Electrochemical properties of hydrogen concentration cell with ceramic protonic conductor

Electrochemical properties of the ceramic protonic conductor cell were investigated to evaluate its feasibility of hydrogen pumping for the purpose of tritium extraction in fusion fuel system Experiments were performed at 873 similar to 1073K. One side of the cell was exposed to pure hydrogen and the other was exposed to 0.01 similar to 10 vol % of hydrogen balanced with helium. Static and dynamic hydrogen pumping properties of the cell were evaluated Electromotive force generated between two electrodes by the difference of hydrogen concentration was measured as static characteristics. In the region of the ratio of hydrogen partial pressure up to 100, the electrochemical potential driven by the difference of hydrogen partial pressure agreed well with the theoretical values derived from Nernst's law. The hydrogen pumping capacity was measured as the current density with applied DC. Hydrogen was selectively transferred at the current density of 7mA/cm(2) at 873K and 9mA/cm(2) at 973K which satisfy our projected requirement (above 5mA/cm(2)) for applying to the blanket tritium recovery system. Voltage-induced degradation of the cell material accompanied with water vapor generation was observed, and voltage region to avoid this degradation was identified.