Materials and chemistry design for low-temperature all-solid-state batteries

All-solid-state batteries (ASSBs) have garnered significant interest due to their exceptional safety features and high theoretical energy density. Despite extensive research demonstrating the impressive electrochemical performance of ASSBs at moderate and high temperatures, their electrochemical performance significantly degrades in a cold environment, with the underlying mechanism yet to be disclosed. In this review, we examine the ion transport kinetics of ASSBs and emphasize the challenges they face at low temperatures. By examining microscopic kinetic processes, including Li-ion migration within solid electrolytes (SEs), interfacial charge transfer, and bulk electrode diffusion, we outline the critical challenges and specific requirements on SEs, interfaces, and electrodes for low-temperature ASSBs. Based on these insights, a range of materials and chemistry design strategies for high-performance ASSBs at low temperatures are reviewed. Finally, future research directions for improving low-temperature ASSB performance are proposed. This study aims to offer a thorough understanding and crucial insights to improve the low-temperature performance of ASSBs.