Study of Capric–Palmitic Acid/Clay Minerals as Form-Stable Composite Phase-Change Materials for Thermal Energy Storage

[Image: see text] As an important method to effectively improve energy efficiency, the study of thermal energy storage is particularly important. In this study, six types of clay mineral-based form-stable phase-change materials (FSPCMs) were prepared by the vacuum adsorption method. The adsorption capacity of vermiculite and diatomite was satisfactory, and sepiolite showed the worst adsorption capacity. Clay minerals can delay the thermal decomposition rate of capric–palmitic acid (CA–PA), and the specific surface area and pore capacity of clay minerals all decrease dramatically after the clay minerals have absorbed CA–PA. FSPCMs exhibited a higher heat storage and release efficiency and reflects a certain temperature control performance. In addition, only physical adsorption between the CA–PA and the clay material occurred, and no chemical reaction occurred. Finally, FSPCMs still have high latent heat of phase transition, and they can be used for low-temperature thermal energy storage.