In-situ construction of tetraethylene glycol diacrylate based gel polymer electrolyte for long lifespan lithium metal batteries

Replacing the liquid electrolytes with polymer electrolytes is an irresistible trend to meet the application requirement of lithium metal batteries. However, for obtaining a better cycling performance, traditional polymer electrolytes typically need to be operated at high temperature, which limits the commercialization of next-generation lithium metal batteries. Here, a flexible gel polymer electrolyte (TGD-TCGG-PAN) is constructed in polyacrylonitrile (PAN) porous spinning membrane via the in-situ free radical polymerization. At 30 °C, the lithium-ion conductivity and lithium-ion transference number of TGD-TCGG-PAN are 1.57 × 10−4 S cm−1 and 0.72, respectively. The LFP|TGD-TCGG-PAN|Li battery can cycle at 3C for more than 700 cycles with a capacity retention rate of 95.02%. Compared with commercial PE membrane, application of PAN makes the TGD-TCGG-PAN perform a better thermal stability. This new process is a viable way for lithium metal batteries using gel polymer electrolyte.