RESEARCH ARTICLE

The use of an experimental design approach to investigate the interactions of additives used in the making of the negative plate in lead-acid batteries

Ernst E. Ferg^*; Charmelle Snyders

Department of Chemistry, Nelson Mandela Metropolitan University, P.O.Box 77000, Port Elizabeth, 6031, South Africa

ABSTRACT

When a conventional starting, lighting and ignition (SLI) lead acid battery is exposed to a high rate partial state of charge (HRPSoC) cycling, it would experience a build-up of irreversible PbSO₄ on the negative plate, resulting in capacity loss and electrode damage. The addition of certain graphites to the negative paste mix has proven to be successful in reducing this effect. This study looked at using statistical design of experimental (DoE) principles to observe interactions between two graphite types and a nanocarbon together with other additives, such as BaSO₄ and Vanisperse, to a negative paste mixture. The response factors considered were in relation to their effect on the battery's cold cranking ability (CCA) at -18 °C, the HRPSoC and its active material utilization. Typical flooded nominal 8 Ah test cells were assembled in a reverse ratio build,with three positive and two negative plates, with three types of added carbons (flake graphite, natural graphite and nanocarbon) added to the negative paste mixture at a two-level design. The study showed the usefulness of a statistical DoE approach in the effective use of additives that are included to the negative plate paste mixture, where there are interactions between the amounts of added carbon, BaSO₄ and Vanisperse, with respect to the responses of CCA and HRPSoC, that do not necessarily act independently - based on their amounts - on the performance of the active material. The study also showed that there are correlations between certain response factors, such as the number of achievable cycles within a HRPSoC test sequence, and the type of added carbon.

Keywords: Pb-acid battery, Pb-plate, graphite, expanders, design of experiment

Full text available only in PDF format.

Acknowledgements

The authors thank Willard Batteries for providing financial assistance, and for the various manufactured components used in the study. The authors thank the South African National Research Foundation (NRF) for their financial contribution. The authors thank Coos Bosma, from Innoventon, for helping with the statistical analysis of the results.

References

1 J. Valenciano, A. S'anchez, F. Trinidad and A.F. Hollenkamp, J. Power Sources, 2006, 158, 851-863.         [ Links ]

2 R. Wagner, M. Schroeder, T. Stephanblome and E. Handschin, J. Power Sources,1999, 78(1-2), 156-163.         [ Links ]

3 P.T. Moseley, J. Power Sources, 2004, 127, 27-32.         [ Links ]

4 M. Calabek, K. Micka, P. Krivak and P. Baca, J. Power Sources, 2006, 158, 864-867.         [ Links ]

5 D.P. Boden, D.V. Loosemore, M.A. Spence and T.D. Wojcinski, J. Power Sources, 2010, 195, 4470-4493.         [ Links ]

6 H. Vermesan, N. Hirai, M. Shiota and T. Tanaka, J. Power Sources, 2004, 133, 52-58.         [ Links ]

7 S. Osumi, M. Shiomi, K. Nakamura, K. Sawai, T. Funato, M. Watanabe and H. Wada, ALABC Project N5.2, August 2005.         [ Links ]

8 A.F. Hollenkamp, W.G.A. Baldsing, S. Lau, O.V Lim, R.H. Newnham, D.A.J. Rand, J.M. Rasalie, D.G. Vella and L.H. Vu, ALABC Project N1.2, Annual Report, July 2000 - June 2001.         [ Links ]

9 M.A. Spence, D.P. Boden and T.D. Wojcinski, ALABC Project C1.1/2.1A. October 2009.         [ Links ]

10 J. Anthony, Design of Experiments for Engineers and Scientists, Elsevier Science, Oxford, UK, 2003.         [ Links ]

11 D. Doerffel and S.Abu Sharkh, J. Power Sources, 2006, 155, 395-400.         [ Links ]

12 D. Pavlov, P. Nikolov and Rogachev, T. J. Power Sources, 2010, 195, 4435-4443.         [ Links ]

Received 28 October 2011
Revised 6 September 2012
Accepted 19 September 2012

* To whom correspondence should be addressed. E-mail: ernst.ferg@nmmu.ac.za