REDOX FLOW SECONDARY BATTERY AND ELECTROLYTE MEMBRANE FOR REDOX FLOW SECONDARY BATTERY

This redox flow secondary battery has an electrolyte tank (6) containing: a positive electrode cell chamber (2) containing a positive electrode (1) comprising a carbon electrode; a negative electrode cell chamber (4) containing a negative electrode (3) comprising a carbon electrode; and an electrolyte membrane (5) as a barrier membrane that separates/isolates the positive electrode cell chamber (2) and the negative electrode cell chamber (4). The positive electrode cell chamber (2) contains a positive electrode electrolyte containing an active substance, the negative electrode cell chamber (4) contains a negative electrode electrolyte containing an active substance, and the redox flow secondary battery charges and discharges on the basis of the change in valency of the active substances in the electrolytes. The electrolyte membrane (5) contains an ion exchange resin composition that is primarily a polyelectrolye polymer, and the electrolyte membrane (5) has a reinforcing material comprising a fluorine-based porous membrane.