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Nickel O, Ahrens-Iwers LJV, Meißner RH, Janssen M. Water, Not Salt, Causes Most of the Seebeck Effect of Nonisothermal Aqueous Electrolytes. PHYSICAL REVIEW LETTERS 2024; 132:186201. [PMID: 38759182 DOI: 10.1103/physrevlett.132.186201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/05/2023] [Accepted: 04/01/2024] [Indexed: 05/19/2024]
Abstract
A temperature difference between two electrolyte-immersed electrodes often yields a voltage Δψ between them. This electrolyte Seebeck effect is usually explained by cations and anions flowing differently in thermal gradients. However, using molecular simulations, we found almost the same Δψ for cells filled with pure water as with aqueous alkali halides. Water layering and orientation near polarizable electrodes cause a large temperature-dependent potential drop χ there. The difference in χ of hot and cold electrodes captures most of the thermovoltage, Δψ≈χ_{hot}-χ_{cold}.
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Affiliation(s)
- Ole Nickel
- Institute of Polymers and Composites, Hamburg University of Technology, Hamburg, Germany
| | | | - Robert H Meißner
- Institute of Polymers and Composites, Hamburg University of Technology, Hamburg, Germany
- Institute of Surface Science, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - Mathijs Janssen
- Norwegian University of Life Sciences, Faculty of Science and Technology, Ås, Norway
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2
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Ouadfel M, De San Féliciano M, Herrero C, Merabia S, Joly L. Complex coupling between surface charge and thermo-osmotic phenomena. Phys Chem Chem Phys 2023; 25:24321-24331. [PMID: 37668541 DOI: 10.1039/d3cp03083k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Thermo-osmotic flows, generated at liquid-solid interfaces by thermal gradients, can be used to produce electric currents from waste heat on charged surfaces. The two key parameters controlling the thermo-osmotic current are the surface charge and the interfacial enthalpy excess due to liquid-solid interactions. While it has been shown that the contribution from water to the enthalpy excess can be crucial, how this contribution is affected by surface charge remained to be understood. Here, we start by discussing how thermo-osmotic flows and induced electric currents are related to the interfacial enthalpy excess. We then use molecular dynamics simulations to investigate the impact of surface charge on the interfacial enthalpy excess, for different distributions of the surface charge, and two different wetting conditions. We observe that surface charge has a strong impact on enthalpy excess, and that the dependence of enthalpy excess on surface charge depends largely on its spatial distribution. In contrast, wetting has a very small impact on the charge-enthalpy coupling. We rationalize the results with simple analytical models, and explore their consequences for thermo-osmotic phenomena. Overall, this work provides guidelines to search for systems providing optimal waste heat recovery performance.
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Affiliation(s)
- Mehdi Ouadfel
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Michael De San Féliciano
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Cecilia Herrero
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Samy Merabia
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
| | - Laurent Joly
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France.
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3
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Zhang W, Liu X, Jiao K, Wang Q, Yang C, Zhao C. Ion Steric Effect Induces Giant Enhancement of Thermoelectric Conversion in Electrolyte-Filled Nanochannels. NANO LETTERS 2023; 23:8264-8271. [PMID: 37590911 DOI: 10.1021/acs.nanolett.3c02469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Ionic thermoelectricity in nanochannels has received increasing attention because of its advantages, such as high Seebeck coefficient and low cost. However, most studies have focused on dilute simple electrolytes that neglect the effects of finite ion sizes and short-range electrostatic correlation. Here, we reveal a new thermoelectric mechanism arising from the coupling of the ion steric effect due to finite ion sizes and ion thermodiffusion in electric double layers, using both theoretical and numerical methods. We show that this mechanism can significantly enhance the thermoelectric response in nanoconfined electrolytes depending on the properties of electrolytes and nanochannels. Compared to the previously known mechanisms, the new mechanism can increase the Seebeck coefficient by 100% or even 1 order of magnitude enhancement under optimal conditions. Moreover, we demonstrate that the short-range electrostatic correlation can help preserve the Seebeck coefficient enhancement in a weaker confinement or in more concentrated electrolytes.
