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 redox battery comprises a plurality of redox battery cells stacked in a stacking direction, wherein each of the redox battery cells comprises a first half cell connected to a positive current collector, a second half cell connected to a negative current collector and an ion exchange membrane separating the first and second half cells. The redox battery additionally comprises a positive conducting bus bar extending in the stacking direction and electrically connecting the positive current collectors of the redox battery cells in parallel, and a negative conducting bus bar extending in the stacking direction and electrically connecting the negative current collectors of the redox battery cells in parallel. One or both of the positive and negative bus bars are configured as fastening means for mechanically fastening the stacked redox battery cells in the stacking direction

A method of operating a fuel cell assembly comprising a plurality of fuel cells connected together for collectively providing power to a load, each fuel cell including an anode and a cathode, the method comprising selectively providing an electrical connection between the anode and the cathode of at least one of the fuel cells of the assembly for lowering the voltage across the fuel cell independent of the load.

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 method for operating a fuel cell stack (11).

A power supply device for the electric power supply of at least one consumer is provided having a primary power grid in which there is present a fuel cell arrangement comprising electric contacts which includes a discharge circuit switched in parallel and connected to the electric contacts comprising a switch element activatable by means of a controller across a switch line as well as a resistance element and having a DC-DC converter which is present in the primary power grid by which the primary power grid is connected to a secondary power grid characterized in that the discharge circuit comprises a safety device or a safety function, which holds the switch element in an opened state and thereby makes the discharge circuit inactive for as long as an actuating possibility exists via the switch line, and which places the switch element in a closed state and thereby makes the discharge circuit active for lowering the voltage of the fuel cell arrangement once the actuating possibility via the switch line is denied. Furthermore, a method for lowering the voltage of a fuel cell arrangement of a power supply device is also provided.

An apparatus configured for controlling emergency driving for a fuel cell vehicle may include a failure detector configured to detect whether a purge valve and a drain valve fails; a determination portion configured to measure voltages of channels of a fuel cell stack to determine whether stability of the fuel cell stack is secured; and a controller configured to control, when the stability of the fuel cell stack is not secured and a failure occurs on one or more of the purge valve and the drain valve, one or more of an operating pressure and an operating temperature of the fuel cell stack and a current applied to the fuel cell stack.

A power supply device for the electric power supply of at least one consumer is provided having a primary power grid, in which there is present a fuel cell arrangement comprising electric contacts, which includes a discharge circuit switched in parallel and connected to the electric contacts, comprising a switch element activatable by means of a controller across a switch line as well as a resistance element, and having a DC-DC converter which is present in the primary power grid, by which the primary power grid is connected to a secondary power grid, characterized in that the discharge circuit comprises a safety device or a safety function, which holds the switch element in an opened state and thereby makes the discharge circuit inactive for as long as an actuating possibility exists via the switch line, and which places the switch element in a closed state and thereby makes the discharge circuit active for lowering the voltage of the fuel cell arrangement once the actuating possibility via the switch line is denied. Furthermore, a method for lowering the voltage of a fuel cell arrangement of a power supply device is also provided.

The invention relates to a device and a method for isolating a fuel cell, which make it possible to safely work on the fuel cell during a servicing or repair operation.

A fuel cell system includes a first plurality of fuel cells having a cathode and an anode. The plurality of fuel cells is configured to produce electrical power having a current and a voltage output. The plurality of fuel cells includes a first conductive plate and a second conductive plate. A shunt is electrically connected to the first conductive plate and the second conductive plate for shunting voltage output between the cathode and the anode. The shunt is mounted to, and supported by, the plurality of fuel cells. The shunt is connected to a control mechanism to control a shorting of one or more fuel cells of the plurality of fuel cells. The control mechanism is mounted to, and supported by, the plurality of fuel cells.

An apparatus configured for controlling emergency driving for a fuel cell vehicle may include a failure detector configured to detect whether a purge valve and a drain valve fails; a determination portion configured to measure voltages of channels of a fuel cell stack to determine whether stability of the fuel cell stack is secured; and a controller configured to control, when the stability of the fuel cell stack is not secured and a failure occurs on one or more of the purge valve and the drain valve, one or more of an operating pressure and an operating temperature of the fuel cell stack and a current applied to the fuel cell stack.