为指导高性能钒电池隔膜材料选择和制备,研究VO^2+/H+体系在阳离子交换膜中的吸附平衡。引入选择性因数表征吸附平衡并考虑膜内水含量的影响,建立较高浓度时的吸附平衡关系,对3种阳离子交换膜进行吸附实验。结果表明:选择性因数的对数值与溶液中VO^2+摩尔分数之间存在线性关系;吸附平衡时膜内水含量越少,VO^2+在膜内的吸附量越小,选择性因数小,其中PE01膜的选择性因数最小,具有较强的阻隔VO^2+的能力。溶液中H^+浓度对选择性因数影响较大,H^+浓度提高,VO^2+选择性因数增大,VO^2+相对选择性吸附增强。
The adsorption equilibria of VO^2+/H^+ through a cation exchange membrane were investigated to provide guidance for selecting and synthesizing membrane materials for high quality vanadium cells. A selectivity coefficient characterized the equilibrium for various solvents for higher solution concentrations and three kinds of cation exchange membranes. The results show that the logarithm of the selectivity coefficient is linearly dependent on the molar fraction of VO^2+ in solution. The adsorption quantity and selectivity coefficient at equilibrium of VO^2+ in the membranes decreased with decreasing water content, but increased with increasing H^+ concentration in solution. The PE01 membrane more effectively prevented VO^2+ diffusion across the membrane with the lowest selectivity coefficient among the three membranes.