Stabilizing the Interphase\nin an Ultra-High-Nickel\nCathode Enabling High-Performance Lithium-Ion Batteries

High-nickel (Ni ≥ 90%) cathodes which have a high\nspecific\ncapacity hold great potential for next-generation lithium-ion batteries\n(LIBs). However, their practical application is restricted by their\nhigh interfacial reactivity because of the presence of residual lithium\n(Li) compounds on the surface. Herein, the LiNi<sub>0.9</sub>Co<sub>0.06</sub>Mn<sub>0.04</sub>O<sub>2</sub> (NCM90) cathode is surface-modified\nwith sulfur (S) via a simple and feasible dry mixing and low-temperature\nheat treatment, converting the residual lithium compound on the surface\ninto inactive lithium sulfate (Li<sub>2</sub>SO<sub>4</sub>). This\ninduces the formation of a stable inorganic enriched electrode–electrolyte\ninterface on the cathode surface and inhibits the occurrence of side\nreactions, ultimately inhibiting lattice collapse and the dissolution\nof transition metal ions. After modifying, the capacity retention\nrates of NCM90/Li and NCM90/graphite cells are both greatly enhanced\nafter long cycling. This work provides a new idea for the rational\ndesign of the electrode–electrolyte interface of high-nickel\ncathodes.