The present invention provides a liquid-circulating battery including a positive electrode, a negative electrode, a permeable membrane interposed between the positive and negative electrodes to hold the same in separated relation to each other and to partition the same into a positive chamber and a negative chamber, two porous liquid-permeable carbon electrodes disposed respectively in the positive and negative electrolytic solutions being circulated respectively into the positive and negative chambers such that an oxidation-reduction reaction occurs and causes charging and discharging, wherein the permeable membrane is an ion-exchange me membrane including as an ion exchanger layer a polymeric pellicle which results from crosslinking of a halogenated alkylated product of an aromatic polysulfone type polymer with use of a polyamine and which has an ion exchange capacity of 0.3 to 8.0 milliequivalent/gram of dry resin and a thickness 0.1 to 120 .mu.m, said polysulfone type polymer having as a recurring unit a group represented at least by the following formula (I); and ##STR1## and wherein each of said positive and negative electrolytic solutions is an electrolytic solution having a vanadium ion concentration of 0.5 to 8 mols/liter.