The Evolution Tracking of Tribasic Lead Sulfates Features in Lead-Acid Battery Positive Electrode using Design of Experiments

Abstract

The positive electrode of lead-acid battery (LAB) still limits battery performance. Several approaches have been attempted to remedy this problem either with the incorporation of additives or by electrode modification. However initial performance and cycling of the LAB is determined by the kind and content of basic lead sulfate in the paste. As a result, it is critical to comprehend the mechanisms that take place during paste manufacture and how they affect the properties of the active materials. In this work, the experimental design methodology was applied to track the crystallite size and content of tribasic lead sulfates (3BS), and specific surface area of cured paste, using the AZURAD® software. The effect of two quantitative factors (water/LO ratio and acid/LO ratio) and one qualitative factor (curing program) were studied. SEM, XRD and BET were used to characterize the cured pastes. The acid/LO ratio plays an important role in determining the 3BS phase content reaching 78% for crystalline phase. At high temperatures, the acid/LO ratio shows, more influence on the 3BS crystallites size attaining a maximum value of 58 nm. The temperature in the curing step mitigates the effect of both ratios on the crystallites size of 3BS and SSA of cured paste. Results reveals two zones of nanostructured paste material evolution delimited at 10% of acid/LO ratio.