Abstract: An operating control method of a fuel cell stack is provide. The method includes diagnosing performance of a fuel cell stack based on an output current of the fuel cell stack, when an operating voltage of the fuel cell stack is within a predetermined diagnostic voltage range. Whether a recovery operation of the fuel cell stack is required is determined based on the diagnosed performance of the fuel cell stack and the voltage of the fuel cell stack is reduced, when the recovery operation of the fuel cell stack is required to recover performance of the fuel cell stack.

Abstract: A method for recovering fuel cell performance by regenerating electrode characteristics through electrode reversal in order to partially recover performance of a degraded polymer electrolyte fuel cell is provided. The method includes reversing electrodes by supplying an anode of a degraded fuel cell stack with air and supplying a cathode thereof with hydrogen and performing a pulse operation by applying current to the reversed electrodes.

Abstract: An operating control method of a fuel cell stack is provide. The method includes diagnosing performance of a fuel cell stack based on an output current of the fuel cell stack, when an operating voltage of the fuel cell stack is within a predetermined diagnostic voltage range. Whether a recovery operation of the fuel cell stack is required is determined based on the diagnosed performance of the fuel cell stack and the voltage of the fuel cell stack is reduced, when the recovery operation of the fuel cell stack is required to recover performance of the fuel cell stack.

Abstract: An operation control system of a fuel cell is provided. The system includes a fuel cell stack and a motor connected to the fuel cell stack via a main bus end to receive power. A booster is disposed between a load and the fuel cell stack of the main bus end to adjust an output voltage of the fuel cell stack. A high-voltage battery is connected between a load and the booster of the main bus end and a voltage sensor is connected between the booster and the fuel cell stack of the main bus end to measure an output voltage of the fuel cell stack.

Abstract: Disclosed are a fuel cell system and a method for controlling the same which enable performance recovery of a stack together with a high potential avoidance operation while operating the fuel cell system. The fuel cell system includes a fuel cell stack, in which a first separation plate having a first air flow path and a second separation plate having a second, different air flow path are alternately stacked with a membrane-electrode assembly interposed therebetween; and the method includes determining whether a high-potential avoidance operation is required while operating the fuel cell system including the fuel cell stack, and selectively supplying air to the air flow path of the first separation plate or the second separation plate when a high-potential avoidance operation is required, so as to easily achieve cathode performance recovery during the high-potential avoidance operation of the fuel cell system and the operation of the fuel cell system.

Abstract: A method for recovering performance of a degraded polymer electrolyte fuel cell stack through electrode reversal. In detail, oxide films formed on the surface of platinum of a cathode is removed through an electrode reversal process that creates a potential difference between an anode and the cathode by supplying air to the anode instead of hydrogen and supplying a fuel to the cathode instead of air, thus rapidly recovering the performance of a degraded polymer electrolyte fuel cell stack.

Abstract: A method for accelerating activation of a fuel cell stack may shorten an activation time of the fuel cell stack and reduce the amount of hydrogen used. The method includes a process of applying a high current to the fuel cell stack for a prescribed amount of time and a shutdown maintenance process of pumping hydrogen to an air electrode reaction surface for a prescribed amount of time.

Abstract: A method of accelerating activation of a fuel cell stack includes repeating, a plurality of times, a process including: applying a specific cyclic voltammetric pulse of high current to the fuel cell stack for a designated time and maintaining shutdown of the fuel cell stack.

Abstract: A method for activating a fuel cell stack without using an electric load includes chemically adsorbing hydrogen into a catalyst of a cathode. Oxygen remaining in the stack is removed to seal and store the fuel cell stack while maintaining a negative pressure in the fuel cell stack. The method for activating a fuel cell stack does not require an electric load device, and therefore does not increase the number of activation equipment, thereby preventing the total production speed of the fuel cell stack from reducing in response to the stack activation.

Abstract: A method for recovering performance of a fuel cell stack includes 1) a first pulse operation process including i) generating a hydrogen pumping reaction in a cathode by applying a current to the cathode after a supply of air to the cathode stops and ii) maintaining an OCV (open circuit voltage) by again supplying air to the cathode after the hydrogen pumping is performed, 2) a pole substitution process of substituting a pole of the fuel cell stack, and 3) a second pulse operation process including iii) generating the hydrogen pumping reaction in the cathode after the pole substitution, and iv) maintaining the CCV (open circuit voltage) by supplying air to the cathode after the pole substitution after the hydrogen pumping is performed.

Abstract: A method for recovering the performance of a fuel cell stack mounted within a vehicle is provided. A method includes a recovery process of continuously applying a predetermined load using a load device when an air supply is stopped and hydrogen is supplied to a fuel cell stack to output current from the fuel cell stack. Further, protons and electrons generated by hydrogen oxidation reaction at an anode are moved to a cathode, to produce hydrogen at the cathode and simultaneously remove oxide on the catalyst surface of the cathode.

