Enhancing thermal energy storage efficiency: Synthesis and analysis of hybrid Nano-PCMs

• This study improves the thermal properties of hybrid nano-PCMs (erythritol and xylitol doped with Cu, Al, and Zn nanoparticles), including thermal conductivity and specific heat capacity. • Hybrid nano-PCMs showed high heat transfer rates, with Er-Zn and Xy-Zn achieving 3596.73 KJ and 2629.54 KJ, respectively, in multi-temperature thermal energy storage systems. • The materials were synthesized using a simple two-step process with 1.5 % nanoparticle doping, ensuring enhanced performance and scalability. • The enhanced properties and energy efficiency of the hybrid nano-PCMs were validated against their parent PCMs, highlighting their suitability for real-world applications. Heating, processing, and drying operations require substantial heat energy across various temperature ranges, necessitating efficient thermal energy storage solutions. Phase change materials (PCMs) are widely used for this purpose, but their low thermal conductivity limits performance. This study enhances the thermo-physical properties of erythritol and xylitol by incorporating copper (Cu), aluminum (Al), and zinc (Zn) nanoparticles at a 1.5 % weight ratio. The synthesized hybrid nano-PCMs were characterized for thermal properties and assessed in a multi-temperature thermal energy storage system using Therminol-66 as the heat transfer fluid. Results showed significant improvements in thermal conductivity, diffusivity, density, and specific heat capacity due to nanoparticle doping. Among the tested materials, Er-Zn and Xy-Zn exhibited the highest thermal conductivities (0.3012 Wm⁻¹K⁻¹ and 0.4496 Wm⁻¹K⁻¹, respectively) and achieved superior heat transfer rates (3596.73 KJ and 2629.54 KJ). These findings demonstrate the potential of hybrid nano-PCMs to enhance the efficiency of thermal energy storage systems, making them viable for advanced energy storage applications. Future research should focus on scaling production, long-term stability, and broader application possibilities.