On the thermally conductive behaviour of compacted graphite nanosheets

Thermally conductive properties of compacts composed of graphite nanosheets (GNSs) are studied. The GNSs were made by the intercalation and exfoliation of natural graphite (NG) flakes. The GNSs were then compressed to make graphite compacts. Thermal diffusivities along the in-plane and transverse directions are measured using a laser flash method. The anisotropic ratio of the thermal conductivities ranges between 20 and 25. The properties of graphite compacts based on NG flakes are also studied. The results reveal that the GNS-based compact can be consolidated at a lower density, whereas the NG-based counterpart is denser and has a higher thermal conductivity. To protect the graphite compact, a method for coating a copper layer on the graphite compact was developed. The results also indicate the copper coating enhances heat transfer into the graphite compact.