Flow control for multiple stacks

The fuel cell of claim 5, wherein said predetermined pressure drop occurs at a predetermined power output level.

A fuel cell stack comprising:

• a plurality of fuel cells arranged adjacent one another, at least one fuel cell of said plurality of fuel cells having an electrode plate having a flow field formed therein, a proton exchange membrane electrode assembly and a compressible fluid-permeable diffusion media disposed between said membrane electrode assembly and said electrode plate, said adjacent fuel cells being compressed together so that said diffusion media in said at least one fuel cell is compressed against said electrode plate with a portion of said diffusion media intruding into said flow field of said adjacent electrode plate.

The fuel cell system of said 16, wherein said feed stream is an H2 feed stream and said electrode plate is a cathode plate.

A method of making a fuel cell comprising positioning a compressible fluid-permeable diffusion media between a membrane electrode assembly and an electrode plate having a flow field formed therein;

• and compressing said diffusion media against said electrode plate so that a portion of said media intrudes into said flow field.

A method of making a fuel cell stack comprising the steps of:

• (a) positioning a plurality of fuel cells adjacent one another, at least one fuel cell of said plurality of fuel cells having an electrode plate with a flow field formed therein, a membrane electrode assembly (MEA) and a compressible fluid-permeable diffusion media disposed between said MEA and said electrode plate;
• and
• (b) compressing said adjacent fuel cells together so that in said at least one fuel cell a portion of said diffusion media intrudes into said flow field of said adjacent electrode plate.

A method of making a fuel cell stack comprising positioning a plurality of fuel cells adjacent one another;

• supplying a feed stream to said plurality of fuel cells;
• monitoring a pressure drop of said feed stream across said plurality of fuel cells;
• and adjusting a compression of said plurality of fuel cells so that said pressure drop is within a predetermined range of pressure drop values.