Abstract: A separator assembly for a fuel cell includes a first separator, a second separator, and a joined portion. In the joined portion, the first separator and the second separator are joined to each other through laser welding. The first separator includes a first surface that is intended to be opposed to the membrane electrode assembly. The first surface of the first separator includes an exposed portion where the base of the first separator is exposed. The second separator includes a second surface that is intended to be opposed to the membrane electrode assembly. A film including conductive particles is arranged on the entire second surface of the second separator. The joined portion is formed by irradiating the exposed portion of the first separator with laser.

Abstract: A fuel cell stack includes a plurality of power generation cells stacked and connected in series and coolant passages configured to circulate coolant. The power generation cells each include a membrane electrode assembly and two separators sandwiching the membrane electrode assembly. The separators are each formed by a metal plate. The coolant passages include through-holes extending through the separators and aligned in a stacking direction of the power generation cells. A method for manufacturing a fuel cell stack includes forming a coating of electrodeposition paint on surfaces of ones of the separators having a high electric potential in the fuel cell stack by operating the fuel cell stack and using the coolant that contains electrodeposition paint particles.

Abstract: A separator assembly for a fuel cell includes a first separator, a second separator, and a joined portion. In the joined portion, the first separator and the second separator are joined to each other through laser welding. The first separator includes a first surface that is intended to be opposed to the membrane electrode assembly. The first surface of the first separator includes an exposed portion where the base of the first separator is exposed. The second separator includes a second surface that is intended to be opposed to the membrane electrode assembly. A film including conductive particles is arranged on the entire second surface of the second separator. The joined portion is formed by irradiating the exposed portion of the first separator with laser.

Abstract: A fuel cell stack includes a plurality of power generation cells stacked and connected in series and coolant passages configured to circulate coolant. The power generation cells each include a membrane electrode assembly and two separators sandwiching the membrane electrode assembly. The separators are each formed by a metal plate. The coolant passages include through-holes extending through the separators and aligned in a stacking direction of the power generation cells. A method for manufacturing a fuel cell stack includes forming a coating of electrodeposition paint on surfaces of ones of the separators having a high electric potential in the fuel cell stack by operating the fuel cell stack and using the coolant that contains electrodeposition paint particles.

Abstract: A fuel cell stack includes a plurality of cells that are stacked in a stacking direction. Each cell includes a power generating body and a pair of separators. The separators respectively are arranged on opposite surfaces of the power generating body in the stacking direction. Each separator includes a first surface and a second surface. A titanium nitride layer is formed on the first surface, and a conductive carbon layer is formed on the titanium nitride layer. A titanium nitride layer is formed on the second surface. Each separator is in contact with the power generating body via the titanium nitride layer and the carbon layer on the first surface and is in contact with one of the separators of an adjacent cell via the titanium nitride layer on the second surface.

Abstract: A separator for a fuel cell includes a base member, a first layer, and a second layer. The base member is made of a metal material. The first layer is made of a plastic material containing first conductive particles and covers the surface of the base member. The second layer is made of a plastic material containing graphite particles and second conductive particles smaller than the graphite particles, and covers the surface of the first layer.

Abstract: A coating forming device forms a coating on a substrate, which is a component of a fuel cell separator, by thermal transfer. The device includes a lower die and an upper die each having a heating portion. A pressing surface of the lower die and a pressing surface of the upper die are both formed by a heat-resistant elastic member.

Abstract: A separator includes a gas flow path forming body, which includes a substrate made of stainless steel, a resin layer arranged on the substrate, and a conductive layer arranged on the surface of the resin layer. The resin layer contains a filler, which has conductivity and greater hardness than an oxide film of the substrate. The conductive layer contains graphite. The filler extends through the oxide film of the substrate and contacts the base material.

Abstract: A fuel cell stack includes a plurality of cells that are stacked in a stacking direction. Each cell includes a power generating body and a pair of separators. The separators respectively are arranged on opposite surfaces of the power generating body in the stacking direction. Each separator includes a first surface and a second surface. A titanium nitride layer is formed on the first surface, and a conductive carbon layer is formed on the titanium nitride layer. A titanium nitride layer is formed on the second surface. Each separator is in contact with the power generating body via the titanium nitride layer and the carbon layer on the first surface and is in contact with one of the separators of an adjacent cell via the titanium nitride layer on the second surface.

Abstract: A separator is provided that has a metal substrate and a conductive resin layer on the surface of the metal substrate. The conductive resin layer contains a resin and a conductive substance dispersed in the resin. The separator is configured such that the proportion of the conductive substance to the resin increases continuously from the metal substrate toward the surface of the separator.

Abstract: A separator includes a gas flow path forming body, which includes a substrate made of stainless steel, a resin layer arranged on the substrate, and a conductive layer arranged on the surface of the resin layer. The resin layer contains a filler, which has conductivity and greater hardness than an oxide film of the substrate. The conductive layer contains graphite. The filler extends through the oxide film of the substrate and contacts the base material.

Abstract: A separator is provided that has a metal substrate and a conductive resin layer on the surface of the metal substrate. The conductive resin layer contains a resin and a conductive substance dispersed in the resin. The separator is configured such that the proportion of the conductive substance to the resin increases continuously from the metal substrate toward the surface of the separator.

Abstract: According to a molding method for a conductive plate of this invention, a substrate having through holes each corresponding to each protruded portion is employed and the substrate is sandwiched between both dies. Then raw powder is filled into each housing portion provided opposing each through hole in the substrate provided in each of both dies, through the through hole in order to form each protruded portion. Then the protruded portion is formed integrally with the substrate by heating the raw powder under pressure.

Abstract: A separator of this invention is so constructed that a plurality of protrusions are implanted in a substrate which forms a reactive chamber of a fuel cell. The substrate has a multiple layered structure in which a single side or both sides of a mesh foundation are covered with resin layer and contains through holes at positions corresponding to each of the protrusions. Each of the protrusions is formed by allowing black lead ink applied on the single side or both sides of the substrate to invade each through hole. Consequently, the substrate can be formed to be super thin, lightweight and the respective protrusions can be easily formed at low cost.

Abstract: According to a molding method for a conductive plate of this invention, a substrate having through holes each corresponding to each protruded portion is employed and the substrate is sandwiched between both dies. Then raw powder is filled into each housing portion provided opposing each through hole in the substrate provided in each of both dies, through the through hole in order to form each protruded portion. Then the protruded portion is formed integrally with the substrate by heating the raw powder under pressure.

Abstract: A separator of this invention is so constructed that a plurality of protrusions are implanted in a substrate which forms a reactive chamber of a fuel cell. The substrate has a multiple layered structure in which a single side or both sides of a mesh foundation are covered with resin layer and contains through holes at positions corresponding to each of the protrusions. Each of the protrusions is formed by allowing black lead ink applied on the single side or both sides of the substrate to invade each through hole. Consequently, the substrate can be formed to be super thin, lightweight and the respective protrusions can be easily formed at low cost.