Oxygen vacancy-driven coherent interface engineering boosts carbon-coated LiNiO₂ performance

The practical application of LiNiO₂ (LNO) is hindered by structural failures such as microcrack propagation and rock-salt phase accumulation, caused by its high reactivity. This study proposes an oxygen vacancy-driven (OVD) strategy, constructing a coherent interface with a Li-containing Ti-doped rock-salt phase on the surface of LNO particles, while introducing a uniform mixed coating layer of TiO₂ and carbon. Unlike electrochemically inert NiO phase, this Li-containing Ti-doped rock-salt phase exhibits high electronic and ionic conductivities, alleviating the anisotropic stress accumulation and suppressing further rock-salt phase formation during cycling. The TiO₂ coating reduces parasitic side reactions at the cathode-electrolyte interface, while the carbon coating further enhances electron transport. As such, OVD-LNO demonstrates exceptional cycling and rate properties, achieving capacity retention of 83.0% after 400 cycles at 1 C and maintaining 188.3 mAh g^-1 at 5 C. This pre-constructed rock-salt phase interface modification strategy opens a new pathway for developing high-capacity, long-life cathodes.