Dry electrode technology for scalable and flexible high-energy sulfur cathodes in all-solid-state lithium-sulfur batteries

Abstract

All-solid-state lithium-sulfur batteries (ASSLSBs) employing sulfide solid electrolytes are one of the most promising next-generation energy storage systems due to their potential for higher energy density and safety. However, scalable fabrication of sheet-type sulfur cathodes with high sulfur loading and excellent performances remains challenging. In this work, sheet-type freestanding sulfur cathodes with high sulfur loading were fabricated by dry electrode technology. The unique fibrous morphologies of polytetrafluoroethylene (PTFE) binders in dry electrodes not only provides excellent mechanical properties but also uncompromised ionic/electronic conductance. Even employed with thickened dry cathodes with high sulfur loading of 2 mg cm−2, ASSLSBs still exhibit outstanding rate performance and cycle stability. Moreover, the all-solid-state lithium-sulfur monolayer pouch cells (9.2 mAh) were also demonstrated and exhibited excellent safety under a harsh test situation. This work verifies the potential of dry electrode technology in the scalable fabrication of thickened sulfur cathodes and will promote the practical applications of ASSLSBs.