HYTEC (Hydrogen Thermo‐Electrochemical Converter) is a thermally regenerative fuel cell for direct conversion of heat into electricity. The principles of basic cell operation involve ionic transport of hydrogen through a hydride‐ion (H) conducting, molten electrolyte, and reaction with alkali metals, oxygen, or air. In order to operate HYTEC in a thermally regenerative mode, pure Li and Na, or a mixture of Li/Na alloy, is used for reaction with hydrogen, to form metal hydride which is subsequently decomposed to metal and hydrogen at higher temperatures. The reactants are then separated and redirected to the electrochemical cell. In the cell the molten, H‐conducting electrolyte is immobilized between two thin hydrogen‐permeable, solid, metallic electrodes which also act as current collectors. The H2 gas first diffuses through the cathode electrode and forms a hydride ion (H+e→H) at the cathode‐electrolyte interface. The H ion subsequently migrated through the electrolyte under a chemical potential gradient created by the presence of the alkali metal in the anode chamber. The H ion releases the electron to form hydrogen atoms (H→H+e) at the anode‐electrolyte interface. The hydrogen atom diffuses through the anode electrode and reacts with the alkali metal to form metal hydride. The electron released passes through the load circuit to complete the cycle. In the regeneration scheme, the fuel cell is operated at temperature T1.

    The metal hydride formed at the anode is pumped to the decomposition chamber through a recuperator. The metal hydride is decomposed at a higher temperature, T2, by an external heat source. The H2 gas is separated from the alkali metal by a H2‐permeable, solid, metallic membrane and fed into the anode chamber of the cell. The hydrogen‐depleted alkali metal is directed to the cathode chamber of the cell, via the recuperator, to complete the cycle. To date, electrochemical feasibility of the concept has been experimentally demonstrated. A system analysis indicates that a HYTEC system can reach efficiencies as high as 30%. The paper describes the unique features of the HYTEC concept as compared to other thermally regenerative fuel cells. The current developmental status is also included.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    ‘‘HYTEC’’—A thermally regenerative fuel cell



    Conference:

    10th SymposiumùSpace Nuclear Power and Propulsion ; 1993 ; Albuquerque, NM, USA


    Published in:

    AIP Conference Proceedings ; 271 , 2 ; 913-921


    Publication date :

    1993-01-15


    Size :

    9 pages





    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English