具有功能涂层的聚乙烯锂电隔膜的制备及表征

Preparation and characterization of PE separator with functional coating for lithium-ion battery

采用浸渍法,在传统聚乙烯(PE)锂离子电池隔膜表面涂覆一层聚乙烯醇(PVA)功能涂层,通过扫描电镜(SEM)、接触角测试、吸液性测试和耐热性能测试对改性后隔膜的基本性能进行表征,并将该隔膜装配成电池进行电化学性能表征。结果表明,PE隔膜表面涂覆PVA涂层后,复合隔膜的吸液性得到明显提高,吸液率由最初的124%提高到192%,在150℃、60min的热处理条件下热收缩率由70%降低至2.5%。相对于未改性的PE隔膜,复合隔膜所装配锂离子电池的循环性能和倍率性能均得到显著改善。

Poly （vinyl alcohol） （PVA） functional layer was coated on the surface of commercial PE separator by dip-coating method and investigated in lithium-ion batteries. Systematical investigations had including morphology charac- terization, contact angle testing, electrolyte wettability, and thermal resistance testing were carried out. The results dem- onstrated that with the porous PVA layer, the electrolyte uptake of the PVA/PE separator increased from 124 % to 192 %, and the thermal shrinkage ratio decreased from 70% to 2.5 %. Compared to PE separator, the PVA/PE separator eghibi- ted better electrochemical performances, such as the discharge C-rate capability and cycling performance. This research presented a low-cost and environment-friendly approach to prepare a high performance separator.