High Thermoelectric Performance and Flexibility in Rationally Treated PEDOT:PSS Fiber Bundles

Abstract

Organic thermoelectric fibers have great potential as wearable thermoelectric textiles because of their one-dimensional structure and high flexibility. However, the insufficient thermoelectric performance, high fabrication cost, and mechanical fragility of most organic thermoelectric fibers significantly limit their practical applications. Here, we employ a rapid and cost-effective wet-spinning method to prepare dimethyl sulfoxide-doped poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fiber bundles, followed by rational post-treatment with concentrated sulfuric acid (98% H₂SO₄) to enhance their thermoelectric performance. The wearable fiber bundles composed of multiple individual PEDOT:PSS fibers have effectively reduced resistance and overall high tensile strength and stability. Rational treatment with H₂SO₄ partially removes excessive PSS, thereby increasing the electrical conductivity to 4464 S cm^‒1, while the parallel bundle is also a major factor in improving the power factor of up to 80.8 μW m^‒1 K^‒2, which is super-competitive compared with those of currently published studies. Besides, the thermoelectric device based on these fiber bundles exhibits high flexibility and promising output power of 2.25 nW at a temperature difference of 25 K. Our work provides insights into the fabrication of all-organic flexible high-conductivity textiles with high thermoelectric properties.

Keywords

Thermoelectric / PEDOT:PSS / Fiber / Flexible device

References

[1] Cao T, Shi X-L, Chen Z-G. Advances in the design and assembly of flexible thermoelectric device. Prog Mater Sci, 2023, 131,

[2] Jiang B, Yu Y, Cui J, Liu X, Xie L, Liao J, Zhang Q, Huang Y, Ning S, Jia B, Zhu B, Bai S, Chen L, Pennycook Stephen J, He J. High-entropy-stabilized chalcogenides with high thermoelectric performance. Science, 2021, 371: 830-834,

[3] Sarkar D, Samanta M, Ghosh T, Dolui K, Das S, Saurabh K, Sanyal D, Biswas K. All-scale hierarchical nanostructures and superior valence band convergence lead to ultra-high thermoelectric performance in cubic GeTe. Energy Environ Sci, 2022, 15: 4625-4635,

[4] Yang Q, Yang S, Qiu P, Peng L, Wei T-R, Zhang Z, Shi X, Chen L. Flexible thermoelectrics based on ductile semiconductors. Science, 2022, 377: 854-858,

[5] Zheng Z-H, Shi X-L, Ao D-W, Liu W-D, Li M, Kou L-Z, Chen Y-X, Li F, Wei M, Liang G-X, Fan P, Lu GQ, Chen Z-G. Harvesting waste heat with flexible Bi₂Te₃ thermoelectric thin film. Nat Sustain, 2023, 6: 180-191,

[6] Xu S, Shi X-L, Dargusch M, Di C, Zou J, Chen Z-G. Conducting polymer-based flexible thermoelectric materials and devices: from mechanisms to applications. Prog Mater Sci, 2021, 121,

[7] Zhang L, Shi X-L, Yang Y-L, Chen Z-G. Flexible thermoelectric materials and devices: from materials to applications. Mater Today, 2021, 46: 62-108,

[8] Xu H, Guo Y, Wu B, Hou C, Zhang Q, Li Y, Wang H. Highly integrable thermoelectric fiber. ACS Appl Mater Interfaces, 2020, 12: 33297-33304,

[9] Liu J, Zhu Z, Zhou W, Liu P, Liu P, Liu G, Xu J, Jiang Q, Jiang F. Flexible metal-free hybrid hydrogel thermoelectric fibers. J Mater Sci, 2020, 55: 8376-8387,

[10] Wu T, Shi X-L, Liu W-D, Sun S, Liu Q, Chen Z-G. Dual post-treatments boost thermoelectric performance of PEDOT:PSS films and their devices. Macromol Mater Eng, 2022, 307: 2200411,

[11] Xu S, Hong M, Shi X-L, Wang Y, Ge L, Bai Y, Wang L, Dargusch M, Zou J, Chen Z-G. High-performance PEDOT:PSS flexible thermoelectric materials and their devices by triple post-treatments. Chem Mater, 2019, 31: 5238-5244,

[12] Zhou J, Anjum DH, Chen L, Xu X, Ventura IA, Jiang L, Lubineau G. The temperature-dependent microstructure of PEDOT/PSS films: insights from morphological, mechanical and electrical analyses. J Mater Chem C, 2014, 2: 9903-9910,

[13] Stöcker T, Köhler A, Moos R. Why does the electrical conductivity in PEDOT:PSS decrease with PSS content? A study combining thermoelectric measurements with impedance spectroscopy. J Polym Sci Pol Phys, 2012, 50: 976-983,

[14] Culebras M, Gómez CM, Cantarero A. Enhanced thermoelectric performance of PEDOT with different counter-ions optimized by chemical reduction. J Mater Chem A, 2014, 2: 10109-10115,

