Alkaline Solid Polymer Electrolyte Preparation And Electrical Properties

The polymer electrolyte has been considerably investigated due to their wide potential applications in electrochemical devices, categories of the polymer electrolyte are briefly related in the present paper, the application, research and development of alkaline solid polymer electrolytes (ASPE) are introduced and the method of modification for ASPE is narrated in detail. On the basis of abundant literatures, the blend ratio, synthesis and ionic conductivity mechanism of ASPE for PVA-KOH-H₂O series are studied.Alkaline solid polymer electrolyte films, which composed of PVA-KOH-H2O series, were synthesized by a solution cast technique. The influences of alkali concentration, temperature, polymer and additive on ionic conductivity and electrochemical stability were studied with orthogonal experiments and single factor experiments design, the relation of structure and ionic conductibility is researched by FIRT, XRD,DSC and SEM analysis ways.The experimental results indicate that the ionic conductivity of ASPE increases progressively up to a maximum, then decreases with the alkali blended, and the voltage of electrochemical potential stability window increases first and then decreases to leveling off;The temperature dependence of the ionic conductivity is neither according with a Vogel-Tamman-Fulcher(VTF) behavior nor completely to Arrhenius equation, but exhibits a kind of complicated curve, the voltage of electrochemical potential stability window is decreasing with temperature increased;Firstly the ionic conductivity falls by inches with poly(ethylene oxide) (PEO) added, and then increases up to a maximum, at last the property of electrolyte film gets worse with excessive PEO;The ionic conductivity decreases before growing gradually up to maximum with plasticizer blended, the effect of propylene carbonate (PC) on improving ionic conductivity is better than that of GROL, all additives make the electrochemical potential stability window narrow.The analysis of polymer structure indicates that the non-crystalline phase is the majority of the agglomerate structure and the crystalline phase is the minority, the highest crystal value only reaches the level of 0.1646;There is a definite interactionadditives and PVA, which not only reduces the crystal value of ASPE to make amorphous areas enlarge but also improve the ability of segmental motion by destroying the well-regulated and orderly character of polymer chain, meanwhile restricts the mobility of potassium cation and enhances the anionic transference number of hydroxide ions, all these improve the ionic conductivity;The ionic conductivity occurs essentially within the amorphous phase of the ASPE;The structure of ASPE doesn't change in the range of our test temperature, this means, the temperature only takes effect on degradation of complex in certain compositions, ionic mobility and segmental motions of the polymer chain.In the end, in terms of above investigations the optimum scheme (PVA:KOH:PEO:GROL:PC:H2O=3:4.5:0:0.5:0.75:40) of the experiments was obtained by orthogonal design experiments.