A study on the reversibility of Pb(II)/PbO2 conversion for the application of flow liquid battery

The conversion behavior of soluble Pb(II) to deposited PbO2 on platinum in methanesulfonic acid solution was studied with voltammetry and compared with those on glassy carbon and lead oxides. The effects of methanesulfonic acid concentration and Pb(II) concentration, and temperature were considered. The conversion reaction of Pb(II) to PbO2 on platinum is irreversible and has a high overpotential, more than 300 mV. Low concentration of methanesulfonic acid, high concentration of Pb(II) and high temperature will favor the conversion reaction of Pb(II) to PbO2. The conversion reaction depends to a great extent on electrode materials. It is more difficult for the conversion reaction of Pb(II) to PbO2 to take place on glassy carbon than on platinum. However, the conversion reaction of Pb(II) to PbO2 becomes easy when it takes place on lead oxides, which was formed by reducing PbO2 under different potentials.