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

Rechargeable lithium-ion batteries (LIBs) are critical for enabling sustainable 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 is homogeneously incorporated into the tetrahedral site of NCM811 through co-precipitation, leading to an inductive effect on transition metal (TM)-O-B bonds that delayed structural collapse and reduced oxygen release. Consequently, these changes culminate in an enhancement of cycling performance, translating to an initial specific capacity of 210 mAh g and a 95.3% capacity retention after 100 cycles. These interesting findings deepen the understanding of boron doping and shed light on the design of better lithium cathode materials on an applicable scale.