Flexible Polymer-based Thermoelectric Materials: From Electronic to Ionic carriers

Thermoelectric materials based on flexible polymers have received considerable attention for their ability to directly harvest waste heat to power wearable electronics and Internet-of-Things sensors because of advantages such as facile solution-processable manufacturing, flexibility, and biocompatibility. Polymer-based thermoelectric materials include electronic conductive polymer films (e-TE) and quasi-solid-state ionic thermoelectric (i-TE) gels. However, plenty of research has concentrated on improving the TE performances of these materials, while paying little consideration to their mechanical qualities. In this dissertation, I report a systematic investigation of flexible polymer based thermoelectric materials in which electrons and ions serve as energy carriers, respectively.

The effects of the ordering structure and oxidation levels on the thermoelectric and mechanical properties of e-TE poly(3,4-ethylene dioxythiophene) (PEDOT): poly(styrene sulfonic acid) (PSS) films were investigated. First, a counterion exchange reaction between the PEDOT: PSS and the ionic liquid Li:nFSI was found to strongly affect the ordering structure of the conductive polymer PEDOT. The degree of counterion exchange reaction increased with the size of nFSI^-. The synergistic optimization of the thermoelectric and mechanical properties of PEDOT: PSS-x Li: nFSI resulted in an electrical conductivity of 1515 S cm^-1, a high Seebeck coefficient of 24 μV K^-1 and a tensile strain of 30%. The tensile strain was approximately 10 times higher than that of pristine PEDOT: PSS (3%), indicating the application potential of PEDOT: PSS-x Li: nFSI for the flexible thermoelectric devices. Second, the oxidation level of the PEDOT: PSS film was also investigated by adding the L-ascorbic acid and EMIm:TCM. The addition of L-ascorbic acid confirmed that the PEDOT polymer chain was effectively reduced, thereby changing the oxidation level and boosting the thermoelectric power factor without a considerable sacrifice of mechanical flexibility. The electrical conductivity of the corresponding film was stable (ΔR/R₀ < 0.12%) over 1000 bending cycles, indicating excellent bendability.

Quasi-solid-state i-TE gels are alternative flexible and stretchable polymer based thermoelectric materials. In this dissertation, a study was conducted on ionogels, including polyacrylamide (PAM)/alginate (Alg)-EMIm: BF₄, agarose (AG)-Na: DBS, and Gelatin-KCl-FeCN^3−/4−. The addition of PEG considerably increased the thermopower of Pam-Alg/EMIm: BF₄ from 5.6 to 19.3 mV K⁻¹, indicating the positive effect of tuning the interaction between the mobile ions EMIM⁺ and the polymeric gel. The micellization effect of DBS⁻ anions could be responsible for the unprecedented high thermopower of 41.0 mV K^-1. The synergy between the thermodiffusion and the thermogalvanic effects was exploited to combine the advantages such as a high thermopower and high output current. A gelatin-based i-TE gel (Gelatin-0.8M KCl-0.42/0.25M FeCN^4-/3-) exhibited a high thermopower of 17 mV K^-1 and high instant output power density of 0.66 mW m⁻² K⁻². Using this material in a quasi-continuous thermal charge/electrical discharge mode for long-time usage delivered a maximum energy density of 12.8 J m^-2 in 1 hour. The tensile strain in the i-TE gels (Pam-Alg-PEG)/EMIm: BF₄ has a high upper limit of > 2000%, which was considerably higher than that in the e-TE polymer film.

由于可穿戴电子产品和物联网传感器的快速发展，基于柔性聚合物的热电材料因其同时具备的柔性，生物相容性与自供电能力近年来而受到了相当大的关注。聚合物基热电材料包括电子型聚合物薄膜(e-TE)和准固态离子型热电凝胶(i-TE)等材料。然而，目前主要研究集中在提高这些材料的热电性能上，而很少考虑它们的机械性能。因此，本文系统地研究了以电子和离子分别作为能量载体的柔性聚合物热电材料所同时具备的高柔性机械性能和高热电转换能力。

首先，本文通过研究有序结构和氧化水平对聚(3,4-乙烯二氧噻吩)(PEDOT):聚苯乙烯磺酸(PSS)薄膜热电性能和力学性能的影响，发现了PEDOT: PSS与离子液体Li:nFSI之间的离子交换反应强烈地影响了导电聚合物PEDOT的有序结构。反交换反应的程度随着nFSI粒径的增大而增大。通过对PEDOT: PSS-x Li: nFSI热电性能和力学性能的协同优化，PEDOT: PSS-x Li: nFSI的电导率达到1515 S cm^-1, Seebeck系数达到24 μV K^-1，最大拉伸应变达到30%，相比未经处理的PEDOT: PSS提高约10倍(3%)，表明PEDOT: PSS-x Li: nFSI在柔性热电器件中的应用潜力。同时，本文通过添加L-抗坏血酸和EMIm:TCM引入氧化态调控策略态优化PEDOT：PSS热电性能。L-抗坏血酸的加入证实了PEDOT聚合物链的有效还原，从而降低PEDOT氧化态提高了热电功率因子，同时又极大程度上维持了离子液体处理所提升的机械柔性。该薄膜在1000次弯曲循环中，对应电导率十分稳定(ΔR/R0 < 0.12%)，表明了其优异的可弯曲性。

其次，准固态离子热电凝胶亦是一种柔性和可拉伸的聚合物基热电材料。本文主要研究了聚丙烯酰胺(PAM)/海藻酸盐(Alg)-EMIm: BF₄、琼脂糖(AG)-Na: DBS、明胶- KCl-FeCN^3−/4−等不同离子凝胶体系。在聚丙烯酰胺基双网络凝胶中，PEG的加入显著提高了Pam-Alg/EMIm: BF4的热电势，从5.6 mV K⁻¹提高到19.3 mV K⁻¹，表明调节离子EMIm⁺与聚合物凝胶之间的相互作用可以优化离子热电材料性能。在琼脂体系中，DBS⁻阴离子所引发的胶束效应实现了41.0 mV K⁻¹的高热电势。此外，本文利用thermodiffusion和thermogalvanic效应之间的协同作用，将高热电势和高输出电流等优点结合起来。明胶基i-TE凝胶(明胶-0.8 m KCl-0.42/0.25M FeCN^3−/4−)具有17 mV K⁻¹的高热功率和0.66 mW m⁻² K⁻²的高瞬时输出功率密度，可在准连续热充/放电模式下长期使用，放电1小时内最大能量密度可达12.8 J m^-2。此外，离子热电凝胶如(Pam-Alg-PEG)/EMIm: BF₄的拉伸应变上限可达> 2000%，明显高于电子型热电聚合物薄膜。

[1. Zhang, P.; Deng, B.; Sun, W.; Zheng, Z.; Liu, W., Fiber-based thermoelectric materials and devices for wearable electronics. Micromachines 2021, 12 (8), 869.2. Park, J. H.; Lee, H. E.; Jeong, C. K.; Hong, S. K.; Park, K.-I.; Lee, K. J., Self-powered flexible electronics beyond thermal limits. Nano Energy 2019, 56, 531-546.3. Park, S.; Heo, S. W.; Lee, W.; Inoue, D.; Jiang, Z.; Yu, K.; Jinno, H.; Hashizume, D.; Sekino, M.; Yokota, T., Self-powered ultra-flexible electronics via nano-grating-patterned organic photovoltaics. Nature 2018, 561 (7724), 516-521.4. Yu, H.; Li, N.; Zhao, N., How far are we from achieving self‐powered flexible health monitoring systems: an energy perspective. Advanced Energy Materials 2021, 11 (9), 2002646.5. Huang, L.; Lin, S.; Xu, Z.; Zhou, H.; Duan, J.; Hu, B.; Zhou, J., Fiber‐based energy conversion devices for human‐body energy harvesting. Advanced Materials 2020, 32 (5), 1902034.6. Snyder, G. J.; Toberer, E. S., Complex thermoelectric materials. Nature Materials 2008, 7 (2), 105-114.7. Bahk, J.-H.; Fang, H.; Yazawa, K.; Shakouri, A., Flexible thermoelectric materials and device optimization for wearable energy harvesting. Journal of Materials Chemistry C 2015, 3 (40), 10362-10374.8. Wang, Y.; Yang, L.; Shi, X. L.; Shi, X.; Chen, L.; Dargusch, M. S.; Zou, J.; Chen, Z. G., Flexible thermoelectric materials and generators: challenges and innovations. Advanced Materials 2019, 31 (29), 1807916.9. Zhang, L.; Shi, X.-L.; Yang, Y.-L.; Chen, Z.-G., Flexible thermoelectric materials and devices: From materials to applications. Materials Today 2021, 46, 62-108.10. Masoumi, S.; O'Shaughnessy, S.; Pakdel, A., Organic-based flexible thermoelectric generators: From materials to devices. Nano Energy 2022, 92, 106774.11. Akbar, Z. A.; Jeon, J.-W.; Jang, S.