Single-Crystal-Layered Ni-Rich Oxide Modified by Phosphate Coating Boosting Interfacial Stability of Li₁₀SnP₂S₁₂-Based All-Solid-State Li Batteries

All-solid-state lithium batteries (ASSLBs) adopting sulfide electrolytes and high-voltage layered oxide cathodes have moved into the mainstream owing to their superior safety and immense potential in high energy density. However, the poor electrochemical compatibility between oxide cathodes and sulfide electrolytes remains a challenge for high-performance ASSLBs. In this study, a nanoscale Li1.4Al0.4Ti1.6(PO4)(3) (LATP) phosphate coating is reasonably constructed on the surface of single-crystal LiNi0.6Co0.2Mn0.2O2 particles to achieve cathode/electrolyte interfacial stability. The conformal LATP layer with inherent high-voltage stability can effectively suppress the oxidation decomposition of the electrolyte and demonstrate chemical inertness to both the oxide cathode and Li10SnP2S12 electrolyte. ASSLBs with an LATP-modified cathode exhibited a high initial discharge capacity (152.1 mAh g(-1)), acceptable rate capability, and superior cycling performance with a capacity retention of 87.6% after 100 cycles at 0.1 C. Interfacial modification is an effective approach for achieving high-performance sulfide-based ASSLBs with superior interfacial stability.