advanced Functional Materials, could lead to the development of more affordable and better performing batteries for electric vehicles.

Searching for high-performance cathode materials
For electric vehicles to deliver the same reliability as gas vehicles they need lightweight yet powerful batteries. Lithium-ion batteries are the most common type of battery found in electric vehicles today, but their high cost and limited lifetimes are limitations to the widespread deployment of electric vehicles. To overcome these challenges, scientists at many of DOE’s national labs are researching ways to improve the traditional lithium-ion battery.

>Read more on the NSLS-II at Brookhaven Lab website

Image: Members of the Brookhaven team are shown at NSLS-II’s ISS beamline, where part of the research was conducted. Pictured from front to back are Eli Stavitski, Xiao-Qing Yang, Xuelong Wang, and Enyuan Hu.

Untangling a strange phenomenon in lithium-ion batteries

New research offers the first complete picture of why a promising approach of stuffing more lithium into battery cathodes leads to their failure.

A better understanding of this could be the key to smaller phone batteries and electric cars that drive farther between charges.
The lithium-ion batteries that power electric vehicles and phones charge and discharge by ferrying lithium ions back and forth between two electrodes, an anode and a cathode. The more lithium ions the electrodes are able to absorb and release, the more energy the battery can store.
One issue plaguing today’s commercial battery materials is that they are only able to release about half of the lithium ions they contain. A promising solution is to cram cathodes with extra lithium ions, allowing them to store more energy in the same amount of space. But for some reason, every new charge and discharge cycle slowly strips these lithium-rich cathodes of their voltage and capacity.
A new study provides a comprehensive model of this process, identifying what gives rise to it and how it ultimately leads to the battery’s downfall. Led by researchers from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory, it was published today in Nature Materials.

>Read more on the Stanford Synchrotron Radiation Lightsource (SSRL)

Image: A mysterious process called oxygen oxidation strips electrons from oxygen atoms in lithium-rich battery cathodes and degrades their performance, shown at left. Better understanding this property and controlling its effects could lead to better performing electric vehicles.
Credit: Gregory Stewart/SLAC National Accelerator Laboratory)

Improving lithium-ion battery capacity

Toward cost-effective solutions for next-generation consumer electronics, electric vehicles and power grids.

The search for a better lithium-ion battery—one that could keep a cell phone working for days, increase the range of electric cars and maximize energy storage on a grid—is an ongoing quest, but a recent study done by Canadian Light Source (CLS) scientists with the National Research Council of Canada (NRC) showed that the answer can be found in chemistry.
“People have tried everything at an engineering level to improve batteries,” said Dr. Yaser Abu-Lebdeh, a senior research officer at the NRC, “but to improve their capacity, you have to play with the chemistry of the materials.”

>Read more on the Canadian Light Source website

Image: The decomposition of a polyvinylidene fluoride (PVDF) binder in a high energy battery.
Credit: Jigang Zhou

First in situ X-ray Absorption study of liquid battery cells

A greener future depends on better batteries: to move away from fossil fuels, we need rechargeable batteries with higher power and energy density to store intermittent energy from solar and wind. Moreover, these batteries could completely replace fossil fuels in vehicles.

Metal-air batteries seem like the answer, with the highest theoretical ability to pack energy into a small space (a property called energy density) of all current battery types.
“If we can achieve the theoretical energy density of metal air batteries and use them in vehicles, we can have much more driving range and make them more competitive with internal combustion engines that are currently used in cars,” says Mohammad Banis, a Western University researcher whose recent work looked at the charge and discharge cycles of a sodium-air battery in action.

Banis, who works in Andy Xueliang Sun’s clean energy research group at Western, spent a full year stationed at the Canadian Light Source to develop new tools for battery research. Observing the real time behaviour of material during charge cycles of a metal air battery presents a puzzle: the soft X-ray technique used typically requires a vacuum chamber, which makes it particularly difficult to study a liquid system.

>Read more on the Canadian Light Source website.

Image: Mohammad Banis at a Canadian Light Source beamline where he studies batteries.

