Low mercury, high discharge rate electrochemical cell
US5721065A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1995 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Oct 16, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention pertains to novel alkaline electrochemical cells having high drain capacities, especially cells having high drain rate capabilities at voltages of at least 1.1 volts for use in small appliances such as hearing aids. The anode includes anode material in the cells including potassium hydroxide, zinc powder, 0.02% to 0.5% indium as indium compound separate from the zinc powder, optionally a low level of mercury, and preferably a surfactant comprising hydroxyethylcellulose. The cathode provides sufficient oxidative capability to oxidize the zinc at a sufficient rate to support the electrical drain demands on the cell. A cathode, in a preferred zinc air cell for a hearing aid, includes at least 5 air ports, evenly distributed over the surface of the bottom of the cathode can. Cells of the invention exhibit prolonged operation at relatively constant voltage over 1.1 volts, and relatively constant power output at a power density of at least about 210 milliwatts per square inch of the reaction surface area of the cathode assembly, for periods significantly longer than conventional cells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.