纳米复合全固态聚膦腈电解质  

ALL-SOLID-STATE POLYPHOSPHAZENE NANOCOMPOSITE ELECTROLYTE

作　　者：周树华[1] 向万春[1] 方世璧[1] 林原[1] 

机构地区：[1]中国科学院化学研究所北京分子科学国家实验室光化学重点实验室,北京100190

出　　处：《高分子学报》2008年第8期805-812,共8页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20333040);国家重点基础研究发展计划(973计划;项目号2006CB202605)资助项目

摘　　要：为了进一步提高聚合物电解质的室温离子电导率和锂离子的迁移数,通过对纳米二氧化硅的表面修饰,并采用可聚合的带氧化乙烯-氧化丙烯共聚侧链取代的聚膦腈大单体制备了纳米复合的全固态电解质.通过X射线光电子能谱,扫描电镜,差热扫描分析对纳米复合电解质的性能和形貌进行了分析,并通过交流阻抗考察了电解质与电极间的界面稳定性,用循环伏安表征了电解质的电化学稳定窗口,考察了锂盐含量对电解质离子电导率的影响,测试了电解质的离子电导率随温度的关系,并对锂离子的迁移数进行了测定.研究结果表明,通过纳米复合的方法,提高了聚合物电解质的离子电导率,降低了界面电阻,提高了锂离子迁移率.In order to improve the ambient conductivity of all-solid-state electrolytes as well as enhance the diffusion number of lithium ion, all-solid-state polyphosphazene electrolytes containing nanoSiO2 modified with poly- （oxyethylene-co-oxypropylene） silane were prepared. The macromonomer of polyphosphazene was prepared through reaction of phosphazene with poly （oxyethylene-co-oxypropylene） monoacrylic ester and poly （ethylene glycol） monomethylether with the yield of 92.6 % . Silane coupling agent with polyether was prepared by the hydrosiloxane addition reaction between tfimethyloxyl siloxane and allyl poly （ethylene-co-propylene glycol） methyl ether. The silane coupling agent refluxed with SiO2 to form nanoSiO2 modified with poly（oxyethylene-co-oxypropylene） silane. The FT-IR spectrum and XPS together show that SiO2 has been successfully modified by the soft chain. The SEM images of composite electrolytes show that modified nano SiO2 could easily disperse among polymer electrolyte with only a little conglomeration. It is found that the nanoSiO2 content in electrolyte fixed at 10% could reach the best ambient conductivity of 3.14×10^-4 S cm^-1, which is 2.4 times higher than that of the noncomposite system. Differential scanning calorimetry of nanocomposite solid state electrolytes showed that the glass transition temperature of the electrolyte did not change with the variation of nanoSiO2 content from 2 % to 10% ,which indicated that nano SiO2 modified with polyether did not change the crosslinking density of nanocomposite system, and the polyether chain could maintain the original flexibility of the solid state electrolytes. The conductivity of electrolyte is increasing with the increase of temperature, which obeys the VTF equation. When the temperature rises up to 50~C, the electrolyte with 10% modified SiO2 shows the best conductivity of 10^-3 S cm^-1, the corresponding active energy is 4.07 kJ mol^-1. The high conductivity can be explained on the one hand, the polyphophazene monomer has t

关 键 词：纳米复合 聚膦腈 全固态聚合物电解质 二氧化硅 

分 类 号：O634.51[理学—高分子化学]