A method for starting a fuel cell and to a fuel cell system which is configured to carry out the method. The fuel cell includes electrically conductive bipolar plates, arranged between which there is in each case a cathode, including a fluid-conducting cathode space, a membrane and an anode, including a fluid-conducting anode space. There is provision that the method includes the following steps in the specified order: purging the anode space with a fluid in order to expel fuel, impressing electricity on a unit composed of the cathode (2k)/membrane (1)/anode (2a) by applying a current and/or a voltage, wherein the fluid is applied to the anode space or continues to be so, switching off the electricity, and introducing a fuel into the anode space.

A method is disclosed for regenerating an electrode of a flow battery. The method can be executed during shutdown of the flow battery from an active charge/discharge mode to an inactive, shut-down mode in which neither a negative electrolyte nor a positive electrolyte are circulated through at least one cell of the flow battery. The method includes driving voltage of the least one cell of the flow battery toward zero by converting, in-situ, the negative electrolyte in the at least one cell to a higher oxidation state. The negative electrolyte is in contact with an electrode of the at least one cell. The higher oxidation state negative electrolyte is used to regenerate, in-situ, catalytically active surfaces of the electrode of the at least one cell.

A fuel cell system according to the present invention comprises a control apparatus which performs performance restoration processing for a catalyst layer by decreasing the output voltage of a fuel cell to a predetermined voltage. When an oxide film formed on the catalyst layer during power generation of the fuel cell contains, in addition to a first oxide film that can be removed by decreasing the output voltage of the fuel cell to a first oxide film removal voltage, a second oxide film that can be removed by decreasing the output voltage of the fuel cell to a second oxide film removal voltage which is lower than the first oxide film removal voltage, the control apparatus estimates the amount of the second oxide film and performs performance restoration processing with a set voltage being equal to or lower than the second oxide film removal voltage only when it determines that the estimated amount exceeds a predetermined amount A.

The fuel cell system of the present disclosure includes: a fuel cell that includes a membrane electrode assembly including a proton conducting ceramic electrolyte membrane, a cathode disposed on a first surface of the electrolyte membrane, and an anode disposed on a second surface of the electrolyte membrane, the fuel cell generating electric power through an electrochemical reaction using a fuel gas and an oxidant gas; a power source that applies a voltage to the fuel cell; and a controller. In a shutdown process, the controller controls the power source to apply the voltage to the fuel cell such that a terminal voltage of the fuel cell is equal to or higher than an open circuit voltage of the fuel cell.

A fuel cell module is configured or operated, or both, such that after a shut down procedure a fuel cell stack is discharged and has its cathode electrodes at least partially blanketed with nitrogen during at least some periods of time. If the fuel cell module is restarted in this condition, electrochemical reactions are limited and do not quickly re-charge the fuel cell stack. To decrease start up time, air is moved into the cathode electrodes before the stack is re-charged. The air may be provided by a pump, fan or blower driven by a battery or by the flow or pressure of stored hydrogen. For example, an additional fan or an operating blower may be driven by a battery until the fuel cell stack is able to supply sufficient current to drive the operating blower for normal operation.

The present disclosure provides a method and apparatus to perform an electrochemical process by manipulating the charge on an electrode involved in the primary circuit of the electrochemical reaction. The amount of charge on the electrode can be manipulated independent of the bias voltage of the primary circuit and is accomplished by coupling the electrode with various different configurations.

A fuel cell system has a fuel cell stack including a plurality of fuel cells and an anode injector system, and a controller programmed. The controller, responsive to an amplitude of cyclic changes in voltage of at least some of the fuel cells exceeding a threshold, a frequency of the cyclic changes being within a predetermined range of a frequency associated with the anode injector system, and the voltage being less than a predetermined value, disables the fuel cell stack.

A method for reducing cell degradation in a fuel cell system includes adding oxygen-containing gas to a fuel in the anode chamber to prevent an increase in a cell voltage above a predetermined maximum value.

A fuel cell module is configured or operated, or both, such that after a shut down procedure a fuel cell stack is discharged and has its cathode electrodes at least partially blanketed with nitrogen during at least some periods of time. If the fuel cell module is restarted in this condition, electrochemical reactions are limited and do not quickly re-charge the fuel cell stack. To decrease start up time, air is moved into the cathode electrodes before the stack is re-charged. The air may be provided by a pump, fan or blower driven by a battery or by the flow or pressure of stored hydrogen. For example, an additional fan or an operating blower may be driven by a battery until the fuel cell stack is able to supply sufficient current to drive the operating blower for normal operation.

The invention relates to a fuel cell (2) comprising at least one membrane/electrode unit (10) comprising a first electrode and a second electrode, which electrodes are separated from one another by a membrane, and comprising at least one polar plate (40) which comprises a first distribution region (50) for distributing a fuel to the first electrode and a second distribution region (60) for distributing an oxidation agent to the second electrode. The first electrode and the second electrode of the at least one membrane electrode unit (10) are electrically connected by means of a conductor (90). The invention also relates to a fuel cell stack (5) which comprises a plurality of the claimed fuel cells (2).