Fuel cell separator

Abstract

A method for manufacturing a fuel cell separator that ensures an improved corrosion resistance under usage environment of a fuel cell and restraining an increase of a contact resistance with a power generation unit by enhancing a sticking force of a conductive carbon film formed on a surface in contact with the power generation unit on a surface of a titanium substrate is provided. It is a methodfor manufacturing a fuel cell separator. The fuel cell separator 3 includes a contact portion 31 that is in contact with a power generation unit 2 so as to partition the power generation units 2 including electrodes 6 of the fuel cell 10, and includes a conductive carbon film 3e formed on the contact portion 31. First, a titanium substrate 3A that has a plurality of projecting portions 31A formedcorresponding to a shape of the contact portion 31 and recessed portions 21A for gas flow channels formed between the projecting portions 31A are prepared as a substrate of the separator 3. Next, a heat treatment is performed on the titanium substrate 3A in a state where a carbon sheet 9 is brought in contact with the projecting portions 31A such that carbon of the carbon sheet 9 diffuses in the projecting portions 31A.

Description

technical field [0001] The present invention relates to a method of manufacturing a separator for a fuel cell that is in contact with a power generation unit so as to partition power generation units including electrodes of the fuel cell. Background technique [0002] Conventionally, for a fuel cell, a power generation unit including a membrane-electrode assembly having a pair of electrodes formed on both sides of a solid polymer electrolyte membrane is used as a unit cell, and the power generation unit passes hydrogen gas as a fuel gas and an oxidant gas such as air. and other gas flow paths are divided by partitions. In a fuel cell, a plurality of single cells are stacked with separators to form a battery pack. Such a separator for a fuel cell plays a role of allowing the current generated in the battery pack to flow to adjacent cells, and thus requires high electrical conductivity and electrical conductivity durability. [0003] As a method of manufacturing such a separ...

AI Technical Summary

Problems solved by technology

[0006] However, in the separators obtained by the production methods disclosed in Patent Documents 1 and 2, there may be regions where the adhesion force between the titanium substrate and the conductive carbon film is weak.

In the weak adhesion area, the interface between the titanium substrate and the conductive carbon film is likely to be oxidized in the fuel cell operating environment, and there is a concern that the contact resistance between the separator and the power generation unit may increase.

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