Gallium based active material for the negative electrode, a negative electrode using the same, and batteries using said negative electrode
US5462821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 1994 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Nov 16, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.