Low temperature double-layer capacitors
US8081418B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2008 |
| Grant date | Dec 20, 2011 |
| Priority date | — |
| Expiry date | Jun 28, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/13
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Double-layer capacitors capable of operating at extremely low temperatures (e.g., as low as −75° C.) are disclosed. Electrolyte solutions combining a base solvent (e.g., acetonitrile) and a cosolvent are employed to lower the melting point of the base electrolyte. Example cosolvents include methyl formate, ethyl acetate, methyl acetate, propionitrile, butyronitrile, and 1,3-dioxolane. An optimized concentration (e.g., 0.10 M to 0.75 M) of salt, such as tetraethylammonium tetrafluoroborate, is dissolved into the electrolyte solution. In some cases (e.g., 1,3-dioxolane cosolvent) additives, such as 2% by volume triethylamine, may be included in the solvent mixture to prevent polymerization of the solution. Conventional device form factors and structural elements (e.g., porous carbon electrodes and a polyethylene separator) may be employed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.