Finding unusual performance in unconventional battery materials

Even as our electronic devices become ever more sophisticated and versatile, battery technology remains a stubborn bottleneck, preventing the full realization of promising applications such as electric vehicles and power-grid solar energy storage.  Among the limitations of current materials are poor ionic and electron transport qualities. While strategies exist to improve these properties, and hence reduce charging times and enhance storage capacity, they are often expensive, difficult to implement on a large scale, and of only limited effectiveness.  An alternative solution is the search for new materials with the desired atomic structures and characteristics.  This is the strategy of a group of researchers who, utilizing ultra-bright x-rays from the U.S. Department of Energy’s Advanced Photon Source (APS), identified and characterized two niobium tungsten oxide materials that demonstrate much faster charging rates and power output than conventional lithium electrodes.  Their work appeared in the journal Nature.

Currently, the usual approach for wringing extra capacity and performance from lithium-ion batteries involves the creation of electrode materials with nanoscale structures, which reduces the diffusion distances for lithium ions.  However, this also tends to increase the practical volume of the material and can introduce unwanted additional chemical reactions. Further, when graphite electrodes are pushed to achieve high charging rates, irregular dendrites of lithium can form and grow, leading to short circuits, overheating, and even fires.  Measures to prevent these dendrites generally cause a decrease in energy density.  These issues seriously limit the use of graphite electrodes for high-rate applications.

>Read more on the Advanced Photon Source website

Image: Artist’s impression of rapidly flowing lithium through the niobium tungsten oxide structure. This is a detail of the image, please see here for the entire art work.
Credit: Ella Maru Studio

X-rays uncover a hidden property that leads to failure in a lithium-ion battery material

Experiments at SLAC and Berkeley Lab uproot long-held assumptions and will inform future battery design.

Over the past three decades, lithium-ion batteries, rechargeable batteries that move lithium ions back and forth to charge and discharge, have enabled smaller devices that juice up faster and last longer.
Now, X-ray experiments at the Department of Energy’s SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory have revealed that the pathways lithium ions take through a common battery material are more complex than previously thought. The results correct more than two decades worth of assumptions about the material and will help improve battery design, potentially leading to a new generation of lithium-ion batteries.

An international team of researchers, led by William Chueh, a faculty scientist at SLAC’s Stanford Institute for Materials & Energy Sciences and a Stanford materials science professor, published these findings today in Nature Materials.
“Before, it was kind of like a black box,” said Martin Bazant, a professor at the Massachusetts Institute of Technology and another leader of the study. “You could see that the material worked pretty well and certain additives seemed to help, but you couldn’t tell exactly where the lithium ions go in every step of the process. You could only try to develop a theory and work backwards from measurements. With new instruments and measurement techniques, we’re starting to have a more rigorous scientific understanding of how these things actually work.”

>Read more on the SLAC website

Image: When lithium ions flow into the battery’s solid electrode – illustrated here in hexagonal slices – the lithium can rearrange itself, causing the ions to clump together into hot spots that end up shortening the battery lifetime.
Credit: Stanford University/3Dgraphic

Empowering multicomponent cathode materials for sodium ion batteries

…by exploring three-dimensional compositional heterogeneities

Energy storage devices have revolutionized the modern electronics industry by enabling the widespread application of portable electronic devices. Moreover, these storage devices also have the potential to reduce the dependence on fossil fuels by implementing electric vehicles in the market. To date, lithium ion batteries have dominated the market because of the high energy density delivered by them. However, one should look into the sustenance of such devices because Li is not one of the most abundant metals on Earth’s crust. Thus, developing an alternative to lithium ion batteries has become one of the key issues to ensure the sustainable future of energy storage devices. Sodium ion batteries provide one such alternative. Out of all the components of a battery, cathode materials play one of the key roles in determining the overall performance of such batteries. Unfortunately, sodium-ion batteries have been lagging behind their lithium ion counterpart in terms of performance. Thus, new design strategies must be undertaken in order to improve the performance of cathode materials for sodium ion batteries.

