Corn straw supported high-performance phase change composites: Strategy to turn agricultural residues into high efficient and stable thermal energy storage materials

Abstract

Using polypyrrole (PPy)-coated agricultural corn straw (CS) as support frameworks, polyethylene glycol (PEG) as phase change components, a shape-stable phase change thermal storage composite (CS@PPy-PEGx) was obtained by simple crosslinking, melt-blending, and freeze-drying processes. With the help of potential non-covalent interactions among each component (e.g., hydrogen bonding), the encapsulation of PEG in these composites reached as high as 90 wt%, and displayed-enhanced thermal conductivities (a maximum of ∼0.22 W/(m·K)), thermal reliabilities and stabilities (with no obvious shape deformation after 100 heating and cooling cycles), promising thermal storage capacities (with max latent melting heat of ∼145.80 J/g and crystallization heat of ∼141.50 J/g), as well as conducive leakage resistance. Thus, this study paved a green and feasible strategy to convert agricultural straw residues into shape-stable and high-performance phase change composites that demonstrated great potential in the field of building thermal energy storage.