二次锂电池用PVDF-HFP/SiO2复合聚合物隔膜的研究

采用倒相法制备了二次锂电池用的聚偏氟乙烯–六氟丙烯复合聚合物(PVDF-HFP/SiO₂)隔膜，测定了它的吸液率、电导率、机械强度等性能，并通过扫描电镜对其形貌进行了分析。研究结果表明， PVDF-HFP/SiO₂隔膜具有较高的吸液率、电导率和韧性：电解质吸收率达184.4%、 室温电导率为1.20mS/cm、断裂伸长率高达163%。利用PVDF-HFP/SiO2隔膜装配的二次锂电池的首放比容量为834.8mAh/g，第40次的放电比容量达到400mAh/g, 循环效率达到99.8%以上，表现出良好的电化学性能。

Study of PVDF-HFP/SiO2 Composite Polymer Separator for Rechargeable Lithium Battery

A polymer(PVDF-HFP) separator and a composite polymer(PVDF-HFP/SiO_2) separator were prepared by the phase-inversion method.The electrolyte uptake,conductivity and mechanical properties of the separators were studied,and the corresponding micro-structures were examined by SEM.The PVDF-HFP/SiO_2 separator exhibits much higher electrolyte uptake,conductivity and ductibility with an electrolyte uptake volume of 184.4%,a conductivity of 1.2 mS/cm and ductibility of 163%.When the PVDF-HFP/SiO_2 separator is employed in a lithium battery a good cycle performance and a high cycling efficiency are observed.The first discharge specific capacity is 834.8 mAh/g,the 40th cycle discharge capacity is 400 mAh/g and the average charge/discharge efficiency is above 99.8%.