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:
Oct. 31, 1995
Filed:
Nov. 16, 1994
Takashi Onoue, Tokyo, JP;
Kiyoshi Araki, Tokyo, JP;
Noriya Ishida, Tokyo, JP;
Toshiya Kitamura, Tokyo, JP;
Yasuhiko Niitsu, Tokyo, JP;
Makiko Yanagisawa, Tokyo, JP;
Ryo Sakamoto, Tokyo, JP;
Fumihiro Sato, Tokyo, JP;
Dowa Mining Co., Ltd., Tokyo, JP;
Abstract
A novel primary or secondary battery whose active material for the negative electrode is composed of metallic gallium, gallium alloys or gallium oxide has first come into the world. Gallium has an electrochemical equivalent of 23.24, which is smaller than those of zinc (32.70) and cadmium (56.21). This indicates that when used as an active material for the negative electrode in batteries, gallium has larger capacity per unit mass than zinc and cadmium by respective factors of ca. 1.4 and 2.4. The potential of the reaction; Ga+6OH.sup.- =GaO.sub.3.sup.3- +3H.sub.2 O+3e.sup.- is obviously less noble than the voltage of hydrogen evolution and this means that a high-potential battery can be made. Due to the high hydrogen overvoltage of gallium, gallium ions in the solution can be precipitated as metallic gallium by electrodeposition. As a further advantage, no dendrite formation occurs during the electrodeposition unlike in the case of zinc. The high hydrogen overvoltage also contributes to the production of a battery that undergoes only limited self-discharge. What is more, gallium which has no toxicity presents few environmental problems.