[15] Shin S, Roh JW, Kim H-S, Chen R. Role of surfactant on thermoelectric behaviors of organic–inorganic composites. J Appl Phys, 2018, 123,

[16] Bharti M, Singh A, Samanta S, Aswal DK. Conductive polymers for thermoelectric power generation. Prog Mater Sci, 2018, 93: 270-310,

[17] Park T, Park C, Kim B, Shin H, Kim E. Flexible PEDOT electrodes with large thermoelectric power factors to generate electricity by the touch of fingertips. Energy Environ Sci, 2013, 6: 788-792,

[18] Komatsu N, Ichinose Y, Dewey OS, Taylor LW, Trafford MA, Yomogida Y, Wehmeyer G, Pasquali M, Yanagi K, Kono J. Macroscopic weavable fibers of carbon nanotubes with giant thermoelectric power factor. Nat Commun, 2021, 12: 4931,

[19] Shi X-L, Chen W-Y, Zhang T, Zou J, Chen Z-G. Fiber-based thermoelectrics for solid, portable, and wearable electronics. Energy Environ Sci, 2021, 14: 729-764,

[20] Chen W-Y, Shi X-L, Zou J, Chen Z-G. Wearable fiber-based thermoelectrics from materials to applications. Nano Energy, 2020, 81,

[21] Liu L, Chen J, Liang L, Deng L, Chen G. A PEDOT:PSS thermoelectric fiber generator. Nano Energy, 2022, 102,

[22] Kim Y, Lund A, Noh H, Hofmann AI, Craighero M, Darabi S, Zokaei S, Park JI, Yoon M-H, Müller C. Robust PEDOT:PSS wet-spun fibers for thermoelectric textiles. Macromol Mater Eng, 2020, 305: 1900749,

[23] Xu C, Yang S, Li P, Wang H, Li H, Liu Z. Wet-spun PEDOT:PSS/CNT composite fibers for wearable thermoelectric energy harvesting. Compos Commun, 2022, 32,

[24] Wen N, Fan Z, Yang S, Zhao Y, Cong T, Xu S, Zhang H, Wang J, Huang H, Li C, Pan L. Highly conductive, ultra-flexible and continuously processable PEDOT:PSS fibers with high thermoelectric properties for wearable energy harvesting. Nano Energy, 2020, 78,

[25] Yildirim E, Wu G, Yong X, Tan TL, Zhu Q, Xu J, Ouyang J, Wang J-S, Yang S-W. A theoretical mechanistic study on electrical conductivity enhancement of DMSO treated PEDOT:PSS. J Mater Chem C, 2018, 6: 5122-5131,

[26] Ouyang J, Xu Q, Chu C-W, Yang Y, Li G, Shinar J. On the mechanism of conductivity enhancement in poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film through solvent treatment. Polymer, 2004, 45: 8443-8450,

[27] Cao T, Shi X-L, Zou J, Chen Z-G. Advances in conducting polymer-based thermoelectric materials and devices. Microstructures, 2021, 1: 2021007

[28] Pan Y, Song Y, Jiang Q, Jia Y, Liu P, Song H, Liu G. Solvent treatment of wet-spinning PEDOT:PSS fiber towards wearable thermoelectric energy harvesting. Synth Met, 2022, 283,

[29] Ge R, Dong X, Sun L, Hu L, Liu T, Zeng W, Luo B, Jiang X, Jiang Y, Zhou Y. Meters-long, sewable, wearable conductive polymer wires for thermoelectric applications. J Mater Chem C, 2020, 8: 1571-1576,

[30] Sarabia-Riquelme R, Shahi M, Brill JW, Weisenberger MC. Effect of drawing on the electrical, thermoelectrical, and mechanical properties of wet-spun PEDOT:PSS fibers. ACS Appl Polym Mater, 2019, 1: 2157-2167,

[31] Liu J, Jia Y, Jiang Q, Jiang F, Li C, Wang X, Liu P, Liu P, Hu F, Du Y, Xu J. Highly conductive hydrogel polymer fibers toward promising wearable thermoelectric energy harvesting. ACS Appl Mater Interfaces, 2018, 10: 44033-44040,

[32] Wen N, Fan Z, Yang S, Zhao Y, Li C, Cong T, Huang H, Zhang J, Guan X, Pan L. High-performance stretchable thermoelectric fibers for wearable electronics. Chem Eng J, 2021, 426,

[33] Liu Y, Liu P, Jiang Q, Jiang F, Liu J, Liu G, Liu C, Du Y, Xu J. Organic/inorganic hybrid for flexible thermoelectric fibers. Chem Eng J, 2021, 405,

[34] Okuzaki H, Harashina Y, Yan H. Highly conductive PEDOT/PSS microfibers fabricated by wet-spinning and dip-treatment in ethylene glycol. Eur Polym J, 2009, 45: 256-261,

