On the origin of the second low-voltage plateau in secondary alkaline batteries with nickel hydroxide positive electrodes
- Univ. de Picardie Jules Verne, Amiens (France). Lab. de Reactivite et de Chimie des Solides
- Centre National d`Etudes Spatiales, Toulouse (France)
- U.J.F.-Grenoble CNRS, Saint Martin d`Heres (France). Lab. de Spectrometrie Physique
The nickel oxyhydroxide electrode (NOE) that acts as the positive electrode in Ni-based rechargeable alkaline batteries was studied. A survey of the influence of crystal-chemistry factors (nature and ratio of the various nickel hydroxide phases), cycling parameters (charge/discharge rates, charge/discharge cutoff voltages, and percentage of overcharge), and technological parameters (nature of the current collector, active material morphology, and type of additives) on the appearance of the second voltage plateau was performed. Direct experimental evidence shows that the appearance of the second plateau is directly linked to the amount of the {gamma}-phase present in the nickel oxyhydroxide electrode prior to its discharge. The occasional appearance of this phase in the electrode results from a poor active material/current collector interface related to the electrode-forming technology, or to secondary reactions that can lead to a physical disconnection of the active material upon cycling. Based on these findings, the presence of this {gamma}-phase accounts for the ohmic drop that has led to previous speculation of a barrier layer as the origin of the second plateau. Finally, tentative recommendations to eliminate or mitigate the appearance of the second plateau phenomena are given.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 564109
- Journal Information:
- Journal of the Electrochemical Society, Vol. 144, Issue 11; Other Information: PBD: Nov 1997
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nickel hydroxide as an active material for the positive electrode in rechargeable alkaline batteries
Fabrication and investigation of nickel--alkaline cells. Part I. Fabrication of nickel-hydroxide electrodes using electrochemical impregnation techniques. Technical report, 1 Jan 1971--1 Jan 1974