THE SINGLE-ELECTRODE PELTIER HEATS OF LI-AL ALLOY ELECTRODES IN LICL-KCL EUTECTIC SYSTEM

This paper presents the single-electrode Peltier heat of cathodic (or anodic) reaction of Li-Al alloy electrode in a coexisting phase state, or an intermetallic compound phase state estimated by thermoelectric- power measurement. The thermoelectric-power measurements of Li-Al allo ys in various coexisting phase states were carried out with both poten tiometric and potential-sweep methods in the LiCl-KCl eutectic system between 673 and 843 K. The values of the thermoelectric power of Li-Al alloys calculated by using thermodynamic literature data were in good agreement with those obtained by experiment. The single-electrode Pel tier heat changes drastically with change of its phase state, and it w as found that the formation reactions of beta (Li0.5Al0.5) and gamma ( Li0.6Al0.4) phases are exothermic, and those of liquid phase from beta and gamma phase are endothermic. The single-electrode Peltier heat fo r the cathodic formation reaction of Li-Al alloy in intermetallic comp ound gamma phase is estimated to be exothermic by using the measured v alues of thermoelectric powers of Li-Al alloys in (beta + gamma) and ( gamma + liq.) regions.