[35] Jalili R, Razal JM, Wallace GG. Exploiting high quality PEDOT:PSS–SWNT composite formulations for wet-spinning multifunctional fibers. J Mater Chem, 2012, 22: 25174-25182,

[36] Xu T, Ji W, Wang X, Zhang Y, Zeng H, Mao L, Zhang M. Support-free PEDOT:PSS fibers as multifunctional microelectrodes for in vivo neural recording and modulation. Angew Chem Int Ed, 2022, 61,

[37] He X, Gu J, Hao Y, Zheng M, Wang L, Yu J, Qin X. Continuous manufacture of stretchable and integratable thermoelectric nanofiber yarn for human body energy harvesting and self-powered motion detection. Chem Eng J, 2022, 450,

[38] Feng D, Wang P, Wang M, Zhu C, Gao Q, Shen M. A facile route toward continuous wet-spinning of PEDOT: PSS fibers with enhanced strength and electroconductivity. Fiber Polym, 2021, 22: 1491-1495,

[39] Sarabia-Riquelme R, Andrews R, Anthony JE, Weisenberger MC. Highly conductive wet-spun PEDOT:PSS fibers for applications in electronic textiles. J Mater Chem C, 2020, 8: 11618-11630,

[40] Meng C, Qian Y, He J, Dong X. Wet-spinning fabrication of multi-walled carbon nanotubes reinforced poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) hybrid fibers for high-performance fiber-shaped supercapacitor. J Mater Sci-Mater El, 2020, 31: 19293-19308,

[41] Liu G, Jiang F, Liu J, Liu C, Xu J, Jiang Q, Zheng N, Nie G, Liu P. Solvent treatment inducing ultralong cycle stability poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) fibers as binding-free electrodes for supercapacitors. Int J Energy Res, 2020, 44: 5856-5865,

[42] Gao Q, Wang M, Kang X, Zhu C, Ge M. Continuous wet-spinning of flexible and water-stable conductive PEDOT: PSS/PVA composite fibers for wearable sensors. Compos Commun, 2020, 17: 134-140,

[43] Zhang J, Seyedin S, Qin S, Lynch PA, Wang Z, Yang W, Wang X, Razal Joselito M. Fast and scalable wet-spinning of highly conductive PEDOT:PSS fibers enables versatile applications. J Mater Chem A, 2019, 7: 6401-6410,

[44] Wang X-Y, Feng G-Y, M-J Li, Ge M-Q. Effect of PEDOT:PSS content on structure and properties of PEDOT:PSS/poly(vinyl alcohol) composite fiber. Polym Bull, 2019, 76: 2097-2111,

[45] Tian G, Zhou J, Xin Y, Tao R, Jin G, Lubineau G. Copolymer-enabled stretchable conductive polymer fibers. Polymer, 2019, 177: 189-195,

[46] Reid DO, Smith RE, Garcia-Torres J, Watts JF, Crean C. Solvent treatment of wet-spun PEDOT: PSS fibers for fiber-based wearable pH sensing. Sensors, 2019, 19: 4213,

[47] Kim Y, Lim T, Kim C-H, Yeo CS, Seo K, Kim S-M, Kim J, Park SY, Ju S, Yoon M-H. Organic electrochemical transistor-based channel dimension-independent single-strand wearable sweat sensors. NPG Asia Mater, 2018, 10: 1086-1095,

[48] Wang X, Feng G-Y, Ge M-Q. Influence of ethylene glycol vapor annealing on structure and property of wet-spun PVA/PEDOT:PSS blend fiber. J Mater Sci, 2017, 52: 6917-6927,

[49] Zhou J, Li EQ, Li R, Xu X, Ventura IA, Moussawi A, Anjum DH, Hedhili MN, Smilgies D-M, Lubineau G, Thoroddsen ST. Semi-metallic, strong and stretchable wet-spun conjugated polymer microfibers. J Mater Chem C, 2015, 3: 2528-2538,

[50] Wang X, Ge M-Q, Feng G-Y. The effects of DMSO on structure and properties of PVA/PEDOT:PSS blended fiber. Fiber Polym, 2015, 16: 2578-2585,

[51] Li X, Liu Y, Shi Z, Li C, Chen G. Influence of draw ratio on the structure and properties of PEDOT-PSS/PAN composite conductive fibers. RSC Adv, 2014, 4: 40385-40389,

[52] Jalili R, Razal JM, Wallace GG. Wet-spinning of PEDOT:PSS/functionalized-SWNTs composite: a facile route toward production of strong and highly conducting multifunctional fibers. Sci Rep, 2013, 3: 3438,

[53] Jalili R, Razal JM, Innis PC, Wallace GG. One-step wet-spinning process of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) fibers and the origin of higher electrical conductivity. Adv Funct Mater, 2011, 21: 3363-3370,

[54] Kadlec L, Kwon YW, Haller C, Park CM, Didoszak JM. Tensile and cyclic loading of fiber bundles. Multiscale Multidiscip Model Exp Des, 2021, 4: 245-257,

Funding

Queensland University of Technology