Flexible MXene@PVP/PEG phase change composite with hydrogen bond assembly for advanced energy storage and thermal management

Abstract

In response to the growing need for advanced thermal management in electronics, energy storage devices, and wearable technology, there has been substantial focus on developing multifunctional phase change materials (PCMs) with capabilities for heat storage, shape stability, and photothermal conversion. However, the rigidity and susceptibility to leakage of PCMs present considerable obstacles to their practical applications. To address these issues, a novel and flexible MXene@PVP/PEG phase change composite membrane (FPCM) are successfully fabricated, which exhibits advanced solar thermal conversion and energy storage capabilities. The FPCM was fabricated through a straightforward mixing process, followed by a vacuum-assisted hydrogen bonding self-assembly method (VASA). The two-dimensional photothermal conversion material MXene, integrated with polyvinylpyrrolidone (PVP) through abundant hydrogen bonds, assembles to form a highly oriented specific interlayer framework. This structure effectively addresses the leakage issue that arises during the phase transition of polyethylene glycol (PEG), which serves as a heat storage medium, while ensuring that its thermal conductivity and photothermal conversion efficiency remain optimal. The optimized FPCMs, comprising 16 wt% MXene and 4 wt% PVP, demonstrated remarkable flexibility, retaining their structural integrity after 100 bending cycles. Moreover, the MXene@PVP/PEG exhibited remarkable thermal reliability, retaining over 98 % of their enthalpy after 100 heating-cooling cycles, with a melting enthalpy of 131.6 J/g. These flexible FPCMs, which combine high latent thermal energy storage and temperature regulation properties, show considerable promise for energy storage and thermal management in electronic devices.