聚乙烯醇-磷酸-硅钨酸聚合物电解质膜的制备及电化学性能

摘要

采用溶液浇铸法制备聚乙烯醇(PVA)-磷酸(H3 PO4)-硅钨酸(STA)聚合物电解质膜，通过 X-射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、热重分析(TGA)对聚合物电解质膜进行了表征，采用交流阻抗法测定聚合物电解质膜的质子电导率，并分析了 H3 PO4含量对质子电导率的影响。结果表明，当 STA含量不变时，随着 H3 PO4含量的增加，聚合物电解质膜的质子电导率先增大后减小；当m(PVA)∶m(H3 PO4)∶m(STA)=1∶4∶8时，在室温下质子电导率达到最大值，为5.50×10-2 S·cm-1；H3 PO4含量的增加使晶态 PVA转变为非晶态，晶态 PVA减少；循环伏安法和充放电测试结果表明，该聚合物电解质膜具有很好的电化学稳定性，有望应用于固态超级电容器。%Polyvinyl alcohol(PVA)-phosphoric acid(H3 PO4 )-silicotungstic acid(STA)polymer electrolyte membranes were prepared by a solution-casting method.The polymer electrolyte membranes were characterized by XRD,FTIR and TGA.The proton conductivity of the polymer electrolyte membranes was detected by an AC impedence method.Effect of H3 PO4 content on proton conductivity was also discussed.Results showed that pro-ton conductivity of the polymer electrolyte membranes increased firstly and then decreased with the increase of H3 PO4 content when the STA content was constant.When m(PVA)∶m(H3 PO4 )∶m(STA)was 1∶4∶8,the polymer electrolyte membranes exhibited the highest proton conductivity of 5.50×10-2 S·cm-1 at room tem-perature.While increasing H3 PO4 content,the crystallized PVA could be converted into amorphous phase,and content of the crystallized PVA reduced.The cyclic voltammograms and charge-discharge results indicated that the polymer electrolyte membranes had good electrochemical stability,and could be applied to solid supercapaci-tors.