Optimizing thermal performance of sodium acetate trihydrate phase-change-materials through synergistic effects of binary graphene nanoadditives for prolonged hot beverage maintenance

Sodium acetate trihydrate (SAT) is a promising candidate for thermal energy storage due to its high latent enthalpy and economic viability. However, limitations like supercooling and low thermal conductivity hinder its practical application. Herein, these challenges are addressed by developing a novel SAT-based composite phase change material (PCM) through incorporation of binary nanoadditives—graphene oxide (GO) and graphene nanoplatelets (GNP) to mitigate supercooling and enhance thermal conductivity, respectively. Notably, the optimal composite, SAT/0.25GO/0.75GNP, identified through systematic formulation optimization, retains a high latent enthalpy (281.09 J/g), comparable to pure SAT (290.47 J/g), with improved thermal conductivity and substantially reduced supercooling and phase separation issues. The combined effects of GO and GNP, likely due to noncovalent interactions, enhanced heat transfer in the composite, which was further tested in a vacuum mug. The SAT/0.25GO/0.75GNP composite achieved ideal drinking temperatures (60–50 °C) for hot water in just 4 minutes–18 times faster than the PCM-free control mug and 6 times faster than the Mug containing pure SAT. While the PCM-free mug maintains hot water within this interval for only 49 min, MugPCM, encapsulating pure SAT, retains heat for 76 min, and that with SAT/0.25GO/0.75GNP keeps remarkably hot for as long as 100 min.