【摘要】 以聚乙烯基吡咯烷酮(PVP)与聚偏氟乙烯-六氟丙烯[P(VDF-HFP)]的共混物为基质,通过溶剂挥发法制备聚合物微孔膜,将其浸取电解液后制成聚合物电解质并组装LiCoO2/Li聚合物锂离子电池。采用扫描电子显微镜、差热-热重分析、交流阻抗、线性伏安扫描等技术对制备的聚合物微孔膜及电解质进行表征,采用恒流充放电方法对组装的聚合物锂离子电池进行电化学性能测试。结果表明:溶剂挥发法制得的聚合物膜孔穴丰富,液态电解质吸液率可达到480%;浸取电解液后获得的聚合物电解质室温离子电导率为4.79×10-3 S/cm,电化学稳定窗口为5.5 V;基于该聚合物电解质装配的LiCoO2/Li电池在0.1C倍率充放电时,首次放电容量为142.37 mA·h/g,放电平台约为3.86 V,30次循环后容量仍保持有136.68 mA·h/g,库仑效率稳定在97%左右。更多还原

【Abstract】 A kind of microporous membrane based on the blend of PVP and P(VDF-HFP) was prepared by solvent evaporation method, and the LiCoO2/Li polymer batteries were assembled with the microporous membrane which absorbed electrolyte. The polymer membrane and electrolyte were characterized by scanning electronic morphology(SEM), differential scanning calorimeter-thermo gravimetry(DSC-TG), electrochemical impedance spectroscopy(EIS) and linear scanning voltammetry(LSV). The electrochemical performance of LiCoO2/Li polymer battery was tested by charge-discharge test with constant current. The results show that this polymer membrane has abundant micro pores and exhibits up to 480% uptake of liquid electrolyte. The ionic conductivity of the polymer electrolyte is 4.79×10-3 S/cm at room temperature and its electrochemical stable window is 5.5 V. The LiCoO2/Li battery based on the polymer electrolyte displays an initial discharge capacity of 142.37 mA·h/g and discharge plateau of about 3.86 V at 0.1C. After 30 cycles, its discharge capacity remains 136.68 mA·h/g, and coulombic efficiency stays around 97%.更多还原