新型全固态聚合物电解质PEG475-DMAA的制备及其电化学性能研究

Study on preparation and electrochemical performance of new all-solid-state polymer electrolyte PEG475-DMAA copolymer

采用无需有机溶剂的光聚合合成工艺,以聚乙二醇甲基丙烯酸酯(PEG475)为基体、N,N二甲基丙烯酰胺(DMAA)为交联剂,引入增塑剂丁二腈(SN),制备新型全固态聚合物电解质PEG475-DMAA,并对其电化学性能进行测试.结果表明:当SN的添加量为10%(质量分数)时,该电解质体系的离子电导率最大,约为4×10-5S/cm,相对于聚氧乙烯体系提高了3个数量级;该电解质的稳定窗口在5. 0 V以上,可满足目前使用的电解质体系对电压稳定性的要求;该电解质在270℃附近有良好的热稳定性;由该电解质膜组装的锂离子电池的初始容量较低与商品化锂离子电池还有比较大的差距,未来需进一步提高该电解质膜的离子电导率,改善其电化学循环性能.

A photo-polymerization synthesis process without organic solvent was used. Polyethylene glycol methacrylate （PEG475） was used as the matrix, N, N dimethyl acrylamide （DMAA） was used as the crosslinking agent, and the plasticizer succinonitrile （SN）was introduced, a new all-solid polymer electrolyte （PEG475-DMAA） was prepared and its electrochemical performance was tested. The results showed that when the addition amount of SN was 10% （mass fraction） , the ionic conductivity of the electrolyte system was the largest, about 4 × 10^（-5） S/cm, which was increased by thine orders of magnitude relative to the polyoxyethyl- ene system. The electrochemical stability window was above 5. 0 V, which satisfied the voltage stability requirements of the currently-used electrolyte system. The electrolyte had good thermal stability in the range of 270 ℃. The lithium ion battery assembled by the electrolyte membrane had a low initial capacity. There was still a big gap with commercial lithium-ion batteries. In the future, it is necessary to further improve the ionic conductivity of the electrolyte membrane and improve the electrochemical cycle performance.