Regulating Conductive Copolymerization Networks in the Polymer Electrolyte for High-Performance Quasi-Solid-State Lithium–Metal Batteries

Quasi-solid polymer electrolytes have been successfully applied to lithium–metal batteries (LMBs) and are worthy of large-scale development. However, some challenges remain in reconciling the contradiction between electrochemical properties and mechanical properties of polymer electrolytes. Herein, a kind of high-quality lithium ion-conducting polymer electrolyte PVDF-HFP/P(PEGMEMA-co-PAMPSLi-x wt %) (PPAx) has been designed and synthesized by free-radical copolymerization. The PPAx electrolytes can satisfactorily balance the contradictions between the electrochemical performance and mechanical strength by incorporating the rational P(PEGMEMA-PAMPSLi) conductive copolymerization networks. It has been found that the optimized PPA10 not only possesses a reinforced fracture strength of 25.5 MPa and fracture strain of 119.1% but also achieves a high ion transference number of 0.6, and a high ionic conductivity of 4.79 × 10–4 S cm–1 at ambient temperature. Moreover, the Li|PPA10|LFP battery can deliver a high discharge specific capacity at 139.7 mAh g–1 with a high retention rate of 87.9% after 200 cycles at 1 C. Therefore, this work provides novel insight into constructing multifunctional polymer electrolytes for practical application in next-generation LMBs.