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Affiliation(s)
- Wenyao Zhang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xinxi Liu
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Kai Jiao
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qiuwang Wang
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Chun Yang
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Cunlu Zhao
- MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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4
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Bae J, Lim H, Ahn J, Kim YH, Kim MS, Kim ID. Photoenergy Harvesting by Photoacid Solution. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201734. [PMID: 35404527 DOI: 10.1002/adma.202201734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Solar energy has seen 180 years of development since the discovery of the photovoltaic effect, having achieved the most successful commercialization in the energy-harvesting fields. Despite its long history, even the most state-of-the-art photovoltaics remain confined to solid-state devices, limiting spatial and light utilization efficiencies. Herein, a liquid-state photoenergy harvester based on a photoacid (PA), a chemical that releases protons upon light irradiation and recombines with them in the dark through a fully reversible reaction, is demonstrated. Asymmetric light exposure on a PA solution contained in a transparent tube generates a pH gradient (ΔpH = 2) along the exposed and dark regions, which charges the Nernst potential up to 0.7 V across the two electrodes embedded at each end, as if a capacitor. Owing to the reversibility of PAs, a PA-driven liquid-state photoenergy harvester (PLPH) generates capacitive currents up to 0.72 mA m-2 on an irradiation. Notably, the transparent nature of the PLPH enables vertical stacking up to 25 units, which multiplies the light-harvesting efficiencies by over 1000%. This unique approach provides a new route to harness solar energy with a form-factor-free design that maximizes spatial and light-use efficiencies.
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Affiliation(s)
- Jaehyeong Bae
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
- John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA, 02138, USA
| | - Haeseong Lim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jaewan Ahn
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Yoon Hwa Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Min Soo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Il-Doo Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
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Wang Q, Liu P, Zhou F, Gao L, Sun D, Meng Y, Wang X. Zinc-Guided 3D Graphene for Thermally Chargeable Supercapacitors to Harvest Low-Grade Heat. Molecules 2022; 27:molecules27041239. [PMID: 35209028 PMCID: PMC8880206 DOI: 10.3390/molecules27041239] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/25/2022] [Accepted: 02/10/2022] [Indexed: 02/04/2023] Open
Abstract
Low-grade heat energy recycling is the key technology of waste-heat utilization, which needs to be improved. Here, we use a zinc-assisted solid-state pyrolysis route to prepare zinc-guided 3D graphene (ZnG), a 3D porous graphene with the interconnected structure. The obtained ZnG, with a high specific surface area of 1817 m2·g−1 and abundant micropores and mesopores, gives a specific capacitance of 139 F·g−1 in a neutral electrolyte when used as electrode material for supercapacitors. At a high current density of 8 A·g−1, the capacitance retention is 93% after 10,000 cycles. When ZnG is used for thermally chargeable supercapacitors, the thermoelectric conversion of the low-grade heat energy is successfully realized. This work thus provides a demonstration for low-grade heat energy conversion.
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Power Supply of Wireless Sensors Based on Energy Conversion of Separated Gas Flows by Thermoelectrochemical Cells. ENERGIES 2022. [DOI: 10.3390/en15041256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This article deals with the creation of a power supply system of wireless sensors which take measurements and transmit data at time intervals, the duration of which is considerably less than the activation period of sensors. The specific feature of the power supply system is the combined use of devices based on various physical phenomena. Electrical energy is generated by thermoelectrochemical cells. The temperature gradient on the sides of these cells is created by a vortex tube. A special boost DC/DC converter provides an increase in the output voltage of thermoelectrochemical cells up to the voltage that is necessary to power electronic devices. A supercapacitor is used to store energy in the time intervals between sensor activation. A study of an experimental sample of the power supply system for wireless sensors was conducted. Using the model in MATLAB + Simulink program, the possibility and conditions for creating the considered system for a particular type of wireless sensor were shown.
