柔性聚合物电解质的制备及其电化学性能

Synthesis of Flexible Polymer Electrolyte and Their Electrochemical Performances

摘要:

以丙烯酸甲酯（MA）和丙烯腈（AN）为反应单体，聚乙烯醇（PVA）为分散剂，通过改性乳液聚合法制备柔性聚合物膜。通过傅里叶红外光谱（FTIR）、扫描电镜（SEM）、力学性能测定、热分析、交流阻抗（EIS）和充放电测试对材料的物理性能化学性能进行了表征。结果表明：当m（MA）：m（AN）=23:2时，聚合物膜的抗拉强度为14.3MPa，断裂伸长率为248%，25℃时的离子电导率为0.95mS/cm。以S2作为隔膜，LiCoO2和石墨活为性材料制备2032扣式锂离子电池并测试其充放电性能，首次放电容量分别为140mAh/g和307 mAh/g，50次循环后分别为132.72和323mAh/g，说明所制备的材料具有较好的电化学性能。

Abstract:

A flexible polymer membrane was synthesized by a emulsion polymerization with methyl acrylate (MA) and acrylonitrile (AN) as monomer and polyvinyl alcohol (PVA) as stabilizer. The physicochemical property of the resultant materials were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM), mechanical strength measurements, thermal analysis, electrochemical impedance spectroscopy (EIS) and charge-discharge test. The results showed the mass ratio of MA to AN was 23:2, the polymer membrane possessed mechanical strength of 14.3MPa and elongation of 248%. And the ionic conductivity of the flexible electrolyte is 0.95 mS cm?1 at 25oC.The electrochemical performances were characterized using the S2 membrane as a separator, LiCoO2 and graphiteas cathode and anode, respectively. The battery initially delivers an initial discharge capacity of 140 mAh g?1 based on the LiCoO2active material in the cathode, 307 mAh g?1 based on graphite in the anode, and 132.7 mAh g?1and 323mAh g?1 after 50th cycle, respectively. The results indicate that the flexible polymer membrane demonstrates satisfactory electrochemical performances.