以聚乙烯醇(PVA)和二氧化锆(ZrO2)为成膜骨架材料和功能填料,利用相转化法制备PVA-ZrO2复合微孔锂电隔膜。通过微观形貌、孔隙率、电解液亲和性、耐热性及电化学性能等对其进行表征,考察ZrO2添加量对隔膜性能的影响,并评价隔膜的电池循环性能和倍率性能。结果表明,当PVA的浓度为10%、ZrO2的添加量为1.5%时,复合隔膜的电解液润湿性和热稳定性较好,其电解液接触角仅为6°,吸液率达到210%,160℃下热收缩率几乎为0。该隔膜装配电池的倍率容量和循环容量保持性优异,16C电流下的放电容量为0.2C电流的50%,循环100次后容量保持约96%,优于聚烯烃隔膜。
Polyvinyl alcohol (PVA) and zirconium dioxide (ZrO2) were used as the matrix material and the functional filler,respectively.PVA-ZrO2 composite separator for Li-ion battery was prepared by a phase inversion method.The PVA-ZrO2 were characterized by morphology,porosity,electrolyte wettability,heat resistance and electrochemical performances.The effects of ZrO2 filler on the performance of the composite separator were investigated.Results shown that when the solution was consisted of 10% PVA,1.5% ZrO2 particles and 88.5% water,the composite separator possessed excellent electrolyte wettability and thermal stability,the contact angle was only 6° and the electrolyte uptake was 210%.Moreover,the thermal shrinkage was about zero at 160℃.Based on the above advantages,the battery assembled with the optimized composite separator exhibited superior rate capacity retention and cycling capacity retention,for example the discharge capacity at 16C was about 50% of that at 0.2C,and the cycling capacity retention after 100 cycles was about 96.4%,which was obviously better than those of the polyolefin-based separators.
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