多孔复合聚合物隔膜的制备及其电化学性质

Preparations and electrochemical properties of porous composite polymer membranes

采用倒相法制备了以Celgard2300隔膜为支撑体的多孔复合聚合物隔膜。通过扫描电镜对隔膜形貌进行分析,研究了干法和湿法制膜过程中孔洞形成的机理。和Celgard2300相比,复合隔膜具有较高的吸液率和保液性:湿法制备的复合隔膜吸PC(碳酸丙二醇酯)量最高,可达到自重的246%。而且放置14d后,PC损失为9%,能有效地防止漏液发生。通过交流阻抗测量,湿法的复合隔膜室温电导率达1.34×10-3S·cm-1。用复合隔膜装配电池,初次充放电效率均>86%,并且有良好的机械强度,可满足锂离子二次电池的应用要求。

The porous composite polymer membranes supported with Celgard 2300 films were prepared by phase-inversion method. The pore formation mechanisms of membranes during the preparation processes with dry and wet methods were investigated. Compared with Celgard 2300, the composite polymer membranes exhibit higher PC uptake and sustain: the membrane made with wet method shows 246% PC uptake. Moreover, the PC leakage was 9% after 14days. The good pore diameter can efficiently prevent solution leakage. Conductivity of the composite membrane made with wet method was found to be high as 1.34×10^(-3)S·cm^(-1) by AC impedance spectroscopy measurement. The batteries assembled with the composite polymer membranes with better mechanics were tested and initial charge-discharge efficiencies have as high as 86%.