Temperature limitation of primary and secondary alkaline battery electrodes
Abstract
The results of studies of the mechanisms of dissolution and passivation of Fe and Zn electrodes in concentrated KOH, as these processes effect the charge/discharge characteristics of alkaline batteries are discussed. The experimental techniques principally employed were: potentiodynamic sweep voltammetry and coulometry, rotating disk and rotating ring disk electrode studies under constant velocity and constant acceleration rotation conditions, and AC impedance studies. The results obtained on Fe electrodes enabled a detailed mechanism for the formation and discharge of an oxide film on iron via a number of dissolved intermediate species. The mechanisms are different at high and low temperatures, but at all temperatures pathways via dissolved phase intermediates result in substantial dissolution of metal and oxide. At 750 C dissolution processes account for more than 7.5% of the total charge stored per cycle. AC impedance measurements were used to characterize the nature of the oxide film, and to determine an effective exchange current density for the Fe/Fe(2) Redox process.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- May 1983
- Bibcode:
- 1983STIN...8411404M
- Keywords:
-
- Alkaline Batteries;
- Dissolving;
- Electrodes;
- Passivity;
- Potassium Hydroxides;
- Temperature Effects;
- Coulometry;
- Impedance Measurement;
- Iron;
- Oxide Films;
- Voltmeters;
- Zinc;
- Electronics and Electrical Engineering