Affiliation:
1. State Key Laboratory of Multiphase Flow in Power Engineering & Frontier Institute of Science and Technology Xi'an Jiaotong University Xi'an 710054 China
2. School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710054 China
Abstract
AbstractGenerating sufficient power from waste heat is one of the most important things for thermoelectric (TE) techniques in numerous practical applications. The output power density of an organic thermoelectric generator (OTEG) is proportional to the power factors (PFs) and the electrical conductivities of organic materials. However, it is still challenging to have high PFs over 1 mW m−1 K−2 in free‐standing films together with high electrical conductivities over 1000 S cm−1. Herein, densifying multi‐walled carbon nanotube (MWCNT) films would increase their electrical conductivity dramatically up to over 10 000 S cm−1 with maintained high Seebeck coefficients >60 µV K−1, thus leading to ultrahigh PFs of 7.25 and 4.34 mW m−1 K−2 for p‐ and n‐type MWCNT films, respectively. In addition, it is interesting to notice that the electrical properties increase faster than the thermal conductivities, resulting in enhanced ZT of 3.6 times in MWCNT films. An OTEG made of compressed MWCNT films is fabricated to demonstrate the heat‐to‐electricity conversion ability, which exhibits a high areal output power of ∼12 times higher than that made of pristine MWCNT films. This work demonstrates an effective way to high‐performance nanowire/nanoparticle‐based TE materials such as printable TE materials comprised of nanowires/nanoparticles.
Funder
National Natural Science Foundation of China
Fundamental Research Funds for the Central Universities
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry