CV results show that with the optimal addition of SnSO4
(2.24 mmol L
1
) in an electrolyte, the WE shows the highest
discharge capacity. The major crystalline phase of the pastes
in WE are PbSO4and a little amount of PbO2and metallic Pb
at the end of discharging procedure in the 250th CV tests,
and the PbSO4crystal particles apparently become smaller
with the addition of SnSO4in an electrolyte