Progress and Perspective of Solid-State Lithium-Sulfur Batteries

Due to high energy density, low cost, and nontoxicity, lithium-sulfur (Li-S) batteries are considered as the most promising candidate to satisfy the requirement from the accelerated development of electric vehicles. However, Li-S batteries are subjected to lithium polysulfides (LiPSs) shuttling due to their high dissolution in liquid electrolyte, resulting in low columbic efficiency and poor cycling performance. Moreover, the Li metal as an indispensable anode of Li-S batteries shows serious safety issues derived from the lithium dendrite formation. The replacement of liquid electrolytes with solid-state electrolytes (SSEs) has been recognized as a fundamental approach to effectively address above problems. In this review, the progress on applying various classes of SSEs including gel, solid-state polymer, ceramic, and composite electrolytes to solve the issues of Li-S batteries is summarized. The specific capacity of Li-S batteries is effectively improved due to the suppression of LiPSs shuttling by SSEs, while the rate and cycling performance remain relatively poor owing to the limited ionic conductivity and high interfacial resistance. Designing smart electrode/electrolyte integrated architectures, enabling the high ionic transportation pathway and compatible electrode/electrolyte interface, may be an effective way to achieve high performance solid-state Li-S batteries.