-Y., Intrinsically self-healable, stretchable thermoelectric materials with a large ionic Seebeck effect. Energy & Environmental Science 2020, 13 (9), 2915-2923.12. Fang, Y.; Cheng, H.; He, H.; Wang, S.; Li, J.; Yue, S.; Zhang, L.; Du, Z.; Ouyang, J., Stretchable and transparent ionogels with high thermoelectric properties. Advanced Functional Materials 2020, 30 (51), 2004699.13. Ding, T.; Zhou, Y.; Wang, X. Q.; Zhang, C.; Li, T.; Cheng, Y.; Lu, W.; He, J.; Ho, G. W., All‐soft and stretchable thermogalvanic gel fabric for antideformity body heat harvesting wearable. Advanced Energy Materials 2021, 11 (44), 2102219.14. Seebeck, T. J., Magnetic polarization of metals and minerals. Abhandlungen der Deutschen Akademie der Wissenschaften zu Berlin 1822, 265, 1822-1823.15. Bell, L. E., Cooling, heating, generating power, and recovering waste heat with thermoelectric systems. Science 2008, 321 (5895), 1457-1461.16. Pichanusakorn, P.; Bandaru, P., Nanostructured thermoelectrics. Materials Science and Engineering: R: Reports 2010, 67 (2-4), 19-63.17. Ioffe, A. F.; Stil'Bans, L.; Iordanishvili, E.; Stavitskaya, T.; Gelbtuch, A.; Vineyard, G., Semiconductor thermoelements and thermoelectric cooling. Physics Today 1959, 12 (5), 42.18. Soleimani, Z.; Zoras, S.; Ceranic, B.; Shahzad, S.; Cui, Y., A review on recent developments of thermoelectric materials for room-temperature applications. Sustainable Energy Technologies and Assessments 2020, 37, 100604.19. Wei, J.; Yang, L.; Ma, Z.; Song, P.; Zhang, M.; Ma, J.; Yang, F.; Wang, X., Review of current high-ZT thermoelectric materials. Journal of Materials Science 2020, 55, 12642-12704.20. Wang, S.; Zuo, G.; Kim, J.; Sirringhaus, H., Progress of conjugated polymers as emerging thermoelectric materials. Progress in Polymer Science 2022, 101548.21. Berggren, M.; Crispin, X.; Fabiano, S.; Jonsson, M. P.; Simon, D. T.; Stavrinidou, E.; Tybrandt, K.; Zozoulenko, I., Ion electron-coupled functionality in materials and devices based on conjugated polymers. Advanced materials 2019, 31 (22), 1805813.22. Al-zubaidi, A.; Ji, X.; Yu, J., Thermal charging of supercapacitors: a perspective. Sustainable Energy & Fuels 2017, 1 (7), 1457-1474.23. Wu, X.; Huang, B.; Wang, Q.; Wang, Y., Thermally chargeable supercapacitor using a conjugated conducting polymer: Insight into the mechanism of charge-discharge cycle. Chemical Engineering Journal 2019, 373, 493-500.24. Gunawan, A.; Lin, C.-H.; Buttry, D. A.; Mujica, V.; Taylor, R. A.; Prasher, R. S.; Phelan, P. E., Liquid thermoelectrics: review of recent and limited new data of thermogalvanic cell experiments. Nanoscale and Microscale Thermophysical Engineering 2013, 17 (4), 304-323.25. Chiang, C. K.; Fincher Jr, C.; Park, Y. W.; Heeger, A. J.; Shirakawa, H.; Louis, E. J.; Gau, S. C.; MacDiarmid, A. G., Electrical conductivity in doped polyacetylene. Physical Review Letters 1977, 39 (17), 1098.26. Heeger, A. J., Nobel Lecture: Semiconducting and metallic polymers: The fourth generation of polymeric materials. Reviews of Modern Physics 2001, 73 (3), 681.27. MacDiarmid, A. G., Nobel lecture:“synthetic metals”: a novel role for organic polymers. Reviews of Modern Physics 2001, 73 (3), 701.28. Shirakawa, H., Nobel lecture: the discovery of polyacetylene film—the dawning of an era of conducting polymers. Reviews of Modern Physics 2001, 73 (3), 713.29. Fesser, K.; Bishop, A.; Campbell, D., Optical absorption from polarons in a model of polyacetylene. Physical Review B 1983, 27 (8), 4804.30. Cheng, H.; Le, Q.; Liu, Z.; Qian, Q.; Zhao, Y.; Ouyang, J., Ionic thermoelectrics: principles, materials and applications. Journal of Materials Chemistry C 2022, 10 (2), 433-450.31. Du, Y.; Shen, S. Z.; Cai, K.; Casey, P. S., Research progress on polymer-inorganic thermoelectric nanocomposite materials. Progress in Polymer Science 2012, 37 (6), 820-841.32. Kwon, O.; Coropceanu, V.; Gruhn, N.; Durivage, J.; Laquindanum, J.; Katz, H.; Cornil, J.; Brédas, J.-L., Characterization of the molecular parameters determining charge transport in anthradithiophene. The Journal of Chemical Physics 2004, 120 (17), 8186-8194.33. Seeman, J. I., Kenichi Fukui, Frontier Molecular Orbital Theory, and the Woodward‐Hoffmann Rules. Part II. A Sleeping Beauty in Chemistry. The Chemical Record 2022, 22 (4), e202100300.34. Fleming, I., Molecular orbitals and organic chemical reactions. John Wiley & Sons, Hoboken: 2011, p27-38.35. Pietro, W. J.; Marks, T. J.; Ratner, M. A., Resistivity mechanisms in phthalocyanine-based linear-chain and polymeric conductors: Variation of bandwidth with geometry. Journal of the American Chemical Society 1985, 107 (19), 5387-5391.36. Kobayashi, S.; Müllen, K., Encyclopedia of polymeric nanomaterials. Springer Berlin Heidelberg, Berlin: 2015, p1157-1166.37. Soos, Z.; Hayden, G.; McWilliams, P.; Etemad, S., Excitation shifts of parallel conjugated polymers due to π‐electron dispersion forces. The Journal of Chemical Physics 1990, 93 (10), 7439-7448.38. Duke, C. B.; Schein, L., Organic solids: is energy-band theory enough? Physics Today 1980, 33 (2), 42-48.39. Lee, J.; Song, K.; Kim, S.; Kim, Y.; Kim, D.; Kim, C., Synthesis and characterization of soluble polypyrrole. Synthetic Metals 1997, 84 (1-3), 137-140.40. Song, K.; Lee, J.; Kim, H.; Kim, D.; Kim, S.; Kim, C., Solvent effects on the characteristics of soluble polypyrrole. Synthetic Metals 2000, 110 (1), 57-63.41. Epstein, A.; Ginder, J.; Zuo, F.; Bigelow, R.; Woo, H.-S.; Tanner, D.; Richter, A.; Huang, W.-S.; MacDiarmid, A., Insulator-to-metal transition in polyaniline. Synthetic Metals 1987, 18 (1-3), 303-309.42. Salzmann, I.; Heimel, G.; Oehzelt, M.; Winkler, S.; Koch, N., Molecular electrical doping of organic semiconductors: fundamental mechanisms and emerging dopant design rules. Accounts of Chemical Research 2016, 49 (3), 370-378.43. Dubey, N.; Leclerc, M., Conducting polymers: Efficient thermoelectric materials. Journal of Polymer Science Part B: Polymer Physics 2011, 49 (7), 467-475.44. Zhang, Q.; Sun, Y.; Xu, W.; Zhu, D., Organic thermoelectric materials: emerging green energy materials converting heat to electricity directly and efficiently. Advanced Materials 2014, 26 (40), 6829-6851.45. Kemp, N.; Kaiser, A.; Liu, C. J.; Chapman, B.; Mercier, O.; Carr, A.; Trodahl, H.; Buckley, R.; Partridge, A.; Lee, J., Thermoelectric power and conductivity of different types of polypyrrole. Journal of Polymer Science Part B: Polymer Physics 1999, 37 (9), 953-960.46. Zhang, Q.; Sun, Y.; Xu, W.; Zhu, D., Thermoelectric energy from flexible P3HT films doped with a ferric salt of triflimide anions. Energy & Environmental Science 2012, 5 (11), 9639-9644.47. Wang, H.; Yin, L.; Pu, X.; Yu, C., Facile charge carrier adjustment for improving thermopower of doped polyaniline. Polymer 2013, 54 (3), 1136-1140.48. Bubnova, O.; Berggren, M.; Crispin, X., Tuning the thermoelectric properties of conducting polymers in an electrochemical transistor. Journal of the American Chemical Society 2012, 134 (40), 16456-16459.49. Bubnova, O.; Crispin, X., Towards polymer-based organic thermoelectric generators. Energy & Environmental Science 2012, 5 (11), 9345-9362.50. Kim, G.-H.; Shao, L.; Zhang, K.; Pipe, K. P., Engineered doping of organic semiconductors for enhanced thermoelectric efficiency. Nature Materials 2013, 12 (8), 719-723.51. Han, S.; Zhai, W.; Chen, G.; Wang, X., Morphology and thermoelectric properties of graphene nanosheets enwrapped with polypyrrole. RSC Advances 2014, 4 (55), 29281-29285.52. Yan, H.; Ishida, T.; Toshima, N., Self-formation and anisotropic electrical conduction of polypyrrole-microtubes. Chemistry Letters 2001, 30 (8), 816-817.53. Bubnova, O.; Khan, Z. U.; Malti, A.; Braun, S.; Fahlman, M.; Berggren, M.; Crispin, X., Optimization of the thermoelectric figure of merit in the conducting polymer poly (3, 4-ethylenedioxythiophene). Nature Materials 2011, 10 (6), 429-433.54. 