LAUSR

Abstract As the anodic deposited material of soluble lead flow battery, the phase composition of PbO2 is an important factor affecting the performance of battery. In this paper, the influences of current density, concentration of H+ and operating temperature on the phase composition of PbO2 are systematically studied in the aqueous solution of lead methanesulfonate / methanesulfonic acid. It has been found that the electrodeposition potential of PbO2 is affected by those three conditions, which is a main factor to produce crystal PbO2 with different phase compositions. The high potential (higher than 1.50 V vs. SCE) is beneficial to producing α-PbO2, and the low potential (lower than 1.50 V vs. SCE) is favor for the formation of β-PbO2. To avoid the cell voltage dropping down during constant current charge/discharge cycling, the constant voltage charge was applied to keep a mixture of α-PbO2 and β-PbO2 during cycling. The cycling performance of flow cell is more stable than that under galvanostatic charge/discharge conditions.