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Shin G, Jeon JG, Kim JH, Lee JH, Lee J, Kim HJ, Baek JY, Kang KM, Han Y, So BJ, Kang TJ. Paper-Based Ionic Thermocouples for Inexpensive and High-Precision Measurement of Temperature. ACS APPLIED MATERIALS & INTERFACES 2021; 13:60154-60162. [PMID: 34844404 DOI: 10.1021/acsami.1c17059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Accurate and yet cost-effective temperature measurements are required in various sectors of academia and industry. Thermocouples (TCs) are most widely used for temperature measurements; however, their low temperature sensitivity and high thermal conductivity should be improved to ensure the reliable measurement of output voltage for small temperature differences. To address this, a paper-based ionic thermocouple (P-iTC) presented here utilizes a pair of paper strips soaked with the electrolytes of potassium ferri-/ferrocyanide and iron (II/III) chloride redox couples, which are used as p- and n-type elements, respectively. The fabricated P-iTC provides 70× higher temperature sensitivity (α, 2.8 mV/K) and 30× lower thermal conductivity (k, 0.8 W/m K) than those of commercial K-type TCs, thereby yielding a remarkably high α/k ratio of 3.5 mV m/W. Reliable sensing performance is measured during three weeks of operation, which indicates that the P-iTC should be stable in long-term operation. To demonstrate the practicality of the P-iTC, a 3 × 3 planar array of P-iTCs is fabricated to monitor the temperature profile of a surface in contact with heat sources. Using pencil-drawn graphite electrodes on paper, a highly cost-effective P-iTC with the material cost of ∼0.5 cents per device is also fabricated, which is successfully used to monitor cold chain temperatures while retaining its excellent temperature-sensing performance.
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Affiliation(s)
- Gilyong Shin
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Jei Gyeong Jeon
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Ju Hyeon Kim
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Ju Hwan Lee
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Junho Lee
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Hyeong Jun Kim
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Jae Yun Baek
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Kyung Mook Kang
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Yusu Han
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Byeong Jun So
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Tae June Kang
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
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Massetti M, Jiao F, Ferguson AJ, Zhao D, Wijeratne K, Würger A, Blackburn JL, Crispin X, Fabiano S. Unconventional Thermoelectric Materials for Energy Harvesting and Sensing Applications. Chem Rev 2021; 121:12465-12547. [PMID: 34702037 DOI: 10.1021/acs.chemrev.1c00218] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Heat is an abundant but often wasted source of energy. Thus, harvesting just a portion of this tremendous amount of energy holds significant promise for a more sustainable society. While traditional solid-state inorganic semiconductors have dominated the research stage on thermal-to-electrical energy conversion, carbon-based semiconductors have recently attracted a great deal of attention as potential thermoelectric materials for low-temperature energy harvesting, primarily driven by the high abundance of their atomic elements, ease of processing/manufacturing, and intrinsically low thermal conductivity. This quest for new materials has resulted in the discovery of several new kinds of thermoelectric materials and concepts capable of converting a heat flux into an electrical current by means of various types of particles transporting the electric charge: (i) electrons, (ii) ions, and (iii) redox molecules. This has contributed to expanding the applications envisaged for thermoelectric materials far beyond simple conversion of heat into electricity. This is the motivation behind this review. This work is divided in three sections. In the first section, we present the basic principle of the thermoelectric effects when the particles transporting the electric charge are electrons, ions, and redox molecules and describe the conceptual differences between the three thermodiffusion phenomena. In the second section, we review the efforts made on developing devices exploiting these three effects and give a thorough understanding of what limits their performance. In the third section, we review the state-of-the-art thermoelectric materials investigated so far and provide a comprehensive understanding of what limits charge and energy transport in each of these classes of materials.
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Affiliation(s)
- Matteo Massetti
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Fei Jiao
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden.,Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Sciences, Tianjin University & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Andrew J Ferguson
- National Renewable Energy Laboratory, Golden, Colorado, 80401 United States
| | - Dan Zhao
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Kosala Wijeratne
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Alois Würger
- Laboratoire Ondes et Matière d'Aquitaine, Université de Bordeaux, 351 cours de la Libération, F-33405 Talence Cedex, France
| | | | - Xavier Crispin
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
| | - Simone Fabiano
- Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
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Jia Y, Jiang Q, Sun H, Liu P, Hu D, Pei Y, Liu W, Crispin X, Fabiano S, Ma Y, Cao Y. Wearable Thermoelectric Materials and Devices for Self-Powered Electronic Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102990. [PMID: 34486174 DOI: 10.1002/adma.202102990] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/05/2021] [Indexed: 05/11/2023]
Abstract
The emergence of artificial intelligence and the Internet of Things has led to a growing demand for wearable and maintenance-free power sources. The continual push toward lower operating voltages and power consumption in modern integrated circuits has made the development of devices powered by body heat finally feasible. In this context, thermoelectric (TE) materials have emerged as promising candidates for the effective conversion of body heat into electricity to power wearable devices without being limited by environmental conditions. Driven by rapid advances in processing technology and the performance of TE materials over the past two decades, wearable thermoelectric generators (WTEGs) have gradually become more flexible and stretchable so that they can be used on complex and dynamic surfaces. In this review, the functional materials, processing techniques, and strategies for the device design of different types of WTEGs are comprehensively covered. Wearable self-powered systems based on WTEGs are summarized, including multi-function TE modules, hybrid energy harvesting, and all-in-one energy devices. Challenges in organic TE materials, interfacial engineering, and assessments of device performance are discussed, and suggestions for future developments in the area are provided. This review will promote the rapid implementation of wearable TE materials and devices in self-powered electronic systems.
