Abstract: A fuel cell stack is provided comprising fuel cell modules least compression plates; and at least one plurality of mechanical linkages connecting a pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between the pair of compression plates. The present invention additionally provides a fuel cell stack comprising: fuel cell modules stacked alternately with compression plates; mechanical linkages connecting a first pair of compression plates directly adjacent to a first fuel cell module; mechanical linkages connecting a second pair of compression plates directly adjacent to a second fuel cell module; where a) the first and second fuel cell modules may be maintained under compression, and b) the compression on each fuel cell module may be adjusted essentially independently of the compression on the other.

Abstract: A fuel cell stack is provided comprising one or more fuel cell modules, each fuel cell module comprising at least one membrane electrode assembly having no hard stop layer; two or more compression plates; and at least one plurality of mechanical linkages connecting a pair of compression plates located on either side of at least one fuel cell module, which may be engaged to maintain a predetermined gap distance between the pair of compression plates.

Abstract: A liquid cooled fuel cell stack is provided which comprises fuel cell modules which comprise one or more membrane electrode assemblies (MEA's); cooling plates which comprise cooling channels; a manifold box communicating with each cooling channel inlet; and a diffuser within the manifold box having a plurality of diffuser outlets distributed evenly with respect to the cooling channel inlets. Typically a two-chamber manifold box is used, to allow counter-flow of coolant in opposite directions in cooling channels on opposite sides of the stack. Typically the stack is insulated around its exterior.