Design and Scalable Fabrication of Liquid Metal and Nano-Sheet Graphene Hybrid Phase Change Materials for Thermal Management.

Here, a paraffin/liquid metal (LM)/graphene hybrid thermal composite material with a high thermal-conductivity as well as  high latent heat is developed. The paraffin is encapsulated in calcium alginate, which produces leakage-free phase change material (PCM) capsules. LM is filled among the gaps of PCM capsules to enhance overall heat conduction. Graphene nano-sheets coating attains efficient heat dissipation because of its high spectral emissivity (>91%) in the spectrum of the mid-infrared region. The developed material is verified to have strong compatibility and durable stability. The composite is utilized as a thermal buffer (TB) for central processing unit thermal management to demonstrate the synergy of these superior thermal properties. In certain cases, active cooling normally used could be replaced by the developed TB without any energy consumption for thermal management, demonstrating a completely passive cooling strategy. Compared to traditional heat sink active cooling, general energy savings of 10.4-26.3% could thus be achieved by the developed composite in wider operating conditions, proving its potential for more efficient and sustainable data center cooling alongside thermal management of other ground-based electrical/electronic equipment.