Alleviating the trade-off interrelation between seebeck coefficient and electrical conductivity by random copolymerization of two-dimensional and one-dimensional monomers. (August 2022)

• Record Type: Journal Article
• Authors: Cao, Guibin; Li, Benzhang; Wu, Yufeng; Ren, Zhibo; Nie, Xiuxiu; Yang, Jing; Wu, Jiatao; Xin, Hong; Wang, Lei; Gao, Chunmei
• Is Part Of: Composites communications. Volume 33(2022)
• Publication Date: 2022-08
• Subjects: Thermoelectric conjugated polymers -- Two-dimensional -- One-dimensional -- Random copolymerization
• DOI: 10.1016/j.coco.2022.101218
• Languages: English
• ISSNs: 2452-2139

Abstract

Abstract: Due to the advantages of good structural tunability, easy processibility, and high mobility, donor-acceptor based polymers are proposed as promising thermoelectric (TE) materials. However, the trade-off phenomenon between Seebeck coefficient ( S ) and electrical conductivity ( σ ) severely impedes their TE performance. Although many efforts have been applied to decouple these two parameters, it remains to be a bottleneck. Recently, we found that two-dimensional (2D) BDTTT-based polymers displayed high S with moderate σ . Combining one-dimensional (1D) conjugated structure (DPP-EDOT) with 2D conjugated structure (BDTTT-DPP) by random copolymerization can endow the polymers with good S and σ, thus alleviating the conflict. Among the polymers, P(BDTTT-DPP)1 :P(DPP-EDOT)2 (P12 ) displayed the best power factor of 12.30 μW m −1 K −2 at room temperature, which is 4 and 1.3 times higher than that of P(BDTTT-DPP) (P10 ) and P(DPP-EDOT) (P01 ), respectively. These results provide an attractive guidance for fabricating the TE polymers with high performance by random copolymerization of two-dimensional and one-dimensional monomers. Graphical abstract: In order to alleviate the trade-off between Seebeck coefficient and electrical conductivity, a series of D-A-D′-A type copolymers were designed and synthesized via random copolymerization. Among them, P(BDTTT-DPP)1 :P(DPP-EDOT)2 (P12 ) films displayed the highest power factor (12.30 μW m −1 K −2 ) at room temperature, which is 4 and 1.3 times higher than that of P(BDTTT-DPP) (P10 ) and P(DPP-EDOT) (P01 ), respectively. Image 1 Highlights: The trade-off relationship between S and σ was successfully alleviated by random copolymerization. The introduction of BDTTT-DPP units to DPP-EDOT chains endows the polymers with high S. Introducing DPP-EDOT units to BDTTT-DPP backbones can improve σ. The power factor of P12 is 4 and 1.3 times higher than that of P10 and P01, respectively.