Form-stable LiNO3-NaNO3-KNO3-Ca(NO3)2/calcium silicate composite phase change material (PCM) for mid-low temperature thermal energy storage

The figure (a) displays the microstructure of calcium silicate and the inset figure is the LiNO3-NaNO3-KNO3-Ca(NO3)2/calcium silicate composite PCM. Calcium silicate is used as a porous skeleton material which could absorb large amounts of the nitrate PCM in voids and prevent the PCM from leakage during phase change process. Figure (b) shows the heat capacity of the composite PCM and the inset figure is the DSC curve of the composite. It indicates that this composite has a low melting point (103.5 °C) and good energy storage property. Based on the novel LiNO3-NaNO3-KNO3-Ca(NO3)2/calcium silicate composite PCM, this work involves fabrication process, thermal and microstructural characterization, and chemical and physical stability measurements.166