A new strontium based reactive carbonate composite for thermochemical energy storage

Abstract

Stable power generation from renewable energy requires the development of new materials that can be used for energy storage. A new reactive carbonate composite (RCC) based on SrCO₃ is proposed as a material with high energy density for thermochemical energy storage. SrCO₃–SrSiO₃ can promote the thermodynamic destabilisation of SrCO₃, making its operating temperature (700 °C) more suitable for concentrated solar thermal power applications. Utilising a eutectic mixture of salts as a catalyst, the reversible carbonation reaction achieves cycle stability of ∼80% of efficiency over multiple cycles. The high volumetric (1878 MJ m⁻³) and gravimetric energy density (500 kJ kg⁻¹) of the RCC allows a compact thermal battery to be developed. Additionally, the low cost of SrCO₃ makes the RCC a highly competitive alternative energy storage material in terms of cost and efficiency when compared to existing molten salt based energy storage technology.