Abstract: The invention relates to a method for operating in hot stand-by mode a fuel cell (SOFC) or a high-temperature electrolysis or co-electrolysis reactor (1), with a stack of solid oxide elementary electrochemical cells (SOEC), the method comprising, during a given period of absence of an electric current respectively flowing out of or applied to the stack or when it is sought to raise or lower the temperature of the cell or reactor, a step of supplying compartments on the side of the hydrogen/water electrodes (H2/H2O) with pulses of a safety gas at regular time intervals during the given period, or when the cell voltage drops below a threshold value, so as to renew the gas(es) present in said compartments.

Abstract: Disclosed is a method for the temperature control of an electrochemical system comprising a stack of electrochemical cells and interconnection plates interposed between the electrochemical cells, means for supplying gas to the electrochemical cells and means for collecting gases produced by the electrochemical cells, and means for electrically connecting the system to the outside, wherein the electrochemical device also comprises heating means integrated into the stack, said heating means comprising at least a first and a second heating element, the first heating element being disposed in a first location in the stack and the second heating element being arranged in a second location in the stack, said method comprising steps of: applying a first control command to the first heating element and a second control command to the second heating element, said control commands being configured such that a thermal gradient in the stack in the direction of the stack is maintained substantially at a defined value.

Abstract: A method for high-temperature electrolysis of steam and another gas to be electrolyzed, chosen from carbon dioxide and nitrogen dioxide, implemented in an electrolysis reactor includes a stack of elementary electrolysis cells each made of a cathode, an anode and an electrolyte inserted between the cathode and the anode, and a plurality of electric and fluid interconnectors each arranged between two adjacent elementary cells with one of the surfaces thereof in electric contact with the anode of one of the two elementary cells and the other one of the surfaces thereof in electric contact with the cathode of the other one of the two elementary cells. The steam is supplied and distributed to the cathode of one of the two adjacent elementary cells and either carbon dioxide or nitrogen dioxide is supplied and distributed to the cathode of the other one of the two elementary cells.

Abstract: A method for high-temperature electrolysis of steam and another gas to be electrolysed, chosen from carbon dioxide and nitrogen dioxide, implemented in an electrolysis reactor includes a stack of elementary electrolysis cells each made of a cathode, an anode and an electrolyte inserted between the cathode and the anode, and a plurality of electric and fluid interconnectors each arranged between two adjacent elementary cells with one of the surfaces thereof in electric contact with the anode of one of the two elementary cells and the other one of the surfaces thereof in electric contact with the cathode of the other one of the two elementary cells. The steam is supplied and distributed to the cathode of one of the two adjacent elementary cells and either carbon dioxide or nitrogen dioxide is supplied and distributed to the cathode of the other one of the two elementary cells.