Biomass porous potatoes/MXene encapsulated PEG-based PCMs with improved photo-to-thermal conversion capability

Encapsulated phase-change materials (PCMs) have been widely studied in the field of solar thermal energy storage due to the advantages of stable shape and repeatability. In this work, a series of potatoes phase-change materials (PPMs) were conceived and synthesized via a common vacuum impregnation method, with biomass porous potatoes (PP) as substrate, polyethylene glycol (PEG) as phase change medium and MXene nanosheets as functional filler . The experimental results show that the introduction of MXene nanosheets not only significantly improve the photo-to-thermal conversion efficiency, but also help to increase the adsorption rate of PEG in PCMs. The PEG percentage of potatoes phase-change material (PPM) increases from 60.9% (PPM-0) to 82.1% (PPM-12.5), melting/freezing enthalpy values are also increases from 94.08 J/g/100.46 J/g of PPM-2.5 to 135.57 J/g/139.88 J/g of PPM-12.5, and its enthalpy efficiency λ and relative enthalpy efficiency η also increase from 57.6%/91.5% to 77.7%/98.3%. The results show that the prepared PPMs can be effectively applied to solar photo-to-thermal energy storage.