The gassing behaviour of lead-acid negative active material and development of a quality control test for lead oxide purity

• Published in: Journal of power sources 1988-09, Vol.24 (2), p.127-136
• Main Authors: Culpin, B., Pilling, M.W., Fleming, F.A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/0378-7753(88)80097-1

Maintenance-free (M.F.) batteries are widely applied, particularly in the areas of automotive SLI and stand-by power. The M.F. characteristics are due to low evolution of hydrogen and oxygen from the plates on open circuit and during constant potential overcharge, thus obviating the need for ‘topping up’. M.F. batteries use a non-antimonial alloy, typically Pb/Ca/Sn, and care is required in the selection of lead feedstock for oxide production to ensure low levels of undesirable impurities. Feedstock lead was analysed for impurities in an attempt to define their safe limits and to see if secondary lead could be used in M.F. batteries. The large number of impurities present, however, together with uncertainties in analytical accuracy led us to a more pragmatic test which measured the gassing rate directly. This served as a rapid method for evaluating lead supplies, a suitable quality control technique for factory use, and a research tool for evaluation of individual impurities and synergistic effects.