Fuel cell

Patent metadata

Field	Value
Publication number	US-9735433-B2
Application number	US-73632909-A
Country	US
Kind code	B2
Filing date	Mar 26, 2009
Priority date	Apr 1, 2008
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The present invention relates to a fuel cell exhibiting a high performance regardless of the humidification conditions. In short, it is a fuel cell comprised of a proton-conducting electrolyte membrane sandwiched between a pair of catalyst layers, wherein a catalyst layer of at least a cathode contains a catalyst ingredient, electrolyte material, and carbon material; the carbon material is comprised of three types of materials of a catalyst-supporting carbon material supporting the catalyst ingredient, a conductivity-aiding carbon material not supporting the catalyst ingredient, and a gas-diffusing carbon material not supporting the catalyst ingredient; the catalyst layer is comprised of two phases of a catalyst aggregated phase having the catalyst-supporting carbon material supporting the catalyst ingredient and the conductivity-aiding carbon material not supporting the catalyst ingredient aggregated as main ingredients and a gas-diffusing carbon material aggregated phase having the gas-diffusing carbon material not supporting the catalyst ingredient aggregated as a main ingredient; and the catalyst aggregated phase is a continuous phase while the gas-diffusing carbon material aggregated phase is dispersed in the catalyst aggregated phase.

First claim

The invention claimed is:

1. A fuel cell comprising: a proton-conducting electrolyte membrane sandwiched between a pair of catalyst layers and a separate pair of gas diffusion layers,
wherein at least a catalyst layer of a cathode comprises a catalyst ingredient, an electrolyte material, and a carbon material,
the carbon material comprising:
a catalyst-supporting carbon material supporting the catalyst ingredient,
a conductivity-aiding carbon material not supporting the catalyst ingredient, and
a gas-diffusing carbon material not supporting the catalyst ingredient; and
wherein the catalyst layer of the cathode comprises:
catalyst aggregates, each of which comprising the catalyst-supporting carbon material supporting the catalyst ingredient, the electrolyte material, and the conductivity-aiding carbon material not supporting the catalyst ingredient as main ingredients aggregated together, and
gas-diffusing carbon material aggregates, each of which comprising the gas-diffusing carbon material not supporting the catalyst ingredient as a main ingredient aggregated together which is free of a fluorinated compound,
wherein the catalyst aggregates connect by direct contact to form a continuous matrix, and the gas-diffusing carbon material aggregates are dispersed in the matrix of the catalyst aggregates.

2. The fuel cell as set forth in claim 1 , wherein the catalyst-supporting carbon material has a specific surface area, S BET , as determined by a BET evaluation, of 1000 m 2 /g to 4000 m 2 /g, and a ratio, S micro /S total , of a micropore surface area, S micro , of micropores having a diameter of 2 nm or less, as determined by t-plot analysis, and a total surface area, S total , of 0.5 or more.

3. The fuel cell as set forth in claim 1 , wherein the conductivity-aiding carbon material has a ratio, X/S BET , of DBP oil absorption, X (mL/100 g), and a specific surface area, S BET (m 2 /g), as determined by a BET evaluation, of 0.2 to 3.0.

4. The fuel cell as set forth in claim 1 , wherein the gas-diffusing carbon material has a ratio, X/S BET , of DBP oil absorption, X (mL/100 g), and a specific surface area, S BET (m 2 /g), as determined by a BET evaluation, of 1.0 or more.

5. The fuel cell as set forth in any one of claims 1 to 4 , wherein in a field of an area of 10 μm×10 μm at a cross-section of the catalyst layer, there is at least one gas-diffusing carbon material aggregate not supporting a catalyst ingredient having a circle equivalent diameter of 300 nm or more.

Assignees

• Tadokoro Kenichiro
• Mizukami Kazumi
• Iijima Takashi
• Sawada Hideaki
• Hada Tomohiro
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Tadokoro Kenichiro
• Mizukami Kazumi
• Iijima Takashi
• Sawada Hideaki
• Hada Tomohiro

Classifications

• H01M4/92 Primary

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• Y02E60/50

  Fuel cells · CPC title