In-situ plasticized polymer electrolyte with double-network for flexible solid-state lithium-metal batteries

Flexible solid polymer electrolyte (SPE) confers lithium-based batteries with high energy densities and diverse packaging. However, the application of SPE is hindered by the contradiction between ionic conductivity and mechanical strength. Herein, this issue can be effectively addressed by constructing an in-situ plasticized SPE with double-network (DN-SPE) through reasonably controlling the chain length of constitutional unit. With the self-plasticization of its double network, the bendable DN-SPE exhibits increased ionic conductivity (from 10-5 to 10-4.5 S cm-1 at room temperature), high thermal stability (up to 200 °C) and good capacity to suppress the growth of lithium dendrite. The resultant solid-state lithium-metal batteries exhibit admirable reversible specific capacity. Notably, pouch cells maintain their electrochemical functions well even under stringent bending and truncated conditions. Structural modulation of the in-situ plasticized DN-SPE demonstrates an effective strategy to enhance the ion conductivity of SPE and might grasp new insights into flexible solid-state lithium-metal batteries.