Uncovering Electrochemical‐Mechanical Interplay of Stable Ultrahigh‐Nickel Cathode via Fine Structure Regulation

Abstract

ABSTRACT Ni‐rich layered oxides with optimized primary particle structures are crucial for developing lithium‐ion batteries with high energy density. Although conventional high‐valence elements doping effectively refines grains for columnar alignment, the industrial understanding of the processing‐structure‐performance relationship is lacking, and thus limits large‐scale production. Herein, we investigate how molybdenum incorporation routes alter microstructure and performance, revealing a link between early structural evolution and capacity increase trends. Unlike the solid‐phase gradient, the co‐precipitation strategy achieves ultra‐dispersed Mo doping, leading to super‐refined primary particles and a dense structure that reduces microcracking through internal stress dissipation. Notably, it also limits electrolyte penetration, thereby influencing the initial Li + transport kinetics. Moreover, this process induces a Li/TM cation‐ordered structure that permeates the entire bulk phase of LiNi 0.95 Co 0.04 Mo 0.01 O 2 , suppressing Li + /Ni 2+ cation disorder and mitigating intragranular/intergranular strain. These combined effects significantly enhance the structural robustness, resulting in a high discharge capacity of 204.9 mAh g − 1 at 5C. This work offers a straightforward and scalable industrial solution for enhancing the overall electrochemical performance of Ni‐rich cathodes.