The Bunsen reaction of the sulfur-iodine cycle was carried out using an electrolysis cell separated by a Nafion 117 membrane. The evolution of cell voltage, which indicates the variation of cell resistance and the dynamics of electrode reactions, the concentration of acids after electrolysis, and the membrane properties were studied. The effects of current density, anolyte and catholyte flow rate, operating temperature, initial H2SO4 concentration, HI concentration, and I-2/HI molar ratio were explored. Higher H2SO4 and HI concentrations and cell voltage could be obtained at higher current densities. A flow rate of 20 mL/min, a temperature of 343 K, an initial H2SO4 concentration of 5.71 mol/kg, a HI concentration of 2.51 mol/kg, and an I-2/HI molar ratio of 0.2 at a current density of 5 A/dm(2) were optimal considering the concentration of acids and the cell voltage. The characterization of the membrane by scanning electron microscopy and Brunauer-Emmett-Teller method, as well as the electrolysis tests, showed that the activation favored the membrane recovery and thus contributed to its repeatability.