UV-Cured Semi-Interpenetrating polymer networks of solid electrolytes for rechargeable lithium metal batteries

A semi-interpenetrating solid state polymer networks electrolytes (SISPEs) for rechargeable lithium metal batteries is proposed. • Semi-interpenetrating polymer solid electrolytes (SISPEs) with are synthesized via ultraviolet light curing. • The PVEC segment of the SISPEs can ensure high ionic conductivity. • The semi-interpenetrating polymer networks enhance the mechanical properties. • The LFP||SISPEs||Li cells exhibit a long-term stability and excellent cycling performance. Electric vehicles and portable electronics pose an insatiable demand for safe and high-energy batteries. Herein, we report semi-interpenetrating solid state polymer networks electrolytes (SISPEs) for rechargeable lithium metal batteries. The synthesized SISPEs combine the poly(vinylethylene carbonate) (PVEC) segment containing carbonate moieties and the high molecular weight poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) with good mechanical properties. The carbonate moieties in the PVEC segment enable high ionic conductivity of 1.03 mS cm −1 at 25 0 C. The incorporation of PVDF-HFP into the semi-interpenetrating polymer networks endows SISPEs with considerable mechanical properties and long-term stability of the symmetric Li cell at a current density of 0.2 mA cm −2 for over 2000 h. As a result, the assembled LiFePO 4 ||SISPEs||Li batteries exhibit excellent cycling performance with high coulombic efficiency over 600 cycles at 0.5C. This study sheds light on rational design of high-performance composite polymeric electrolytes for rechargeable solid lithium metal batteries.