The Li+ transference numbers of three different liquid electrolytes for Li-ion batteries were measured in a symmetrical Li I electrolyte I Li cell by means of very-low-frequency impedance spectroscopy (VLF-IS). The electrolytes were: (i) The standard battery electrolyte LP30; (ii) an equimolar mixture of tetraglyme (G4) and lithium bis(trifluoromethylsulfonyl)imide (Li-TFSI); (iii) Li-TFSI dissolved in the ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP-TFSI). We found that the Li+ transference numbers of the two electrolytes LP30 and G4/Li-TFSI are much smaller than the Li+ transport numbers t(Li+)(NMR) obtained from pulsed-field gradient NMR measurements. On the other hand, in the case of BMP-TFSI/Li-TFSI, the values for t(Li+)(current) and t(Li+)(NMR) are more similar. In order to rationalize the large differences between t(Li+)(current) and t(Li+)(NMR) found for LP30 and G4/Li-TFSI, we combined the Onsager reciprocal relations with linear response theory, and we derived expressions for t(Li+)(current) which take into account all correlations between ionic movements in the electrolyte. Thereby, we show that t(Li+)(current) can be considerably smaller than t(Li+)(NMR) if strong directional correlations exist between the movements of cations and anions. Finally, we discuss differences in Li+ transference numbers obtained by VLF-IS and by potentiostatic polarization measurements. (C) 2016 The Electrochemical Society. All rights reserved.