In Situ Polymerized Flame-Retardant Crosslinked Quasi Solid-State Electrolytes for High-Voltage Lithium Metal Batteries

The construction of poly-dioxolane (PDOL) solid-state electrolytes by in situ polymerization is an effective way to achieve high performance lithium-metal batteries. However, the poor electrochemical stability and safety issues of linear PDOL limit their further application. In this work, a multifunctional crosslinker has been introduced to construct a flame retardant crosslinked quasi solid-state electrolyte (FCDOL). Due to the synergistic effect of the crosslinked network, the prepared FCDOL achieves excellent room temperature ionic conductivity (0.72 mS cm −1 ), high Li + transference number (0.655), wide electrochemical stabilization window (4.8 V vs Li/Li + ), and impressive performance when matched with lithium metal anodes (>4000 h plating/stripping) and high-voltage cathodes, and the corresponding pouch cells can withstand abusive tests such as bending and cutting, encouraging that in situ polymerization of SPEs provides new insights into high-energy density and high-safety solid-state batteries.