摘要 |
An extended life capacitor is disclosed in which an enclosing body is made from a tantalum can and tantalum cap and enclosing a plurality of double layer capacitor cells. Each of the capacitor cells includes a conductive material, such as activated carbon, with an aqueous electrolyte therein such as dilute sulfuric acid. In the preferred embodiment, this is about 38% by weight of sulfuric acid, and the remainder water. Lead-ins are provided to make electronic connection to the two ends of the capacitor cell stack as anode and cathode electrodes. The entire unit is hermetically sealed to inhibit the loss of electrolyte from the capacitor body to less than 2% per year, and the electrodes are at least partly coated with a noble metal such as gold to limit the establishment of a spurious capacitor which would be in series with the stack of plurality cells, which would otherwise greatly decrease the capacity of the entire unit.
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