The invention relates to a fuel cell (1) for a fuel cell stack (11), comprising a polymer membrane (2) which serves as an electrolyte and has respectively on both sides a catalyst layer (3, 4) for forming an anode (3) on the one side and a cathode (4) on the other side, a gas diffusion layer (5) and a bipolar plate (6) being applied to each of the two analyst layers (3, 4). According to the invention, a short-circuit element (7) is applied, preferably printed, to at least one bipolar plate (6). namely on the side facing away from the gas diffusion layer (5). The invention also relates to a fuel cell stack (11) and to a inetliod for operating a fuel cell stack (11).

The invention relates to a fuel cell (1) for a fuel cell stack (11), comprising a polymer membrane (2) which serves as an electrolyte and has respectively on both sides a catalyst layer (3, 4) for forming an anode (3) on the one side and a cathode (4) on the other side, a gas diffusion layer (5) and a bipolar plate (6) being applied to each of the two analyst layers (3, 4). According to the invention, a short-circuit element (7) is applied, preferably printed, to at least one bipolar plate (6). namely on the side facing away from the gas diffusion layer (5). The invention also relates to a fuel cell stack (11) and to a inetliod for operating a fuel cell stack (11).

A layer system for coating a metal substrate in order to form a flow field plate includes at least one cover layer made of metal oxide; at least one intermediate layer, which supports the cover layer; and a lower layer, which supports the intermediate layer(s). The cover layer is formed of indium tin oxide; wherein the indium tin oxide is optionally doped with at least one element from the group comprising carbon, nitrogen, boron, fluorine, hydrogen, silicon, titanium, tin and zirconium. At least one intermediate layer is formed of titanium nitride and/or titanium carbide and/or titanium carbonitride and/or titanium niobium nitride and/or titanium niobium carbide and/or titanium niobium carbonitride and/or chromium nitride and/or chromium carbide and/or chromium carbonitride. The lower layer is formed of titanium or a titanium-niobium alloy or chromium.

A layer system for coating a metal substrate in order to form a flow field plate includes at least one cover layer made of metal oxide; at least one intermediate layer, which supports the cover layer; and a lower layer, which supports the intermediate layer(s). The cover layer is formed of indium tin oxide; wherein the indium tin oxide is optionally doped with at least one element from the group comprising carbon, nitrogen, boron, fluorine, hydrogen, silicon, titanium, tin and zirconium. At least one intermediate layer is formed of titanium nitride and/or titanium carbide and/or titanium carbonitride and/or titanium niobium nitride and/or titanium niobium carbide and/or titanium niobium carbonitride and/or chromium nitride and/or chromium carbide and/or chromium carbonitride. The lower layer is formed of titanium or a titanium-niobium alloy or chromium.

An electrode catalyst layer that suppresses degradation due to repeated starting and stopping and has excellent durability, and a membrane electrode assembly using the electrode catalyst layer. The electrode catalyst layer is an electrode catalyst layer used in a polymer fuel electrolyte fuel cell, which contains carbon particles which support catalyst, a polymer electrolyte, and a fiber material which is at least one of a carbon fiber and an organic electrolyte fiber, and the thickness of the electrode catalyst layer after performing a start-stop test from 1 V to 1.5 V for 10,000 cycles is 70% or more of the thickness of the electrode catalyst layer before the start-stop test.

An electrode catalyst layer that suppresses degradation due to repeated starting and stopping and has excellent durability, and a membrane electrode assembly using the electrode catalyst layer. The electrode catalyst layer is an electrode catalyst layer used in a polymer fuel electrolyte fuel cell, which contains carbon particles which support catalyst, a polymer electrolyte, and a fiber material which is at least one of a carbon fiber and an organic electrolyte fiber, and the thickness of the electrode catalyst layer after performing a start-stop test from 1 V to 1.5 V for 10,000 cycles is 70% or more of the thickness of the electrode catalyst layer before the start-stop test.

Disclosed is a membrane-electrode assembly having increased active area, improved fluid management capability, and decreased gas transfer resistance due to electrodes having patterned structures on both sides. Also disclosed are a method for manufacturing same, and a fuel cell comprising same. A membrane-electrode assembly according to the present invention comprises: a first electrode; a second electrode; and a polymer electrolyte membrane between the first and second electrodes, wherein the first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite the first surface, the first surface having a first patterned structure, and the second surface having a second patterned structure.

A membrane electrode assembly for the fuel cell includes a solid polymer electrolyte membrane, an anode catalyst layer assembled to one surface of the solid polymer electrolyte membrane, and a cathode catalyst layer assembled to another surface of the solid polymer electrolyte membrane. The membrane electrode assembly contains cerium ions. The membrane electrode assembly includes a power-generation region and a non-power-generation region. The power-generation region includes the catalyst layers on both surfaces of the solid polymer electrolyte membrane in a center portion. The non-power-generation region is without the catalyst layer on at least one surface of the solid polymer electrolyte membrane in an outer periphery portion. A cerium ion content per area in the power-generation region is larger than a cerium ion content per area in the non-power-generation region.

A membrane electrode assembly that can enhance power generation performance, and a polymer electrolyte fuel cell. The membrane electrode assembly for use in a polymer electrolyte fuel cell according to an aspect of the present invention includes a polyelectrolyte membrane, a fuel electrode-side electrocatalyst layer, and an oxygen electrode-side electrocatalyst layer. The fuel electrode- and oxygen electrode-side electrocatalyst layers and contain voids which include pores having a diameter in the range of 3 nm or more and 5.5 μm or less. When the integrated pore volume for all the pores in the fuel electrode- and oxygen electrode-side electrocatalyst layers and is a first integrated volume, the value obtained by dividing the first integrated volume by the mass of the catalytic material contained in both of the electrocatalyst layers is in the range of 2.8 or more and 4.5 or less.

A membrane electrode assembly that can enhance power generation performance, and a polymer electrolyte fuel cell. The membrane electrode assembly for use in a polymer electrolyte fuel cell according to an aspect of the present invention includes a polyelectrolyte membrane, a fuel electrode-side electrocatalyst layer, and an oxygen electrode-side electrocatalyst layer. The fuel electrode- and oxygen electrode-side electrocatalyst layers and contain voids which include pores having a diameter in the range of 3 nm or more and 5.5 μm or less. When the integrated pore volume for all the pores in the fuel electrode- and oxygen electrode-side electrocatalyst layers and is a first integrated volume, the value obtained by dividing the first integrated volume by the mass of the catalytic material contained in both of the electrocatalyst layers is in the range of 2.8 or more and 4.5 or less.