Lewis Acidity Organoboron-Modified Li-Rich Cathode Materials for High-Performance Lithium-Ion Batteries

Layered Li-rich manganese-based oxides (LLMO) with high capacity are a promising cathode material. However, the capacity loss and voltage decay issues hinder its application. Herein, Lewis acidity material bis(catecholato)diboron (BCD) with unique Lewis basic groups and reduction ability is employed for forming surface B³⁺-doped LiMn₂O₄-type spinel structure coated and (BO₃)^3–-doped LLMO (SLLMO), which efficiently protects the surface and adjusts the electronic structure of M-O (M = Mn, Co, Ni) bond of LLMO. Furthermore, the Jahn–Teller effect of coating layer is suppressed by B³⁺ doping, the oxygen release is alleviated by hindering the formation of oxygen electronic holes and the layered structure is stabilized by high energy of B-O bonding. After modification, the diffusion rate of Li-ion and the stability of the LLMO are significantly improved. As a result, the SLLMO electrode exhibits excellent rate and cycle performance with a capacity retention of 97% (224 mAh g⁻¹) at 0.5 C after 100 cycles and 72.5% (151.8 mAh g⁻¹) at 1 C after 400 cycles. This work provides a novel and effective strategy to modify LLMO, which broaden its pathways toward practical applications.