Gas diffusion electrode and production method for same; membrane electrode assembly and production method for same

摘要

[Object] To provide a gas diffusion electrode capable of a high current density operation of a fuel cell.;[Solving means] A gas diffusion electrode including a hydrophilic porous layer having an electrically conductive material and an ion conductive material; and a catalyst layer adjacent to the hydrophilic porous layer, wherein a water transport resistance of the hydrophilic porous layer is smaller than a water transport resistance of the catalyst layer.

主权项

1. A gas diffusion electrode for a fuel cell, comprising;
a hydrophilic porous layer including an electrically conductive material and an ion conductive material; and a catalyst layer adjacent to the hydrophilic porous layer, wherein a water transport resistance of the hydrophilic porous layer is smaller than a water transport resistance of the catalyst layer; wherein the hydrophilic porous layer comprises a first electrically conductive material, a first ion conductive material covering a part of a surface of the first electrically conductive material, a second electrically conductive material, and a second ion conductive material covering a part of a surface of the second electrically conductive material; and wherein the first electrically conductive material has a cover area of 200 to 1600 m2/g and the second electrically conductive material has a cover area of less than 200 m2/g, a cover area being defined as an area of the part of the surface of the electrically conductive material covered by the ion conductive material and is given by Sion=SBET×θion, where Sion is the cover area; SBET is a specific surface area of the electrically conductive material as measured by a BET nitrogen absorption method; and θion is a covering ratio of the ion conductive material on the electrically conductive material.