Toward Fast-Charging Polymer-Electrolyte Based All-Solid-State Li-S Batteries: Insights into Limiting Factors and Perspectives.

The pursuit for high-energy, fast-charging all-solid-state lithium-sulfur batteries (ASSLSBs) has intensified due to the increasing demand of next-generation energy storage devices for electric vehicles. Polymer-based solid electrolytes (PSEs) have distinct advantages, including mechanical flexibility, interfacial adaptability, and processability; however, their inherent limits in ionic conductivity, interfacial stability, and polysulfide shuttling impede fast charge-discharge performance. This perspective scrutinizes the primary challenges influencing fast-charging features of PSE-based ASSLSBs, such as constrained lithium-ion transport pathway, polysulfide shuttling, and elevated interfacial polarization. Also, the recent advancements in polymer molecular design, composite engineering, and interfacial modification are outlined, highlighting approaches to attain high ionic conductivity, increased Li-ion transference number, and stable electrode-electrolyte interfaces are addressed. Further, research directions for adaptive, high-rate ASSLSBs are explored, including design strategies for increasing the ionic conductivity, mitigating polysulfide shuttling and designing a stable interface. Moreover, a comprehensive design framework that incorporates ion-transport optimization, chemical selectivity, and interface engineering is proposed to facilitate stable and dendrite-free fast-charging ASSLSBs. We believe this perspective offers a comprehensive overview of the progression of PSEs for practical, high-power Li-S batteries, connecting laboratory advancements with practical applications.