Details

Autor(en) / Beteiligte

• Suemori, Kouji
• Kamata, Toshihide

Titel

Thermoelectric characteristics in out-of plane direction of thick carbon nanotube-polystyrene composites fabricated by the solution process

Ist Teil von

• Synthetic metals, 2017-05, Vol.227, p.177-181

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •Anisotropy of thick-printed carbon nanotube-polystyrene thermoelectric composites.•Method to measure in-plane and out-of-plane direction of an identical composite.•In-plane direction of the composites showed higher figure of merit.•The anisotropy may be caused by orientation of the carbon nanotubes (CNT).•Controlling the orientation of the CNTs is required to realize high performance. When sheet-like flexible devices are placed on heat sources, a thermal flow is induced along the out-of-plane direction in regards to the device surface. To obtain carbon nanotube-based (CNT-based) thermoelectric devices that work under thermal flows along the out-of-plane direction, it is indispensable to fabricate sufficiently thick CNT-based materials that will allow for an out-of-plane temperature difference to occur. Therefore, we investigated the out-of-plane thermoelectric characteristics of thick CNT-polymer composites (thickness=0.74–0.84mm), which were fabricated by over-coating a dense CNT-dispersed solution, and found that the electrical and thermal conductivities of the composites in the out-of-plane direction were significantly lower than those in the in-plane direction, respectively. We observed that the composites’ figure of merit values in the out-of plane direction was approximately one order of magnitude lower than those in the in-plane direction. This anisotropy in the characteristics of thick CNT-polystyrene composites may be caused by the orientation of the CNTs along the in-plane direction. Therefore, the results indicate that controlling the orientation of CNTs in thick composites is a key factor to improve the performance of devices that work on the basis of temperature differences along the out-of plane direction.