Lithium-ion conducting sulfide solid electrolytes are promising candidates for all-solid-state lithium ion batteries, which are being developed to meet the increasing demand for high-capacity rechargeable batteries. In this study, a new type of solid electrolyte with a core–shell structure consisting of oxidized-shell surrounding sulfide solid electrolyte (O-SSE) was developed. The influence of the surface oxidation of 80Li₂S·20P₂S₅ glass–ceramic electrolyte on a battery using 4 V class cathode material was investigated. The results of X-ray photoelectron spectroscopy depth profiling confirmed that >80% of the surface of the O-SSE was oxidized from PS bonds to PO bonds, and the oxygen remained localized at the surface. The interfacial resistance between the sulfide solid electrolyte and LiNi_0.8Co_0.15Al_0.05O₂ (NCA) was significantly decreased by this surface oxidation. The ASSB cell using O-SSE as a cathode solid electrolyte exhibited better discharge performance than 80Li₂S·20P₂S₅ glass–ceramic electrolyte and could discharge at a high current density of 2.0 mA·cm⁻². These results demonstrate that surface oxidation of a sulfide solid electrolyte is a new and effective method for reducing the interfacial resistance between the cathode material and solid electrolyte and improving the charge–discharge performance.

锂离子导电硫化物固体电解质是全固态锂离子电池的有前途的候选者，目前正在开发锂离子电池以满足对大容量可充电电池不断增长的需求。在这项研究中，开发了一种新型的具有核-壳结构的固体电解质，该结构由氧化壳周围的硫化物固体电解质（O-SSE）组成。研究了80Li ₂ S·20P ₂ S ₅玻璃陶瓷电解质的表面氧化对使用4 V级正极材料的电池的影响。X射线光电子能谱深度剖析的结果证实，> 80％的O-SSE表面被P S键氧化成PO键，并且氧保持局限在表面。通过该表面氧化，硫化物固体电解质与LiNi _0.8 Co _0.15 Al _0.05 O ₂（NCA）之间的界面电阻显着降低。使用O-SSE作为阴极固体电解质的ASSB电池比80Li ₂ S·20P ₂ S ₅玻璃陶瓷电解质具有更好的放电性能，并且可以在2.0 mA·cm ^{- 2}的高电流密度下放电。这些结果表明，硫化物固体电解质的表面氧化是减少阴极材料与固体电解质之间的界面电阻并改善充放电性能的一种新的有效方法。