High-performance n-Type PVDF/Ag2Se Free-standing Flexible Composite Thermoelectric Films Fabricated by Powder Hot-pressing

doi:10.15541/jim20250158

Abstract

Abstract: Rapid development of applications in wearable devices, microelectronics, and internet of things has created an urgent demand for free-standing flexible thermoelectric films. Currently, research on n-type free-standing flexible thermoelectric films significantly lags behind, and there is an urgent need to enhance film performance through the optimization of preparation processes. In this study, high-performance n-type poly(vinylidene fluoride)/silver selenide (PVDF/Ag₂Se) free-standing flexible thermoelectric composite films using a simple and efficient powder hot-pressing method were developed. The high-temperature and high-pressure conditions during hot pressing induced recrystallization and grain growth of Ag₂Se, effectively reducing grain boundary density, significantly decreasing carrier scattering and interfacial resistance, thereby simultaneously enhancing carrier mobility, electrical conductivity, and Seebeck coefficient. Meanwhile, the melted PVDF filled interstices of the Ag₂Se conductive network during hot pressing, substantially improving material flexibility while increasing density. Experimental results demonstrate that the hot-pressed sample with 80% (in mass) Ag₂Se exhibits outstanding room-temperature thermoelectric performance with an electrical conductivity of 277 S·cm^-1 and a Seebeck coefficient of -135 μV·K^-1, and thermoelectric power factor (PF) and estimated figure of merit (ZT value) reaches 509 μW·m^-1·K^-2 and 0.26, respectively. This performance not only significantly surpasses previously reported PVDF/ Ag₂Se free-standing films but also ranks among the highest for all reported Ag₂Se-based organic/inorganic free-standing flexible thermoelectric films. Furthermore, mechanical tests reveal that the film maintained over 92% of its original conductivity after 500 bending cycles at a 5 mm radius, while exhibiting a maximum tensile strain four times greater than pure Ag₂Se films. This study provides a novel strategy for the synergistic optimization of thermoelectric performance and mechanical flexibility in organic/inorganic composite thermoelectric materials.

Key words: silver selenide, composite thermoelectric film, free-standing, flexible, hot-pressing

CLC Number:

TB34

XU Zishuo, HU Yuejuan, HU Yuchen, CHEN Lidong, YAO Qin. High-performance n-Type PVDF/Ag₂Se Free-standing Flexible Composite Thermoelectric Films Fabricated by Powder Hot-pressing[J]. Journal of Inorganic Materials, DOI: 10.15541/jim20250158.

