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 lambda and relative enthalpy efficiency eta 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.