Title :
Influence of alloying additives (Sb, Sn, Ca, Ag) on the oxygen evolution reaction on Pb/PbO2 electrodes
Author :
Monahov, B. ; Pavlov, D. ; Petrov, D.
Author_Institution :
Central Lab. of Electrochem. Power Sources, Bulgarian Acad. of Sci., Sofia, Bulgaria
Abstract :
When the lead-acid battery is charged over 70% SOC, oxygen is evolved on the positive plates due to water decomposition. In valve-regulated lead-acid batteries, the evolved oxygen forms a closed recombination cycle. The rate of O2 evolution depends on potential, temperature and alloying additives. In this work, the influence of alloying elements (Sb, Sn, Ca, Ag) on oxygen overvoltage is studied and their effect on the activation energy of the process is determined using smooth model electrodes. It is established that Sn increases both the oxygen overvoltage and the activation energy, Ag and Sb have the opposite effect (weaker for Sb). Ca has a small influence on O2 evolution. Besides, the additives increase the ratio α-/β-PbO2 in the corrosion layer
Keywords :
electrochemical electrodes; electrochemistry; lead; lead compounds; oxygen; secondary cells; O2; Pb-PbO2; Pb-PbO2 electrodes; Pb-acid secondary batteries; VRLA; activation energy; alloying additives; closed recombination cycle; oxygen evolution reaction; oxygen overvoltage; positive plates; water decomposition; Alloying; Batteries; Electrodes; Laboratories; Lead compounds; Mercury (metals); Oxygen; Temperature dependence; Tin; Voltage control;
Conference_Titel :
Battery Conference on Applications and Advances, 1999. The Fourteenth Annual
Conference_Location :
Long Beach, CA
Print_ISBN :
0-7803-4967-9
DOI :
10.1109/BCAA.1999.796004
