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. A novel strategy for fabricating biomass PP@MXene/PEG phase change materials with reliable thermal cycle performance and excellent photo-to-thermal conversion efficiency were developed through the freeze drying and simple vacuum impregnation. [Display omitted] •The bio-based PPMs were fabricated via simple vacuum impregnation technology.•The crystallization enthalpy and melting enthalpy of PPM-12.5 are 135.57 J/g and 139.88 J/g.•The photo-to-thermal conversion efficiency of PPMs can reach 98.51%.•The obtianed PPMs owns excellent thermal reusability.