Surface-Reconstructed High-Nickel Cathodes for Ultrastable 4.5 V Tolerant Sulfide-Based All-Solid-State Batteries

Abstract

Sulfide solid-state electrolytes combined with high-nickel cathodes present a compelling option due to their high safety and high energy density at high voltages. However, the practical implementation remains challenging, particularly concerning the cathode structural degradation and the unfavorable interfacial reaction between the cathode and the sulfide solid electrolyte. To tackle these issues, we propose a surface reconstruction approach to convert the residual lithium compounds on the surface of LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) particles into a uniform Li₃VO₄ coating (LVO-NCM). Benefiting from the suppressed interfacial side reactions and enhanced structural stability at high cutoff voltages, all-solid-state batteries (ASSBs) with LVO-NCM demonstrate an impressive cyclic stability at 4.5 V. The capacity retention after 2000 cycles is 80.0%, and even after a cycle duration of 270 days, the capacity retention remains as high as 86.24%. This work provides a promising strategy to stabilize the high-nickel cathode–sulfide electrolyte interface, boosting the development of high-energy-density all-solid-state batteries.