Fuel cell stack

Abstract

The invention provides a fuel cell stack in which at least one of a plurality of fuel cell units constituting a fuel cell stack includes a water absorbing member with a surface exposed to the atmosphere in a portion where an oxidizer flow path forming member and a separator are in contact with each other, and an area of a surface exposed to the atmosphere of the water absorbing member of the fuel cell unit the temperature of which becomes relatively lower is larger than an area of a surface exposed to the atmosphere of the water absorbing member of the fuel cell unit the temperature of which becomes relatively higher.

Description

technical field [0001] The present invention relates to a fuel cell stack, and more particularly, to a fuel cell stack in which drainage capacity and water retention performance of oxidant flow paths of fuel cell units in the stack are designed depending on temperature distribution during power generation. Background technique [0002] A polymer electrolyte fuel cell basically includes a polymer electrolyte membrane having proton conductivity and a pair of catalyst layers and electrodes provided on both surfaces of the polymer electrolyte membrane. [0003] The catalyst layer generally includes a catalyst layer made of platinum or a platinum group metal catalyst. A gas diffusion layer is provided on the outside of the catalyst layer for supplying gas and collecting current. [0004] An assembly that integrates a polymer electrolyte membrane and a catalyst layer is called a membrane electrode assembly (MEA), and supplies fuel (hydrogen) to one of the electrodes and oxidant (...

AI Technical Summary

Problems solved by technology

[0021] Therefore, for example, in mobile applications where the fuel cell system needs to be reduced in size as much as possible, problems have been caused in terms of size and weight

Images