Insights into Homogenous Bulk Boron Doping at the Tetrahedral Site of NCM811 Cathode Materials: Structure Stabilization by Inductive Effect on TM-O-B Bonds

Abstract

Rechargeable lithium-ion batteries (LIBs) are critical for enabling sustainable electrochemical energy storage. The capacity of cathode materials is a major limiting factor in the LIB performance, and doping has emerged as an effective strategy for enhancing the electrochemical properties of nickel-rich layered oxides such as NCM811. In this study, boron was successfully incorporated onto a tetrahedral site of NCM811 through a co-precipitation method using a Couette-Taylor Flow Reactor (CTFR). The outcome of this homogeneous bulk boron incorporation onto a tetrahedral site led to an inductive effect on TM (transition metal)-O-B bonds, resulting in a delay of structural collapse and a decrease in oxygen release. Consequently, these changes culminated in an enhancement of cycling performance, translating to an initial specific capacity of 210 mAh g− 1 and a 95.3% capacity retention after 100 cycles. These interesting findings deepen our understanding of boron doping and shed light on the design of better lithium cathode materials on an applicable scale.