A shape-stabilized phase change composite from biomass cork powder as a matrix for thermal energy storage and photothermal conversion

Cork powder (CP) is a natural biodegradable biomass material. In this work, a series of shape stable-phase change composites (SSPCCs) based on n-docosane (ND) and CP are fabricated to avoid waste of resources. Four different mesh numbers (80-600) of CP are utilized as supporting skeletons for ND. The honeycomb structure of the CP is gradually destroyed, and the folded construction of the cell wall is straightened with the increase of the CP mesh number. Among them, CP80 and CP160 have a complete honeycomb structure, which can better encapsulate ND inside the cell, and the encapsulation ratio of ND is about twice as high as that of CP400 and CP600. Due to the excellent hermeticity of CP160, the corresponding SSPCC has a maximum melting and freezing latent heat are 122.81 J/g and 121.31 J/g, respectively, and the mass retention after leakage experiments is still as high as 99.43 %. In heat recovery and photothermal experiments, CP-based SSPCCs can be in with good storage performance. Moreover, the melting and crystallization coefficients for ND/CP160 after cycling are only 1.72 % and 2.44 %, respectively, representing excellent thermal reliability and reusability. In summary, cheap and abundant CP can be applied to prepare SSPCC with favorable thermal energy storage and conversion performance.