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 & Environmental Science 2013, 6 (3), 788-792.55. Hiraishi, K.; Masuhara, A.; Nakanishi, H.; Oikawa, H.; Shinohara, Y., Evaluation of thermoelectric properties of polythiophene films synthesized by electrolytic polymerization. Japanese Journal of Applied Physics 2009, 48 (7R), 071501.56. Yan, H.; Ohta, T.; Toshima, N., Stretched polyaniline films doped by (±)‐10‐camphorsulfonic acid: anisotropy and improvement of thermoelectric properties. Macromolecular Materials and Engineering 2001, 286 (3), 139-142.57. Liang, J.; Yin, S.; Wan, C., Hybrid Thermoelectrics. Annual Review of Materials Research 2020, 50 (1), 319-344.58. Gao, C.; Chen, G., Conducting polymer/carbon particle thermoelectric composites: Emerging green energy materials. Composites Science and Technology 2016, 124, 52-70.59. He, M.; Qiu, F.; Lin, Z., Towards high-performance polymer-based thermoelectric materials. Energy & Environmental Science 2013, 6 (5), 1352-1361.60. Jin, H.; Li, J.; Iocozzia, J.; Zeng, X.; Wei, P.-C.; Yang, C.; Li, N.; Liu, Z.; He, J. H.; Zhu, T.; Wang, J.; Lin, Z.; Wang, S., Hybrid organic-inorganic thermoelectric materials and devices. Angewandte Chemie International Edition 2019, 58 (43), 15206-15226.61. Zhang, K.; Zhang, Y.; Wang, S., Enhancing thermoelectric properties of organic composites through hierarchical nanostructures. Scientific Reports 2013, 3 (1), 1-7.62. We, J. H.; Kim, S. J.; Cho, B. J., Hybrid composite of screen-printed inorganic thermoelectric film and organic conducting polymer for flexible thermoelectric power generator. Energy 2014, 73, 506-512.63. Wang, L.; Zhang, Z.; Liu, Y.; Wang, B.; Fang, L.; Qiu, J.; Zhang, K.; Wang, S., Exceptional thermoelectric properties of flexible organic− inorganic hybrids with monodispersed and periodic nanophase. Nature Communications 2018, 9 (1), 1-8.64. Kim, C.; Baek, J. Y.; Lopez, D. H.; Kim, D. H.; Kim, H., Interfacial energy band and phonon scattering effect in Bi2Te3-polypyrrole hybrid thermoelectric material. Applied Physics Letters 2018, 113 (15), 153901.65. Cho, C.; Wallace, K. L.; Tzeng, P.; Hsu, J. H.; Yu, C.; Grunlan, J. C., Outstanding low temperature thermoelectric power factor from completely organic thin films enabled by multidimensional conjugated nanomaterials. Advanced Energy Materials 2016, 6 (7), 1502168.66. Kivelson, S., Electron hopping conduction in the soliton model of polyacetylene. Molecular Crystals and Liquid Crystals 1981, 77 (1-4), 65-79.67. Peierls, R.; Peierls, R. E., Quantum theory of solids. Oxford University Press: 1955.68. Bally, T.; Hrovat, D. A.; Borden, W. T., Attempts to model neutral solitons in polyacetylene by ab initio and density functional methods. The nature of the spin distribution in polyenyl radicals. Physical Chemistry Chemical Physics 2000, 2 (15), 3363-3371.69. Yuan, B.; Li, C.; Zhao, Y.; Gröning, O.; Zhou, X.; Zhang, P.; Guan, D.; Li, Y.; Zheng, H.; Liu, C.; Mai, Y.; Liu, P.; Ji, W.; Jia, J.; Wang, S., Resolving quinoid structure in poly(para-phenylene) chains. Journal of the American Chemical Society 2020, 142 (22), 10034-10041.70. Le, T.-H.; Kim, Y.; Yoon, H., Electrical and electrochemical properties of conducting polymers. Polymers 2017, 9 (4), 150.71. Mikhnenko, O.; Cordella, F.; Sieval, A.; Hummelen, J.; Blom, P.; Loi, M., Temperature dependence of exciton diffusion in conjugated polymers. The Journal of Physical Chemistry B 2008, 112 (37), 11601-11604.72. Grell, M.; Bradley, D.; Inbasekaran, M.; Ungar, G.; Whitehead, K.; Woo, E., Intrachain ordered polyfluorene. Synthetic Metals 2000, 111, 579-581.73. Herz, L.; Phillips, R., Effects of interchain interactions, polarization anisotropy, and photo-oxidation on the ultrafast photoluminescence decay from a polyfluorene. Physical Review B 2000, 61 (20), 13691.74. Lu, Y.; Wang, J.-Y.; Pei, J., Strategies to enhance the conductivity of n-type polymer thermoelectric materials. Chemistry of Materials 2019, 31 (17), 6412-6423.75. Sun, Y.; Di, C. A.; Xu, W.; Zhu, D., Advances in n‐type organic thermoelectric materials and devices. Advanced Electronic Materials 2019, 5 (11), 1800825.76. Jia, H.; Lei, T., Emerging research directions for n-type conjugated polymers. Journal of Materials Chemistry C 2019, 7 (41), 12809-12821.77. Shi, K.; Zhang, F.; Di, C.-A.; Yan, T.-W.; Zou, Y.; Zhou, X.; Zhu, D.; Wang, J.-Y.; Pei, J., Toward high performance n-type thermoelectric materials by rational modification of BDPPV backbones. Journal of the American Chemical Society 2015, 137 (22), 6979-6982.78. Hwang, S.; Potscavage, W. J.; Yang, Y. S.; Park, I. S.; Matsushima, T.; Adachi, C., Solution-processed organic thermoelectric materials exhibiting doping-concentration-dependent polarity. Physical Chemistry Chemical Physics 2016, 18 (42), 29199-29207.79. Wang, Y.; Nakano, M.; Michinobu, T.; Kiyota, Y.; Mori, T.; Takimiya, K., Naphthodithiophenediimide-benzobisthiadiazole-based polymers: versatile n-type materials for field-effect transistors and thermoelectric devices. Macromolecules 2017, 50 (3), 857-864.80. Lüssem, B.; Riede, M.; Leo, K., Doping of organic semiconductors. Physica Status Solidi (a) 2013, 210 (1), 9-43.81. Collins, B. A.; Cochran, J. E.; Yan, H.; Gann, E.; Hub, C.; Fink, R.; Wang, C.; Schuettfort, T.; McNeill, C. R.; Chabinyc, M. L., Polarized X-ray scattering reveals non-crystalline orientational ordering in organic films. Nature Materials 2012, 11 (6), 536-543.82. Kang, S. D.; Snyder, G. J., Charge-transport model for conducting polymers. Nature Materials 2017, 16 (2), 252-257.83. Tietze, M. L.; Rose, B. D.; Schwarze, M.; Fischer, A.; Runge, S.; Blochwitz‐Nimoth, J.; Lüssem, B.; Leo, K.; Brédas, J. L., Passivation of molecular n‐doping: exploring the limits of air stability. Advanced Functional Materials 2016, 26 (21), 3730-3737.84. Meng, B.; Liu, J.; Wang, L., Recent development of n-type thermoelectric materials based on conjugated polymers. Nano Materials Science 2021, 3 (2), 113-123.85. Chen, M. S.; Lee, O. P.; Niskala, J. R.; Yiu, A. T.; Tassone, C. J.; Schmidt, K.; Beaujuge, P. M.; Onishi, S. S.; Toney, M. F.; Zettl, A., Enhanced solid-state order and field-effect hole mobility through control of nanoscale polymer aggregation. Journal of the American Chemical Society 2013, 135 (51), 19229-19236.86. Yao, Z. F.; Zheng, Y. Q.; Li, Q. Y.; Lei, T.; Zhang, S.; Zou, L.; Liu, H. Y.; Dou, J. H.; Lu, Y.; Wang, J. Y., Wafer‐scale fabrication of high‐performance n‐type polymer monolayer transistors using a multi‐level self‐assembly strategy. Advanced Materials 2019, 31 (7), 1806747.87. Zheng, Y. Q.; Yao, Z. F.; Lei, T.; Dou, J. H.; Yang, C. Y.; Zou, L.; Meng, X.; Ma, W.; Wang, J. Y.; Pei, J., Unraveling the solution‐state supramolecular structures of donor-acceptor polymers and their influence on solid‐state morphology and charge‐transport properties. Advanced Materials 2017, 29 (42), 1701072.88. De Leeuw, D.; Simenon, M.; Brown, A.; Einerhand, R., Stability of n-type doped conducting polymers and consequences for polymeric microelectronic devices. Synthetic Metals 1997, 87 (1), 53-59.89. Yan, H.; Chen, Z.; Zheng, Y.; Newman, C.; Quinn, J. R.; Dötz, F.; Kastler, M.; Facchetti, A., A high-mobility electron-transporting polymer for printed transistors. Nature 2009, 457 (7230), 679-686.90. Chen, Z.; Zheng, Y.; Yan, H.; Facchetti, A., Naphthalenedicarboximide-vs perylenedicarboximide-based copolymers. Synthesis and semiconducting properties in bottom-gate n-channel organic transistors. Journal of the American Chemical Society 2009, 131 (1), 8-9.91. Liu, J.; Shi, Y.; Dong, J.; Nugraha, M. I.; Qiu, X.; Su, M.; Chiechi, R. C.; Baran, D.; Portale, G.; Guo, X., Overcoming coulomb interaction improves free-charge generation and thermoelectric properties for n-doped conjugated polymers. ACS Energy Letters 2019, 4 (7), 1556-1564.92. Yan, X.; Xiong, M.; Li, J.