A fuel cell in a fuel cell stack that provides a transition from nested
bipolar plates in the active region of the stack to non-nested bipolar
plates in the inactive regions of the stack without giving up the reduced
stack thickness provided by the nested plates or changing the size of the
flow channels. Particularly, the diffusion media layers in the fuel cells
are removed in the inactive regions where the bipolar plates are
non-nested so that the volume necessary to maintain the size of the flow
channels is provided without the need to increase the distance between
adjacent MEAs. A thin shim can be provided between the membranes and the
plates in the inactive regions to support the membrane where the
diffusion media layer has been removed to prevent the membrane from
intruding into the flow channels and blocking the reactive flow.