References

[1] BASKARAN P, RAJASEKAR M.Recent progress in thermoelectric devices and applications. Chemical Engineering Journal, 2025, 506: 159929.
[2] MAO J, CHEN G, REN Z F. Thermoelectric cooling materials. Nature Materials, 2021, 20(4): 454.
[3] BERETTA D, NEOPHYTOU N, HODGES J M, et al. Thermoelectrics: from history, a window to the future. Materials Science and Engineering: R: Reports, 2019, 138: 100501.
[4] SHI X L, WANG L J, LYU W Y, et al. Advancing flexible thermoelectrics for integrated electronics. Chemical Society Reviews, 2024, 53(18): 9254.
[5] PEI J, CAI B W, ZHUANG H L, et al. Bi2Te3-based applied thermoelectric materials: research advances and new challenges. National Science Review, 2020, 7(12): 1856.
[6] SHARMA P K, SENGUTTUVAN T D, SHARMA V K, et al. Revisiting the thermoelectric properties of lead telluride. Materials Today Energy, 2021, 21: 100713.
[7] ABBASI M S, SULTANA R, AHMED I, et al. Contemporary advances in organic thermoelectric materials: fundamentals, properties, optimization strategies, and applications. Renewable and Sustainable Energy Reviews, 2024, 200: 114579.
[8] JIN P H, LI D J, IOCOZZIA J, et al. Hybrid organic-inorganic thermoelectric materials and devices. Angewandte Chemie International Edition, 2019, 58(43): 15206.
[9] ZHANG B T, SUN T T, WANG L J, et al. Inkjet printing preparation of AgCuTe thermoelectric thin films. Journal of Inorganic Materials, 2024, 39(12): 1325.
[10] DENG L H, LIU Y R, ZHANG Y Y,et al. Organic thermoelectric materials: niche harvester of thermal energy. Advanced Functional Materials, 2023, 33(3): 2210770.
[11] NANDIHALLI N, LIU C J, MORI T. Polymer based thermoelectric nanocomposite materials and devices: fabrication and characteristics. Nano Energy, 2020, 78: 105186.
[12] TRIPATHI A, LEE Y, LEE S, et al. Recent advances in n-type organic thermoelectric materials, dopants, and doping strategies. Journal of Materials Chemistry C, 2022, 10(16): 6114.
[13] LIU M, ZHANG X Y, ZHANG S X, et al. Ag₂Se as a tougher alternative to n-type Bi₂Te₃ thermoelectrics. Nature Communications, 2024, 15: 6580.
[14] ZHANG Z, SUN T T, WANG L J,et al. Flexible thermoelectric films with different Ag₂Se dimensions: performance optimization and device integration. Journal of Inorganic Materials, 2024, 39(11): 1221.
[15] LIU Y, ZHANG Q H, HUANG A B, et al. Fully inkjet-printed Ag₂Se flexible thermoelectric devices for sustainable power generation. Nature Communications, 2024, 15: 2141.
[16] LIU Y, LI J J, WANG Z X, et al. High thermoelectric performance of flexible Ag/Ag₂Se composite film on Nylon for low-grade energy harvesting. Journal of Materials Science & Technology, 2024, 179: 79.
[17] YANG D, SHI X L, LI M, et al. Flexible power generators by Ag₂Se thin films with record-high thermoelectric performance. Nature Communications, 2024, 15: 923.
[18] PEREZ-TABORDA J A, CABALLERO-CALERO O, VERA-LONDONO L, et al. High thermoelectric zT in n-type silver selenide films at room temperature. Advanced Energy Materials, 2018, 8(8): 1702024.
[19] DU J J, ZHANG B T, JIANG M, et al. Inkjet printing flexible thermoelectric devices using metal chalcogenide nanowires. Advanced Functional Materials, 2023, 33(26): 2213564.
[20] ZHANG L, SHI X L, YANG Y L, et al. Flexible thermoelectric materials and devices: from materials to applications. Materials Today, 2021, 46: 62.
[21] AGHAYARI S.PVDF composite nanofibers applications.Heliyon, 2022, 8(11): e11620.
[22] PARK D, JU H, KIM J. Enhanced thermoelectric properties of flexible N-type Ag₂Se nanowire/polyvinylidene fluoride composite films synthesized via solution mixing. Journal of Industrial and Engineering Chemistry, 2021, 93: 333.
[23] PARK D, KIM M, KIM J. High-performance PANI-coated Ag₂Se nanowire and PVDF thermoelectric composite film for flexible energy harvesting. Journal of Alloys and Compounds, 2021, 884: 161098.
[24] ZHOU H J, ZHANG Z J, SUN C X, et al. Biomimetic approach to facilitate the high filler content in free-standing and flexible thermoelectric polymer composite films based on PVDF and Ag₂Se nanowires. ACS Applied Materials & Interfaces, 2020, 12(46): 51506.
[25] DING Y F, QIU Y, CAI K F, et al. High performance n-type Ag₂Se film on nylon membrane for flexible thermoelectric power generator. Nature Communications, 2019, 10: 841.
[26] ZHANG M C, LI J J, LIU Y, et al. Screen printing high-performance free-standing Ag₂Se/carbon composite film for flexible thermoelectric converters. Nano Energy, 2025, 138: 110836.
[27] YUE Y C, LYU W Y, LIU W D, et al. Solvothermal synthesis of micro-pillar shaped Ag₂Se and its thermoelectric potential. Materials Today Chemistry, 2024, 39: 102183.
[28] LU Y, QIU Y, CAI K, et al. Ultrahigh performance PEDOT/Ag₂Se/CuAgSe composite film for wearable thermoelectric power generators. Materials Today Physics, 2020, 14: 100223.
[29] JIN Q, JIANG S, ZHAO Y, et al. Flexible layer-structured Bi₂Te₃ thermoelectric on a carbon nanotube scaffold. Nature Materials, 2019, 18: 62.
[30] LIU D, ZHAO Y X, YAN Z Q, et al. Screen-printed flexible thermoelectric device based on hybrid silver selenide/PVP composite films. Nanomaterials, 2021, 11(8): 2042.
[31] PALAPORN D, MONGKOLTHANARUK W, FAUNGNAWAKIJ K, et al. Flexible thermoelectric paper and its thermoelectric generator from bacterial cellulose/Ag₂Se nanocomposites. ACS Applied Energy Materials, 2022, 5(3): 3489.
[32] PARK D, KIM M, KIM J. Conductive PEDOT:PSS-based organic/inorganic flexible thermoelectric films and power generators. Polymers, 2021, 13(2): 210.

