PMMA添加量对PVDF-HFP聚合物电解质结构及性能的影响

Effect of PMMA Addition on Characterization and Electrochemical Performance of PVDF-HFP

采用溶剂挥发法,以丙酮和DMF做混合溶剂制备PVDF-HFP/PMMA聚合物电解质,通过X射线衍射、热失重分析、交流阻抗、恒流充放电循环及倍率充放电等测试手段,考察了PMMA的添加量对聚合物电解质性能的影响.研究发现当PMMA的添加量为50%时,聚合物电解质表现出最佳性能,室温离子电导率从0.26 m S/cm提升到1.35 m S/cm,以Li Co O2作正极材料,锂片作负极材料组装的聚合物锂离子电池初始容量从80.1 m Ah/g提升到143.6 m Ah/g,在0.2 C倍率条件下,50个循环后容量保持率还能达到80%,表现出优异的锂离子电池性能.

The different addition of PVDF-HFP/PMMA films are prepared with different concentrations by solvent evaporation method. As an electrochemical the films are characterized by using X-ray diffraction （ XRD）, thermo gravimetric analysis （ TGA）, electrochemical impedance spectroscopy （EIS） and lithium ion batteries performance test. It is found that the 50% content of PMMA polymer electrolyte can lead to the enhancement on ionic conductivity increasing from O. 26 mS/cm to 1.35 mS/cm at room tempera- ture. What＇s more, LiCoO2/Li ceils with PVDF-HFP/PMMA exhibit good C-rate performances which are confirmed by AC impedance results, which shows a remarkable enhancement in the interfacial compatibility between the PVDF-HFP/PMMA and the electrode. These results show that it is of great potential application in polymer lithium ion batteries.