Energy storage properties and thermal management mechanisms of high-efficiency biomass-based composite phase change materials using carbonized poplar wood flour: Experimental and molecular dynamics simulations

Utilizing wood cellulose to construct porous frameworks offers an effective approach to address phase change material (PCM) leakage and enhance thermal energy storage efficiency. This study selected lauric acid (LA) as the phase change material (PCM) and utilized natural wood flour (WF) and high-temperature carbonized wood flour (WF/C) as carriers. Two composite phase change energy storage materials (LA-WF and LA-WF/C) were prepared via the melt impregnation method. Through a combination of experimental characterization and molecular dynamics (MD) simulations, this study systematically reveals the regulatory mechanisms of carbonized frameworks on the energy storage mechanisms and thermal properties of composite materials (CPCMs). Research indicates that carbonization treatment significantly enhances the pore structure of the framework. Molecular dynamics simulations confirm the strengthened interfacial interactions and hydrogen bond networks between WF/C and LA, endowing CPCMs with outstanding structural stability. The experimentally measured thermal conductivity of LA-WF/C has been enhanced to 0.436 W/m·K, representing a 174% improvement over pure LA, due to the highly efficient phonon transport channels formed by the carbonized skeleton. Additionally, LA-WF/C demonstrates exceptional photothermal conversion capability, achieving a conversion efficiency of 86.58%. It also excels in electronic device thermal management, effectively suppressing surface temperatures and extending the operational lifespan of electronic components. This work innovatively proposes an integrated experimental-simulation analysis framework, providing both theoretical and experimental foundations for the development of high-performance biomass-based energy storage materials.