A Mathematical Model of a Sealed Nickel-Cadmium Battery

Deyuan Fan
1991 Journal of the Electrochemical Society  
A mathematical model for the charge and discharge of a sealed nickel-cadmium (Ni-Cd) battery is presented. The model is used to study the effect of transport properties of the electrolyte and kinetic parameters of the electrode reactions on the cell performance during the charge and discharge period. The model can also be used to demonstrate the changes of cell performance during cycling. Some comparisons between model predictions and experimental results indicate that the model predictions
more » ... del predictions appear to fit the experimental data well. Sensitivity analyses illustrate that the sealed nickel-cadmium battery operates under activation control. It is also shown theoretically that oxygen generated on the positive electrode during charge is reduced electrochemically on the negative electrode. ABSTRACT Impedance spectra were obtained during anodic dissolution of copper in 0.5M H2SO4 and 40 mM benzotriazole (BTA) at 25~ The spectra were evaluated according to the hypothesis that the electrode is covered with a barrier film having a stoichiometric composition through which the current is transported by ionic conduction. This barrier film is itself covered with an outer porous film of corrosion products. The experimental impedance spectra were fit to the model with a nonlinear least squares program. A detailed analysis of the physical parameters obtained with this procedure suggested that the metallic ions transfer through the barrier film, which is likely to be hydrated copper sulfate or contains a nonnegligible amount of BTA, under high-field conduction. Experiments carried out at the mass-transfer limiting current in the absence of BTA suggested that the electrode was also covered with a similar dual salt film, the inner layer of which, however, has a different chemical composition than in the presence of BTA.
doi:10.1149/1.2085532 fatcat:lkhdv6wefnglbfb7iu3gw26ote