Overcharge protection systems for rechargeable batteries
US5882812A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1997 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jan 14, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is an electrochemical device having a shuttle-type redox mechanism for overcharge protection in which the redox reaction is "tuned" with a tuning agent to adjust the potential at which the redox reaction occurs. Such device may be characterized as including the following elements: (1) a negative electrode (e.g., lithium); (2) a positive electrode containing one or more intermediate species (e.g., polysulfides) which are oxidized to one more oxidized species during overcharge; and (3) a tuning species (e.g., an organosulfur compound) which adjusts the rate at which the oxidized species are reduced and thereby adjusts the voltage at which overcharge protection is provided. The oxidized species produced during overcharge move to the negative electrode where they are reduced back to said intermediate species as in a normal redox shuttle. However, the oxidized species react more rapidly than the intermediate species at the negative electrode. Thus, the overcharge protection mechanism becomes more active as the oxidized species' concentration increases--as occurs during more severe overcharge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.