Low-temperature high-conductivity polyether electrolyte and preparation method thereof

Abstract

The application provides a low-temperature high-conductivity polyether electrolyte and a preparation method thereof. The polyether crosslinking network is formed by crosslinking polyethylene glycol monomethyl ether methacrylate and polyethylene glycol diacrylate, tri(pentafluorophenyl)borane and lithium salt are introduced to form a borane-lithium salt complex system, the molar ratio of lithium ions to borane is accurately controlled to be 1:0.02-0.20, and the acetonitrile complexing-vacuum desolventizing-in-situ polymerization curing process is used, so that the high-purity thin film electrolyte with the ion conductivity ≥1*10 ‑4 S / cm, residual acetonitrile ≤500 ppm and moisture ≤1000 ppm at low temperature is realized, technical problems that the low-temperature conduction capacity decreases when the crosslinking modulus of the traditional polyether electrolyte is improved, the processing window of the high-lithium salt system is narrow, and the interface stability of residual solvent and moisture is difficult to consider are effectively solved, and the low-temperature performance, processing stability and wide solid-state lithium battery application prospect are excellent.

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