Research Information System
Environmental Science and Pollution Research, vol.33, no.7, pp.2708-2726, 2026 (Scopus)
Thermal energy storage systems have gained increasing attention in recent years as effective solutions for improving energy efficiency and promoting sustainability. In this study, an eco-friendly phase change material (PCM) composite was developed by upcycling spent coffee grounds (SCG) into a value-added thermal energy storage material. SCG were employed as a natural supporting matrix, while a eutectic mixture of lauric acid (LA) and stearic acid (SA) with a mass ratio of 70:30 served as latent heat storage component. The composite was prepared by using a vacuum impregnation method. To determine the optimal PCM loading, the LA–SA content was varied between 10 and 70 wt%, and a maximum stable loading of 30 wt% was identified based on leakage performance. The leakage behavior, morphological structure, chemical composition, and thermal properties of composites were systematically investigated by leakage tests, FTIR, XRD, DTA/TG, and DSC analyses. 5%CuO@e-PCMC coded composite showed an effective heat storage efficiency (E), relative thermal storage efficiency (μ), and enthalpy efficiency (λ) as 9%, 80%, and 0.1, respectively. Thermal analysis tests confirmed that the composite structure remained stable without significant degradation over repeated phase change cycles. The results demonstrated that the developed SCG-based PCM composite was a cost-effective and an environmentally friendly candidate for low-temperature thermal energy storage applications, particularly in 33–36 °C range, making it well suited for textile and thermal comfort applications. The ability of SCG to stably accommodate up to 30 wt% of the LA–SA eutectic mixture highlighted their potential as a sustainable and natural alternative supporting material for thermal energy storage and thermal management systems.