Synthesis optimisation of copper-based layered perovskites as thermal energy storage materials

Abstract

Solid-solid phase change materials (ss-PCMs) are promising materials for thermal energy storage applications because they do not require shape stabilisation or encapsulation. In addition, depending on the ss-PCM used, they can reduce corrosion issues and allow faster charging and discharging. Organometallic ss-PCM, particularly layered hybrid organic-inorganic compounds, have been investigated in this work due to the scientific interest in their potential use as phase change materials to store energy via polymorphic transitions. Here we have assessed the synthesis of (C12H28N)2CuCl4, a potential material for thermal energy storage. The transition enthalpy and specific heat are the key values to maximise. Two different synthesis procedures were followed: reflux and recrystallisation, and direct synthesis. Three different solvents were also used: methanol, ethanol and isopropanol. In order to find out which processes and solvent media were most promising, the synthesis yield, crystal and molecular structure, and thermal parameters such as transition enthalpy and specific heat were evaluated. Direct synthesis processes produced the most promising material for thermal energy storage due to higher yield and better enthalpy ratio.