Murata Manufacturing Co., Ltd.

Hiroyuki Mukouyama

Masanori Endo

Michinobu Maesaka

Koichi Watanabe

Kouichi Watanabe

Kouichi Tanaka

One method of manufacturing a polarizable electrode for an electric double-layer capacitor includes, in order, the steps of: preforming a kneaded substance of fine carbon powder, a polymer resin containing fluorine, and a liquid lubricant into a sheet-type preform; adjusting the content of the liquid lubricant in the sheet-type preform to 10 to 47 percent by weight; shaping the preform into a prescribed thickness, optionally but advantageously with heated rolls; and then substantially removing the liquid lubricant from the preform. In another disclosed method, first the liquid lubricant is substantially removed, and then the sheet-type preform is rolled with rollers that are heated to substantially 90.degree.-120.degree. C. In either of the above methods, the rollers are controlled to have a circumferential speed of 0.7-5 m/min and the rollers shape the preform into a sheet substantially 0.04 to 0.5 mm in thickness for serving as a polarizable electrode.

Method of manufacturing polarizable electrode for electric double-layer

The present invention relates to capacitors utilizing an electric double layer formed in the interface of polarizable electrodes and an electrolyte. By using as the primary material of the polarizable electrodes an activated carbon in which the difference in titration value between the cases where sodium carbonate is used for neutralization titration of the activated carbon and where sodium hydrogencarbonate is used therefor is 0.195 meq/g or more to the weight of the activated carbon, the quantity of presence of the acidic functional group II (carboxyl group present as lactone) on the surface of the activated carbon is increased and, as a result, the affinity between the polarizable electrodes and the electrolyte is enhanced, thus providing electric double-layer capacitors low in variation with time and yet large in capacity.

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Nagaokakyo, Japan

Hiroyuki Mukouyama