Direct oxidation fuel cell system with uniform vapor delivery of fuel

A system comprising:

• a membrane electrode assembly of a fuel cell having an anode aspect and a cathode aspect;
• a fuel distribution structure disposed adjacent to the anode aspect of a membrane electrode assembly, the fuel distribution structure having a fuel feed port configured to receive liquid fuel and exit ports or pores configured to deliver vaporous fuel to the anode aspect, the fuel distribution structure configured to receive heat from fuel cell operation and convey the heat to the liquid fuel within the fuel distribution structure to convert the liquid fuel to vaporous fuel therein;
• and
• an enthalpy exchanger and heat spreader assembly that includes a heat spreader configured to collect heat generated from fuel cell operation, and a heat switch coupled to the heat spreader and configured to, at a predetermined temperature, direct heat from the heat spreader to the fuel distribution structure.

A method comprising:

• introducing liquid fuel into a fuel feed port of a fuel distribution structure that is disposed adjacent to an anode aspect of a membrane electrode assembly of a fuel cell, the fuel distribution structure including a flow field plate having flow channels formed therein;
• providing heat to the fuel distribution structure from an enthalpy exchanger and heat spreader assembly in thermal contact with the fuel distribution structure;
• conveying the heat to fuel passing through the flow channels to substantially convert the liquid fuel to vaporous fuel within the flow channels;
• and
• delivering the vaporous fuel via exit ports of the fuel distribution structure to the anode aspect to substantially uniformly distribute fuel across the anode aspect.