High-performance n-Type PVDF/Ag₂Se Free-standing Flexible Composite Thermoelectric Films Fabricated by Powder Hot-pressing

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

References

Related Articles 15

Recommended Articles

Metrics

Comments

[1]	WEI Xiangxia, ZHANG Xiaofei, XU Kailong, CHEN Zhangwei. Current Status and Prospects of Additive Manufacturing of Flexible Piezoelectric Materials [J]. Journal of Inorganic Materials, 2024, 39(9): 965-978.
[2]	XUN Daoxiang, LUO Xuwei, ZHOU Mingran, HE Jiale, RAN Maojin, HU Zhiyi, LI Yu. ZIF-L Derived Nitrogen-doped Carbon Nanosheets/Carbon Cloth Self-supported Electrode for Lithium-selenium Battery [J]. Journal of Inorganic Materials, 2024, 39(9): 1013-1021.
[3]	SHI Tong, GAN Qiaowei, LIU Dong, ZHANG Ying, FENG Hao, LI Qiang. Boost Electrochemical Reduction of CO₂ to Formate Using a Self-supporting Bi@Cu Nanotree Electrode [J]. Journal of Inorganic Materials, 2024, 39(7): 810-818.
[4]	CHEN Tian, LUO Yuan, ZHU Liu, GUO Xueyi, YANG Ying. Organic-inorganic Co-addition to Improve Mechanical Bending and Environmental Stability of Flexible Perovskite Solar Cells [J]. Journal of Inorganic Materials, 2024, 39(5): 477-484.
[5]	LI La, SHEN Guozhen. 2D MXenes Based Flexible Photodetectors: Progress and Prospects [J]. Journal of Inorganic Materials, 2024, 39(2): 186-194.
[6]	ZHANG Botao, SUN Tingting, WANG Lianjun, JIANG Wan. Inkjet Printing Preparation of AgCuTe Thermoelectric Thin Films [J]. Journal of Inorganic Materials, 2024, 39(12): 1325-1330.
[7]	ZHANG Zhe, SUN Tingting, WANG Lianjun, JIANG Wan. Flexible Thermoelectric Films with Different Ag₂Se Dimensions: Performance Optimization and Device Integration [J]. Journal of Inorganic Materials, 2024, 39(11): 1221-1227.
[8]	WANG Bo, CAI Delong, ZHU Qishuai, LI Daxin, YANG Zhihua, DUAN Xiaoming, LI Yanan, WANG Xuan, JIA Dechang, ZHOU Yu. Mechanical Properties and Thermal Shock Resistance of SrAl₂Si₂O₈ Reinforced BN Ceramic Composites [J]. Journal of Inorganic Materials, 2024, 39(10): 1182-1188.
[9]	ZHAO Yawen, QU Fajin, WANG Yanyi, WANG Zhiwen, CHEN Chusheng. Preparation and Properties of Aluminum Silicate Fiber Supported PtTFPP-PDMS Flexible Oxygen Sensing Components [J]. Journal of Inorganic Materials, 2024, 39(10): 1084-1090.
[10]	MAO Aiqin, LU Wenyu, JIA Yanggang, WANG Ranran, SUN Jing. Flexible Piezoelectric Devices and Their Wearable Applications [J]. Journal of Inorganic Materials, 2023, 38(7): 717-730.
[11]	YANG Yang, CUI Hangyuan, ZHU Ying, WAN Changjin, WAN Qing. Research Progress of Flexible Neuromorphic Transistors [J]. Journal of Inorganic Materials, 2023, 38(4): 367-377.
[12]	LIU Dan, ZHAO Yaxin, GUO Rui, LIU Yantao, ZHANG Zhidong, ZHANG Zengxing, XUE Chenyang. Effect of Annealing Conditions on Thermoelectric Properties of Magnetron Sputtered MgO-Ag₃Sb-Sb₂O₄ Flexible Films [J]. Journal of Inorganic Materials, 2022, 37(12): 1302-1310.
[13]	LUO Yi, XIA Shuhai, NIU Bo, ZHANG Yayun, LONG Donghui. Preparation and High Temperature Inorganic Transformation of Flexible Silicone Aerogels [J]. Journal of Inorganic Materials, 2022, 37(12): 1281-1288.
[14]	LIANG Hanqin, YIN Jinwei, ZUO Kaihui, XIA Yongfeng, YAO Dongxu, ZENG Yuping. Mechanical and Dielectric Properties of Hot-pressed Si₃N₄ Ceramics with BaTiO₃ Addition [J]. Journal of Inorganic Materials, 2021, 36(5): 535-540.
[15]	FANG Huajing, ZHAO Zetian, WU Wenting, WANG Hong. Progress in Flexible Electrochromic Devices [J]. Journal of Inorganic Materials, 2021, 36(2): 140-151.