聚合物锂离子电池用凝胶电解质的研究进展

Research progress of gel electrolyte for polymer lithium-ion battery

综述聚氧化乙烯(PEO)、聚偏氟乙烯(PVDF)、聚甲基丙烯酸甲酯(PMMA)和聚丙烯腈(PAN)等聚合物材料用作锂离子电池凝胶电解质的特性.PAN体系凝胶电解质的离子电导率一般在10-3 S/cm数量级,其锂离子迁移数比PEO体系大,可达到0.5;与PAN基凝胶电解质相比,以PMMA为基的凝胶电解质与锂电极的界面稳定性和循环性能更好,但是机械强度较差;PVDF大分子链上含有很强的推电子基(-CF2),且介电常数较高(ε=8.4),有利于促进锂盐更充分的溶解,增加载流子浓度.提出添加无机纳米粒子的凝胶电解质是目前的研究热点,是凝胶电解质的发展趋势.

The polymer materials＇ eharaeteristies of polyethylene oxide （PEO）, polyvinylidene fluoride （PVDF）, polymethyl methacrylate （PMMA） and polyaerylonitrile （PAN） for lithium-ion battery gel electrolyte are summarized. Ionic conduetivity of PAN system gel electrolyte is 10^-3 S/era magnitude commonly, and its lithium-ion＇s transferred amount is larger than PEO system and can reach 0.5. PMMA-based gel electrolyte and lithium electrode＇s interface stability, cycle performanee are better than PAN-based gel electrolyte, but mechanical strength is poor than PAN-based. PVDF maeromoleeular chain contains strong electron group （- CF2）, and its high dielectric constant （ε =8.4） is beneficial to promote Lithium Salt Dissolved more sufficiently, increase carrier concentration. Gel electrolyte with inorganic nano particle is the research hotspot at present, and it＇s the progress direction of gel electrolyte.