Current-voltage curve of a bipolar membrane at high current density

The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from outside of the bipolar membrane to the interface between a cation and an anion exchange layer is the rate limiting step for the water dissociation process. The dependence of the current-voltage curve on external conditions such as temperature and feed solution concentration was also investigated. The position of the inflection point changed with the temperature and the concentration of the external solution.