MCM-41介孔分子筛掺杂的微孔型聚合物电解质的制备与表征

Preparation and Characterization of MCM-41/ PVdF-HFP Composite Microporous Polymer Electrolytes for Li-ion Batteries

以介孔分子筛MCM-41作填料,丙酮与二甲基甲酰胺混合液为溶剂,用直接造孔成膜的方法制备了微孔型聚合物电解质膜.该法避免使用造孔增塑剂,既简化了制膜工序,又减少电池中副反应的发生,使电池性能得以提高.MCM-41分子筛具有六方有序排列的单一柱状孔道结构和纳米级的粒子尺度,其骨架结构单元与一般聚合物电解质常用的纳米SiO2填料具有相同的化学成分,该分子筛堆积时形成的表面空隙及其独有的一维介孔孔道对聚合物电解质微孔的形成与连通、电导率的提高都具有重要作用,是一种极具实用价值的新型无机填料.

MCM-41/vinylidine fluoride-hexafluropropene copolymer (PVdF-HFP) composite microporous polymer electrolytes were prepared with mixed solvent of N, N-Dimethylformamide (DMF) and acetone. The influence of MCM-41 and nano-SiO_(2) on the porous structure of the microporous polymer electrolytes were studied with SEM. The results show that MCM-41 could take the place of the plasticizer in the process of making pores, and bring the preparation of microporous membranes easily. The preliminary electrochemical tests showed that the ion conductivity of composite microporous polymer electrolyte with 10% MCM-41 was about 10^(-3) S cm^(-1), and the performance of batteries was improved. The mesoporous MCM-41selected in the paper possesses the framework unit of SiO_(2), that is widely used as inorganic filler in polymer electrolyte. In addition, it possesses the particular channels arranged in hexagonal array and a large surface interstice as stacking, that could lead to the formation and connectivity of micropores, finally a higher ion conductivity. These properties make MCM-41 the favorable and promising inorganic filler in polymer electrolyte.