Low temperature double-layer capacitors using asymmetric and spiro-type quaternary ammonium salts
US8804309B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2011 |
| Grant date | Aug 12, 2014 |
| Priority date | — |
| Expiry date | Jul 18, 2031 |
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 −80° 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. A quaternary ammonium salt including at least one of triethylmethylammonium tetrafluoroborate (TEMATFB) and spiro-(1,1′)-bipyrrolidium tetrafluoroborate (SBPBF4), is used in an optimized concentration (e.g., 0.10 M to 0.75 M), dissolved into the electrolyte 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.