-T.; Zhang, S.; Ahmad, Z.; Lu, Y.; Wang, Z.-Y.; Yao, Z.-F.; Wang, J.-Y.; Gu, X., Pyrazine-flanked diketopyrrolopyrrole (DPP): a new polymer building block for high-performance n-type organic thermoelectrics. Journal of the American Chemical Society 2019, 141 (51), 20215-20221.93. Sun, Y.; Sheng, P.; Di, C.; Jiao, F.; Xu, W.; Qiu, D.; Zhu, D., Organic thermoelectric materials and devices based on p‐and n‐type poly (metal 1, 1, 2, 2‐ethenetetrathiolate) s. Advanced Materials 2012, 24 (7), 932-937.94. Huang, D.; Yao, H.; Cui, Y.; Zou, Y.; Zhang, F.; Wang, C.; Shen, H.; Jin, W.; Zhu, J.; Diao, Y., Conjugated-backbone effect of organic small molecules for n-type thermoelectric materials with ZT over 0.2. Journal of the American Chemical Society 2017, 139 (37), 13013-13023.95. Schlitz, R. A.; Brunetti, F. G.; Glaudell, A. M.; Miller, P. L.; Brady, M. A.; Takacs, C. J.; Hawker, C. J.; Chabinyc, M. L., Solubility‐limited extrinsic n‐type doping of a high electron mobility polymer for thermoelectric applications. Advanced Materials 2014, 26 (18), 2825-2830.96. Liu, J.; Qiu, L.; Alessandri, R.; Qiu, X.; Portale, G.; Dong, J.; Talsma, W.; Ye, G.; Sengrian, A. A.; Souza, P. C., Enhancing molecular n‐type doping of donor-acceptor copolymers by tailoring side chains. Advanced Materials 2018, 30 (7), 1704630.97. Yang, C.-Y.; Ding, Y.-F.; Huang, D.; Wang, J.; Yao, Z.-F.; Huang, C.-X.; Lu, Y.; Un, H.-I.; Zhuang, F.-D.; Dou, J.-H., A thermally activated and highly miscible dopant for n-type organic thermoelectrics. Nature Communications 2020, 11 (1), 3292.98. Sun, Y.; Qiu, L.; Tang, L.; Geng, H.; Wang, H.; Zhang, F.; Huang, D.; Xu, W.; Yue, P.; Guan, Y. s., Flexible n‐type high‐performance thermoelectric thin films of poly (nickel‐ethylenetetrathiolate) prepared by an electrochemical method. Advanced Materials 2016, 28 (17), 3351-3358.99. Bredas, J. L.; Street, G. B., Polarons, bipolarons, and solitons in conducting polymers. Accounts of Chemical Research 1985, 18 (10), 309-315.100. Lee, S. H.; Park, H.; Kim, S.; Son, W.; Cheong, I. W.; Kim, J. H., Transparent and flexible organic semiconductor nanofilms with enhanced thermoelectric efficiency. Journal of Materials Chemistry A 2014, 2 (20), 7288-7294.101. Hwang, J.; Amy, F.; Kahn, A., Spectroscopic study on sputtered PEDOT· PSS: Role of surface PSS layer. Organic Electronics 2006, 7 (5), 387-396.102. 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 (25), 8443-8450.103. Kim, N.; Kee, S.; Lee, S. H.; Lee, B. H.; Kahng, Y. H.; Jo, Y. R.; Kim, B. J.; Lee, K., Highly conductive PEDOT: PSS nanofibrils induced by solution‐processed crystallization. Advanced Materials 2014, 26 (14), 2268-2272.104. Yeo, J.-S.; Yun, J.-M.; Kim, D.-Y.; Park, S.; Kim, S.-S.; Yoon, M.-H.; Kim, T.-W.; Na, S.-I., Significant vertical phase separation in solvent-vapor-annealed poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) composite films leading to better conductivity and work function for high-performance indium tin oxide-free optoelectronics. ACS Applied Materials & Interfaces 2012, 4 (5), 2551-2560.105. Takano, T.; Masunaga, H.; Fujiwara, A.; Okuzaki, H.; Sasaki, T., PEDOT nanocrystal in highly conductive PEDOT: PSS polymer films. Macromolecules 2012, 45 (9), 3859-3865.106. Cho, B.; Park, K. S.; Baek, J.; Oh, H. S.; Koo Lee, Y.-E.; Sung, M. M., Single-crystal poly (3, 4-ethylenedioxythiophene) nanowires with ultrahigh conductivity. Nano Letters 2014, 14 (6), 3321-3327.107. Zhang, B.; Sun, J.; Katz, H.; Fang, F.; Opila, R., Promising thermoelectric properties of commercial PEDOT: PSS materials and their Bi2Te3 powder composites. ACS Applied Materials & Interfaces 2010, 2 (11), 3170-3178.108. Jin Bae, E.; Hun Kang, Y.; Jang, K.-S.; Yun Cho, S., Enhancement of thermoelectric properties of PEDOT: PSS and tellurium-PEDOT: PSS hybrid composites by simple chemical treatment. Scientific Reports 2016, 6 (1), 1-10.109. Ju, H.; Kim, J., Fabrication of conductive polymer/inorganic nanoparticles composite films: PEDOT: PSS with exfoliated tin selenide nanosheets for polymer-based thermoelectric devices. Chemical Engineering Journal 2016, 297, 66-73.110. Xiong, J.; Jiang, F.; Shi, H.; Xu, J.; Liu, C.; Zhou, W.; Jiang, Q.; Zhu, Z.; Hu, Y., Liquid exfoliated graphene as dopant for improving the thermoelectric power factor of conductive PEDOT: PSS nanofilm with hydrazine treatment. ACS Applied Materials & Interfaces 2015, 7 (27), 14917-14925.111. Lee, W.; Kang, Y. H.; Lee, J. Y.; Jang, K.-S.; Cho, S. Y., Improving the thermoelectric power factor of CNT/PEDOT: PSS nanocomposite films by ethylene glycol treatment. RSC Advances 2016, 6 (58), 53339-53344.112. Peng, J.; Snyder, G. J., A figure of merit for flexibility. Science 2019, 366 (6466), 690-691.113. Soret, C., Concentrations differentes d’une dissolution dont deux parties sont a’des temperatures differentes. Arch Sci Phys Nat, Geneva 1879, 2, 48-61.114. Ludwig, C.; Akad, S. B., Wiss. Wien 1856, 20, 539.115. Eastman, E. D., Thermodynamics of non-isothermal systems. Journal of the American Chemical Society 1926, 48 (6), 1482-1493.116. Würger, A., Thermopower of ionic conductors and ionic capacitors. Physical Review Research 2020, 2 (4), 042030.117. Nernst, W., Die elektromotorische Wirksamkeit der Jonen. 