Garnet conductor network with Zr doping to implement surface bifunctional modification for Ni-rich cathodes

High‑nickel oxides are promising cathode materials for next-generation lithium batteries due to their high discharge capacity. LiNi0.83Co0.11Mn0.06O2(NCM83), a polycrystalline material widely used for its excellent performance, faces challenges such as interfacial side reactions and lattice oxygen release that hinder its electrochemical performance under high voltage. To promote the high-voltage performance of NCM83, Li7La3Zr2O12, a fast ion conductor with high conductivity and a wide electrochemical window, is taken into account. Here, the oxidation reaction and element diffusion are employed during high-temperature sintering to realize dual functional modification of NCM83 materials, including La-rich conductor network construction and near-surface Zr doping. Impressively, the modified electrode shows excellent cycling performance with 82.14 % retention after 200 cycles at 2.8–4.6 V, and splendid rate capability. Detailed studies reveal that ZrO bonds inhibit the migration of transition metal ions, preventing the distortion of the material structure. The surface ionic conductor network layer provides fast Li+ diffusion channels and protects the interfacial layer from electrolyte decomposition products. The facile Li7La3Zr2O12 modification method proposed in this paper is suitable for solving the interfacial and structural stability of cathode materials, offering hope for the application of high-energy lithium-ion batteries.