Construction of Flexible, Self-Supporting, and In-Plane Anisotropic PEDOT:PSS Thermoelectric Films via the Wet-Winding Approach

作者：Zhonghua Chen, Xin Guan, Ningxuan Wen, Lujun Pan, Zeng Fan · 发表于：ACS Applied Polymer Materials · 年份：2023 · DOI：10.1021/acsapm.3c00122 · 被引用次数：18 · 研究领域：Advanced Thermoelectric Materials and Devices、Conducting polymers and applications、Advanced Sensor and Energy Harvesting Materials

In-plane anisotropic thermoelectric (TE) films with TE properties optimized in preferred orientation can establish a good match between the direction with optimal property for materials and the direction of temperature difference. Based on the highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) fibers previously produced via wet-spinning, in this work, we further developed flexible and self-supporting PEDOT:PSS thick films with evident TE property anisotropy by a wet-winding approach. The as-obtained films were mainly composed of orderly tiled PEDOT:PSS fibers, thus possessing intrinsically highly oriented and ordered PEDOT:PSS chain packing. On the basis of their Raman spectra, a large portion of expanded chain conformation of quinoids was also evidenced, which thereby greatly facilitated intra-chain charge transport along the PEDOT-conjugated backbones. As a result, the as-obtained anisotropic films delivered a power factor of up to 35.8 μW m –1 K –2, which was 2.4 times that of the isotropic counterpart prepared via drop-casting and also superior over that of many binary inorganic–organic TE composite films reported previously. Besides, the fiber-wound PEDOT:PSS films also showed high mechanical strength and excellent stability upon cyclic bending. With five stripes of the anisotropic films, a prototype TE generator was further assembled, for which a good match between the optimal property direction and temperature difference direction was...