Patent ID: 7807312

Claim:
A stack for use in an electrical energy generator, the stack comprising: a first bi-polar plate including a) a first sheet with a first bi-polar plate channel field formed through an entire thickness of the first sheet and b) a second sheet attached directly to the first sheet and including a second bi-polar plate channel field formed through an entire thickness of the second sheet; a second bi-polar plate including a) a third sheet with a third bi-polar plate channel field formed through an entire thickness of the third sheet and b) a fourth sheet attached directly to the third sheet and including a fourth bi-polar plate channel field formed through an entire thickness of the fourth sheet; and at least one spacer attached to perimeter portion of the first bi-polar plate and attached to perimeter portion of the second bi-polar plate, wherein the at least one spacer is configured to form a socket between the first bi-polar plate and the second bi-polar plate; and a membrane electrode assembly disposed between the first bi-polar plate and the second bi-polar plate; wherein the first bi-polar plate channel field is offset from the second bi-polar plate channel field and the third bi-polar plate channel field is offset from the fourth bi-polar plate channel field.