Active material redistribution rates in zinc electrodes: effect of alkaline electrolyte compositions having reduced zinc oxide solubility

Technical Report · Tue Nov 01 04:00:00 EST 1983

OSTI ID:5046069

Nichols, J T; McLarnon, F R; Cairns, E J

A series of electrolytes with low hydroxide concentration (approx. 3.5M OH/sup -/) have been tested in 1.35 Ah tri-electrode Zn/NiOOH cells for their ability to reduce zinc redistribution rates. Three electrolytes were evaluated: a 3.5M OH/sup -/ electrolyte, a 3.5M OH/sup -/ to 3.4M F/sup -/ electrolyte, and a hydroxide-borate electrolyte. The electrolytes were chosen to have a ZnO solubility approximately 25% of that in the standard 30% KOH-1% LiOH electrolyte (7.4 M OH/sup -/). A 6-hour charge rate and a 2.5-hour discharge rate were employed for the Teflon-bonded, zinc oxide electrodes, to which 2% PbO was added to reduce hydrogen evolution. The zinc redistribution rates were found to be lower for the electrolytes with reduced ZnO solubility. In addition, no zinc penetration of the separator occurred for some of the electrolytes, even with overpotentials of 100 to 290 mV. After 125 cycles, none of the cell capacities were limited by the zinc electrode during discharge, less than 2% inactive zinc was found in the zinc electrodes cycled in the hydroxide-fluoride and borate electrolytes.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5046069
• Report Number(s): LBL-17397; ON: DE84010709
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250903* -- Energy Storage-- Batteries-- Materials
Components
& Auxiliaries
ALKALI METAL COMPOUNDS
CHALCOGENIDES
ELECTRIC BATTERIES
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
ELEMENTS
HYDROGEN COMPOUNDS
HYDROXIDES
METALS
OXIDES
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
SOLUBILITY
ZINC
ZINC COMPOUNDS
ZINC OXIDES