微孔型聚丙烯腈固体电解质的结构与导电性能研究

INVESTIGATION ON STRUCTURE AND CONDUCTIVITY OF MICROPOROUS PAN ELECTROLYTE

用蒸汽相沉析法和液相沉析法分别制备了两类高孔隙率的聚丙烯腈 (PAN)微孔膜 .用扫描电子显微镜对微孔膜的形态进行了观察 ,发现前者为均匀的蜂窝状结构 ,而后者则具有不对称的三层次结构 .又用这两类微孔膜分别制备了两个系列的微孔型PAN电解质 .电性能测试表明前者的室温电导率较高 ,可以达到 4×10 - 3 S cm ,后者的电导率则相对较低 .

In order to prepare microporous polymer electrolyte used in lithium ion batteries, two types (A-series and B-series) of microporous PAN membranes with high porosity were prepared in vapour atmosphere or coagulating bath from PAN-DMF solutions, respectively. SEM observed the sections of those membranes. It was found that there was a kind of honeycomb structure in the A-series microporous membrane, the size of the pores was in the order of mum, and their porosity was about 80% While in the B-series microporous membrane there was an asymmetric structure composed of three layers. The highest ion conductivity of microporous PAN electrolyte of A-series was about 4 x 10 (-3) S/cm at room temperature. While the ion conductivity of microporous PAN electrolyte of B-series was relatively low. The effect of influence factors of the microporous membrane on the ion conductivity of microporous PAN electrolyte changes in an order: membrane structure > porosity > pore size.