Construction of Multifunctional Conductive Carbon-Based Cathode Additives for Boosting Li6PS5Cl-Based All-Solid-State Lithium Batteries

• A novel 'conversion-protection' strategy is introduced to mitigate interfacial degradation in all-solid-state lithium batteries. • The Mo3Ni3N nanosheets on N-doped porous carbon (Mo-Ni@NPCs) effectively suppress hydroxide-induced decomposition of sulfide electrolytes. • In situ formation of MoS2-Mo3Ni3N heterostructures enhances electron and Li+ ion transport at cathode interfaces. • The optimized Mo-Ni@NPCs enable high capacity retention (90.62% after 1000 cycles) and excellent Coulombic efficiency (94.01%).