>Read more on the SSRL at SLAC website

Image (extract): Three-dimensional elemental associations of pristine Na0.9Cu0.2Fe0.28Mn0.52O2 studied through transmission x-ray tomography. a) Visualizing the surface elemental associations at different angles with different colors corresponding to different association, and b) 2D cross-sectional association maps showing the bulk elemental associations. [Energy Environ. Sci., DOI: 10.1039/C8EE00309B (2018)] See entire figure here.

Demonstrating a new approach to lithium-ion batteries

A team of researchers from the University of Cambridge, Diamond Light Source and Argonne National Laboratory in the US have demonstrated a new approach that could fast-track the development of lithium-ion batteries that are both high-powered and fast-charging.

In a bid to tackle rising air pollution, the UK government has banned the sale of new diesel and petrol vehicles from 2040, and the race is on to develop high performance batteries for electric vehicles that can be charged in minutes, not hours. The rechargeable battery technology of choice is currently lithium-ion (Li-ion), and the power output and recharging time of Li-ion batteries are dependent on how ions and electrons move between the battery electrodes and electrolyte. In particular, the Li-ion diffusion rate provides a fundamental limitation to the rate at which a battery can be charged and discharged.

>Read more on the Diamond Light Source website

X-Ray Experiment confirms theoretical model for making new materials

By observing changes in materials as they’re being synthesized, scientists hope to learn how they form and come up with recipes for making the materials they need for next-gen energy technologies.

Over the last decade, scientists have used supercomputers and advanced simulation software to predict hundreds of new materials with exciting properties for next-generation energy technologies.

Now they need to figure out how to make them.

To predict the best recipe for making a material, they first need a better understanding of how it forms, including all the intermediate phases it goes through along the way – some of which may be useful in their own right.

Now experiments at the Department of Energy’s SLAC National Accelerator Laboratory have confirmed the predictive power of a new computational approach to materials synthesis. Researchers say that this approach, developed at the DOE’s Lawrence Berkeley National Laboratory, could streamline the creation of novel materials for solar cells, batteries and other sustainable technologies.

>Read more on the Stanford Synchrotron Radiation Lightsource at SLAC website

Image: In an experiment at SLAC, scientists loaded ingredients for making a material into a thin glass tube and used X-rays (top left) to observe the phases it went through as it was forming (shown in bubbles). The experiment verified theoretical predictions made by scientists at Berkeley Lab with the help of supercomputers (right).
Credit: Greg Stewart/SLAC National Accelerator Laboratory

Tripling the energy storage of lithium-ion batteries

Scientists have synthesized a new cathode material from iron fluoride that surpasses the capacity limits of traditional lithium-ion batteries.

As the demand for smartphones, electric vehicles, and renewable energy continues to rise, scientists are searching for ways to improve lithium-ion batteries—the most common type of battery found in home electronics and a promising solution for grid-scale energy storage. Increasing the energy density of lithium-ion batteries could facilitate the development of advanced technologies with long-lasting batteries, as well as the widespread use of wind and solar energy. Now, researchers have made significant progress toward achieving that goal.

A collaboration led by scientists at the University of Maryland (UMD), the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, and the U.S. Army Research Lab have developed and studied a new cathode material that could triple the energy density of lithium-ion battery electrodes. Their research was published on June 13 in Nature Communications.

>Read more on the NSLS-II at Brookhaven National Lab website

Image: Brookhaven scientists are shown at the Center for Functional Nanomaterials. Pictured from left to right are: (top row) Jianming Bai, Seongmin Bak, and Sooyeon Hwang; (bottom row) Dong Su and Enyuan Hu.

Takeuchi Receives European Inventor Award 2018

Prolific patent-holder won for inventing battery that increases the lifespan of implantable defibrillators fivefold, greatly reducing need for reoccurring surgery.

