High-temperature and high-pressure electrolyser of allothermal operation

An electrolyzer for high temperature electrolysis capable of operating in an allothermal mode, including an enclosure, at least one electrolysis plate including an anode and a cathode in combination and means for heating an active fluid intended to undergo high temperature electrolysis, the enclosure being capable of maintaining an electrolyte bath under high or very high pressure of several tens of bars, said heating means being positioned in the enclosure and use a heat transfer fluid, the active fluid being a gas, the heating means being in the form of at least one plate positioned parallel and adjacently to the electrolysis plate, the heating plate substantially having the same size as the electrolysis plate and includes a metal casing in which a heat exchange body is positioned, including a plurality of channels extending between an end supplied with hot heat transfer fluid and an end connected to cold heat transfer fluid manifold.