Okra functional biomimetic composite phase change materials integrated with high thermal conductivity, remarkable latent heat, and multicycle stability for high temperature thermal energy storage

• Published in: Energy (Oxford) Vol. 308; p. 132934
• Main Authors: Ren, Tianze, Yao, Haichen
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2024
• Subjects: Composite phase change materials; Functional biomimetic ceramic materials; High-temperature thermal energy storage; Thermal conductivity; Thermal cyclic stability; Thermal conductivity; Functional biomimetic ceramic materials; High-temperature thermal energy storage; Composite phase change materials; Thermal cyclic stability
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2024.132934

High-temperature phase change materials (h-PCMs) offer viable solutions for efficient thermal energy storage systems within large-scale industrial facilities. However, h-PCMs still face enormous challenges owing to low thermal conductivity and restricted thermal storage efficiency. Herein, we report okra functional biomimetic high-temperature composite phase change materials (h-CPCMs) that exhibit excellent comprehensive thermal storage properties and operational reliability, inspired by the okra seed storage process. The okra biomimetic SiC ceramic skeleton, featuring unique macropores and crosslinked axially fibrous thermal transfer pathways, significantly boosts the thermal storage efficiency of loaded molten-salt-based h-PCMs. The resulting h-CPCMs exhibit excellent thermal conductivity with a maximum value of 31 W/(m·K) accompanied by a notable latent heat of 207 J/g. Of note, the h-CPCMs with high porosity maintain superior thermal storage properties after 500 cycles. The overall thermal storage performance under 400–700 °C outperformed that of h-CPCMs reported in previous works. Furthermore, utilizing a self-designed thermal storage performance testing device, the thermal storage power density of h-CPCMs performs a 101 % enhancement compared to pure h-PCMs, suggesting a significant improvement in thermal storage efficiency. This work provides valuable insights and advancements for the further design of highly performance h-CPCMs. •An okra functional biomimetic high-temperature composite PCMs are developed.•CPCMs achieve leading thermal conductivity up to 31 W/m·K in high-temperature CPCMs.•CPCMs attain leading both latent heat of 208 J/g and total heat density of 422 J/g.•CPCMs have superior thermal storage properties after 500 thermal cycles.•The thermal storage power density of composite PCMs is 101 % higher than pure PCMs.