Proof-of-concept experiments of an acid-base junction flow battery by reverse bipolar electrodialysis for an energy conversion system

The acid-base junction potential can be used to generate electricity instead of the reduction-oxidation potential, which is often used for energy conversion between chemical energy and electricity. In this study, reverse bipolar electrodialysis was designed for energy conversion between acid-base solutions and electricity. Operating a flow battery with various HCl/NaOH concentrations, or an ABJFB, the current-voltage relationships showed typical polarization curves that were similar to those obtained in power generation from a fuel cell. We further demonstrated that the cell can be operated in a charge/discharge cyclic mode in a single cell. To the best of our knowledge, this study is the first report on a proof-of-concept experiment demonstrating the cyclic operation of an ABJFB.