A flow battery includes a cell that has a first electrode, a second electrode spaced apart from
the first electrode and an electrolyte separator layer arranged between the first electrode
and the second electrode. A supply/storage system is external of the at least one cell and
includes first and second vessels that are fluidly connected with the at least one cell. First
and second fluid electrolytes are located in the supply/storage system. The electrolyte
separator layer includes a hydrated ion-exchange membrane of a polymer that has a carbon …