Flexible thermoelectric(TE)films and devices have potential applications in wearable technology and the Internet of Things.One of the main challenges is how to simultaneously achieve good TE performance and high chemi...Flexible thermoelectric(TE)films and devices have potential applications in wearable technology and the Internet of Things.One of the main challenges is how to simultaneously achieve good TE performance and high chemical/thermal stability in air with low cost and large-scale production.To address this,we utilized tape casting to fabricate composite films of polyvinylidene fluoride(PVDF)and multi-walled carbon nanotubes(MWCNTs).In the composite,polarβ-PVDF introduced by hot pressing can decouple the electrical conductivity and Seebeck coefficient and significantly lead to enhanced power factor of MWCNTs/PVDF composite film.As a result,the MWCNTs(60 wt%)/PVDF film has a power factor of 1.1-1.4µW m^(-1) K^(-2) near room temperature.The film also has excellent flexibility and stability in the air.Its power factor is decreased by only 9%after 1000 bends and can keep stable in air for above 6 months,which is much longer than that(15 days)of Bi2Te3/PEDOT:PSS film.A demo TE device with 10 p-type legs has an output voltage of 11.5 mV and output power of 47.53 nW at a temperature difference of 60°C.The above descriptions make the MWCNTs/PVDF films have a significant advantage in the commercial application of flexible TE devices.展开更多
基金supported by the National Natural Science Foundation of China(52273293 and 52172187)。
文摘Flexible thermoelectric(TE)films and devices have potential applications in wearable technology and the Internet of Things.One of the main challenges is how to simultaneously achieve good TE performance and high chemical/thermal stability in air with low cost and large-scale production.To address this,we utilized tape casting to fabricate composite films of polyvinylidene fluoride(PVDF)and multi-walled carbon nanotubes(MWCNTs).In the composite,polarβ-PVDF introduced by hot pressing can decouple the electrical conductivity and Seebeck coefficient and significantly lead to enhanced power factor of MWCNTs/PVDF composite film.As a result,the MWCNTs(60 wt%)/PVDF film has a power factor of 1.1-1.4µW m^(-1) K^(-2) near room temperature.The film also has excellent flexibility and stability in the air.Its power factor is decreased by only 9%after 1000 bends and can keep stable in air for above 6 months,which is much longer than that(15 days)of Bi2Te3/PEDOT:PSS film.A demo TE device with 10 p-type legs has an output voltage of 11.5 mV and output power of 47.53 nW at a temperature difference of 60°C.The above descriptions make the MWCNTs/PVDF films have a significant advantage in the commercial application of flexible TE devices.
