In Situ Coating of Li7P3S11 Electrolyte on CuCo2S4/Graphene Nanocomposite as a High-Performance Cathode for All-Solid-State Lithium Batteries.

A cathode material, CuCo2S4/graphene@10%Li7P3S11, is reported for all-solid-state lithium batteries with high performance. The electrical conductivity of CuCo2S4 is improved by compounding with graphene. Meanwhile, Li7P3S11 electrolyte is coated on the surface of CuCo2S4/graphene nanosheets to build an intimate contact interface between the solid electrolyte and the electrode effectively, facilitating lithium-ion conduction. Benefitting from the balanced and efficient electronic and ionic conductions, all-solid-state lithium batteries using CuCo2S4/graphene@10%Li7P3S11 composite as cathode materials demonstrate superior cycling stability and rate capabilities, exhibiting an initial discharge specific capacity of 1102.25 mAh g-1 at 50 mA g-1 and reversible capacity of 556.41 mAh g-1 at a high current density of 500 mA g-1 after 100 cycles. These results demonstrate that the CuCo2S4/graphene@10%Li7P3S11 nanocomposite is a promising active material for all-solid-state lithium batteries with superior performances.