Honda Giken Kogyo Kabushiki Kaisha

Kuraray Chemical Co., Ltd.

Kashima Oil Co., Ltd.

Yuji Kawabuchi

Shigeki Oyama

Takeshi Fujino

Shushi Nishimura

Hideharu Iwasaki

Nozomu Sugo

Minoru Noguchi

Kenji Sato

Mitsunori Hitomi

Naohiko Oki

Takashi Maeda

Takanori Kitamura

Teruhiro Okada

Tatsuo Morotomi

Tsuyoshi Kowaka

Takahiro Haga

In activated carbon obtained by subjecting a carbonaceous material to an activation treatment, the overall content of alkali metals is set at 100 ppm or less, or the overall content of heavy metals is set at 20 ppm or less and the overall content of alkali metals is set at 200 ppm or less. In cases where such activated carbon is used as a raw material in electronic devices, the formation of dendrites by the reductive deposition of alkali metals or heavy metals tends not to occur, so that problems such as short-circuiting or the like tend not to arise, and a good rate of self-discharge retention is shown.

Activated carbon, method for production thereof, polarizing electrode and electrical double layer capacitor

Activated carbon useful as polarizable electrode material for an electric double-layer capacitor can be obtained by mixing a carbonaceous material and an alkali metal hydroxide while maintaining a solid state, granulating the obtained mixture while maintaining its solid state, dehydrating the obtained granulated substance while maintaining its solid state, and subjecting the granulated dehydration product obtained in the dehydration step to an activation treatment. The preferred pressure of the granulation treatment in the granulation step is 0.01 to 300 Torr, and the preferred temperature of the granulation treatment is 90 to 140&#xb0; C. The preferred pressure of the dehydration treatment in the dehydration step is 0.01 to 10 Torr, and the preferred temperature of the dehydration treatment is 200 to 400&#xb0; C.

Method for manufacturing activated carbon, polarizable electrode, and electric double-layered capacitor

To produce activated carbon for an electrode of an electric double-layer capacitor, the following steps are carried out sequentially: a step of subjecting a massive mesophase pitch to a pulverizing treatment to provide a pulverized powder; a step of subjecting the pulverized powder to an infusibilizing treatment under conditions of a temperature in a range of 300&#xb0; C. (inclusive) to 450&#xb0; C. (inclusive) in the atmospheric air current, a step of subjecting the pulverized powder to a carbonizing treatment under conditions of a temperature in a range of 600&#xb0; C. (inclusive) to 900&#xb0; C. (inclusive) in an inert gas current to provide a carbonized powder, a step of subjecting the carbonized powder to an alkali activating treatment under conditions of a temperature in a range of 500&#xb0; C. (inclusive) to 1,000&#xb0; C. (inclusive) in an inert gas atmosphere, followed by the post treatments, thereby producing alkali-activated carbon, and a step of subjecting the alkali-activated carbon to a pulverizing treatment. If an electrode is produced using the activated carbon, the electrode density can be increased.

Method for producing activated carbon for electrode of electric double-layer capacitor

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Saitama, Japan

Yuji Kawabuchi