Application of the commercial ion exchange membranes in the all-vanadium redox flow battery

[Display omitted] •The commercial ion exchange membranes were evaluated to use as a separator in the all-vanadium redox flow battery (VRFB).•Membrane properties such as an ionic conductivity and the permeability of each vanadium ion were tested.•Performances of VRFB using the commercial ion exchange membranes were evaluated.•The commercial ion exchange membranes used in this research are well suited for a separator in the VRFB with a high energy efficiency. Three commercial anion exchange membranes and two commercial cation exchange membranes were tested to use as a separator in the all-vanadium redox flow battery (VRFB). Membrane properties such as an ionic conductivity and a permeability of each vanadium ion were evaluated. Ionic conductivities decreased in the order: Nafion117≈APS>NEPEM115>FAP-PP-475>FAP-PE-420. An anion exchange membrane had a low permeability of each vanadium ion compared to a cation exchange membrane. Energy efficiencies of VRFB using the commercial ion exchanges membrane had almost the same value in the range of 76.0–78.7%.