Improving the capacity of LiNixMnyCo1–x–yO2 (NMC) by increasing the Ni content results in materials with poor cycling performance and reduced thermal stability. These problems can be alleviated by creating concentration gradients in the materials, but this requires more expensive batch processing. Herein, a simple process is described that can create a coating that penetrates into the precursor particles, creating unique gradients in the precursor material. The coated material demonstrates improved cycling performance and thermal stability as compared to uncoated materials. Rapid heating to simulate a thermal runaway event while observing these materials with X-rays gives a deeper understanding of how the coating affects the decomposition process.
Albert L. Lipson, Bradley J. Ross, Jessica L. Durham, Donghao Liu, Michael LeResche, Timothy T. Fister, Lei Liu, Kitae Kim, “Stabilizing NMC 811 Li-Ion Battery Cathode through a Rapid Coprecipitation Process”, ACS Appl. Energy Mater., 2021, abstract