基于氧化石墨烯的锂硫电池用聚乙烯隔膜的改性

Modification of Polyethylene Separators Based on Graphene Oxide in Lithium-Sulfur Batteries

通过简单刮涂法制备了氧化石墨烯(GO)涂覆改性的聚乙烯(PE)隔膜,并分析研究了GO的氧化程度对隔膜电学性能的影响。采用X射线光电子能谱分析(XPS)、扫描电子显微镜(SEM)、充放电实验、多硫化物透过性测试和交流阻抗等方法对GO及其改性隔膜的结构和性能进行了研究。结果表明:GO改性隔膜可以抑制锂硫电池的"穿梭效应";并且既具有较高的氧化程度,又具有较高的导电性的GO-4改性隔膜的电学性能最优;引入该隔膜的锂硫电池在0.2C条件下,首圈放电比容量为900.0mA·h/g,高于未改性PE隔膜的763.2mA·h/g。

Graphene oxide （GO） coated polyethylene （PE） separator was successfully prepared by a quadruple film applicator and the effect of the oxidation degree of GO on performances of lithium-sulfur batteries was studied.The structures of GO were characterized by XPS.The properties of GO coated separator were investigated by SEM,A.C.impedance,polysulfide permeability test and charge-discharge experiments.Results revealed that GO coated separator could prohibit the ＂shuttle effect＂of lithiumsulfur batteries.Moreover,it was found that the battery assembled with the GO-4 coated separator showed the best cycle performance,because GO-4 had high electrical and high oxidation degree.The initial specific discharge capacity of lithium-sulfur batteries using the GO-4 coated separator was 900.0mA·h/g,higher than that of PE separator （763.2mA·h/g）.