Countering Voltage Decay, Redox Sluggishness, and Calendering Incompatibility by Near‐Zero‐Strain Interphase in Lithium‐Rich, Manganese‐Based Layered Oxide Electrodes

Abstract

AbstractLithium‐rich, manganese‐based layered oxides are considered one of the most valuable cathode materials for the next generation of high‐energy density lithium‐ion batteries (LIBs) for their high specific capacity and low cost. However, their practical implementation in LIBs is hindered by the rapid voltage/capacity decay on cycling and the long‐standing contradictions between redox kinetics and volumetric energy density due to their poor calendaring compatibility. Herein, a coherent near‐zero‐strain interphase is constructed on the grain boundaries of cathode secondary particles by infusing LiAlO2 material through the reactive infiltration method (RIM). Theoretical calculations, multi‐scale characterizations, and electrochemical tests show that this coherent interphase with near‐zero‐strain feature upon electrochemical (de)lithiation inhibits volume changes of the lattice and structural degradation of cathode primary particles during cycling. More importantly, the ionically conductive LiAlO2 nanolayer infiltrated in the grain boundaries of cathode secondary particles can not only promote the rapid Li+ migration and act as a barrier to protect the material from the corrosion of the electrolyte but also effectively improve the mechanical strength of the cathode secondary particles. Collectedly, the LiAlO2‐infiltrated cathode materials display superior electrochemical cyclability, enhanced rate capability, and industrial calendaring performance, marking a significant step toward commercial implementation.