1889, 4U (1), 129-181.118. Onsager, L., Reciprocal relations in irreversible processes. I. Physical Review 1931, 37 (4), 405.119. Onsager, L., Reciprocal relations in irreversible processes. II. Physical Review 1931, 38 (12), 2265.120. Zhao, D.; Martinelli, A.; Willfahrt, A.; Fischer, T.; Bernin, D.; Khan, Z. U.; Shahi, M.; Brill, J.; Jonsson, M. P.; Fabiano, S.; Crispin, X., Polymer gels with tunable ionic Seebeck coefficient for ultra-sensitive printed thermopiles. Nature Communications 2019, 10 (1), 1093.121. Bard, A. J.; Faulkner, L. R.; White, H. S., Electrochemical methods: fundamentals and applications. John Wiley & Sons, Hoboken: 2022, p105-107.122. Bratsch, S. G., Standard electrode potentials and temperature coefficients in water at 298.15 K. Journal of Physical and Chemical Reference Data 1989, 18 (1), 1-21.123. Im, H.; Kim, T.; Song, H.; Choi, J.; Park, J. S.; Ovalle-Robles, R.; Yang, H. D.; Kihm, K. D.; Baughman, R. H.; Lee, H. H., High-efficiency electrochemical thermal energy harvester using carbon nanotube aerogel sheet electrodes. Nature Communications 2016, 7 (1), 1-9.124. Bouty, E., Phénomènes thermo-électriques et électro-thermiques au contact d'un métal et d'un liquide. Journal de Physique Théorique et Appliquée 1880, 9 (1), 306-320.125. Holtan, H., On the theory of non-isothermal systems. Proc. K. Akad. Wetensch. B 1953, 56, 402-406.126. Mazur, P., Thermopotentials in thermocells. The Journal of Physical Chemistry 1954, 58 (9), 700-702.127. De Groot, S.; Jansen, L.; Mazur, P., Non-equilibrium thermodynamics and liquid helium II. Physica 1950, 16 (9), 691-708.128. Levin, H.; Bonilla, C. F., Thermogalvanic Potentials: I. The application of thermodynamics to thermogalvanic data (A study of the silver chloride electrode from 25° to 90° C). Journal of The Electrochemical Society 1951, 98 (10), 388.129. Carr, D. S.; Bonilla, C. F., Thermogalvanic potentials: II. Nickel in neutral sulfate solution. Journal of The Electrochemical Society 1952, 99 (12), 475.130. Intersociety Energy Conversion Engineering, C., Record of the 10th Intersociety energy conversion engineering conference : John Clayton conference center, University of Delaware, Newark, Delaware, August 18-22, 1975. Institute of Electrical and Electronics Engineers: New York, 1975.131. Burrows, B., Discharge behavior of redox thermogalvanic cells. Journal of The Electrochemical Society 1976, 123 (2), 154.132. Quickenden, T.; Mua, Y., A review of power generation in aqueous thermogalvanic cells. Journal of The Electrochemical Society 1995, 142 (11), 3985.133. Kang, T. J.; Fang, S.; Kozlov, M. E.; Haines, C. S.; Li, N.; Kim, Y. H.; Chen, Y.; Baughman, R. H., Electrical power from nanotube and graphene electrochemical thermal energy harvesters. Advanced Functional Materials 2012, 22 (3), 477-489.134. Hu, R.; Cola, B. A.; Haram, N.; Barisci, J. N.; Lee, S.; Stoughton, S.; Wallace, G.; Too, C.; Thomas, M.; Gestos, A., Harvesting waste thermal energy using a carbon-nanotube-based thermo-electrochemical cell. Nano Letters 2010, 10 (3), 838-846.135. Zhang, L.; Kim, T.; Li, N.; Kang, T. J.; Chen, J.; Pringle, J. M.; Zhang, M.; Kazim, A. H.; Fang, S.; Haines, C., High power density electrochemical thermocells for inexpensively harvesting low‐grade thermal energy. Advanced Materials 2017, 29 (12), 1605652.136. Duan, J.; Feng, G.; Yu, B.; Li, J.; Chen, M.; Yang, P.; Feng, J.; Liu, K.; Zhou, J., Aqueous thermogalvanic cells with a high Seebeck coefficient for low-grade heat harvest. Nature Communications 2018, 9 (1), 1-8.137. Yu, B.; Duan, J.; Cong, H.; Xie, W.; Liu, R.; Zhuang, X.; Wang, H.; Qi, B.; Xu, M.; Wang, Z. L., Thermosensitive crystallization-boosted liquid thermocells for low-grade heat harvesting. Science 2020, 370 (6514), 342-346.138. Liang, Y.; Ka-Ho Hui, J.; Morikawa, M.-a.; Inoue, H.; Yamada, T.; Kimizuka, N., High positive seebeck coefficient of aqueous I–/I3– thermocells based on host-guest interactions and LCST behavior of PEGylated α-Cyclodextrin. ACS Applied Energy Materials 2021, 4 (5), 5326-5331.139. Lin, J.-L.; Christenson, M. A., Heats of transport of some chlorides in H2O and D2O. Journal of Solution Chemistry 1973, 2, 83-94.140. Bonetti, M.; Nakamae, S.; Roger, M.; Guenoun, P., Huge Seebeck coefficients in nonaqueous electrolytes. The Journal of Chemical Physics 2011, 134 (11), 114513.141. Yang, P.; Liu, K.; Chen, Q.; Mo, X.; Zhou, Y.; Li, S.; Feng, G.; Zhou, J., Wearable thermocells based on gel electrolytes for the utilization of body heat. Angewandte Chemie International Edition 2016, 55 (39), 12050-12053.142. Liang, L.; Lv, H.; Shi, X.-L.; Liu, Z.; Chen, G.; Chen, Z.-G.; Sun, G., A flexible quasi-solid-state thermoelectrochemical cell with high stretchability as an energy-autonomous strain sensor. Materials Horizons 2021, 8 (10), 2750-2760.143. Xu, C.; Sun, Y.; Zhang, J.; Xu, W.; Tian, H., Adaptable and wearable thermocell based on stretchable hydrogel for body heat harvesting. Advanced Energy Materials 2022, 12 (42), 2201542.144. Wang, H.; Zhao, D.; Khan, Z. U.; Puzinas, S.; Jonsson, M. P.; Berggren, M.; Crispin, X., Ionic thermoelectric figure of merit for charging of supercapacitors. Advanced Electronic Materials 2017, 3 (4), 1700013.145. Li, Z.; Xu, Y.; Wu, L.; An, Y.; Sun, Y.; Meng, T.; Dou, H.; Xuan, Y.; Zhang, X., Zinc ion thermal charging cell for low-grade heat conversion and energy storage. Nature Communications 2022, 13 (1), 132.146. Ren, J.; Bai, W.; Guan, G.; Zhang, Y.; Peng, H., Flexible and weaveable capacitor wire based on a carbon nanocomposite fiber. Advanced Materials 2013, 25 (41), 5965-5970.147. Alipoori, S.; Mazinani, S.; Aboutalebi, S. H.; Sharif, F., Review of PVA-based gel polymer electrolytes in flexible solid-state supercapacitors: Opportunities and challenges. Journal of Energy Storage 2020, 27, 101072.148. Zhang, Y.; Dai, Y.; Xia, F.; Zhang, X., Gelatin/polyacrylamide ionic conductive hydrogel with skin temperature-triggered adhesion for human motion sensing and body heat harvesting. Nano Energy 2022, 104, 107977.149. Han, L.; Liu, K.; Wang, M.; Wang, K.; Fang, L.; Chen, H.; Zhou, J.; Lu, X., Mussel‐inspired adhesive and conductive hydrogel with long‐lasting moisture and extreme temperature tolerance. Advanced Functional Materials 2018, 28 (3), 1704195.150. Hu, L.; Chee, P. L.; Sugiarto, S.; Yu, Y.; Shi, C.; Yan, R.; Yao, Z.; Shi, X.; Zhi, J.; Kai, D., Hydrogel‐based flexible electronics. Advanced Materials 2022, 2205326.151. Liu, K.; Lv, J.; Fan, G.; Wang, B.; Mao, Z.; Sui, X.; Feng, X., Flexible and robust bacterial cellulose‐based ionogels with high thermoelectric properties for low‐grade heat harvesting. Advanced Functional Materials 2022, 32 (6), 2107105.152. Xu, J.; Wang, H.; Du, X.; Cheng, X.; Du, Z.; Wang, H., Highly stretchable pu ionogels with self-healing capability for a flexible thermoelectric generator. ACS Applied Materials & Interfaces 2021, 13 (17), 20427-20434.153. Le Bideau, J.; Viau, L.; Vioux, A., Ionogels, ionic liquid based hybrid materials. Chemical Society Reviews 2011, 40 (2), 907-925.154. Zhao, D.; Wang, H.; Khan, Z. U.; Chen, J.; Gabrielsson, R.; Jonsson, M. P.; Berggren, M.; Crispin, X., Ionic thermoelectric supercapacitors. Energy & Environmental Science 2016, 9 (4), 1450-1457.155. Li, T.; Zhang, X.; Lacey, S. D.; Mi, R.; Zhao, X.; Jiang, F.; Song, J.; Liu, Z.; Chen, G.; Dai, J., Cellulose ionic conductors with high differential thermal voltage for low-grade heat harvesting. Nature Materials 2019, 18 (6), 608-613.156. Zhao, W.; Sun, T.; Zheng, Y.; Zhang, Q.; Huang, A.; Wang, L.; Jiang, W., Tailoring intermolecular interactions towards high‐performance thermoelectric ionogels at low humidity. Advanced Science 2022, 9 (20), 2201075.157. Chen, Y.; Shi, C.; Zhang, J.; Dai, Y.; Su, Y.; Liao, B.; Zhang, M.; Tao, X.; Zeng, W., Ionic thermoelectric effect inducing cation‐enriched surface of hydrogel to enhance output performance of triboelectric nanogenerator. Energy Technology 2022, 10 (5), 2200070.158. Shindrov, A.; Artyukhov, D.; Vikulova, M.; Spirin, N.; Nikitina, N.; Savin, N.; Gorshkov, N.; Burmistrov, Thermo-electrochemical cells based on polymer and mineral hydrogels for low-grade waste heat conversion, AIP Conference Proceedings 2017, 1899, 020016.159. Zhang, J.; Xue, W.; Dai, Y.; Li, B.; Chen, Y.; Liao, B.; Zeng, W.; Tao, X.; Zhang, M., High ionic thermopower in flexible composite hydrogel for wearable self-powered sensor. Composites Science and Technology 2022, 230, 109771.160. Chen, B.; Chen, Q.; Xiao, S.; Feng, J.; Zhang, X.; Wang, T., Giant negative thermopower of ionic hydrogel by synergistic coordination and hydration interactions. Science Advances 2021, 7 (48), eabi7233.161. He, X.; Cheng, H.; Yue, S.; Ouyang, J., Quasi-solid state nanoparticle/(ionic liquid) gels with significantly high ionic thermoelectric properties. Journal of Materials Chemistry A 2020, 8 (21), 10813-10821.162. Jiao, F.; Naderi, A.; Zhao, D.; Schlueter, J.; Shahi, M.; Sundström, J.; Granberg, H.; Edberg, J.; Ail, U.; Brill, J., Ionic thermoelectric paper. Journal of Materials Chemistry A 2017, 5 (32), 16883-16888.163. Kim, S. L.; Hsu, J.