Realizing high-performance all-solid-state batteries with sulfide solid electrolyte and silicon anode: A review

Sulfide solid electrolyte (SE) is one of the most promising technologies for all-solid-state batteries (ASSBs) because of its high ionic conductivity and ductile mechanical properties. In order to further improve the energy density of sulfide-based ASSBs and promote practical applications, silicon anodes with ultrahigh theoretical capacity (4,200 mAh.g(-1)) and rich resource abundance have broad commercial prospects. However, significant challenges including bulk instability of sulfide SEs and poor utilization of silicon materials have severely impeded the ASSBs from becoming viable. In this review, we first introduce the critical bulk properties of sulfide SEs and the most recent improving strategies covering the ionic conductivity, air stability, electrochemical window, mechanical stability, thermostability and solvent stability. Next, we introduce the main factors affecting the compatibility of silicon and sulfide SE, including the carbon's effect, particle size of silicon, external pressure, silicon composite matrix and the depth of silicon's lithiation. Finally, we discuss possible research directions in the future. We hope that this review can provide a comprehensive picture of the role of nanoscale approaches in recent advances in ASSBs with sulfide and silicon, as well as a source of inspiration for future research.

Automated summary

Sulfide solid electrolyte (SE) and silicon anodes play important roles in all-solid-state batteries (ASSBs), but the bulk instability of sulfide SE and poor utilization of silicon materials pose significant challenges. Improving strategies for sulfide SEs and factors affecting silicon-sulfide SE compatibility, such as carbon's effect and particle size of silicon, need to be considered.