Disclosed is a performance evaluation apparatus of a fuel cell electrode. The performance evaluation apparatus includes a working electrode unit configured such that a working electrode is disposed therein, gas is supplied to an inside of the working electrode unit, and voltage and current are measured by a current collection rod, a counter electrode unit provided to guide mounting of the working electrode unit so that a counter electrode faces the working electrode, and configured to store an electrolyte solution, current is measured by the current collection rod, and voltage is measured by a reference electrode immersed in the electrolyte solution, a heater unit immersed in the electrolyte solution to heat the electrolyte solution, and a control unit configured to selectively adjust a temperature of the heater unit within a set temperature range, and to evaluate performance of the working electrode.

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 method for determining an average oxidation state (AOS) of a redox flow battery system includes measuring a charge capacity for a low potential charging period starting from a discharged state of the redox flow battery system to a turning point of a charge voltage; and determining the AOS using the measured charge capacity and volumes of anolyte and catholyte of the redox flow battery system. Other methods can be used to determine the AOS for a redox flow battery system or use discharge voltage instead of charging voltage.

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.

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 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.

A fuel cell system wherein the controller preliminarily stores a data group indicating a correlation between a voltage of the fuel cell and a concentration of impurity gas in the fuel gas; wherein the controller controls ON and OFF of the fuel gas supplier, wherein the controller operates the fuel gas supplier and determines whether or not the fuel cell voltage measured by the voltage sensor after an elapse of a predetermined time is less than a first threshold; and wherein, when the controller determines that the fuel cell voltage measured by the voltage sensor is less than the first threshold, the controller compares the voltage with the data group and determines that the concentration of the impurity gas in the fuel gas is higher than a predetermined concentration threshold.

A method for preparation of electrolyte for a redox flow battery includes reducing chromium ore using a carbon source to convert the chromium ore to an iron/chromium alloy with carbon particles; dissolving the iron/chromium alloy with carbon particles in sulfuric acid to form a first solution; adding calcium chloride or barium chloride to the first solution to produce a second solution including FeCl.sub.3 and CrCl.sub.3; and adding an acid to the second solution to form the electrolyte. Other methods can be used for preparing an electrolyte from chromium waste material.

A redox flow battery system includes an anolyte; a catholyte; a first electrode structure including a base having a first surface and a second surface opposite the first surface, a first electrode disposed on the first surface, a second electrode disposed on the second surface, and conductive elements that extend through the base, wherein the base resists flow of anolyte and catholyte through the base and each of the conductive elements includes a first end portion exposed at the first surface and a second end portion exposed at the second surface, wherein the first electrode includes the first end portions of the conductive elements and the second electrode includes the second end portions of the conductive elements; a first half-cell in which the first electrode is in contact with the anolyte; and a second half-cell in which the second electrode is in contact with the catholyte.

A redox flow battery system includes an anolyte having chromium ions in solution, wherein at least a portion of the chromium ions form a chromium complex with at least one of the following: NH.sub.3, NH.sub.4.sup.+, CO(NH.sub.2).sub.2, SCN.sup.−, or CS(NH.sub.2).sub.2; a catholyte having iron ions in solution; a first half-cell including a first electrode in contact with the anolyte; a second half-cell including a second electrode in contact with the catholyte; and a first separator separating the first half-cell from the second half-cell.