Thermochemical Heat Storage Using Strontium Bromide Hexahydrate (SrBr2·6H2O): Thermodynamics, Kinetics, and Applications

Abstract

Geruganti Sudhakar

Thermochemical energy storage (TCES) using salt hydrates offers a promising solution for seasonal solar heat storage. This study comprehensively investigates strontium bromide hexahydrate (SrBr2·6H2O) as a highperformance material for reversible heat storage and release. Through coupled thermodynamic modeling and experimental validation, we characterize the material’s endothermic dehydration (heat absorption at 80–100°C) and exothermic hydration (heat release at 50–70°C), achieving an energy density of 0.84 GJ/m3 – 3× higher than conventional phasechange materials. The Gibbs free energy analysis reveals a temperaturedependent equilibrium vapor pressure (12 mbar at 25°C to 200 mbar at 80°C), while kinetic studies show a dehydration rate constant of 10−3 s−1 following the AvramiErofeev model. Field tests in Arctic Sweden demonstrate 75% roundtrip efficiency over 3month storage periods, with composite material engineering (graphite/silica additives) addressing kinetic limitations and corrosion. Technoeconomic analysis projects a 12year payback period for residential systems at scale. This work establishes SrBr2·6H2O as a viable candidate for zeroemission seasonal thermal storage, with material optimization pathways identified for commercial deployment.

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