Electrochemical capacitor containing ruthenium oxide electrodes
US8385052B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2008 |
| Grant date | Feb 26, 2013 |
| Priority date | — |
| Expiry date | Nov 16, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/13
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A capacitor containing an electrochemical cell that includes ruthenium oxide electrodes and an aqueous electrolyte containing a polyprotic acid (e.g., sulfuric acid) is provided. More specifically, the electrodes each contain a substrate that is coated with a metal oxide film formed from a combination of ruthenium oxide and inorganic oxide particles (e.g., alumina, silica, etc.). Without intending to be limited by theory, it is believed that the inorganic oxide particles may enhance proton transfer (e.g., proton generation) in the aqueous electrolyte to form hydrated inorganic oxide complexes (e.g., [Al(H2O)63+] to [Al2(H2O)8(OH2)]4+). The inorganic oxide thus acts as a catalyst to both absorb and reversibly cleave water into protons and molecular bonded hydroxyl bridges. Because the anions (e.g., sulfate and bisulfate ions) in the electrolyte are not bound in the coordination sphere of the formed aqua complexes, they do not impede the condensation of these complexes required to achieve the additional capacitance over the potential range. As a result, the ionic charges are kept separate and the chemical process may generate pseudo-capacitance. This, in turn, may result in an increa…
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