Study on thermal conductivity of graphene paperbased on the transient electrical heating technique.

Graphene materials have become one of the materials widely studied and applied in many fields for their excellent thermal, electrical, and mechanical properties. As the cause of deep space exploration continues to develop, the study of the performance of materials in low-temperature and even ultra-low-temperature environments is becoming increasingly important. In this paper, graphene paper was studied and analyzed in the temperature interval of 290 K~20 K using the transient electrical heating technique, and the effect of high temperature heating by electric current on the thermal conductivity of graphene paper was investigated. The thermal diffusion coefficient, thermal conductivity and volumetric specific heat capacity of graphene paper gradually decrease with decreasing temperature, and the resistance gradually increases with decreasing temperature, exhibiting strong non-metallic properties. After the structure of graphene paper is optimized by high temperature heating by electric current, the thermal conductivity of sample 1 increased from 2.31 W/(m ⋅ K) to 5.47 W/(m ⋅ K) and the thermal conductivity of sample 2 increased from 6.09 W/(m ⋅ K) to 22.21 W/(m ⋅ K) at 290 K. The thermal conductivity mechanism of phonon scattering from graphene paper was analyzed, and the Debye temperature and phonon mean free range of graphene paper were calculated using the thermal reffusivity model. [ABSTRACT FROM AUTHOR]