Thermodynamic properties of a Li-Al alloy in the two-phase (alpha Al + beta LiAl), (beta LiAl + gamma Li3Al2), and (gamma Li(3)Al2 + liquid) regions, and in the single beta LiAl phase region were determined from electromotive force measurements in a LiCl-KCl eutectic melt at temperatures from 650 to 760 K. From the obtained thermodynamic properties, the single-electrode Peltier heat of a Li-Al alloy electrode was evaluated as a function of the alloy composition. It turned out that the single-electrode Peltier heat of a Li-Al alloy electrode exhibits discontinuities at the compositions of coexisting-single phase boundaries. The change of the single-electrode Peltier heat on a phase boundary was interpreted thermodynamically and was found to follow from thermodynamic data for the single phases and the phase diagram data.