Operando visualization of kinetically induced lithium heterogeneities in single-particle layered Ni-rich cathodes

• DOI: 10.1016/j.joule.2022.09.008
• Publication Date: 2022-10-12T15:53:51Z
• Authors: Chao Xu; Alice J. Merrywea...; Shrinidhi S. Pand...; Zhengyan Lun; David S. Hall; Vikram S. Deshpande; Norman A. Fleck; Christoph Schnede...; Akshay Rao; Clare P. Grey
• Keywords: Particle (ecology)

Understanding how lithium-ion dynamics affect the (de)lithiation mechanisms of state-of-the-art nickel-rich layered oxide cathodes is crucial to improve electrochemical performance. Here, we directly observe two distinct kinetically induced lithium heterogeneities within single-crystal LiNixMnyCo(1−x−y)O2 (NMC) particles using recently developed operando optical microscopy, challenging notion that uniform occurs individual particles. Upon delithiation, a rapid increase in diffusivity at beginning charge results with lithium-poor peripheries and lithium-rich cores. The slow ion diffusion near-full lithiation states—and transfer kinetics—also leads heterogeneity end discharge, surface preventing complete lithiation. Finite-element modeling confirms concentration-dependent necessary reproduce these phenomena. Our demonstrate kinetic limitations cause significant first-cycle capacity losses Ni-rich cathodes.