Effect of Sodium Dodecyl Sulphate (SDS) and Electrochemical Behavior of Electrodeposited PbO2 on Nickel Substrate for Lead Acid Battery Application

Abstract

An investigation has been made to electrodeposit PbO2 anodically by galvanostatic deposition method on Ni substrate from highly alkaline lead acetate bath (0.2 M CH3(COO)2 and 5 M NaOH) containing an anionic surfactant sodium dodecyl sulfate (SDS) for the application of lead-acid battery positive electrode. The electrodeposited PbO2 was characterized sequentially by current efficiency and thickness measurement, visual and optical microscopic observation, cyclic voltammetry (CV) study, scanning electron microscopic (SEM), and X-ray diffraction (XRD) test. The results revealed that with the increase of SDS concentration the current efficiency as well as the thickness of PbO2 deposits increased up to 100 mgL-1 SDS and afterward it decreased. The morphological study showed that with the variation of SDS concentrations the morphology and particle size of deposited PbO2 can be controlled. The electrochemical performance of the deposited samples in 4.7 M H2SO4 solution (lead-acid battery electrolyte concentration) was investigated using cyclic voltammetry. In the absence of SDS, a pure PbO2 deposit with a lower charge-discharge density and a lower stability (lasting up to 100 cycles) was formed. A small amount of SDS added to the electrolyte improved grain refinement of α-PbO2 with compact and small-grained crystals, increasing the PbO2 film's stability (up to 350 cycles) and charge-discharge density in the battery environment.