-H.; Yu, C., Thermoelectric effects in solid-state polyelectrolytes. Organic Electronics 2018, 54, 231-236.164. Chang, W. B.; Evans, C. M.; Popere, B. C.; Russ, B. M.; Liu, J.; Newman, J.; Segalman, R. A., Harvesting waste heat in unipolar ion conducting polymers. ACS Macro Letters 2016, 5 (1), 94-98.165. Kim, S. L.; Lin, H. T.; Yu, C., Thermally chargeable solid-state supercapacitor. Advanced Energy Materials 2016, 6 (18), 1600546.166. Bonetti, M.; Nakamae, S.; Huang, B. T.; Salez, T. J.; Wiertel-Gasquet, C.; Roger, M., Thermoelectric energy recovery at ionic-liquid/electrode interface. The Journal of Chemical Physics 2015, 142 (24), 244708.167. Yang, S.; Qiu, P.; Chen, L.; Shi, X., Recent developments in flexible thermoelectric devices. Small Science 2021, 1 (7), 2100005.168. Lu, Y.; Li, X.; Cai, K.; Gao, M.; Zhao, W.; He, J.; Wei, P., Enhanced-performance PEDOT: PSS/Cu2Se-based composite films for wearable thermoelectric power generators. ACS Applied Materials & Interfaces 2021, 13 (1), 631-638.169. Liang, L.; Wang, M.; Wang, X.; Peng, P.; Liu, Z.; Chen, G.; Sun, G., Initiating a stretchable, compressible, and wearable thermoelectric generator by a spiral architecture with ternary nanocomposites for efficient heat harvesting. Advanced Functional Materials 2022, 32 (15), 2111435.170. Chen, Q.; Chen, B.; Xiao, S.; Feng, J.; Yang, J.; Yue, Q.; Zhang, X.; Wang, T., Giant thermopower of hydrogen ion enhanced by a strong hydrogen bond system. ACS Applied Materials & Interfaces 2022, 14 (17), 19304-19314.171. Sikora, A.; Ftouni, H.; Richard, J.; Hebert, C.; Eon, D.; Omnes, F.; Bourgeois, O., Highly sensitive thermal conductivity measurements of suspended membranes (SiN and diamond) using a 3omega-Volklein method. Rev Sci Instrum 2012, 83 (5), 054902.172. Linseis, V.; Völklein, F.; Reith, H.; Nielsch, K.; Woias, P., Advanced platform for the in-plane ZT measurement of thin films. Review of Scientific Instruments 2018, 89 (1), 015110.173. Kresse, G.; Furthmüller, J., Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Physical Review B 1996, 54 (16), 11169.174. Blöchl, P. E., Projector augmented-wave method. Physical Review B 1994, 50 (24), 17953.175. Perdew, J. P.; Ruzsinszky, A.; Csonka, G. I.; Vydrov, O. A.; Scuseria, G. E.; Constantin, L. A.; Zhou, X.; Burke, K., Restoring the density-gradient expansion for exchange in solids and surfaces. Physical Review Letters 2008, 100 (13), 136406.176. Dal Poggetto, G.; Favaro, D. C.; Nilsson, M.; Morris, G. A.; Tormena, C. F., 19F DOSY NMR analysis for spin systems with nJFF couplings. Magnetic Resonance in Chemistry 2014, 52 (4), 172-177.177. Cohen, Y.; Avram, L.; Frish, L., Diffusion NMR spectroscopy in supramolecular and combinatorial chemistry: an old parameter—new insights. Angewandte Chemie International Edition 2005, 44 (4), 520-554.178. Miorandi, D.; Sicari, S.; De Pellegrini, F.; Chlamtac, I., Internet of things: Vision, applications and research challenges. Ad hoc networks 2012, 10 (7), 1497-1516.179. Hu, L.; Song, J.; Yin, X.; Su, Z.; Li, Z., Research progress on polymer solar cells based on PEDOT: PSS electrodes. Polymers 2020, 12 (1), 145.180. Wang, Y.; Zhu, C.; Pfattner, R.; Yan, H.; Jin, L.; Chen, S.; Molina-Lopez, F.; Lissel, F.; Liu, J.; Rabiah, N. I., A highly stretchable, transparent, and conductive polymer. Science Advances 2017, 3 (3), e1602076.181. Sangeeth, C. S.; Jaiswal, M.; Menon, R., Correlation of morphology and charge transport in poly (3, 4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT-PSS) films. Journal of Physics: Condensed Matter 2009, 21 (7), 072101.182. Murthy, N.; Minor, H., General procedure for evaluating amorphous scattering and crystallinity from X-ray diffraction scans of semicrystalline polymers. Polymer 1990, 31 (6), 996-1002.183. Zabihi, F.; Xie, Y.; Gao, S.; Eslamian, M., Morphology, conductivity, and wetting characteristics of PEDOT: PSS thin films deposited by spin and spray coating. Applied Surface Science 2015, 338, 163-177.184. Skotheim, T. A.; Reynolds, J., Conjugated polymers: theory, synthesis, properties, and characterization. CRC press, Boca Raton: 2006, p110-115.185. Gustafsson, J.; Liedberg, B.; Inganäs, O., In situ spectroscopic investigations of electrochromism and ion transport in a poly (3, 4-ethylenedioxythiophene) electrode in a solid state electrochemical cell. Solid State Ionics 1994, 69 (2), 145-152.186. Stavytska-Barba, M.; Kelley, A. M., Surface-enhanced Raman study of the interaction of PEDOT: PSS with plasmonically active nanoparticles. The Journal of Physical Chemistry C 2010, 114 (14), 6822-6830.187. Stepien, L.; Roch, A.; Tkachov, R.; Leupolt, B.; Han, L.; van Ngo, N.; Leyens, C., Thermal operating window for PEDOT: PSS films and its related thermoelectric properties. Synthetic Metals 2017, 225, 49-54.188. Sixou, B.; Mermilliod, N.; Travers, J. P., Aging effects on the transport properties in conducting polymer polypyrrole. Physical Review B 1996, 53 (8), 4509-4521.189. Mateeva, N.; Niculescu, H.; Schlenoff, J.; Testardi, L., Correlation of Seebeck coefficient and electric conductivity in polyaniline and polypyrrole. Journal of Applied Physics 1998, 83 (6), 3111-3117.190. Mazaheripour, A.; Majumdar, S.; Hanemann-Rawlings, D.; Thomas, E. M.; McGuiness, C.; d’Alencon, L.; Chabinyc, M. L.; Segalman, R. A., Tailoring the Seebeck coefficient of PEDOT:PSS by controlling ion stoichiometry in ionic liquid additives. Chemistry of Materials 2018, 30 (14), 4816-4822.191. Bubnova, O.; Khan, Z. U.; Wang, H.; Braun, S.; Evans, D. R.; Fabretto, M.; Hojati-Talemi, P.; Dagnelund, D.; Arlin, J.