修饰涂层对聚酰亚胺隔膜性能的影响

探讨聚合物涂层、无机陶瓷涂层改性对锂离子电池用聚酰亚胺(PI)隔膜物理性能及电化学性能的影响。聚合物和无机陶瓷涂层改性,均可改善PI隔膜的孔隙结构和孔径分布,进而提高耐高温性能和电化学性能。采用无机陶瓷涂层改性的PI隔膜,综合性能最优,在250℃下保温4 h,尺寸无明显变化。使用该隔膜组装的单体电池,以0.5 C在4.20~3.00 V循环1 000次,容量保持率可达到92.57%。

Effects of modified coating on the performance of polyimide separator

The effects of polymer or inorganic ceramic coating on the physical properties and electrochemical performance of polyimide(PI) separator for Li-ion battery were investigated.Both polymer and inorganic ceramic coatings could modify the pore structure,disgusting the holes diameter distribution,thus improved the high temperature resistant and electrochemical performance of PI separator.In contrast,the modified PI separator with inorganic ceramic coating exhibited the best comprehensive performance,there was no significant change of its size after annealing at 250 ℃ for 4 h.The capacity retention of the Li-ion battery assembled with the modified PI separator could be up to 92.57% after 1 000 cycles at 0.5 C in 4.20-3.00 V.