Multilayer Graphite–Ga68.5In21.5Sn10 Composites as Highly Thermal Conductive and Low‐Cost Material

With the emergence of numerous capabilities, electronic devices with high‐frequency central processing units (CPUs) are achieving high performance. In the meantime, immense heat generated in a confined space makes the cooling of semiconductor circuits a critical challenge. People are looking for ways to improve the heat dissipation capacity of commercial graphite films (GFs), as the thicknesses of the synthetic GFs are limited to below 20 μm. Herein, a new strategy utilizing liquid Galinstan (GaInSn) with high thermal conductivity (TC) as interfacial layers between GFs to reduce thermal resistance is proposed. Through numerical simulation and experimental verification, it is found that the multilayer GF–GaInSn composite films reveal strongly enhanced heat conducting properties compared with commercial GF. The resulting five‐layer GF–GaInSn composite exhibits superior equivalent TC at room temperature along the α‐axis (KRT = 1809.05 ± 68.66 W m−1 K−1). The presence of GaInSn enables the heat to diffuse unimpeded onto graphite of each layer, endowing the composites with potential application in electronic devices for advanced thermal management. A layer‐by‐layer graphite film–Galinstan composite with ultrahigh thermal conductivity (KRT = 1809.05 ± 68.66 W m−1 K−1) and fine interface morphology is fabricated through a high‐pressure spraying process that is time‐ and energy‐saving. The composite shows highly reliable heat conduction performance in a mobile device and has great potential in large‐scale thermal management areas.