ScholarWorks@성균관대학교

초록

Sulfide-based all-solid-state batteries (ASSBs) garner significant attention because of safety and high ionic conductivity of sulfide electrolytes (SSEs). However, the direct application of sulfide SSEs is hampered by reactivity at the sulfide SSE/cathode active material (CAM) interface and solid–solid interfacial resistance. Ionically conductive inorganic oxides or polymers can be used to coat the CAM surface and stabilize the interface; however, single-material coatings have several limitations. Here, we report a hybrid CAM coating combining inorganic oxide and organic polymer. Rate capability and cycling stability analysis reveal an optimal inorganic-to-organic coating ratio of 0.1:2.0 wt%. Surface and interfacial property analyses of the composite cathode reveal that the optimized hybrid coating mitigates mechanical stress and void formation and suppresses interfacial reactivity. The cells demonstrate a cycle retention of 83% after 100 cycles, improving long-term cycle performance and avoiding rate capability degradation. The proposed hybrid coating effectively resolves the issues at the CAM/sulfide SSE interface associated with organic or inorganic coatings alone, and provides a strategy for developing more stable sulfide-based ASSBs.

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