An apparatus for measuring an impedance of a fuel cell is configured to: output an AC current to a fuel cell; and adjust an impedance so that an impedance between the fuel cell and a load device becomes higher than an impedance between a secondary battery and the load device at a frequency of the AC current outputted to the fuel cell. The apparatus is also configured to: adjust the AC current so that a positive-electrode side AC potential difference matches a negative-electrode side AC potential difference, the positive-electrode side AC potential difference being a difference between an electric potential of the fuel cell on a positive electrode side and a middle electric potential, the negative-electrode side AC potential difference being a difference between an electric potential of the fuel cell on a negative electrode side and the middle electric potential; and calculate an impedance of the fuel cell on the basis of the adjusted AC current and at least one AC potential difference of the positive-electrode side AC potential difference and the negative-electrode side AC potential difference.

The invention relates to a method for cooling a fuel cell system by operating a cooling system, comprising a coolant pump, a cooler through which coolant can flow, a bypass with a bypass valve for selectively, at least partially bridging the cooler, and a coolant passage of a fuel cell stack thermally coupled to the fuel cell system, said method comprising the following steps: determining a flooding risk of the fuel cell system at least once according to current operating conditions of the fuel cell system; determining a maximum permissible temperature gradient based on the determined flooding risk; operating the coolant pump such that it conveys a volumetric flow of a coolant through the coolant passages of the stack and the cooler; actuating the bypass valve such that it divides the volumetric flow through the bypass and the cooler; and limiting a cooling output by limiting the volumetric flow and a status of the bypass valve in order to limit the temperature gradient to the determined maximum permissible temperature gradient.

A control device of a fuel cell system includes an electric conductivity comparing unit for comparing the electric conductivity of the water inside the ion exchanger which is measured by the electric conductivity measuring unit with a predetermined electric conductivity range, and an ion exchange environment determining unit for arbitrarily determining whether or not air has been mixed into an ion exchanger and whether or not the ion exchange efficiency of the ion exchanger has been degraded, based on a comparison result by the electric conductivity comparing unit.

A direct isopropanol fuel cell adapted for use in ambient conditions and utilizing as fuel isopropanol and water preferably with isopropanol at relatively high concentrations representing 30% to 90% isopropanol.

A fuel cell system includes: a processing unit configured to perform an activation process of temporarily reducing a cathode potential of a single fuel cell to a target potential for a duration time at a processing frequency; a cationic impurity amount estimating unit configured to estimate an amount of cationic impurities included in an electrolyte membrane of the single fuel cell; and a process degree determining unit configured to determine, when the amount of cationic impurities is large, a degree of the activation process which is higher than that determined when the amount of cationic impurities is small by performing at least one action among actions of changing conditions of the activation process, the actions including an action of reducing the target potential, an action of increasing the duration time, and an action of increasing the processing frequency. The processing unit performs the activation process to the determined degree.

A structure for increasing durability of an ion filter, which includes a reservoir configured to store cooling water discharged from a fuel cell stack, an ion filter configured to remove ions from the cooling water discharged from the fuel cell stack, a flow rate adjustment valve disposed between the ion filter and the fuel cell stack, a first pipe which flows the cooling water from the ion filter to the reservoir, and a second pipe that is a passage through which air or the cooling water is moved between the reservoir and the ion filter according to a change in level of the cooling water inside the ion filter.

A fuel cell system includes a fuel cell for generating electrical power upon being supplied with anode gas and cathode gas. The fuel cell system includes a wetness control state determination unit that determines whether or not a wetness control of controlling a degree of wetness of an electrolyte membrane of the fuel cell is normally executed, a combined capacitance calculation unit that calculates a combined capacitance of the fuel cell, and an anode gas concentration control unit that determines the occurrence of decrease in an anode gas concentration in the fuel cell or executes a control for increasing the anode gas concentration if the combined capacitance of the fuel cell is smaller than a predetermined value when the wetness control is determined to be normally executed.

A electrochemical battery including: a battery module including one or more metal air cells which use oxygen gas as a positive electrode active material; an air supply configured to supply air to the battery module and to adjust an oxygen concentration in air supplied to the battery module; and a control unit configured to control an oxygen concentration adjusting operation of the air supply unit. Also a method of operating the electrochemical battery including: supplying air to a battery module using an air supply unit, the battery module including one or more metal air cells which use oxygen in air as a positive electrode active material; and controlling the air supply unit to adjust an oxygen concentration in the air supplied to the battery module.

A high-voltage (HV) component is reconfigurable to be included in a centralized HVIL system or reconfigurable to be included in a de-centralized HVIL system. The HV component comprises an internal Hazardous Voltage Interlock Loop (HVIL) system comprising a signal continuity detection circuit comprising a signal detector and a high-voltage connector. A first signal generator of the internal HVIL system is configured to generate a signal in the signal continuity detection circuit and is reconfigurable to either be connected to or disconnected from an external HVIL system of the vehicle. A signal communication interface of the HV component is configurable to provide an electrical connection between the signal continuity detection circuit of the internal HVIL system and the external HVIL system, and is configurable to allow the first signal generator to be disconnected from the signal continuity detection circuit.

In an embodiment, a diagnosis apparatus for an electrochemical module in which at least one of an anode and a cathode includes a catalyst is provided, and the diagnosis apparatus includes an output circuit and a processor. The processor, in a state in which the operation power is input to the electrochemical module or the operation power is output from the electrochemical module, superimposes the inspection power on the operation power by supplying the inspection power from the output circuit to the electrochemical module, and measures measurement data for diagnosis by measuring a current and a voltage for the electrochemical module in a state in which the inspection power is superimposed on the operation power.