Fuel cell plates and assemblies

A fuel cell basic unit, comprising:

• (a) a first fuel cell plate;
• and,
• (b) a second fuel cell plate, wherein the first and second fuel cell plates sandwich an ion exchange membrane therebetween;
• wherein the first fuel cell plate comprises:
• a plate having a pair of major surfaces;
• and,
• a first flow field on a surface of the first fuel cell plate facing the ion exchange membrane for flow of a first fluid therethrough, comprising a plurality of channels extending from an inlet end of the first flow field to an outlet end of the first flow field, wherein at least one channel has a cross-section that continuously diminishes in size along the channel between the inlet end and the outlet end, and wherein the channels are arranged on the plate surface such that the first flow field has a substantially trapezoidal configuration with the inlet end being wider than the outlet end;
• wherein the second fuel cell plate comprises:
• a plate having a pair of major surfaces;
• and,
• a second flow field on a surface of the second fuel cell plate facing the ion exchange membrane for the flow of a second fluid therethrough, comprising a channel sinusoidally extending from an inlet end of the second flow field to an outlet end of the second flow field, wherein the channel is arranged on the plate surface such that the second flow field has a substantially trapezoidal configuration;
• and,
• wherein portions of the ion exchange membrane contacting the first flow field of the first fuel cell plate define a reaction active area that continuously diminishes in size along the first flow field between the inlet end and the outlet end.