l-Cysteine-Functionalized MXene Porous Scaffold-Based Phase Change Films for Efficient Thermal Management

Phase change materials (PCMs) hold great promise for thermal management, yet their low thermal conductivity and liquid leakage severely hinder practical applications. Herein, we designed a high-enthalpy phase change composite film (LMAP) based on l-Cysteine-functionalized MXene (l-MXene) and aramid nanofibers (ANFs). l-cysteine was bonded to MXene via covalent and coordination bonds, and further crosslinked with ANF through hydrogen bonds to form layered aerogel films with a porous scaffold structure, which was subsequently impregnated with polyethylene glycol (PEG). The unique porous layered architecture of LMAP-20 achieved a PEG loading of 86.71%, a phase-change enthalpy of 169.33 J/g, and a tensile strength of 17.26 MPa for favorable energy storage performance. Moreover, l-MXene nanosheets endowed LMAP-50 with a high thermal conductivity of 1.58 W/(m·K), which enabled outstanding thermal management and reduced the operating temperature of the LED chip by 21.4 °C. These results suggest that the l-MXene/ANF porous scaffold holds great potential for fabricating phase change composites with high thermal conductivity and suppressed leakage, which could be applied for efficient thermal management in advanced electronic devices.