-B.; Geerts, Y. H., Semi-metallic polymers. Nature Materials 2014, 13 (2), 190-194.192. Li, M.; Zeng, F.; Luo, M.; Qing, X.; Wang, W.; Lu, Y.; Zhong, W.; Yang, L.; Liu, Q.; Wang, Y., Synergistically improving flexibility and thermoelectric performance of composite yarn by continuous ultrathin PEDOT: PSS/DMSO/Ionic liquid coating. ACS Applied Materials & Interfaces 2021, 13 (42), 50430-50440.193. Li, Q.; Zhou, Q.; Wen, L.; Liu, W., Enhanced thermoelectric performances of flexible PEDOT: PSS film by synergistically tuning the ordering structure and oxidation state. Journal of Materiomics 2020, 6 (1), 119-127.194. Pei, Y.; Shi, X.; LaLonde, A.; Wang, H.; Chen, L.; Snyder, G. J., Convergence of electronic bands for high performance bulk thermoelectrics. Nature 2011, 473 (7345), 66-69.195. Wu, M.; Cai, K.; Li, X.; Li, Y.; Liu, Y.; Lu, Y.; Wang, Z.; Zhao, W.; Wei, P., Ultraflexible and high-thermoelectric-performance sulfur-doped Ag2Se film on nylon for power generators. ACS Applied Materials & Interfaces 2022, 14 (3), 4307-4315.196. de Izarra, A.; Choi, C.; Jang, Y. H.; Lansac, Y., Molecular dynamics of PEDOT: PSS treated with ionic liquids. Origin of anion dependence leading to cation design principles. The Journal of Physical Chemistry B 2021, 125 (30), 8601-8611.197. Ouyang, J., Solution-processed PEDOT: PSS films with conductivities as indium tin oxide through a treatment with mild and weak organic acids. ACS Applied Materials & Interfaces 2013, 5 (24), 13082-13088.198. Li, W.; Zhang, Z.; Han, B.; Hu, S.; Xie, Y.; Yang, G., Effect of water and organic solvents on the ionic dissociation of ionic liquids. The Journal of Physical Chemistry B 2007, 111 (23), 6452-6456.199. Wang, T.; Qi, Y.; Xu, J.; Hu, X.; Chen, P., Effects of poly (ethylene glycol) on electrical conductivity of poly (3, 4-ethylenedioxythiophene)-poly (styrenesulfonic acid) film. Applied Surface Science 2005, 250 (1-4), 188-194.200. Nollau, A.; Pfeiffer, M.; Fritz, T.; Leo, K., Controlled n-type doping of a molecular organic semiconductor: Naphthalenetetracarboxylic dianhydride (NTCDA) doped with bis (ethylenedithio)-tetrathiafulvalene (BEDT-TTF). Journal of Applied Physics 2000, 87 (9), 4340-4343.201. Devreux, F.; Genoud, F.; Nechtschein, M.; Villeret, B., ESR investigation of polarons and bipolarons in conducting polymers:: the case of polypyrrole. Synthetic Metals 1987, 18 (1-3), 89-94.202. Wei, Q.; Mukaida, M.; Naitoh, Y.; Ishida, T., Morphological change and mobility enhancement in PEDOT: PSS by adding co‐solvents. Advanced Materials 2013, 25 (20), 2831-2836.203. Ugur, A.; Katmis, F.; Li, M.; Wu, L.; Zhu, Y.; Varanasi, K. K.; Gleason, K. K., Low‐dimensional conduction mechanisms in highly conductive and transparent conjugated polymers. Advanced Materials 2015, 27 (31), 4604-4610.204. Zhu, Z.; Liu, C.; Jiang, F.; Xu, J.; Liu, E., Effective treatment methods on PEDOT: PSS to enhance its thermoelectric performance. Synthetic Metals 2017, 225, 31-40.205. 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. Chemistry of Materials 2019, 31 (14), 5238-5244.206. Fan, Z.; Du, D.; Guan, X.; Ouyang, J., Polymer films with ultrahigh thermoelectric properties arising from significant seebeck coefficient enhancement by ion accumulation on surface. Nano Energy 2018, 51, 481-488.207. Lee, S. H.; Park, H.; Son, W.; Choi, H. H.; Kim, J. H., Novel solution-processable, dedoped semiconductors for application in thermoelectric devices. Journal of Materials Chemistry A 2014, 2 (33), 13380-13387.208. Ouyang, J.; Chu, C. W.; Chen, F. C.; Xu, Q.; Yang, Y., High‐conductivity poly (3, 4‐ethylenedioxythiophene): poly (styrene sulfonate) film and its application in polymer optoelectronic devices. Advanced Functional Materials 2005, 15 (2), 203-208.209. Kozub, V.; Aleshin, A., Transport anomalies in highly doped conjugated polymers at low temperatures. Physical Review B 1999, 59 (17), 11322.210. MacDiarmid, A.; Epstein, A. J., The concept of secondary doping as applied to polyaniline. Synthetic Metals 1994, 65 (2-3), 103-116.211. Dominici, L.; Michelotti, F.; Brown, T. M.; Reale, A.; Di Carlo, A., Plasmon polaritons in the near infrared on fluorine doped tin oxide films. Optics Express 2009, 17 (12), 10155-10167.212. Ulbricht, R.; Hendry, E.; Shan, J.; Heinz, T. F.; Bonn, M., Carrier dynamics in semiconductors studied with time-resolved terahertz spectroscopy. Reviews of Modern Physics 2011, 83 (2), 543.213. Mecerreyes, D.; Marcilla, R.; Ochoteco, E.; Grande, H.; Pomposo, J. A.; Vergaz, R.; Pena, J. M. S., A simplified all-polymer flexible electrochromic device. Electrochimica Acta 2004, 49 (21), 3555-3559.214. Shu, Y.; Odunmbaku, G. O.; He, Y.; Zhou, Y.; Cheng, H.; Ouyang, J.; Sun, K., Cation effect of inorganic salts on ionic Seebeck coefficient. Applied Physics Letters 2021, 118 (10), 103902.215. Banerjee, P.; Bagchi, B., Ions’ motion in water. The Journal of Chemical Physics 2019, 150 (19), 190901.216. Ogston, A., The spaces in a uniform random suspension of fibres. Transactions of the Faraday Society 1958, 54, 1754-1757.217. De Gennes, P.-G.; Gennes, P.-G., Scaling concepts in polymer physics. Cornell university press, Ithaca: 1979.218. Marras-Marquez, T.; Peña, J.; Veiga-Ochoa, M., Agarose drug delivery systems upgraded by surfactants inclusion: Critical role of the pore architecture. Carbohydrate polymers 2014, 103, 359-368.219. Zhao, X.; Huang, L.; Wu, J.; Huang, Y.-D.; Zhao, L.; Wu, N.; Zhou, W.-Q.; Hao, D.-X.; Ma, G.-H.; Su, Z.-G., Fabrication of rigid and macroporous agarose microspheres by pre-cross-linking and surfactant micelles swelling method. Colloids and Surfaces B: Biointerfaces 2019, 182, 110377.220. Chen, C.; Li, X.; Zhao, D.; Li, Y.; Shi, H.; Ma, G.; Su, Z., Precise control of agarose media pore structure by regulating cooling rate. Journal of Separation Science 2017, 40 (22), 4467-4474.221. Pernodet, N.; Maaloum, M.; Tinland, B., Pore size of agarose gels by atomic force microscopy. Electrophoresis 1997, 18 (1), 55-58.222. Chen, H.; Han, L.; Luo, P.; Ye, Z., The interfacial tension between oil and gemini surfactant solution. Surface Science 2004, 552 (1-3), L53-L57.223. Urano, R.; Pantelopulos, G. A.; Straub, J. E., Aerosol-OT surfactant forms stable reverse micelles in apolar solvent in the absence of water. The Journal of Physical Chemistry B 2019, 123 (11), 2546-2557.224. Kumar, D.; Singh, A.; Tarsikka, P. S., Interrelationship between viscosity and electrical properties for edible oils. Journal of Food Science and Technology 2013, 50 (3), 549-554.225. Liu, J.; Li, L., SDS-aided immobilization and controlled release of camptothecin from agarose hydrogel. European Journal of Pharmaceutical Sciences 2005, 25 (2-3), 237-244.226. Takeyama, N.; Nakashima, K., Steady-state thermodynamics of thermal diffusion with micelle formation of aqueous ionic surfactants. Journal of the Physical Society of Japan 1993, 62 (6), 2180-2181.227. Stilbs, P.; Lindman, B., Determination of organic counterion binding to micelles through Fourier transform NMR self-diffusion measurements. The Journal of Physical Chemistry 1981, 85 (18), 2587-2589.228. Zheng, Y.-Z.; Zhou, Y.; Deng, G.; Guo, R.; Chen, D.-F., A combination of FTIR and DFT to study the microscopic structure and hydrogen-bonding interaction properties of the [BMIM][BF4] and water. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2020, 226, 117624.229. Cheng, H.; He, X.; Fan, Z.; Ouyang, J., Flexible quasi-solid state ionogels with remarkable Seebeck coefficient and high thermoelectric properties. Advanced Energy Materials 2019, 9 (32), 1901085.230. Yusof, Y. M.; Shukur, M. F.; Hamsan, M. H.; Jumbri, K.; Kadir, M. F. Z., Plasticized solid polymer electrolyte based on natural polymer blend incorporated with lithium perchlorate for electrical double-layer capacitor fabrication. Ionics 2019, 25 (11), 5473-5484.231. Xie, X.; Li, D.; Tsai, T.