Electrochemical characterisation of these three candidate membranes revealed good Li-ion transport properties, in line with those of the Nafion TM 117 membrane as a benchmark, with a conductivity of 6.2  0.8 mS cm -1 and high transport number of 0.98  0.04 for the P(LiMTFSI-IBMA)-10% EGDMA composition. The use of higher crosslinking levels proved to be beneficial for an improved permselectivity of the membranes due to the lower water uptake of the membranes which limits counter-ion leaking, without a detrimental effect on the Li-ion conductivity. Li PFG NMR revealed similar local diffusion coefficients of the order of 10 -10 m 2 s -1 for each of the three membranes when swollen with LiCl aqueous solution, which was in line with coefficients found for the Nafion TM 117 membrane.