摘要
为优化陶瓷涂敷隔膜热稳定性,提高锂离子电池的安全性和电化学性能,本工作选用热稳定性优异的聚酰亚胺和电化学稳定的聚偏氟乙烯六氟丙烯作为复合黏结剂,将Al_2O_3无机颗粒涂敷于商品级聚烯烃隔膜两侧。通过调控两种黏结剂组分含量,测试隔膜性能发现,增加聚酰亚胺的含量可以明显提高涂覆隔膜的热稳定性,但隔膜的电化学性能不理想;在黏结剂中引入适量的聚偏氟乙烯六氟丙烯组分,涂覆隔膜可在保持其热稳定性的同时,获得良好的离子电导率、电化学稳定性和金属锂电极兼容性等性能。最后选用电化学性能表现最为优异且热稳定性良好的黏结剂组分制备陶瓷涂敷隔膜,在Li|LiCoO_2电池中,比聚烯烃隔膜表现出更优异的电化学性能,在8 C倍率下的放电比容量为109.3 mA/g,容量保持率为66.1%,而使用PE隔膜的电池的放电比容量和容量保持率仅为88.7 mA/g和54.7%。
In order to optimize the thermal stability of the ceramic coated separators and improve the safety and electrochemical performance of lithium ion batteries, polyimide （PI） with good thermal stability and poly（vinylidene fluoride-co-hexafluoropropylene） （PVDF-HFP） with excellent electrochemical stability are used as binder to coat the aluminum oxide （A1203） particles onto both sides of commercial PE separator in this work. According to the test results of ceramic coated separators prepared by different binder components, the PI binder can obviously improve the thermal stability of the ceramic coated separator, however the cell performance is not satisfying. In addition, the poor electrochemical properties of the PI binder can reduce the electrochemical stability and compatibilities with electrodes. PVDF-HFP has been widely used in lithium-ion batteries because of its excellent electrochemical properties. PVDF-HFP can swell in the electrolyte, the swollen PVDF-HFP can adhere electrode so that lithium ions can pass across the separator. Adding an appropriate amount of PVDF-HFP in the binder can improve the ionic conductivity, electrochemical stability, lithium metal-electrode compatibility and other properties of the ceramic coated separator while maintaining its good thermal stability because of the presence of PI binder. Therefore, the using of appropriate components of PI and PVDF-HFP binders can synergistically improve the performance of the using of ceramic coated separator. Finally, the cell performances of the LilLiCoO2 cells with the optimized inorganic composite separator are enhanced obviously. The capacity and the capacity retention of the cell using the optimized ceramic coated separator at 8 C is 109.3 mA.h.g 1 and 66.1%, which are much better than those （88.7 mA·h·g-1 and54.7%） of the cell using the PE separatorceramic coated separator. Finally, the cell performances of the LilLiCoO2 cells with the optimized inorganic composite separator are enhanced obviously. The capacity and the capacity retention of the cell using the optimized ceramic coated separator at 8 C is 109.3 mA.h.g 1 and 66.1%, which are much better than those （88.7 mA·h·g-1 and54.7%） of the cell using the PE separator.
作者
钟国彬
王中会
梁鑫
项宏发
ZHONG Guobin;WANG Zhonghui;LIANGXin;XIANG Hongfa(Electric Power Research Institute of Guangdong Power Grid Company Limited,Guangzhou 510080,Guangdong,China;School of Material Science and Engineering,Hefei University of Technology,Hefei 230009,Anhui,China)
出处
《储能科学与技术》
CAS
CSCD
2018年第6期1139-1145,共7页
Energy Storage Science and Technology
基金
南方电网公司科技项目(GDKJQQ20152008)
关键词
陶瓷涂敷隔膜
黏结剂
聚酰亚胺
聚偏氟乙烯六氟丙烯
锂离子电池
ceramic coated separator
binders
polyimide
poly（vinylidene fluoride-co-hexafluoropro-pylene）
lithium-ion batteries
作者简介
钟国彬（1984-），男，博士，高级工程师，主要从事锂离子电池研究，E-mail：zhongguobin@gddky．csg．cn;通讯联系人：项宏发，教授，博士生导师，主要从事锂离子电池研究，E．mail：hfxiang@hfut．edu．cn。
