Thermal energy storage wood with anti-leakage and fire-retardant for indoor low-grade thermal energy utilization

Thermal energy storage wood (TESW) is a passive energy-efficient building material that effectively regulates indoor temperature and homogenizes the heat distribution. However, the energy storage performance of TESW is diminished by leakage. In addition, the flammable phase change materials incorporated within the wood are potential fire hazards. In this study, TESW with flame-retardant and anti-leakage (P 9 A 1 –UP–wood C ) was prepared by impregnating wood cell lumen with polyethylene glycol (PEG), phytic acid, urea and acrylic acid, and thermally initiating cross-linking. Accordingly, the enthalpy and phase change temperature of P 9 A 1 –UP–wood C were 47.98 J g −1 and 25.07 °C, respectively. Meanwhile, 98.95 % of the enthalpy remained after 100 cycles. In addition, the total smoke release of P 9 A 1 –UP–wood C was reduced by 28.61 % from that of raw wood (wood C ), and the production rates of CO 2 and CO during the combustion process were also significantly decreased, indicating good smoke-suppressing and toxicity-reducing effects of the flame retardants. The building-energy efficiency of the TESW was simulated in Designbuilder software. This flame-retardant, leakage-resistant TESW prepared via a toxic solvent-free method can improve the safety and long-term stability of passive energy-saving materials and promotes the storage and reuse of low-grade thermal energy.