Effect of phosphoric acid on the performance of low antimony grid of Pb-acid cell under constant current charging and discharging

✍ Scribed by H.A. Abd El-Rahman; S.A. Salih; A. M. Abd El-Wahab

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 965 KB
• Volume: 42
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.201100770

✦ Synopsis

Effect of phosphoric acid on the performance of Pb-1.7%Sb grid of lead-acid cell is studied in 5 M H 2 SO 4 by cyclic galvanostatic polarization and impedance spectroscopy. An increase in capacitance to a maximum is recorded during the initial stages of the electro-reduction of PbO 2 into Pb(II) compounds and attributed to concurrent compositional and dimensional changes. These changes include removal of O 2 bubbles, insertion of large amounts of H 2 SO 4 and H 2 O. Efficiency of PbO 2 formation decreases, while its rate of self-discharge increases with increasing the charging current and in the presence of H 3 PO 4 . The charge capacity increases with increasing the discharging current due to the decrease in the self-discharge. The charge capacity is lower in the presence of H 3 PO 4 . On increasing the cycle number, the corrodibility of the grid increases, because more layers of the surface Pb are involved in the self-discharge. H 3 PO 4 significantly retards the effect of cycle number.