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　LiFePO4/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.　©　2020　Elsevier　B.V.