Wood Lamella‐Inspired Photothermal Stearic Acid‐Eutectic Gallium‐Indium‐Based Phase Change Aerogel for Thermal Management and Infrared Stealth

Abstract Eutectic Gallium‐Indium (EGaIn) liquid metal is an emerging phase change metal material, but its low phase transition enthalpy and low light absorption limit its application in photothermal phase change energy storage materials (PCMs) field. Here, based on the dipole layer mechanism, stearic acid (STA)‐EGaIn‐based PCMs which exhibit extraordinary solar‐thermal performance and phase change enthalpy are fabricated by ball milling method. The wood lamella‐inspired cellulose‐derived aerogel and molybdenum disulfide (MoS 2 ) are used to support the PCMs by the capillary force and decrease the interfacial thermal resistance. The resulted PCMs achieved excellent photothermal conversion performance and leakage proof. They have excellent thermal conductivity of 0.31 W m −1 K −1 (this is increased by 138% as compared with pure STA), and high phase change enthalpy of187.50 J g −1 , which is higher than the most of the reported PCMs. Additionally, the thermal management system and infrared stealth materials based on the PCMs are developed. This work provides a new way to fabricate smart EGaIn‐based PCMs for energy storage device thermal management and infrared stealth.