Improving particle size of BaSO_4 with a unique glycerol base method and its impact on the negative active material of the lead-acid battery

摘要

Present work proposes a unique and simple method for synthesizing small and uniform Barium sulfate particles within a novel auxiliary solution based on the glycerol. Glycerol acts as a molecular spacer and prevents growth and agglomeration of the synthesizing particles. Barium sulfate is the isomorph of PbSO4 and provides the centers for nucleation of PbSO4 particles during the discharge process. Smaller particles of BaSO4 leads to more and smaller PbSO4 particles per volume of Negative Active Material (NAM). Therefore, electrochemical reactions including oxidation (discharge) and reduction (charge) are performed utterly in deeper parts of the NAM. The battery containing synthesized BaSO4 exhibits much better capacity, cranking performance, charge acceptance and cycle-life in relation to the reference battery. After cycling test, NAM of the battery is investigated with Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to study the particle size and morphology of it. More, uniform and smaller PbSO4 particles are produced at discharge state. Through the complete reduction process, PbSO4 particles completely turn back to the spongy Pb on the negative electrode which reduces the "sulfation" of the electrodes. Consequently, synthesized Barium sulfate particles with the proposed method, improve the overall performance of the lead-acid battery.