Thermal properties improvement of Lithium nitrate/Graphite composite phase change materials

•Preparation of new Lithium nitrate/Graphite PCM-composites.•Experimental investigation of the thermo-physical properties of PCM-composites.•Prediction of theoretical thermo-physical properties by using different analytical models. This paper addresses the development and the thermal investigation of new composite materials with improved thermo-physical properties destined for solar thermal energy storage at high temperature. The thermo-physical properties of composites are characterized by using several techniques based on the temperature measurement and the obtained results are compared to the theoretical values calculated by different analytical models. The results of these experiments revealed a clear improvement in the different thermal properties when integrating graphite particles in the composite. In the other hand, a good agreement between experimental and theoretical values was obtained.