Abstract: A composite material for a bipolar plate of fuel cells is comprised of conductive carbon dispersed in polybenzoxazine matrix. The present invention also provides a composite material for preparing a bipolar plate for fuel cells comprising a polymer where a volume reduction percent is less than 5%, preferably 3%, and more preferably 1% after polymerization of the monomers with respect to total volume of the monomers before the polymerization thereof, and conductive carbon. The polymers of the present invention have good workability since there is little volume change during polymerization, and good mechanical and chemical properties, and they can be manufactured at a low cost.

Abstract: A fuel cell system includes at least one electricity generator which generates electric energy through electrochemical reaction between hydrogen and oxygen, a fuel supply unit which supplies fuel containing hydrogen to the electricity generator, and an oxygen source which supplies oxygen to the at least one electricity generator. The fuel supply unit comprises an outer tank defining an inner space, and an inner fuel storage tank with deformable walls which is provided in the inner space of the outer tank to store fuel. Fuel is discharged from the inner fuel storage tank by the deformation of the inner fuel storage tank by applying a compressive force to the inner space of the outer tank through the use of a biasing mechanism.

Abstract: A composite material for a bipolar plate of fuel cells is comprised of conductive carbon dispersed in polybenzoxazine matrix. The present invention also provides a composite material for preparing a bipolar plate for fuel cells comprising a polymer where a volume reduction percent is less than 5%, preferably 3%, and more preferably 1% after polymerization of the monomers with respect to total volume of the monomers before the polymerization thereof, and conductive carbon. The polymers of the present invention have good workability since there is little volume change during polymerization, and good mechanical and chemical properties, and they can be manufactured at a low cost.