Compact fuel cell layer

A fuel cell layer with a central axis comprising:

• a. at least a first unit fuel cell and a second unit fuel cell, wherein the first and second unit fuel cells are disposed adjacent each other;
• b. an oxidant plenum comprising an oxidant;
• and
• c. a fuel plenum comprises a fuel;
• wherein each unit fuel cell comprises:
• i. a first process layer
• ii. a second process layer:
• iii. a first cavity formed between the first and second process layers;
• iv. a second cavity formed between the second process layer and a first process layer of an adjacent unit fuel cell;
• v. a first perimeter barrier disposed on the second process layer substantially surrounding the second cavity;
• and
• vi. a second perimeter barrier disposed on the first process layer substantially surrounding the first cavity forming a unit fuel cell comprising a front face and a back face, and wherein the first cavity is in communication with the oxidant plenum and the second cavity is in communication with the fuel plenum, and wherein at least one of the process layers transports ions between the first and second cavities wherein at least the first cavity or the second cavity is at least partially filled with a catalyst.

A fuel cell layer, with a central axis comprising:

• a. at least a first unit fuel cell and a second unit fuel cell, wherein the first and second unit fuel cells are disposed adjacent each other;
• b. an oxidant plenum comprising an oxidant;
• and
• c. a fuel plenum comprises a fuel;
• wherein each unit fuel cell comprises:
• i. a first process layer;
• ii. a second process layer;
• iii. a first cavity formed between the first and second process layers;
• iv. a second cavity formed between the second process layer and a first process layer of an adjacent unit fuel cell;
• v. a first perimeter barrier disposed on the second process layer substantially surrounding the second cavity;
• and
• vi. a second perimeter barrier disposed on the first process layer substantially surrounding the first cavity forming a unit fuel cell comprising a front face and a back face, and wherein the first cavity is in communication with the oxidant plenum and the second cavity is in communication with the fuel plenum, and wherein at least one of the process layers transports ions between the first and second cavities, and wherein at least one cavity is at least partially filled with at least one gas diffusion electrode containing at least one catalyst layer and at least one porous conductive layer.