In-situ generation of high performance thiol-conjugated solid polymer electrolytes via reliable thiol-acrylate click chemistry

A kind of high performance thiol-conjugated solid polymer electrolytes is in situ generated via a facile thiol-acrylate Michael addition reaction between ethylene glycol dimethacrylate (EGDMA) and 3,6-dioxa-1,8-octane dithiol (DODT) without UV irradiation or thermal initiation. The resulting amorphous linear polymer P(EGDMA-DODT) has a high average molecular weight of 47,000 Da with a low glass transition temperature of −50 °C. The in-situ generated P(EGDMA-DODT) solid polymer electrolyte exhibits room temperature ionic conductivity up to 2.7 × 10 −5  S cm −1 with a high lithium ion transference number above 0.40 and electrochemical stability window up to 4.3 V vs. Li/Li + . Advantages of longer C–S bond length (1.81 Å), lower electronegativity (2.58) and moderate coordination facilitate the segment motion and contribute to higher room temperature ionic conductivity . It is demonstrated that the all-solid-state LiFePO 4 /Li cells using the in-situ generated P(EGDMA-DODT) electrolytes delivers considerable specific capacities, rate capability and excellent cyclic performance at room temperature. These results demonstrate that this thiol-acrylate click chemistry without UV irradiation or thermal initiation is a facile and intriguing strategy for in-situ preparing high performance solid polymer electrolytes .