The single electrode Peltier heats of Li +/Li, H 2/H − and Li +/Pd–Li couples in molten LiCl–KCl systems

Abstract

The thermoelectric power of the Li +/Li couple was measured in a LiCl–KCl eutectic melt at 633–773 K. The obtained value, 0.089 mV K −1, gives the single electrode Peltier heat for the reaction Li + + e − ⇌ Li as − 5.8 kJ F −1 at 673 K (endothermic cathodic reaction). The single electrode Peltier heat for the reaction 1 2 H 2 + e − ⇌ H − in a molten LiCl–KCl–LiH system has been calculated using the temperature dependence of the equilibrium potential of the H 2/ H − couple measured with reference to the Li +/Li potential, which gives 5.8 kJ F − 1 (exothermic cathodic reaction) under the condition of hydrogen pressure of 1.0 atm, H − ion concentration of 0.01 (anion fraction) and 673 K. The single electrode Peltier heats for formation of Pd–Li alloys have been also evaluated.