Poly(vinylidene fluoride)Separators with Dual-asymmetric Structure for High-performance Lithium Ion Batteries

作     者：Hong-qing Liang Ling-shu Wan 徐志康 

作者机构：MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province Department of Polymer Science and Engineering Zhejiang University 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2016年第34卷第12期

页      面：1423-1435页

核心收录：

学科分类：081704[工学-应用化学] 0808[工学-电气工程] 07[理学] 0817[工学-化学工程与技术] 08[工学] 070305[理学-高分子化学与物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21174124 and 21534009) 

主　　题：Polymer separator Lithium ion battery Dual-asymmetric structure Porous membrane Thermally induced phaseseparation. 

摘      要：Dual-asymmetric poly（vinylidene fluoride） （PVDF） separators have been fabricated by thermally induced phase separation with dimethyl sulfone （DMSO2） and glycerol as mixed diluents. The separators have a porous bulk with large interconnected pores （-1.0 μm） and two surfaces with small pores （-30 nm）. This dual-asymmetric porous structure endows the separators with higher electrolyte uptake amount and rapider uptake rate, as well as better electrolyte retention ability than the commercialized Celgard 2400. The separators even maintain their dimensional stability up to 160 ℃, at which temperature the surface pores close up, leading to a dramatic decrease of air permeability. The electrolyte filled separators also show high ion conductivity （1.72 ***-1） at room temperature. Lithium iron phosphate （LiFePO4）/lithium （Li） cells using these separators display superior discharge capacity and better rate performance as compared with those from the commercialized ones. The results provide new insight into the design and development of separators for high-performance lithium ion batteries with enhanced safety.