Understanding the Synthesis Kinetics of Single‐Crystal Co‐Free Ni‐Rich Cathodes

Abstract

Non‐equilibrium kinetic intermediates are usually preferentially generated instead of thermodynamic stable phases in the solid‐state synthesis of layered oxides. Understanding the inherent complexity between thermodynamics and kinetics is important for designing high cationic ordering cathodes. Single‐crystal strategy is an effective way to solve the intrinsic chemo‐mechanical problems of Ni‐rich cathodes. However, the synthesis of high‐performance single‐crystal is very challenging. Herein, the kinetic reaction path and the formation mechanism of non‐equilibrium intermediates in the synthesis of single‐crystal Co‐free Ni‐rich were explored. We demonstrate that the formation of non‐equilibrium intermediate and the electrochemical‐thermo‐mechanical failure can be effectively inhibited by driving low‐temperature topotactic lithiation. This work provides a basis for designing high‐performance single‐crystal Ni‐rich layered oxides by regulating the defective structures.