Abstract:
A polymer electrolyte fuel cell of the present invention includes conductive separator plates comprising molded plates of a composition comprising a binder, conductive carbon particles whose average particle diameter is not less than 50 μm and not more than ⅓ of the thickness of the thinnest portion of the conductive separator plate, and at least one of conductive carbon fine particles and micro-diameter carbon fibers. The separator plates do not require conventional cutting processes for gas flow channels, etc., and can be easily mass produced by injection molding and achieve a reduction in the cost.
Abstract:
Even if reaction gas flows into a substantially rectangular anode-side and cathode-side gaps formed between an annular main body portion and a membrane electrode assembly in an anode side and a cathode side of a fuel cell, the reaction gas is prevented from flowing out from an outlet without passing through an electrode to cause degradation of power generation efficiency. At least one of anode-side gasket and cathode-side gasket in the fuel cell is provided with an extra sealing portion connected to an annular main body portion in such a manner that, among two pairs of gap portions opposing to each other in the anode-side gap and the cathode-side gap, the extra sealing portion intersects with one pair of gap portions having a larger pressure gradient of fuel gas and oxidant gas in a direction from an upstream side to a downstream side of a fuel gas flow channel and an oxidant gas flow channel.
Abstract:
A decrease in voltage in a polymer electrolyte fuel cell comprising stack of unit cells caused by the temperature difference between the cells located at the ends and the other cells due to a differential in heat dissipation from end plates is prevented by controlling the cooling temperature of the cells closest to the end plates of the fuel cell without affecting the output voltage of the cells in the middle by not including a coolant flow channel in the conductive separator plate between at least one of the end plates and the unit cell located closest to the one of the end plates.
Abstract:
The temperature of cooling fluid in an inlet side manifold is increased during power generation by influence of the temperature of heat generation sections of cells. This causes variation in temperature among unit cells in a fuel cell stack, causing flooding and variation in output voltage. The invention provides a fuel cell in which an increase in temperature of cooling fluid in an inlet side manifold is suppressed, and that has an excellent durability and a stable output voltage. The fuel cell has flow paths for cooling fluid in cathode side separator plates and anode side separator plates, the flow paths connecting an inlet side manifold and an outlet side manifold for cooling fluid. Each of the flow paths for cooling fluid includes a first cooling section for cooling a heat generation section, that is, an area corresponding to a cathode or an anode, and a second cooling section located between the first cooling section and the inlet side manifold for cooling fluid.
Abstract:
Provided is a method of preserving a PEFC stack, which is capable of controlling degradation of performance of the PEFC stack during a time period that elapses from when the stack is placed in an uninstalled state until it is placed in an installation position and is practically used. Provided is a preservation assembly of the PEFC stack which is capable of sufficiently inhibiting degradation of performance of the PEFC stack particularly during a time period that elapses from when the stack is placed in the uninstalled state until it is placed in the installation position and is practically used. A method of preserving a PEFC stack that is provided with an oxidizing agent passage (30) having an inlet and an outlet and extending through a cathode and a reducing agent passage (40) having an inlet and an outlet and extending through an anode, comprising preserving the PEFC (200) stack in an uninstalled state in such a manner that an interior of the oxidizing agent passage (30) and an interior of the reducing agent passage (40) are set in a pressure-reduced state.
Abstract:
There is provided a polymer electrolyte fuel cell capable of: sufficiently suppressing the progress of drying of the polymer electrolyte in the catalyst layers and of the polymer electrolyte membrane, and in addition, the occurrence of flooding, even if the moistened conditions of the fuel gas or the oxidant gas fed to the fuel cell change; suppressing the degradation of the anode, cathode and polymer electrolyte membrane; and thus reducing the deterioration of the cell performance readily and reliably. The polymer electrolyte fuel cell includes: a polymer electrolyte membrane; an anode and a cathode which are arranged in such a manner as to hold the polymer electrolyte membrane between them; and a pair of separators having a first gas flow path for feeding fuel gas to the anode and discharging fuel gas from the anode and a second gas flow path for feeding oxidant gas to the cathode and discharging oxidant gas from the cathode, where a notched portion is made on each of the anode and the cathode in such a position so as to allow the two notched portions to face each other, the polymer electrolyte membrane is held by the pair of separators in that position, and the polymer electrolyte membrane is supported by reinforcing members having gas permeability in the notches.
Abstract:
A fuel cell including a cell stack including plural electrically conductive separator plates and MEAs (electrolyte membrane-electrode assemblies) inserted among the separator plates. The fuel cell further includes gas communication grooves, where the gas communication grooves on one main surface of each separator plate are positioned to correspond to the ribs on the other main surface thereof, whereby thin wall portions in the separator plate can be avoided as much as possible, thereby to solve above described problems.
Abstract:
A method of preserving a PEFC stack of the present invention is a method of preserving a PEFC stack that is provided with an oxidizing agent passage having an inlet and an outlet and extending through a cathode and a reducing agent passage having an inlet and an outlet and extending through an anode. The method comprises preserving the polymer electrolyte fuel cell stack in an uninstalled state under a condition in which an oxygen concentration within the oxidizing agent passage and within the reducing agent passage is lower than an oxygen concentration in atmospheric air.
Abstract:
A conductive separator plate for a polymer electrolyte fuel cell is disclosed which includes a cell stack and a plurality of conductive separator plates, the conductive separator plates being formed of a carbon powder and a binder, the conductive separator plates having a main portion which is raised from a peripheral portion surrounding the main portion, the main portion being in contact with an anode or cathode of the fuel cell and being provided with a gas flow path for supplying a fuel gas to the anode or a gas flow path for supplying an oxidant gas to the cathode.
Abstract:
A separator for use in a fuel cell of the present disclosure includes: a plate; a first gas manifold hole (51) for supplying a reactant gas, formed to penetrate said plate in a thickness direction thereof; a second gas manifold hole (52) for discharging the reactant gas, formed to penetrate said plate in a thickness direction thereof; one or more groove-like first main gas channels (18) formed on a surface of said plate to have one end connected to said first gas manifold hole (51) and the other end connected to said second gas manifold hole; a groove-like first sub-gas channel (28) formed on the surface of said plate to have one end connected to at least one of said first gas manifold hole (51) and said second gas manifold hole (52); and a groove-like second sub-gas channel (38) formed on the surface of said plate to have one end branching from said first sub-gas channel (28) and the other end being closed.