Abstract
The performance of positive plates depends on the structure of the lead dioxide active mass. The positive active materials (PAM) consists of a skeleton, built up of agglomerates and macropores. Agglomerates, in their turn, comprise particles and micropores. This paper described a study conducted to determine the effects of different soaking times between the acid fill and formation stages of the tubular plate production. For the positive plates a lead oxide were filled into tubular bag with a red lead. After filling the positive plates were soaked in $H_2SO_4$ solution. X-ray diffraction(XRD), scanning electron microscopy(SEM) and electrical testing had been used to study the compositional and morphological aspects of the positive active material(PAM) just prior and after formation. Results indicate that PAM compositions were effected by the soaking time and acid density of $H_2SO_4$ solution. It can be seen that as the soaking time duration increases, $\alpha$-PbO, $Pb_3O_4$, and Pb were all gradually sulphating. Composition of 3BS reached a maximum at around 3 h duration and $H_2SO_4$ of sp. gr. 1.10 on soaking. This results would suggest that the most beneficial conditions for soaking were the $H_2SO_4$ of sp. gr. 1.10 and 2 to 6 h of soaking.
