聚丙烯酸甲酯用作聚合物锂离子电池电解质基材的研究

POLYMERIC GEL ELECTROLYTES BASED ON CROSSLINKED-POLY(METHYL ACRYLATE)

用自交联的方法制备了一种以聚丙烯酸甲酯 (PMA)为基材、含丙二醇碳酸酯 (PC)和 L i Cl O4电解液的凝胶型聚合物电解质。考察了电解液含量和聚合物结构对离子导电性能、电化学稳定性等的影响 ,并将所得结果与以聚甲基丙烯酸甲酯 (PMMA)为基材的相应体系做了对比研究。结果表明 ,在聚合物含量较大时 ,聚合物的链结构对离子导电行为有较大的影响 ,具有刚性链结构的 PMMA比具有柔性链结构的 PMA更不利于相应凝胶型电解质离子的传递 ;而在聚合物含量较小时 ,聚合物的结构对凝胶型电解质的离子导电行为的影响较小。以 2 7% (质量 )的交联 PMA为基材、摩尔比为 12∶ 1的 PC- L i Cl O4为增塑电解液而制备的凝胶型电解质 ,具有良好的粘附性能和较高的室温电导率 (4 .8× 10 -3S/cm)。循环伏安的研究结果表明 ,PMA体系的阳极分解电压在 4 .7V(vs Li+/Li)。

The gel electrolytes prepared from crosslinked poly(methyl acrylate)(PMA), propylene carbonate and LiClO 4 have been investigated by differential scanning calorimetry, conductivity and cyclic voltammetry. The results show that both the structure of matrix and the amount of liquid electrolyte have a great effect on the properties of the samples. By comparison with the gel electrolytes containing the polymer with similar structure--PMMA, the PMA-based ones have much higher conductivity at the low concentration of liquid electrolyte and much lower anodic potential limit, about 4.7 V(vs Li +/Li), whereas the conductivity disparity of both electrolytes becomes smaller with increasing the liquid electrolyte content, until the same conductivity of 4.8 × 10 -3 S/cm at room temperature is obtained, when liquid electrlyte content is up to 78.7 mass% .