The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 2000
Filed:
Feb. 24, 1998
Randall L Collien, Madison, WI (US);
Patrick J Spellman, Middleton, WI (US);
Robert B Dopp, Madison, WI (US);
John Edward Oltman, Mount Horeb, WI (US);
John David Burns, Newton Hall Estate, GB;
Joseph Lynn Passaniti, Fitchburg, WI (US);
Michael Joseph Root, Verona, WI (US);
Rayovac Corporation, Madison, WI (US);
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% of a reaction rate enabling compound selected from a compound of indium, cadmium, gallium, thallium, germanium, tin, or lead, with indium compounds being preferred. The anode material optionally further includes 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 of the same type.