Sulfide-Based All-Solid-State Lithium-Sulfur Batteries: Challenges and Perspectives

Lithium-sulfur batteries with liquid electrolytes have been obstructed by severe shuttle effects and intrinsic safety concerns. Introducing inorganic solid-state electrolytes into lithium-sulfur systems is believed as an effective approach to eliminate these issues without sacrificing the high-energy density, which determines sulfide-based all-solid-state lithium-sulfur batteries. However, the lack of design principles for high-performance composite sulfur cathodes limits their further application. The sulfur cathode regulation should take several factors including the intrinsic insulation of sulfur, well-designed conductive networks, integrated sulfur-electrolyte interfaces, and porous structure for volume expansion, and the correlation between these factors into account. Here, we summarize the challenges of regulating composite sulfur cathodes with respect to ionic/electronic diffusions and put forward the corresponding solutions for obtaining stable positive electrodes. In the last section, we also outlook the future research pathways of architecture sulfur cathode to guide the develop high-performance all-solid-state lithium-sulfur batteries.