Sulphuration reduction interphase constructed by a simple solid phase to stabilize the LiCoO2/Li6PS5Cl interface in all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSLIBs) with many advantages are excellent candidates for eVTOL batteries. However, a significant challenge arises from the incompatibility between cathode materials and sulfide solid-state electrolytes (S-SSEs). To overcome this, a sulphuration reduction interphase consisting of CoO/Li 2 SO 4 /Li 2 CO 3 is formed on the surface of the cathode through a simplified sulfur-induced thermal reduction process applied to lithium cobalt oxide (LCO) in this work. The introduction of sulfur transforms the LCO surface, enhancing compatibility with S-SSEs. Consequently, ASSLIBs exhibit a notable initial capacity of 143.3 mAh g −1 at 0.2 C, with 86.19 % capacity retention after 200 cycles. Furthermore, the batteries in this study demonstrate an outstanding rate capacity of 77 mAh g −1 at 2 C (pristine sample with 0 mAh g −1 at 2 C). This evidence strongly substantiates the remarkable efficacy of the sulphuration reduction interphase in effectively mitigating interfacial reactions and ensuring rate ability. Essentially, this study opens new avenues for fostering a stable cathode/SSEs interface, providing a novel framework for designing high-performance and safe eVTOL batteries.