In-situ polymerization with dual-function electrolyte additive toward future lithium metal batteries

As a promising choice of next-generation energy storage system, high-energy lithium metal batteries (LMBs) are facing degradation and safety problems mainly caused by undesired side reactions and growth of lithium dendrite. Thus, electrode design, modification of electrode interphase and electrolyte have therefore become key issues for future LMBs. Herein, we report that introducing a dual-function electrolyte additive, tin trifluoromethanesulfonate (Sn(OTf)2), into DOL-based electrolyte can in-situ fabricate poly(1,3-dioxolane) gel polymer electrolyte and a Li–Sn alloy anode interphase. The formed quasi-solid LMB utilizing various cathodes, including LiFePO4, sulfide, and LiCoO2, presents low internal resistance, robust and compatible interface as well as satisfying thermal, mechanical, and electrochemical stability even in air. This work provides a facile and accessible approach to manufacture qualified quasi-solid LMBs with improved safety and elongated lifetime.