Issue 30/2014 - Progress in graphene thermal conductivity research

The Shanxi Coal Chemical Institute of the Chinese Academy of Sciences has made two major advances
in the field of graphene flexible heat sinks this year.
Recently, the institute systematically studied the evolution mechanism of thermal conductivity of graphene oxide film in the carbonization process, and obtained high-performance thermal reduction graphene oxide film
.
Previously, they also worked with relevant teams from Tsinghua University and the Institute of Metal Research of the Chinese Academy of Sciences to successfully develop a high thermal conductivity graphene/carbon fiber flexible composite film
.

Macroscopic assembly of nanographene to form thin film materials, while maintaining its nano effect, is an important way for the large-scale application of
graphene.
Shanxi Coal Chemical Institute and related companies use self-assembly technology to construct carbon/carbon composite films
with integrated structure and function.
This all-carbon film has a multi-level structure similar to reinforced concrete, its thickness is controllable between 10~200μm, the thermal conductivity at room temperature is as high as 977W/m·K, and the tensile strength exceeds 15MPa
.
This study solves the problem of graphene thermal conduction application and is a breakthrough
in the field of graphene.

Thin film materials are easily obtained using graphene oxide as a precursor, but this material needs to be heat treated to restore its thermal/electrical conductivity
.
The research results of Shanxi Coal Chemical Institute show that 1000°C is the key point of film performance transformation, and the performance of the film changes qualitatively at
this point.
This discovery not only solves the basic scientific problems of graphene thermochemical transformation, but also provides a basis
for the large-scale preparation of graphene thermally conductive films.

Graphene-based film can be used as a flexible heatsink material to meet the heat dissipation requirements
of high-power and high-integration systems such as LED lighting, computers, satellite circuits, laser weapons, and handheld terminal equipment.
These findings provide a new perspective
on the design of structural/functional carbon/carbon composites.
(Li Meng)