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Affiliation(s)
- Yanhua Jia
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Qinglin Jiang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Hengda Sun
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Peipei Liu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Dehua Hu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Yanzhong Pei
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, China
| | - Weishu Liu
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xavier Crispin
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, SE-60174, Sweden
| | - Simone Fabiano
- Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, Norrköping, SE-60174, Sweden
| | - Yuguang Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Yong Cao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
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Riedl JC, Sarkar M, Fiuza T, Cousin F, Depeyrot J, Dubois E, Mériguet G, Perzynski R, Peyre V. Design of concentrated colloidal dispersions of iron oxide nanoparticles in ionic liquids: Structure and thermal stability from 25 to 200 °C. J Colloid Interface Sci 2021; 607:584-594. [PMID: 34509733 DOI: 10.1016/j.jcis.2021.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Some of the most promising fields of application of ionic liquid-based colloids imply elevated temperatures. Their careful design and analysis is therefore essential. We assume that tuning the structure of the nanoparticle-ionic liquid interface through its composition can ensure colloidal stability for a wide temperature range, from room temperature up to 200 °C. EXPERIMENTS The system under study consists of iron oxide nanoparticles (NPs) dispersed in ethylmethylimidazolium bistriflimide (EMIM TFSI). The key parameters of the solid-liquid interface, tuned at room temperature, are the surface charge density and the nature of the counterions. The thermal stability of these nanoparticle dispersions is then analysed on the short and long term up to 200 °C. A multiscale analysis is performed combining dynamic light scattering (DLS), small angle X-ray/neutron scattering (SAXS/SANS) and thermogravimetric analysis (TGA). FINDINGS Following the proposed approach with a careful choice of the species at the solid-liquid interface, ionic liquid-based colloidal dispersions of iron oxide NPs in EMIM TFSI stable over years at room temperature can be obtained, also stable at least over days up to 200 °C and NPs concentrations up to 12 vol% (≈30 wt%) thanks to few near-surface ionic layers.
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Affiliation(s)
- J C Riedl
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - M Sarkar
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - T Fiuza
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France; Inst. de Fisica, Complex Fluid Group, Universidade de Brasília, Brasília, Brazil.
| | - F Cousin
- Laboratoire Léon Brillouin, UMR 12 CNRS-CEA, CEA-Saclay, 91191 Gif-sur-Yvette, France.
| | - J Depeyrot
- Inst. de Fisica, Complex Fluid Group, Universidade de Brasília, Brasília, Brazil
| | - E Dubois
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - G Mériguet
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - R Perzynski
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - V Peyre
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
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11
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Li M, Hong M, Dargusch M, Zou J, Chen ZG. High-efficiency thermocells driven by thermo-electrochemical processes. TRENDS IN CHEMISTRY 2021. [DOI: 10.1016/j.trechm.2020.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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12
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Fiuza T, Sarkar M, Riedl JC, Cēbers A, Cousin F, Demouchy G, Depeyrot J, Dubois E, Gélébart F, Mériguet G, Perzynski R, Peyre V. Thermodiffusion anisotropy under a magnetic field in ionic liquid-based ferrofluids. SOFT MATTER 2021; 17:4566-4577. [PMID: 33949423 DOI: 10.1039/d0sm02190c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ferrofluids based on maghemite nanoparticles (NPs), typically 10 nm in diameter, are dispersed in an ionic liquid (1-ethyl 3-methylimidazolium bistriflimide - EMIM-TFSI). The average interparticle interaction is found to be repulsive by small angle scattering of X-rays and of neutrons, with a second virial coefficient A2 = 7.3. A moderately concentrated sample at Φ = 5.95 vol% is probed by forced Rayleigh scattering under an applied magnetic field (up to H = 100 kA m-1) from room temperature up to T = 460 K. Irrespective of the values of H and T, the NPs in this study are always found to migrate towards the cold region. The in-field anisotropy of the mass diffusion coefficient Dm and that of the (always positive) Soret coefficient ST are well described by the presented model in the whole range of H and T. The main origin of anisotropy is the spatial inhomogeneities of concentration in the ferrofluid along the direction of the applied field. Since this effect originates from the magnetic dipolar interparticle interaction, the anisotropy of thermodiffusion progressively vanishes when temperature and thermal motion increase.
