Preparation of highly thermally conductive composite phase change materials based on MXene aerogel with superb electromagnetic shielding properties.

Thermal phase-change materials (PCMs) serve as highly efficient solutions to achieve thermal stored energy and thermal insulation, but their application is largely limited by issues such as poor thermal conductivity and susceptibility to leakage. Furthermore, ice-gel-based adsorbent PCMs can significantly improve thermal conductivity and reduce the leakage rate of PCMs. In this study, we have effectively integrated chitosan (CS) with a family of 2D transition metal carbides and nitrides (MXene) lamellae and introduced directed freezing to achieve an ordered arrangement of MXene nanosheets. The resulting continuous three-dimensional MXene aerogel structure, following impregnation with PCMs, markedly elevated the thermo-stability of polyethylene glycol (PEG) and reduced its leakage rate. Moreover, this composite phase-change material (PCM) features a latent heat of 174.86 J/g and delivers a heat of formation efficacy of 93.1%. With this high enthalpy efficiency, the composite material achieves a thermal conductivity of 1.446 W/(m·K) and an electro-magnetic shielding performance of 40 dB, whilst also demonstrating excellent electrothermal conversion capabilities, indicating its prospective applications in the field of phase-change energy storage.