The electrophoretic NMR method was used to measure lithium transference numbers in gel electrolytes consisting of various salts in propylene carbonate-swollen poly (vinylidene fluoride)-hexafluoropropylene copolymer. We compare the concentration dependence of the lithium transference numbers obtained for a series of anions. The anions considered are CF3SO3- (Tf), N(CF3SO2)(2)(-) (TFSI), N(C2F5SO2)(2)(-) (BETI) and (C(CF3SO2)(3)(-) (TFSM). Larger anions were generally found to result in higher lithium transference numbers. t(Li) in LiTf containing electrolytes decreases steadily with the salt concentration. However, in LiTFSI-containing gel electrolytes, t(Li) is almost invariant over a large concentration range. The results are discussed in the context of the effect of ion-ion interaction, the extent of which is dependent on the degree of anion charge delocalization.