Effectively stabilizing electrode/electrolyte interface of high-energy LiNi_0.9Co_0.1O₂//Si–C system by simple cathode surface-coating

Despite the high energy density, LiNi_0.9Co_0.1O₂//Si–C batteries suffer from severe structural instability of electrodes and their interfaces with electrolyte, leading to rapid performance degradation. Here we report a simple surface-coating method for constructing a multifunctional aminosilica-like skin on LiNi_0.9Co_0.1O₂ cathodes using coordination mechanism. The conformal aminosilica-like skin provides fast Li-ion and charge transport channels at the cathode surface, significantly suppresses undesired layered to spinel/rock-salt phase transformations and dissolution of transition metals from the cathode and subsequent migration to anode, and effectively stabilizes both cathode/electrolyte and anode/electrolyte interfaces as well as the bulk electrodes. This approach remarkably enhances the cyclability of LiNi_0.9Co_0.1O₂//Si-Graphite full-cell, which shows a high reversible capacity of 200 mAh g⁻¹ and stable cycling performance (83% retention for 300 cycles at 1 C rate). This simple, efficient and environmentally friendly cathode surface-engineering offers a promising design strategy for high-energy Li-ion batteries.