1. Field of the Invention
This invention relates to a fuel cell using methanol as a fuel, and more particularly to an improvement of a fuel cell using an electrolyte ion exchange membrane.
2. Description of the Prior Art
A fuel cell using an electrolyte ion exchange membrane is disclosed, for example, in Japanese patent application Kokai (Laid-open) No. 56-138874, where catalyst particles are fixed to the surface of an ion exchange membrane, and the ion exchange membrane and an electrode are integrated into one body. The procedures for fixing catalyst particles to the surface of an ion exchange membrane are described in detail therein together with the prior art ones. According to one of the procedures disclosed therein, the surface of an ion exchange membrane is roughened and catalyst particles are fixed to the roughened surface, where a binder such as polytetrafluoroethylene, etc. is required when the amount of catalyst particles to be fixed exceeds about 2 mg/cm.sup.2.
According to another procedure disclosed in U.S. Pat. No. 3,134,697, an electrode material comprising metal or alloy powder and a resin binder is distributed onto the surface of an ion exchange resin membrane and integrated with the ion exchange resin membrane at an elevated temperature under pressure.
All of the integrated electrodes disclosed in Japanese patent application Kokai (Laid-open) No. 56-138874 are hydrophilic on the electrode surfaces, and even if polytetrafluoroethylene having a water-repellent property is used as a binder, the electrode surfaces are substantially hydrophilic and not water-repellent.
Thus, the integrated electrode having catalyst particles integrated with an ion exchange membrane so far proposed is hydrophilic, and is not suitable for an oxidizer electrode (or cathode or air electrode) of a fuel cell using methanol as fuel, because, in the case of using such an oxidizer electrode, a three-phase boundary is hardly obtainable among catalyst particles (solid), a fuel (liquid) and an oxidizer (gas) with the result of a poor cell performance.