Synergistic Bulk-to-Surface Modification of Ni-Rich Cathodes for High-Performance Lithium-Ion Batteries

Abstract

Ni-rich layered cathodes are key materials for next-generation lithium-ion batteries (LIBs) aiming for a higher energy density and lower cost. However, their bulk and interface structural instability significantly impair their electrochemical performance, hindering their widespread application. Herein, we report a bulk-to-surface modification strategy for Ni-rich cathodes by Ti doping and Gd₂O₃ surface coating (NCMT@Gd₂O₃). In this work, Ti doping and Gd₂O₃ coating synergistically suppress cation mixing, lattice oxygen loss, and surface side reactions, thereby enhancing the structural and electrochemical stability, particularly under high-voltage operation (≥4.5 V). As a result, the NCMT@Gd₂O₃ cathode demonstrates excellent electrochemical performance with a high discharge capacity of 194.14 mAh g^–1 and a high capacity retention ratio of 89.69% after 100 cycles (1C, cutoff voltage of 4.5 V). This work paves the way for the development of next-generation high-energy-density LIBs.