A metal-air battery apparatus includes an inlet module and a main module each having a metal-air battery cell structure including a positive electrode and a negative electrode. The inlet module and the main module are electrically controlled and independently controlled from each other, and a channel through which a fluid such as air flows is defined between the inlet module and the main module. A temperature of the inlet module and a temperature of the main module are independently controlled by adjusting a discharge current density or by charging or a temperature adjustor.

The control method for a flow battery includes acquiring a current electrolyte capacity decay rate of the flow battery; comparing the current electrolyte capacity decay rate with a first preset decay rate and a second preset decay rate; when the current electrolyte capacity decay rate is greater than the first preset decay rate and less than the second preset decay rate, adjusting a liquid level of positive electrolyte and a liquid level of negative electrolyte, such that a difference between these two liquid levels is less than a preset value, a ratio of the total amount of vanadium in the positive electrolyte to the total amount of vanadium in the negative electrolyte remains in a first preset ratio range, or a ratio of a vanadium ion concentration in the positive electrolyte to a vanadium ion concentration in the negative electrolyte remains in a second preset ratio range.

A method of controlling a temperature of metal-air battery apparatus includes measuring the temperature of the metal-air battery apparatus to obtain the temperature and a temperature deviation of the metal-air battery apparatus, comparing the measured temperature and the temperature deviation of the metal-air battery apparatus with a preset temperature and a preset temperature deviation, respectively; and adjusting the temperature of an inlet module or a main module when the measured temperature of the metal-air battery apparatus is less than the preset temperature or the temperature deviation of the metal-air battery apparatus is greater than the preset temperature deviation.

A fuel cell system may include a fuel cell; a hydrogen gas supply passage configured to supply hydrogen gas to the fuel cell; a solenoid valve configured to change an opening degree of the hydrogen gas supply passage; a pressure sensor configured to detect a pressure in a downstream supply passage which is a part of the hydrogen gas supply passage from the solenoid valve to the fuel cell; and a control circuit configured to control the solenoid valve. The control circuit may be configured to perform: detecting and storing a conducted electric current conducted in the solenoid valve and the pressure at plural points while changing the conducted electric current at a first sweep speed; and detecting and storing the conducted electric current and the pressure at plural points while changing the conducted electric current at a second sweep speed different from the first speed.

Methods and systems are provided for iron preformation in a redox flow battery. In one example, a method may include, in a first condition, discharging and then charging the redox flow battery, and in a second condition, charging the redox flow battery including preforming iron metal at a negative electrode of the redox flow battery, and thereafter entering an idle mode of the redox flow battery including adjusting one or more electrolyte conditions. In some examples, each of preforming the iron metal and adjusting the one or more electrolyte conditions may increase a battery charge capacity to greater than a threshold battery charge capacity.

Methods and systems are provided for iron preformation in a redox flow battery. In one example, a method may include, in a first condition, discharging and then charging the redox flow battery, and in a second condition, charging the redox flow battery including preforming iron metal at a negative electrode of the redox flow battery, and thereafter entering an idle mode of the redox flow battery including adjusting one or more electrolyte conditions. In some examples, each of preforming the iron metal and adjusting the one or more electrolyte conditions may increase a battery charge capacity to greater than a threshold battery charge capacity.

The invention relates to a device (1) having at least one fuel cell (2) and a DC/DC converter (3) assigned to the latter. A variable voltage generated in the fuel cell (2) is converted, by means of the DC/DC converter (3), into a DC voltage for a system (4) to be supplied. The DC/DC converter (3) is designed to capture internal characteristic variables of the fuel cell (2). Operating states of the fuel cell (2) are captured and/or controlled in dependence on these characteristic variables.

A power supply device disposed on an aircraft to provide a power to the aircraft is provided. The aircraft has an average required power value. The power supply device includes a secondary battery, a transformer and a fuel cell. The transformer is coupled between the secondary battery and the aircraft. The fuel cell is coupled to the aircraft and is adapted to provide a first output current to the aircraft. The transformer has an output voltage set value. When the first output end voltage of the fuel cell is lower than the output voltage set value, the transformer provides a second output current of the secondary battery to the aircraft. The output voltage set value is in a voltage range with a fuel cell output power between the maximum power value of characteristic curve of the fuel cell and the average required power value of the aircraft.

The invention relates to a device (1) having at least one fuel cell (2) and a DC/DC converter (3) assigned to the latter. A variable voltage generated in the fuel cell (2) is converted, by means of the DC/DC converter (3), into a DC voltage for a system (4) to be supplied. The DC/DC converter (3) is designed to capture internal characteristic variables of the fuel cell (2). Operating states of the fuel cell (2) are captured and/or controlled in dependence on these characteristic variables.

A controller of a fuel cell system detects catalytic layer deterioration and drainage malfunction by the following inspection process. The controller may: execute drainage of water from a fuel cell, and acquire first/second output voltages of the fuel cell when an output current density of the fuel cell is a first reference current density A1/A2 (A2>A1). When the first output voltage is lower than a first threshold voltage and the second output voltage is higher than a second threshold voltage, the controller may output a first determination signal indicating that the catalytic layer is deteriorated and the drainage is executed without malfunction. When the first output voltage is higher than the first threshold voltage and the second output voltage is lower than the second threshold voltage, the controller may output a second determination signal indicating that the catalytic layer is not deteriorated and the drainage is executed with malfunction.