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

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

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

A highly promising sustainable battery for electric vehicles

McGill University researchers show that affordable materials could prove key for improving the batteries used in electric vehicles. The breakthrough was analyzed and confirmed with the Canadian Light Source (CLS) at the University of Saskatchewan. The research was funded by NSERC and supported by Hydro-Quebec.

As we move to greener technologies, the need for affordable, safe and powerful batteries is increasing constantly.

Battery-powered electric vehicles, for example, have much higher safety standards than our phones, and to travel the long distances required in Canada, lighter weight, high-energy capacity batteries make a world of difference.

Current rechargeable batteries tend to use expensive non-abundant metals, like cobalt, that carry an environmental and human rights toll under the poor labour conditions in mines in Africa. All are barriers to wider adoption.

The battery’s cathode, or positive electrode, is one of the best candidates for Li-ion battery improvement. “Cathodes represent 40 per cent of the cost of the batteries that we are using in our phones right now. They are absolutely crucial to improve battery performance and reduce dependency on cobalt,” says Rasool.

Read more on the Canadian Light Source website

Image : Lithium ion silicate nanocrystals coated in a conducting polymer known as PEDOT enhance battery performance even after 50 cycles, paving the way for high energy density cathodes.

Titanium-based potassium-ion battery positive electrode

Small energy storage devices (like the ones used in cell phones, tablets, and laptops) based on the mature Lithium-ion technology have become a key element of our daily life. Facing the pressing challenges posed by Global Warming, the increasing demand of storage systems for the large-scale automotive industry will soon clash with the sparse provision of lithium in the Earth’s crust.
In this panorama, the development of economically feasible emerging battery technologies based on alternative, earth-abundant, elements, is thus highly desirable.
Potassium-ion batteries could represent a viable substitute to Lithium-ion technology in a large-scale green economy. However, the key problem preventing the success of the K-ion technology is linked to the low efficiency of cathode materials. 

>Read more on the Elettra website

Image: Structural evolution of KTiPO4F. (a) Initial crystal structure (b) In operando SXPD: phase transformations. (c) Corresponding charge-discharge profile

Expertise in characterising materials for lithium ion batteries

Pioneering work on materials for energy production, such as lithium ion batteries, has made ANSTO a centre of specialist capabilities and expertise.

In addition to the research on lithium-ion batteries; the team also investigates other types of batteries that can reversibly host ions, such as sodium and potassium ion batteries. 
Dr Christophe Didier, a post-doc working with Peterson at the ACNS and shared with Peterson’s University of Wollongong collaborators, published work in Advanced Energy Materials providing structural insights into layered manganese oxide electrodes for potassium-Ion batteries.
“In this case, we were able to use X-rays on an operating battery at the Australian Synchrotron,  because potassium has a lot more electrons than lithium.”
These results again confirm the importance of understanding the detailed structural evolution that underpins performance that will inform the strategic design of electrode materials for high-performance potassium ion batteries. “We do have many collaborators but we are always interested in new projects.  Because we are knowledgeable in the materials themselves, we can contribute to the selection of suitable materials as well as leading the characterisation effort.

>Read more on the Australian Synchrotron (ANSTO) website

Image: Powder diffraction instrument scientist, Dr Qinfen Gu at the Australian Synchrotron.

Canadian researchers extend the life of rechargeable batteries

Carbon coating that extends lithium ion battery capacity by 50% could pave the way for next-generation batteries in electric vehicles.

Researchers from Western University, using the Canadian Light Source (CLS) at the University of Saskatchewan, found that adding a carbon-based layer to lithium-ion rechargeable batteries extends their life up to 50%.
The finding, recently published in the journal ACS Applied Materials and Interfaces, tackles a problem many Canadians will be familiar with: rechargeable batteries gradually hold less charge over time.
“We added a thin layer of carbon coating to the aluminum foil that conducts electric current in rechargeable batteries,” said lead researcher Dr. Xia Li of Western University. “It was a small change, but we found the carbon coating protected the aluminum foil from corrosion of electrolyte in both high voltage and high energy environments – boosting the battery capacities up to 50% more than batteries without the carbon coating.”

>Read more on the Canadian Light Source website

Image: Dr. Li in the lab. 

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)

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