Experimental thermodynamics of the Li-Sn system by Knudsen Effusion Mass Spectrometry

The vapourization of five liquid binary Li-Sn alloys (xLi = 0.1; 0.2; 0.3; 0.4 and 0.5) and three solid binary Li-Sn alloys (xLi = 0.71; 0.76 and 0.81) was investigated in the temperature range from 648 K to 1014 K by Knudsen Effusion Mass Spectrometry (KEMS). It is the first time that an intensive KEMS investigation was carried out for a wide composition range of this binary system. From the obtained temperature dependence of the thermodynamic activities, thermodynamic properties, such as mixing enthalpies and entropies, were calculated. In addition, sublimation enthalpies for pure lithium, recalculated to 0 K by the enthalpy increment functions of Li(c) and Li(g), demonstrated the stability and accuracy of the experimental setup. The obtained thermodynamic data agree with the corresponding literature data, thus showing the feasibility of this method for determining the thermodynamic data of lithium-ion battery materials.