Thermodynamics of Electrochemical reaction in Lead-acid Battery
No Thumbnail Available
Date
2018
Authors
Akinbulu I.A. and Ogunbayo B.T.
Journal Title
Journal ISSN
Volume Title
Publisher
Faculty of Science, Lagos State University, Lagos
Abstract
The quest to construct efficient and reliable electric cars can be achieved with the use of highly efficient and dependable batteries. Electric cars are projected to replace the current petrol-powered automobiles. The debilitating effects of global warming have made this task more imperative. The design of such batteries requires broad understanding of their operations; in order to optimize their outputs. The study of the thermodynamics of the electrochemical reactions occurring
in these batteries offers a veritable platform to achieving this aim. In this study, thermodynamics of electrochemical reaction in a Lead-acid battery was investigated. Electromotive force (e.m.f.) of the battery, containing sulphuric acid
electrolyte of known concentration, was measured at different temperatures (303, 308, 313, 318 and 323 K).
Necessary thermodynamic parameters were determined from the measured e.m.fs. A negative value of change in Gibbs’ free energy, ΔG, and positive entropy change, ΔS, were obtained for the reaction. ΔG was more negative at increased temperature. The reaction was exothermic, with a negative value of enthalpy change, ΔH. A relatively small value of temperature coefficient of the electromotive force of the cell was also obtained. Values of these thermodynamic
parameters indicate that reaction in the Lead-acid battery is thermodynamically feasible. Variation in the value of ΔG, with varying temperature, suggests that electrical work obtainable from the battery may be varied, by controlling temperature. Specifically, decrease in ΔG, with moderate increase in temperature, offers the prospect of enhanced efficiency, at moderately high temperature. Therefore, operation of the battery may be optimized, with an in-built temperature-control device
Description
Keywords
Thermodynamics parameters, electrochemical reaction, temperature coefficient, electromotive force and Lead-acid battery
Citation
LASU Journal of Research and Review in Science 5(2018) 72-79