Experimental validation of bulk-graphene as a thermoelectric generator

Muhammad Uzair Khan,Muhammad Aslam,Muhammad Sadiq,Saadia Tabassum,Zeeshan Ahad,Muhammad Hamyun,Shaista Afridi,Muhammad Arif,Muhammad Lais,Syed Ehtisham Gillani,Muhammad Asif,Saeed Ullah Jan,Dawar Awan,Amir Naveed

doi:10.1088/2053-1591/abfc03

Abstract

Quest for alternate energy sources is the core of most of the research activities these days. No matter how small or large amount of energy can be produced by utilizing the non-conventional techniques and sources, every bit of innovation can reshape the future of energy. In this work, experimental analysis of the thermoelectric (TE) properties of bulk-graphene in the temperature range of (303 to 363) K is presented. Graphene powder was pressed to form a pellet which was used to fabricate the TE device. The effects of temperature on the Seebeck coefficient, electrical and thermal conductivities, and the dimensionless figure of merit (FOM) were measured. The increasing value of the Seebeck coefficient (thermopower) with temperature is indicant of the metallic behavior. Additionally, the observed thermopower (TEP) is positive, which shows that the majority charge carriers are holes and peaked to a value of 56 μV K−1 at 363 K. The thermopower of the pellet is four times larger than the previously reported values for single layer graphene (SLG) and few layer graphene (FLG). In addition to this, low values of the thermal conductivity were observed for the pellet which is one of the requirements of a good TE material. Besides this, an upward trend is observed with increasing temperature for FOM, which attains a peak value of 0.0016 at 363 K, which is almost ten times that of the previously reported values.

Highlights

Energy has been the most important part of human society since long
Thermoelectric generators (TEGs) cannot replace the conventional generators due to their low conversion efficiencies, but can be used in cogeneration systems where they can convert waste heat into useful energy improving the overall efficiency of the generation system
Besides the TEP of the graphene pellet (GP), the TEP of single layer graphene (SLG) [36] and few layer graphene (FLG) [38] is shown for comparison

Summary

Introduction

Energy has been the most important part of human society since long. The modern-day lifestyle of humanity cannot survive without continuous supply of energy. A solution to such energy crisis is to develop renewable energy resources which include the wind, tides, sunlight, waves, and geothermal heat. These areas of energy production are the focus of many researches since decades. Thermoelectric generators (TEGs), which can use waste heat to generate electrical energy is one another highly appreciated way of energy generation. TEGs convert the waste heat energy directly into useful electrical power [3]. TEGs cannot replace the conventional generators due to their low conversion efficiencies, but can be used in cogeneration systems where they can convert waste heat into useful energy improving the overall efficiency of the generation system. Efforts are needed to develop highly efficient TEGs so that they can function as stand-alone power systems

Methods

Results

Conclusion