关键词： CONDUCTIVITY ENHANCEMENT   NANOCOMPOSITES   LUMINESCENCE   TRANSPORT  

摘要： Solid polymer nanocomposite electrolytes composed of polyethylene oxide (PEO) macromolecules, LiN(CF3SO2)(2) (LiTFSI) and polyether-grafted nano-ZnO (designated ZnO(PEGME)), are prepared and characterized in comparison with the prototypical PEO-LiTFSI film and that doped with conventional acetate group modified ZnO nanoparticles (designated ZnO(Ac)). High resolution transmission electron microscopic (HRTEM) results show that ZnO nanoparticles are dispersed homogeneously in the present PEO-LiTFSI-ZnO(PEGME) films, while those particles in PEO-LiTFSI-ZnO(Ac) aggregate badly. Atomic force microscopic (AFM) analyses prove that after storage at room temperature for a month, PEO-LiTFSI forms large dendrites while only a small amount of tiny crystals can be observed in the PEO-LiTFSI-ZnO(PEGME) film. In contrast, ZnO(Ac) particles agglomerate around the PEO-LiTFSI dendrites and separate from the original phase. This is the first direct observation on the micromorphology of the SPE films after long-term storage, which elucidates why the PEO LiTFSI-ZnO(PEGME) electrolyte is much more stable than its counterparts. Conductivity evolutions, Li+ transport number measurements and cycle performances of the above-mentioned three typical films in all-solid-state lithium batteries also suggest that the structural merits of the polyether-grafted nanoparticles render this type of SPEs attractive in the future applications.

关键词： 锂电池   聚合物   固态电解质  

摘要： 用碳酸乙烯酯、碳酸丙烯酯作为增塑剂制备了PEO-LiCl_4 聚合物电解质,实验结表明增塑剂不仅阻止了聚氧化乙烯结晶的生长,减小了聚合物的结晶度,降低了玻璃化温度,增加了聚合物分子链段的运动能力,而且促进了聚合物电解质中LiClO_4的电离,增加了聚合物电解质中的载流子数,因此提高了聚合物电解质的电导率.其室温下电导率可达到2X10^(-3)S/cm.讨论了改性聚合物电解质电导率提高的机理,在室温下测试了聚苯胺全固态锂电池的性能.