Sintered carbon nanotube (CNT) blocks and porous CNT sponges were prepared, and their thermoelectric properties were measured. The maximum dimensionless thermoelectric figure-of-merit, ZT , at room temperature of the sintered single-walled carbon nanotube (SWCNT) block is 9.34 × 10 −5 , which is twice higher than that of the sintered multi-walled carbon nanotube (MWCNT) block in this work and also higher than that of other sintered MWCNT blocks reported previously. In addition, the porous MWCNT sponge showed an ultra-low thermal conductivity of 0.021 W/(m K) and significantly enhanced ZT value of 5.72 × 10 −4 at room temperature and 1 atm. This ZT value is higher than that of other 3D macroscopic pure CNT materials reported. The pronounced enhancement of the ZT in the porous MWCNT sponge is attributed to the ultra-low density, ultra-high porosity, and interconnected structure of the material, which lead to a fairly low thermal conductivity and better Seebeck coefficient. The finding of this work provides an understanding for exploring potential enhancement mechanisms and improving the thermoelectric properties of CNT-based thermoelectric composites.

中文翻译：

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3D宏观纯碳纳米管材料中的热导率和热电特性

制备了碳纳米管（CNT）烧结块和多孔CNT海绵，并测量了它们的热电性能。烧结单壁碳纳米管（SWCNT）室温下的最大无量纲热电品质因数ZT为9.34×10 -5，是烧结多壁碳纳米管（MWCNT）的最大无因次热电系数。 ）块，并且比以前报道的其他烧结MWCNT块还要高。另外，多孔MWCNT海绵在室温和1atm下显示出0.021W /（m·K）的超低导热率并且显着提高了5.72×10 -4的ZT值。该ZT值高于报道的其他3D宏观纯CNT材料的ZT值。多孔MWCNT海绵中ZT的显着增强归因于超低密度，超高孔隙率，以及材料的互连结构，导致较低的热导率和更好的塞贝克系数。这项工作的发现为探索潜在的增强机理和改善CNT基热电复合材料的热电性能提供了一种理解。