Esther Sans Takeuchi, PhD, has won the 2018 European Inventor Award in the “Non-EPO countries”, the European Patent Office (EPO) announced today. The award was given to her by the EPO at a ceremony held today in Paris, Saint-Germain-en-Laye. Of the four U.S. scientists nominated for the award, Takeuchi is the only American to bring home Europe’s most prestigious prize of innovation.

Takeuchi is the Chief Scientist of the Energy Sciences Directorate at the U.S. Department of Energy’s Brookhaven National Laboratory, Stony Brook University’s (SBU) William and Jane Knapp Endowed Chair in Energy and the Environment, and a Distinguished Professor of Chemistry in the College of Arts & Sciences and in Materials Science and Chemical Engineering in the College of Engineering and Applied Sciences at SBU. She was honored for developing the compact batteries that power tiny, implantable cardiac defibrillators (ICDs)—devices that detect and correct irregular, potentially fatal, heart rhythms. Her lithium silver vanadium oxide (“Li/SVO”) battery extended the power-source lifetime for ICDs to around five years, considerably longer than its predecessors, thus reducing the number of surgeries patients needed to undergo to replace them. Her invention led not only to an advance in battery chemistry, but also enabled the production and widespread adoption of ICDs and significantly improved patient well-being.

>Read more on the National Synchrotron Light Source II (NSLS-II) website

Image: Esther Sans Takeuchi, a joint appointee of Brookhaven National Laboratory and Stony Brook University, has won the 2018 European Inventor Award in the category “Non-EPO countries.”

 

 

Monovalent Manganese for High-Performance Batteries

The discovery enables the design of a high-performance, low-cost battery that, according to its developers, outperforms Department of Energy goals on cost and cycle life for grid-scale energy storage.

The widespread deployment of renewable energy sources such as solar and wind power destabilizes the electric grid because conventional power-generation systems cannot ramp quickly enough to balance the power variations from these intermittent sources. Storing energy in batteries could help to even things out, but the cost of most existing technologies—including lithium-ion batteries—is significant, hindering grid-scale applications.

Emerging storage technologies such as aqueous sodium (Na) systems offer low costs for long-duration storage, but they do not have the charge/discharge rates needed to balance volatile power generation. In particular, it remains a critical challenge to develop a stable negative electrode (anode) for high-rate Na-ion battery systems.

A battery breakthrough

Compared with the relatively mature designs of anodes used in Li-ion batteries, anodes for Na-ion batteries remain an active focus of research and development. Natron Energy (formerly Alveo Energy), a battery-technology company based in Santa Clara, California, developed an unconventional anode design using a blend of elements chemically similar to the paint pigment known as Prussian blue.

>Read more on the Advanced Light Source website

Image: Atomic structure of an electrode material, manganese hexacyanomanganate (MnHCMn), that achieved high performance in a sodium-ion battery. The open framework contains large interstices and channels that allow sodium (Na) ions to move in and out with near-zero strain. Manganese (Mn) ions form the corners of the cage: Mn(N) has six nitrogen nearest neighbors and Mn(C) has six carbon nearest neighbors.

Phase diagram leads the way to tailored metamaterial responses

COSMIC impact: next-gen X-ray microscopy platform now operational

A next-generation X-ray beamline now operating at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) brings together a unique set of capabilities to measure the properties of materials at the nanoscale.

Called COSMIC, for Coherent Scattering and Microscopy, this X-ray beamline at Berkeley Lab’s Berkeley Lab’s Advanced Light Source (ALS) allows scientists to probe working batteries and other active chemical reactions, and to reveal new details about magnetism and correlated electronic materials.
COSMIC has two branches that focus on different types of X-ray experiments: one for X-ray imaging experiments and one for scattering experiments. In both cases, X-rays interact with a sample and are measured in a way that provides, structural, chemical, electronic, or magnetic information about samples.

The beamline is also intended as an important technological bridge toward the planned ALS upgrade, dubbed ALS-U, that would maximize its capabilities.

>Read more on the Advanced Light Source website

Image: X-rays strike a scintillator material at the COSMIC beamline, causing it to glow.
Credit: Simon Morton/Berkeley Lab