-H.; Liu, J.; Braun, P. V.; Cahill, D. G., Thermal conductivity, heat capacity, and elastic constants of water-soluble polymers and polymer blends. Macromolecules 2016, 49 (3), 972-978.232. Liu, K.; Ding, T.; Li, J.; Chen, Q.; Xue, G.; Yang, P.; Xu, M.; Wang, Z. L.; Zhou, J., Thermal-electric nanogenerator based on the electrokinetic effect in porous carbon film. Advanced Energy Materials 2018, 8 (13), 1702481.233. Savoie, B. M.; Webb, M. A.; Miller III, T. F., Enhancing cation diffusion and suppressing anion diffusion via Lewis-acidic polymer electrolytes. The Journal of Physical Chemistry Letters 2017, 8 (3), 641-646.234. Brown, B. R., Sensing temperature without ion channels. Nature 2003, 421 (6922), 495-495.235. Brown, B. R.; Hughes, M. E.; Russo, C., Thermoelectricity in natural and synthetic hydrogels. Physical Review E 2004, 70 (3), 031917.236. Saihara, K.; Yoshimura, Y.; Ohta, S.; Shimizu, A., Properties of water confined in ionic liquids. Scientific Reports 2015, 5 (1), 10619.237. Hayamizu, K.; Aihara, Y.; Nakagawa, H.; Nukuda, T.; Price, W. S., Ionic conduction and ion diffusion in binary room-temperature ionic liquids composed of [emim][BF4] and LiBF4. The Journal of Physical Chemistry B 2004, 108 (50), 19527-19532.238. Kim, B.; Na, J.; Lim, H.; Kim, Y.; Kim, J.; Kim, E., Robust high thermoelectric harvesting under a self-humidifying bilayer of metal organic framework and hydrogel layer. Advanced Functional Materials 2019, 29 (7), 1807549.239. Zinovyeva, V.; Nakamae, S.; Bonetti, M.; Roger, M., Enhanced thermoelectric power in ionic liquids. ChemElectroChem 2014, 1 (2), 426-430.240. Wu, T. Y.; Wang, H. C.; Su, S. G.; Gung, S. T.; Lin, M. W.; Lin, C. B., Aggregation influence of polyethyleneglycol organic solvents with ionic liquids BMIBF4 and BMIPF6. Journal of the Chinese Chemical Society 2010, 57 (1), 44-55.241. Sun, J.-Y.; Zhao, X.; Illeperuma, W. R. K.; Chaudhuri, O.; Oh, K. H.; Mooney, D. J.; Vlassak, J. J.; Suo, Z., Highly stretchable and tough hydrogels. Nature 2012, 489 (7414), 133-136.242. Ofner III, C.; Schott, H., Shifts in the apparent ionization constant of the carboxylic acid groups of gelatin. Journal of Pharmaceutical Sciences 1985, 74 (12), 1317-1321.243. Kamcev, J.; Paul, D. R.; Manning, G. S.; Freeman, B. D., Ion diffusion coefficients in ion exchange membranes: significance of counterion dondensation. Macromolecules 2018, 51 (15), 5519-5529.244. Aryal, D.; Ganesan, V., Reversal of salt concentration dependencies of salt and water diffusivities in polymer electrolyte membranes. ACS Macro Letters 2018, 7 (6), 739-744.245. Manning, G. S., Limiting laws and counterion condensation in polyelectrolyte solutions. 8. Mixtures of counterions, species selectivity, and valence selectivity. The Journal of Physical Chemistry 1984, 88 (26), 6654-6661.246. Agar, J. N.; Mou, C. Y.; Lin, J. L., Single-ion heat of transport in electrolyte solutions: a hydrodynamic theory. The Journal of Physical Chemistry 1989, 93 (5), 2079-2082.247. Alzahrani, H. A.; Buckingham, M. A.; Marken, F.; Aldous, L., Success and failure in the incorporation of gold nanoparticles inside ferri/ferrocyanide thermogalvanic cells. Electrochemistry Communications 2019, 102, 41-45.248. Yang, Y.; Lee, S. W.; Ghasemi, H.; Loomis, J.; Li, X.; Kraemer, D.; Zheng, G.; Cui, Y.; Chen, G., Charging-free electrochemical system for harvesting low-grade thermal energy. Proceedings of the National Academy of Sciences 2014, 111 (48), 17011-17016.249. Chen, G., Nanoscale energy transport and conversion: a parallel treatment of electrons, molecules, phonons, and photons. Oxford university press, New York: 2005, p245-250.250. Newman, J., Thermoelectric effects in electrochemical systems. Industrial & Engineering Chemistry Research 1995, 34 (10), 3208-3216.251. Kuzminskii, Y.; Zasukha, V.; Kuzminskaya, G., Thermoelectric effects in electrochemical systems. Nonconventional thermogalvanic cells. Journal of Power Sources 1994, 52 (2), 231-242.252. Hornut, J.; Storck, A., Experimental and theoretical analysis of a thermogalvanic undivided flow cell with two aqueous electrolytes at different temperatures. Journal of Applied Electrochemistry 1991, 21, 1103-1113.253. Debethune, A.; Licht, T.; Swendeman, N., The temperature coefficients of electrode potentials: the isothermal and thermal coefficients—the standard ionic entropy of electrochemical transport of the hydrogen ion. Journal of The Electrochemical Society 1959, 106 (7), 616.254. Weber, J.; Potje-Kamloth, K.; Haase, F.; Detemple, P.; Völklein, F.; Doll, T., Coin-size coiled-up polymer foil thermoelectric power generator for wearable electronics. Sensors and Actuators A: Physical 2006, 132 (1), 325-330.255. Wang, S.; Wu, Y.; Zhang, N.; He, G.; Xin, Q.; Wu, X.; Wu, H.; Cao, X.; Guiver, M. D.; Jiang, Z., A highly permeable graphene oxide membrane with fast and selective transport nanochannels for efficient carbon capture. Energy & Environmental Science 2016, 9 (10), 3107-3112.256. Zhou, Q.; Zhu, K.; Li, J.; Li, Q.; Deng, B.; Zhang, P.; Wang, Q.; Guo, C.; Wang, W.; Liu, W., Leaf-inspired flexible thermoelectric generators with high temperature difference utilization ratio and output power in ambient air. Advanced Science 2021, 8 (12), 2004947.257. Romano, M. S.; Li, N.; Antiohos, D.; Razal, J. M.; Nattestad, A.; Beirne, S.; Fang, S.; Chen, Y.; Jalili, R.; Wallace, G. G., Carbon nanotube-reduced graphene oxide composites for thermal energy harvesting applications. Advanced Materials 2013, 25 (45), 6602-6606.258. Li, Y.; Li, Q.; Zhang, X.; Deng, B.; Han, C.; Liu, W., 3D hierarchical electrodes boosting ultrahigh power output for gelatin‐KCl‐FeCN4−/3− ionic thermoelectric cells. Advanced Energy Materials 2022, 12 (14), 2103666.259. Wang, L.; Nitopi, S.; Wong, A. B.; Snider, J. L.; Nielander, A. C.; Morales-Guio, C. G.; Orazov, M.; Higgins, D. C.; Hahn, C.; Jaramillo, T. F., Electrochemically converting carbon monoxide to liquid fuels by directing selectivity with electrode surface area. Nature Catalysis 2019, 2 (8), 702-708.260. Vojnović, M.; Sepa, D., Effect of electrode materials on the kinetics of electron exchange reactions. The Journal of Chemical Physics 1969, 51 (12), 5344-5351.261. Horike, S.; Wei, Q.; Kirihara, K.; Mukaida, M.; Sasaki, T.; Koshiba, Y.; Fukushima, T.; Ishida, K., Outstanding electrode-dependent Seebeck coefficients in ionic hydrogels for thermally chargeable supercapacitor near room temperature. ACS Applied Materials & Interfaces 2020, 12 (39), 43674-43683.262. Zhao, D.; Würger, A.; Crispin, X., Ionic thermoelectric materials and devices. Journal of Energy Chemistry 2021, 61, 88-103.263. Gurney, R. W. Ionic processes in solution; McGraw-Hill: 1953, p248-255.264. Brune, B. J.; Koehler, J. A.; Smith, P. J.; Payne, G. F., Correlation between adsorption and small molecule hydrogen bonding. Langmuir 1999, 15 (11), 3987-3992.265. Nagy, P. I., Competing intramolecular vs. intermolecular hydrogen bonds in solution. International Journal of Molecular Sciences 2014, 15 (11), 19562-19633.