Abstract: A method for recovering performance of a fuel cell stack includes 1) a first pulse operation process including i) generating a hydrogen pumping reaction in a cathode by applying a current to the cathode after a supply of air to the cathode stops and ii) maintaining an OCV (open circuit voltage) by again supplying air to the cathode after the hydrogen pumping is performed, 2) a pole substitution process of substituting a pole of the fuel cell stack, and 3) a second pulse operation process including iii) generating the hydrogen pumping reaction in the cathode after the pole substitution, and iv) maintaining the OCV (open circuit voltage) by supplying air to the cathode after the pole substitution after the hydrogen pumping is performed.

Abstract: Disclosed are a fuel cell system and a method for controlling the same which enable performance recovery of a stack together with a high potential avoidance operation while operating the fuel cell system. The fuel cell system includes a fuel cell stack, in which a first separation plate having a first air flow path and a second separation plate having a second, different air flow path are alternately stacked with a membrane-electrode assembly interposed therebetween; and the method includes determining whether a high-potential avoidance operation is required while operating the fuel cell system including the fuel cell stack, and selectively supplying air to the air flow path of the first separation plate or the second separation plate when a high-potential avoidance operation is required, so as to easily achieve cathode performance recovery during the high-potential avoidance operation of the fuel cell system and the operation of the fuel cell system.

Abstract: A method for activating a stack of a fuel cell is provided. The method includes supplying oxygen and hydrogen to the stack after starting an activation process to change the stack to an open circuit voltage (OCV) state and terminating the supply. Adjacent cells of the stack are electrically connected by a cell voltage sensing terminal board and the adjacent cells are shorted to allow a cell voltage to be 0V. Additionally, oxygen and hydrogen are resupplied to the stack and predetermined current density is applied for a predetermined time is executed. The voltage is again decreased to be 0V by applying current density exceeding the predetermined current density for a time exceeding the predetermined time through the open circuit voltage state to remove oxygen remaining in the stack. Oxygen and hydrogen are resupplied after a silent period has elapsed for a predetermined time after removing the remaining oxygen.

Abstract: A method of accelerating activation of a fuel cell stack includes repeating, a plurality of times, a process including: applying a specific cyclic voltammetric pulse of high current to the fuel cell stack for a designated time and maintaining shutdown of the fuel cell stack.

Abstract: A method for activating a stack of a fuel cell is provided. The method includes supplying oxygen and hydrogen to the stack after starting an activation process to change the stack to an open circuit voltage (OCV) state and terminating the supply. Adjacent cells of the stack are electrically connected by a cell voltage sensing terminal board and the adjacent cells are shorted to allow a cell voltage to be 0V. Additionally, oxygen and hydrogen are resupplied to the stack and predetermined current density is applied for a predetermined time is executed. The voltage is again decreased to be 0V by applying current density exceeding the predetermined current density for a time exceeding the predetermined time through the open circuit voltage state to remove oxygen remaining in the stack. Oxygen and hydrogen are resupplied after a silent period has elapsed for a predetermined time after removing the remaining oxygen.

Abstract: Disclosed is an apparatus and method for activating a fuel cell stack, which significantly reduces the time required for activation and the amount of hydrogen used for the activation by employing a vacuum wetting process in a shutdown operation. In particular, a high humidity open circuit voltage operation humidifies the fuel cell stack and operates the fuel cell stack at an open circuit voltage, and a vacuum wetting operation wets the surface of a polymer electrolyte membrane by creating a vacuum atmosphere in the fuel cell stack. The high humidity open circuit voltage operation and the vacuum wetting operation are performed alternately and repeatedly.

Abstract: A method for recovering performance of a fuel cell stack includes 1) a first pulse operation process including i) generating a hydrogen pumping reaction in a cathode by applying a current to the cathode after a supply of air to the cathode stops and ii) maintaining an OCV (open circuit voltage) by again supplying air to the cathode after the hydrogen pumping is performed, 2) a pole substitution process of substituting a pole of the fuel cell stack, and 3) a second pulse operation process including iii) generating the hydrogen pumping reaction in the cathode after the pole substitution, and iv) maintaining the OCV (open circuit voltage) by supplying air to the cathode after the pole substitution after the hydrogen pumping is performed.

Abstract: A method for accelerating activation of a fuel cell stack may shorten an activation time of the fuel cell stack and reduce the amount of hydrogen used. The method includes a process of applying a high current to the fuel cell stack for a prescribed amount of time and a shutdown maintenance process of pumping hydrogen to an air electrode reaction surface for a prescribed amount of time.

Abstract: A hydrogen supply apparatus of fuel cell stack is provided. In particular, a plurality of unit cells includes a membrane electrode assembly, a separating plate disposed on two sides of the membrane electrode assembly, a coolant path, an air path, a fuel path, and an air inlet manifold communicated with the air path. An end plate is disposed on each end of the plurality of unit cells and forms an air inlet manifold in a location corresponding to the air inlet manifold of the separating plate. Additionally, a hydrogen supply apparatus is provided in the air inlet manifold of the separating plate and the air inlet manifold of the end plate that selectively supplies additional hydrogen to the cathode through the air path when needed.