摘要
通过静电纺丝和热亚胺化处理制备热固性聚酰亚胺(PI)纳米纤维膜,并研究隔膜的力学性能及在2种充电截止电压(常用的4.2 V和高电压4.4 V)下的电化学循环性能.结果表明:PI纳米纤维的平均直径为276 nm,作为隔膜的孔隙率高达92%,且其吸液率远远高于商业用Celgard2400隔膜;0.2C/0.2C速率50次充放电循环下,2种电压范围下的容量保持率均在80%以上,且在2.8~4.4 V高电压下的容量保持率高达91.6%,明显优于Celgard2400;在2种电压范围内,随着放电倍率的增大,其比容量衰减较Celgard2400隔膜缓慢,PI膜表现出更优异的倍率性能.
The thermosetting polyimide (PI) nano-fibers based nonwoven membrane is prepared by electrospinning technique and followed by thermal imidization. The physical and mechanical properties of PI nano-fibers based nonwoven separators are tested and the electrochemical performance of the PI membrane for lithium ion battery at different charge cut-off voltage (herein, common voltage 4.2 V and higher 4.4 V) is investigated. The results show that the average diameter of PI nano-fibers is as fine as 276 nm; the porosity of PI nano-fibers based nonwoven separators is up to 92% and they exhibit better wettability for the polar electrolyte compared to the commercial Celgard 2400 membrane; After 50 cycles at 0.2C/0.2C charge and discharge rate, the capacity retention ratio of the cell assembled with PI nano-fibers based nonwoven separators at both voltage range is higher than 80%, especially that of 4.4 V charge is up to 91.6%, which are obviously superior to commercial Celgard 2400 membrane; moreover, the special capacity of PI separators fades slower than Celgard 2400 membrane with the increase of discharge rate at both situation.
出处
《天津工业大学学报》
CAS
北大核心
2014年第1期15-19,共5页
Journal of Tiangong University
基金
国家自然科学基金项目(51102178)
关键词
静电纺
聚酰亚胺
纳米纤维
锂电隔膜
电化学性能
electrospinning
polyimide
nano-fibers
membrane for lithium ion battery
electrochemical properties