具有三维离子迁移通道的共混凝胶聚合物电解质及其电化学性能

Blended Gel Polymer Electrolytes with Three-Dimensional Channels for Ion Transportation and Their Electrochemical Performances

采用聚合诱导相分离法,通过N-乙烯基吡咯烷酮(NVP)在偏氟乙烯-六氟丙烯共聚物(P(VDF-HFP))溶液中原位聚合生成聚乙烯吡咯烷酮(PVP),合成共混凝胶聚合物电解质(BGPE)。对共混聚合物膜的微观结构、形貌和结晶性能,BPGE的热稳定性及电化学性能进行了表征。在BGPE中,P(VDF-HFP)相起骨架支撑作用,PVP相则形成三维Li+迁移通道。当P(VDF-HFP)∶NVP质量比为2∶1时,所得样品BGPE-3的室温离子电导率为0.712×10^-3 S/cm,而且具有339℃的热分解温度和4.9 V(vs. Li^+/Li)的阳极稳定电位。研究结果表明,离子液体增塑的半互穿凝胶聚合物电解质膜可由聚合诱导相分离法简易制备,具有优异的电化学性能。

P(VFD-HFP)/PVP blended gel polymer electrolytes(BGPE) were prepared by the polymerization-induced phase separation(PIPS) method, where N-vinyl pyrrolindone(NVP) monomer was in-situ polymerized in a solution of P(VDF-HFP) in N-methyl pyrrolindone(NMP). The microstructure, morphology, and crystallinity of the blended polymer membranes were characterized as well as the thermal stability and electrochemical properties of the resultant BGPE. The synthesized PVP phase provides three-dimensional channels for the Li+ ions transportation in the BGPE while the P(VDF-HFP) phase acts as the supporting backbone. When the mass ratio of P(VDF-HFP) to NVP is 2∶1, the resultant BGPE-3 sample has a room-temperature ionic conductivity of 0.712×10^-3 S/cm, a decomposition temperature of 339 ℃ and an anodic stability up to 4.9 V(vs. Li^+/Li). It suggests that semi-interpenetrating gel polymer electrolytes plasticized with ionic liquid can be prepared facilely by the PIPS method, and the assembled batteries present excellent electrochemical performances.