Flexible polyvinylidene fluoride/multiwall carbon nanotube-based thermoelectric composite films with excellent environmental stability and enhanced power factor from ferroelectric polarization  

柔性聚偏二氟乙烯(PVDF)/多壁碳纳米管热电复合薄膜:铁电极化增强的功率因子和良好的环境稳定性

作　　者：Qinghui Jiang Zhenxiang Yu Xinyue Zhang Shanliang Chen Jitao Yi Yong Liu 姜庆辉;于振祥;张馨月;陈善良;伊记涛;刘勇

机构地区：[1]State Key Laboratory of Materials Processing and Die and Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]Foshan(Southern China)Institute for New Materials,Foshan 528220,China

出　　处：《Science China Materials》2025年第4期1240-1248,共9页中国科学(材料科学)(英文版)

基　　金：supported by the National Natural Science Foundation of China(52273293 and 52172187)。

摘　　要：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.柔性热电薄膜和器件在可穿戴技术和物联网中具有巨大的应用前景,其主要挑战是如何以低成本和大规模生产同时实现良好的热电性能和高的化学/热稳定性.为了解决这个问题,我们利用流延技术制备了聚偏二氟乙烯(PVDF)和多壁碳纳米管(MWCNT)的复合薄膜.热压工艺引入PVDF的铁电极性相,该相的存在可以解耦电导率和泽贝克系数,显著提高MWCNTs/PVDF复合薄膜的功率因子(60 wt%MWCNT复合薄膜在室温达到1.1-1.4μW m^(-1) K^(-2)).同时,该薄膜经过1000次弯曲后,功率因子仅降低9%,并可在空气中保持6个月,远长于Bi2Te3/PEDOT:PSS薄膜的15天,因此具有良好的柔韧性和稳定性.10个p型腿组装的演示热电器件在60°C的温差下提供11.5 mV的输出电压和47.53 nW的输出功率.因此,MWCNTs/PVDF薄膜作为柔性热电薄膜具有重要的商业应用价值.

关 键 词：THERMOELECTRIC PVDE carbon nanotube tape casting FERROELECTRIC POLARIZATION 

分 类 号：TB3[一般工业技术—材料科学与工程]