直接挥发法制备无纺布增强型聚合物电解质

以N,N-二甲基-甲酰胺(DMF)为溶剂, 采用直接挥发法制备无纺布增强型聚偏氟乙烯-六氟丙烯(PVDF-HFP)聚合物电解质, 并以锂为负极制备了聚合物电池.用扫描电子显微镜、交流阻抗和循环伏安对所制聚合物膜性能进行了表征,用充放电实验对所制聚合物电池电化学性能进行了测试.实验结果表明,直接挥发法制得的聚合物膜孔穴丰富,微孔呈蜂窝状,吸液率为280%,电化学稳定窗口为4.5V,浸取电解液后室温离子电导率为1.5mS/cm;以LiCoO2为正极制得的聚合物电池0.1C充放电, 放电平台为3.9V左右, 首次放电容量为137.5mAh/g,20次循环后容量保持在134mAh/g以上,充放电库仑效率高于95%,0.5C放电时放电平台为3.7V,0.5和1C放电分别能保持0.1C放电容量的96%和93%.

Preparation of non-woven fabrics reinforced polymer electrolyte by evaporation

A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene(PVDF-HFP) was prepared by evaporation solvent of dimethyl formamide(DMF),and the polymer electrolyte was reinforced by non-woven fabrics.Lithium-ion polymer batteries were assembled by using LiCoO_2 as cathode material.The polymer mambrane's morphologies and its electrochemical properties were studied by scanning electron microscopy,ac impedance and cyclic voltammetry test.Experimental results show that: this polymer membrane has rich microporous and exhibits 280% uptake of electrolyte solution.The electrochemical stability window of this polymer electrolyte is 4.5V,and its ionic conductivity at room temperature reaches 1.5mS/cm.The polymer Lithium battery displays an initial discharge capacity of 137.5mAh/g and discharge plateau of about 3.9V at 0.1 current rate.After 20 cycles,its discharge capacity is 134mAh/g,and coulombic efficiency is above 95%.When discharging at 0.5C,the voltage plateau is still 3.7V.The discharge capacity of 0.5 and 1C is 96% and 93% of the discharge capacity of 0.1C,respectively.