Carbon and carbon composites for thermoelectric applications

The urgent need for consistent, reliable, ecofriendly, and stable power sources drives the development of new green energy materials. Thermoelectric (TE) materials receive increasing attention due to their unique capability of realizing the direct energy conversion between heat and electricity, showing diverse applications in harvesting waste heat and low-grade heat. Carbon materials such as carbon nanotubes (CNTs) and graphene have experienced a rapid development as TE materials because of their intrinsic ultrahigh electrical conductivity and light weight. Besides, polymer-based carbon composites are particularly fascinating as the combination of the merits of polymers and filler materials leads to high TE performance and superior flexibility. Herein, the recent TE advances are systematically summarized in the studied popularity of carbon materials (ie, CNTs and graphene) and the category of polymers. The conducting polymer-based carbon materials are particularly highlighted. Finally, the remaining challenges and some tentative suggestions possibly guiding future developments are proposed, which may pave a way for a bright future of carbon and carbon composites in the energy market.