Thermal conductive enhanced phase change composites with high latent-heat for constant temperature thermal management

Phase change materials (PCMs) can absorb and release heat without the temperature changing to realize the constant temperature thermal management. The low thermal conductivity (K) of PCM molecules leads to slow heat absorbing and releasing. In this study, a polyethylene glycol (PEG) based cross-linked polyurethane network is synthesized to wrap PCMs microcapsules. The composites have a high latent heat (152–164 J g⁻¹) at 38 °C. Carbon fiber (CF) and Al powder with high K is composted to improve the thermal conductivity of the PCMs. After doping with CF, the K increases to two-fold to 0.306 W m⁻¹ K⁻¹. The experimental result reveals that the heat transfer inside the PCMs is improved obviously after doping with CF, which is further verified by a simulation result, and the composites show excellent shape stability and latent heat retention rate (>92 %) under 30 days' cycle test. This thermal conductivity enhanced PCMs composite is also formable which may have the potential applications for the thermal management of electronic devices, such as chips, fast charging, and battery.