| abstract |
Disclosed is a bipolar membrane comprising a cation-exchange membrane in which a cation-exchange group present at least at its adhered surface has been ion-exchanged with a heavy metal ion, which is adhered closely to an anion-exchange membrane at a peel strength of not less than 0.2 kg f/25 mm, and having a water-splitting current efficiency of not less than 80% and a water-splitting membrane potential of not more than 2.0 V. |