Phase change composites with ultra-high through-plane thermal conductivity achieved by vertically-aligned graphite film and double-shelled microcapsules

Abstract

The heat dissipation in electronic devices has become bottleneck problem. One of the best solutions is to develop high performance materials which can not only dissipate the heat away, but also absorb heat energy. This kind of double function materials can be obtained by simultaneously using high thermal conductivity (TC) materials and phase change materials. The formation of continuous network of thermally conductive fillers is demonstrated as one of the most effective methods for fabricating highly thermally conductive composites. Here, graphite films (GF) are stacked and vertically cut to endow the composites with high through-plane TC. The obtained composites exhibit a through-plane TC of 51.55 W m−1 K−1 and a low thermal resistance of 0.398 °C cm2 W−1. Besides, double-shelled PDA@SiO2@paraffin (Pa) microcapsules are embedded into the composite to give its good heat-absorption capacity. Via a CPU thermal stress test, the composites demonstrate satisfactory temperature controlling performance.