S. Motupally et al., PROTON DIFFUSION IN NICKEL-HYDROXIDE - PREDICTION OF ACTIVE MATERIAL UTILIZATION, Journal of the Electrochemical Society, 145(1), 1998, pp. 29-34
Citations number
23
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
Galvanostatic charge and discharge experiments reveal that the active
material in nickel electrodes cannot be fully accessed at high current
s or for thick films. It has been proposed that the utilization of the
active material is controlled by the diffusion rate of protons throug
h the film. This hypothesis is supported by the good agreement between
mathematical simulations of material utilization and experimental dat
a over a range of charge and discharge currents and film thicknesses.
Furthermore, the fraction of material utilized is larger on charge tha
n on discharge. The asymmetry on charge and discharge is due to a diff
usion coefficient that is a function of the state-of-charge of the act
ive material. The mathematical model is used to perform a parametric s
tudy of material utilization as a function of charge and discharge cur
rents, and material loading (i.e., film thickness, concentration of ni
ckel sites) in order to improve battery design and operation.