Strategies to Boost Ionic Conductivity and Interface Compatibility of Inorganic - Organic Solid Composite Electrolytes

All-solid-state electrolytes have attracted widely attentions due to their adequate safety assurance, which demonstrates great potential in high energy batteries with lithium metal anode. In the view of practical application, the inorganic-organic solid composite electrolytes (SCEs) show most promising because of their excellent processability. However, poor ionic conductivity and unstable interface between electrodes and solid electrolytes hinder their development. In this review, we summarized the strategies to improve the ionic conductivity of the active inorganic fillers based SCEs and interface compatibility between electrodes and solid electrolytes. Tuning the physical-chemical properties (concentration, geometry, orientation and etc.) of the fillers, surface decoration and small-molecular additives can regulate polymer crystallization kinetics and trigger fast Li-ions transport pathways, which promotes the ionic conductivity. To ameliorate interfacial performance, the approaches mainly involve designing multilayered SCE with symmetric or asymmetric configuration, utilizing chemical interactions and liquid phase therapy, and blending of polymers with various molecular weights and functional groups to ameliorate interface contact, prevent the interface reaction and inhibit lithium dendrites. We hope this review can provide deeply understanding and guidance on the design of SCEs for all-solid-state lithium metal batteries.