Enhanced thermoelectric performance of low carbon cement-based composites by reduced graphene oxide

Abstract

Cement-based composites with thermoelectric effect have broad application prospects in the fields of urban heat island effect mitigation, winter road snow melting and ice melting and energy harvesting. Although cement-based composites have made great strides in terms of thermoelectric properties, the high carbon content makes their mechanical properties low, this is the main obstacle to further improvement of thermoelectric performance. In this paper, we added reduced graphene oxide (RGO) to cement through a liquid-phase mixing process to make cement particles adhere to RGO flakes, which effectively reduced the degree of mutual agglomeration between the RGO and improves the dispersion effect of RGO in cement-based materials. When the RGO content is 5.0 wt%, it has higher electrical conductivity (2.01 S/cm) compared with the RGO cement-based composite prepared by the ball milling process, achieve the ZTmax value of 0.23 × 10−4, and have good temperature stability with the highest output power of 8.27 × 10−3 mW/m2. This facilitates large-scale energy harvesting using thermoelectric cement-based composites.