Influence of Different Specific Gravity H2SO4 on Formation and Performance of Lead Acid Cell with Graphite Powder and Acetylene Carbon

Abstract

A study on the influence of sulphuric acid (H2SO4) concentration on the electrochemical activity, phase composition, structure and morphology of the lead dioxide (PbO2) particle thereby its impact on performance of battery was carried out. For the formation process, cells made up of two positive and two negative plates with graphite powder/acetylene carbon and H2SO4 with different concentrations (1.05, 1.15 and 1.25 specific gravity (SG) are used. During the soaking period, lead oxide (PbO) and basic lead sulphate (PbO.PbSO4) react with H2SO4, and sulfation of the plate starts. These processes changes the structure and morphology of the crystals in the cured paste. The results showed that the concentration of H2SO4 decreases gradually during soaking indicating that H2SO4 is reacting with PbO present in the paste. After the formation process the phase composition and morphology of active material are characterized using X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM) studies respectively. After formation, the concentration of H2SO4 is altered to 1.24 SG. The simulated 2 V lead-acid cells are subjected to capacity and service life measurement. The results proved indeed the acid SG in formation alters the structure of active material and life of battery.