氧化铝/聚乙烯醇涂层对聚丙烯隔膜性能的影响

Effect of Alumina/polyvinyl alcohol Layers on Performance of Polypropylene Separators

摘要:

为解决聚丙烯（PP)隔膜对电解液润湿性能差、耐热性能差的问题，选用氧化铝(Al2O3)为陶瓷填料、聚乙烯醇(PVA)为粘结剂、去离子水为溶剂制备涂覆浆料，采用刮涂法在传统PP隔膜表面涂覆上Al2O3 /PVA层。通过X射线衍射图谱(XRD)、扫描电镜（SEM）、接触角测试、润湿性能测试和耐热性能测试对改性前后隔膜进行表征，并将改性前后隔膜组装成纽扣电池进行电化学性能表征。结果表明：在PP隔膜表面成功引入Al2O3 /PVA涂层后，润湿性能和耐热性能得到明显改善，吸液率由98%提高到203%，在170℃下热处理1 h的热收缩率由46.1%减小至24.4%。与原隔膜相比，改性隔膜组装的电池的循环性能和倍率性能更好。

Abstract:

In order to improve the electrolyte wettability and thermal stability of polypropylene separator, an Al2O3-coated composite polypropylene separator was prepared with Al2O3 as ceramic particle, polyvinyl alcohol as binder and燿eionized爓ater as solvent through a direct coating process. The bare pp separator and coated pp separator were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), contact angle testing, elecrolyte wettability and thermal resistance testing. It was found that with the Al2O3/PVA layer, the electrolyte uptake of the coated separator increased from 98% to 203%, and the thermal shrinkage in 170℃ for 1 h decreased from 46.1% to 24.4%. Moreover, compared to bare PP separator, the coated PP separator exhibited better discharge C-rate capability and cycling performance when investigated in Lithium-ion Batteries.