Sulfide All‐Solid‐State Battery with Ultrahigh Nickel Layered Oxide Cathode and Capacity

Abstract The application of nickel‐rich layered oxide cathodes to sulfide all‐solid‐state batteries (SASSBs) is the most promising way to achieve high capacity, high energy density, and high safety. However, the disadvantages of the space charge layer, elemental diffusion, and poor interfacial contact lead to excessive interfacial impedance. Herein, a hybrid coating of LPO and LBO is designed for NCM cathode with 95% Ni content. The hybrid coating not only improves the ionic conductivity and Li ⁺ migration efficiency of the surface layer, but also improves the mechanical strength and effectively mitigates the stress–strain effect of the cathode during long‐term cycling. SC‐NCM92@LPO+LBO||Li ₆ PS ₅ Cl||Li‐In SASSB delivers a high specific discharge capacity of 220.5 mAh g ⁻¹ with excellent high‐rate performance. SC‐NCM95@LPO+LBO||Li ₆ PS ₅ Cl||Li‐In SASSB presents a high specific capacity of 253.3 mAh g ⁻¹ excellent high‐rate performance (137.9 mAh g ⁻¹ at 10C) and cycling stability, maintaining its electrochemical performance under various conditions. This work provides a valuable reference for the application of ultrahigh nickel‐layered oxide cathodes in SASSBs.