Effects of gold on the structure and electrochemical behavior of lead-gold composite in different temperatures sulfuric acid

Lead is still dominantly used as the main material for lead-acid batteries electrodes and active materials. Lead-gold composites were made in efforts to improve the performance of the active materials component for lead-acid batteries. The electrochemical behavior of Pb-Au composite in sulfuric acid solution (H2SO4) were investigated. Au was chosen as the reinforcement material for lead composite because of its high electrical conductivity and its resistance to chemical reaction which is important to resist the formation of lead sulfate (PbSO4) crystal on the surface of electrodes. Lead-gold composite were made by mixing lead powder and auric chloride (AuCl3) solution. The fabrication of Pb-Au composites was done by mixing Pb powders and auric chloride (AuCl3) solution and using hot-press method. Material characterizations were performed using X-ray fluorescence technique to investigate material composition and X-ray diffraction technique to investigate material structure. The electrochemical properties of Pb-Au composites were investigated by electrochemical polarization testing, specifically linear sweep voltammetry technique (LSV) in H2SO4 solution with various solution temperature at 10° C, 25° C, and 40° C to simulate common active vehicle condition. The results show that the crystal structure of lead-gold composites is face-centered cubic (FCC) structure. Also, the addition of Au lower the Icorr and shift the Ecorr to a more cathodic potential.