Patent ID: 7829241
Filing Date: 2010-11-09
Classification: H01M,Y02E

Abstract:
1. A method of maintaining a compression of a fuel cell stack in a predetermined range during dimensional changes in fuel cells of the fuel cell stack, the fuel cell stack being compressed to an initial compressive state, the fuel cell stack including a plurality of bipolar plates with at least one diffusion media member compressed between a pair of adjacent bipolar plates, the method comprising: (a) operating the fuel cell stack to meet a power demand placed on the fuel cell stack; and (b) compensating for dimensional changes with at least one of the bipolar plates thereby maintaining the compression of the fuel cell stack within the predetermined range; and (c) creating said at least one bipolar plate of first and second sheets each having alternating lands and channels, said at least one bipolar plate having an internal flow field at least partially defined by a plurality of opposing pairs of said lands of said first and second sheets with some of said opposing pairs of lands in contact with one another and others of said opposing pairs of lands spaced apart with a gap therebetween.