Cause of cathode degradation identified for nickel-rich materials – revolution-green gas 87 89 91

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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 electricity and magnetism study guide answers 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.

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.

Batteries are composed of an anode, a cathode, and an electrolyte, but many scientists consider the cathode to be the most pressing challenge. Researchers at Brookhaven are part gas and water mix of a DOE-sponsored consortium called Battery500, a group that is working to triple the energy density of the batteries that power today’s electric vehicles. One of their goals is to optimize a class of cathode materials called nickel-rich layered materials.

Lithium cobalt oxide is a layered material that has been used gas leak los angeles as the cathode for lithium-ion batteries for many years. Despite its successful application in small energy storage systems such as portable electronics, cobalt’s cost and toxicity are barriers for the material’s use in larger systems. Now, researchers are investigating how to replace cobalt with safer and more affordable elements without compromising the material’s performance.

Cathode materials can degrade in several ways. For nickel-rich materials, the problem is mainly capacity fading—a reduction in the battery’s charge-discharge capacity after use. To fully understand this process in their nickel-rich layered materials, the scientists gas cap code needed to use multiple research techniques to assess the material from different angles.

“This is a very complex material. Its properties can change at different length scales during cycling,” Hu said. “We needed to understand how the material’s structure changed during the charge-discharge process both physically—on the atomic scale up—and chemically, which involved multiple elements: nickel, cobalt, manganese, oxygen, and lithium.”

“At every length scale in this material, from angstroms to nanometers and to micrometers, something is happening during the battery’s charge-discharge process,” said co-author Eli Stavitski, beamline scientist at NSLS-II’s Inner Shell Spectroscopy (ISS) beamline. “We used a technique called x-ray absorption spectroscopy (XAS) here at ISS to reveal an atomic picture of the environment around the electricity voltage in china active metal ions in the material.”

“These experiments produced a huge amount of data, which is where our computing contribution came in,” said co-author Yijin Liu, a SLAC staff scientist. “It wouldn’t have been practical for humans to analyze all of this data, so we developed a machine learning approach that searched through the data and made judgments on which locations were problematic. This told us where to look and guided our analysis.”

Hu said, “The major conclusion we drew from this experiment was that there were considerable inhomogeneities in the oxidation states of the nickel atoms throughout the particle. Some nickel within the particle maintained an oxidized state gas tax oregon, and likely deactivated, while the nickel on the surface was irreversibly reduced, decreasing its efficiency.”

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.