Probing and Resolving the Heterogeneous Degradation of Nickel‐Rich Layered Oxide Cathodes across Multi‐Length Scales

Abstract Ni‐rich layered oxides (NRLO) are widely considered among the most promising cathode materials for high energy‐density lithium ion batteries. However, the high proportion of Ni content accelerates the cycling degradation that restricts their large‐scale applications. The origins of degradation are indeed heterogeneous and thus there are tremendous efforts devoted to understanding the underlying mechanisms at multi‐length scales spanning atom/lattice, particle, porous electrode, solid‐electrolyte interface, and cell levels and mitigating the degradation of the NRLO. This review combines various advanced in situ/ex situ analysis techniques developed for resolving NRLO degradation at multi‐length scales and aims to convey a comprehensive picture of its heterogeneous degradation mechanism. This contribution starts with discussing various factors influencing NRLO stability and procee…