Mitsubishi Chemical Corporation

Mitsubishi Rayon Company, Limited

Hiroto Tatsuno

Kazuhiro Sumioka

Tadao Samejima

Kyu Ota

Makoto Nakamura

Kota Hideshima

A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles &#x3b8;of water on both surfaces in a thickness direction being 0 to 15&#xb0; and a contact angle &#x3b8;of water in a middle portion in the thickness direction being 0 to 15&#xb0;. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000&#xb0; C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800&#xb0; C. in a direction perpendicular to a direction in which the hydrophilic porous carbon electrode is transported to be subjected to hydrophilization.

Hydrophilic porous carbon electrode and manufacturing method of same

Disclosed herein is a porous electrode substrate in which carbon fibers are dispersed in the structure thereof have a fiber diameter of 3-15 micron and a fiber length of 2-30 mm, and are bound to one another by carbonized resin such that, when a pore distribution in the porous electrode is determined with a mercury intrusion porosimeter, such that a pore distribution curve is plotted on a graph having a common logarithmic scale on the horizontal axis, and a 1-100 micron pore diameter range of the pore distribution curve includes 80 or more measurement points at equal intervals along the common logarithmic scale, the pore distribution has a skewness S of &#x2212;2.0&#x3c;S&#x3c;&#x2212;0.8 and a kurtosis K of 3.5&#x3c;K&#x3c;10 in the 1-100 micron pore diameter range.

Porous electrode substrate, membrane-electrode assembly using same, and polymer electrolyte fuel cell using same

According to the present invention, a porous electrode substrate with greater sheet strength, lower production cost, and excellent gas permeability and conductivity as well as its manufacturing method are provided. Also provided are a precursor sheet for forming such a substrate, and a membrane electrode assembly and a polymer electrolyte fuel cell containing such a substrate. The method for manufacturing such a porous electrode substrate includes the following steps [1]&#x2dc;[3]: [1] a step for manufacturing a sheet material in which short carbon fibers (A) are dispersed; [2] a step for manufacturing a precursor sheet by adding a water-soluble phenolic resin and/or water-dispersible phenolic resin to the sheet material; and [3] a step for carbonizing the precursor sheet at a temperature of 1000&#xb0; C. or higher. The present invention also relates to a porous electrode substrate obtained by such a manufacturing method as well as a precursor sheet to be used for manufacturing the substrate, a membrane electrode assembly and a polymer electrolyte fuel cell.

Porous electrode substrate, method for manufacturing same, precursor sheet, membrane electrode assembly, and polymer electrolyte fuel cell

The present invention relates to a method for manufacturing a porous electrode base material including the following steps [1] to [3]: [1] a step for dispersing short carbon fibers (A) to form a sheet-form product; [2] a step for adding, to the sheet-form product, at least one phenolic resin (c) selected from a group consisting of a water soluble phenolic resin and a water dispersible phenolic resin along with carbon powder (d) to form a precursor sheet; and [3] a step for carbonizing the precursor sheet at the temperature of 1000&#xb0; C. or higher, after the step [2].

Growing community of inventors

Tokyo, Japan

Hiroto Tatsuno