Boosting the Electrochemical Properties of LiNi _0.90 Co _0.05 Mn _0.05 O ₂ Cathode Materials via In Situ Constructed Li ₃ VO ₄ Surface Coating

Nickel-rich cathode materials are widely valued for their high-energy-density and elevated voltage platform. Nevertheless, their limited cycling stability and rate performance significantly restrict their large-scale application in lithium–ion batteries. Herein, the electrochemical performance of LiNi0.90Co0.05Mn0.05O2 was enhanced by the in situ formation of a Li3VO4 coating layer on its surface. LiNi0.90Co0.05Mn0.05O2 was first synthesized by cofiring coprecipitated nickel–cobalt-manganese hydroxide precursor with LiOH·H2O. Subsequently, a dense Li3VO4 modification layer was formed on the LiNi0.90Co0.05Mn0.05O2 surface via a wet chemical method. The modified cathode material exhibits an excellent rate performance (specific discharge capacity of 185.8 mAh·g–1 at 10 C) and superior capacity retention (75.86% after 300 cycles at 2.7–4.5 V). The excellent electrochemical performance of the modified material is attributed to the in situ formation of Li3VO4 on its surface. This formation results in a dense protective layer and stabilizes the material structure. It also inhibits particle cracking, harmful rock-salt phase formation, and lattice distortion during cycling. This coating improves surface and interface properties, accelerates charge transfer kinetics, and reduces electrochemical polarization. This protective layer isolation of the electrode from direct electrolyte contact suppresses electrolyte decomposition and side reactions. Consequently, the Li3VO4 coating exerts synergistic effects, comprehensively enhancing cycling stability and rate capability. This method, based on the in situ growth of protective layers on the surface, provides an advanced and effective strategy for modifying cathode materials, offering valuable guidance for addressing structural and interfacial instability in other high-energy-density rechargeable batteries.