<p>The thermophysical properties of three Sn-based alloys (Sn–Zn, Sn–Bi and Sn–In) were systematically measured for their potential use as energy storage and heat transfer media in concentrated solar power systems and as solders in electronic packaging, including thermal conductivity, specific heat capacity, phase change temperature, latent heat and thermal expansion coefficient. The heat storage capacity of the alloys was comprehensively evaluated based on the experimental results. The results show that the Sn–Zn alloy exhibits the highest thermal conductivity in the solid state (approximately 65.38 W·m⁻¹·K⁻¹), while the Sn–Bi alloy shows the lowest value (approximately 17.47 W·m⁻¹·K⁻¹). The specific heat capacity of the Sn–Zn alloy remains nearly constant at about 235 J·kg⁻¹·K⁻¹, whereas the specific heat capacities of the Sn–Bi and Sn–In alloys increase with temperature. The Sn–Zn alloy also shows the highest phase change temperature and latent heat, reaching 198.65&#xa0;°C and 78.7 kJ·kg⁻¹, respectively. When heated to 30&#xa0;°C below the phase change temperature, the measured linear elongations of Sn–Zn, Sn–Bi and Sn–In alloys are 4.3%, 1.7% and 2.4%, respectively. Within the temperature range from room temperature to the phase change temperature, the total heat storage capacities of Sn–Zn, Sn–Bi and Sn–In are 989658, 549828 and 390494 kJ·m⁻³, respectively. The results of this study provide experimental data and a theoretical basis for the selection of phase change materials in CSP systems and for evaluating solder alloys in electronic packaging.</p>