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Affiliation(s)
- T Fiuza
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France. and Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - M Sarkar
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - J C Riedl
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - A Cēbers
- MMML Lab, Faculty of Physics and Mathematics, University of Latvia, Zellu-8, LV- 1002 Riga, Latvia
| | - F Cousin
- Lab. Léon Brillouin - UMR 12 CNRS-CEA CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - G Demouchy
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France. and Dpt de physique, Univ. de Cergy Pontoise, 33 Bd du Port, 95011 Cergy-Pontoise, France
| | - J Depeyrot
- Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - E Dubois
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - F Gélébart
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - G Mériguet
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - R Perzynski
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - V Peyre
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
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Rezende Franco L, Sehnem AL, Figueiredo Neto AM, Coutinho K. Molecular Dynamics Approach to Calculate the Thermodiffusion (Soret and Seebeck) Coefficients of Salts in Aqueous Solutions. J Chem Theory Comput 2021; 17:3539-3553. [PMID: 33942620 DOI: 10.1021/acs.jctc.1c00116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An approach to investigate the physical parameters related to ion thermodiffusion in aqueous solutions is proposed herein by calculating the equilibrium hydration free energy and the self-diffusion coefficient as a function of temperature, ranging from 293 to 353 K, using molecular dynamics simulations of infinitely diluted ions in aqueous solutions. Several ion force field parameters are used in the simulations, and new parameters are proposed for some ions to better describe their hydration free energy. Such a theoretical framework enables the calculation of some single-ion properties, such as heat of transport, Soret coefficient, and mass current density, as well as properties of salts, such as effective mass and thermal diffusion, Soret and Seebeck, coefficients. These calculated properties are compared with experimental data available from optical measurements and showed good agreement revealing an excellent theoretical predictability of salt thermodiffusion properties. Differences in single-ion Soret and self-diffusion coefficients of anions and cations give rise to a thermoelectric field, which affects the system response that is quantified by the Seebeck coefficient. The fast and slow Seebeck coefficients are calculated and discussed, resulting in values with mV/K order of magnitude, as observed in experiments involving several salts, such as K+Cl-, Na+Cl-, H+Cl-, Na+OH-, TMA+OH-, and TBA+OH-. The present approach can be adopted for any ion or charged particle dispersed in water with the aim of predicting the thermoelectric field induced through the fluid. It has potential applications in designing electrolytes for ionic thermoelectric devices in order to harvest energy and thermoelectricity in biological nanofluids.
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Affiliation(s)
- Leandro Rezende Franco
- Universidade de Sao Paulo, Instituto de Fisica, Cidade Universitaria, Sao Paulo 05508-090, SP, Brazil
| | - André Luiz Sehnem
- Universidade de Sao Paulo, Instituto de Fisica, Cidade Universitaria, Sao Paulo 05508-090, SP, Brazil
| | | | - Kaline Coutinho
- Universidade de Sao Paulo, Instituto de Fisica, Cidade Universitaria, Sao Paulo 05508-090, SP, Brazil
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14
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Abstract
Single-ion Soret coefficients αi characterize the tendency of ions in an electrolyte solution to move in a thermal gradient. When these coefficients differ between cations and anions, an electric field can be generated. For this so-called electrolyte Seebeck effect to occur, different thermodiffusive fluxes need to be blocked by boundaries-electrodes, for example. Local charge neutrality is then broken in the Debye-length vicinity of the electrodes. Confusingly, many authors point to these regions as the source of the thermoelectric field yet ignore them in derivations of the time-dependent Seebeck coefficient S(t), giving a false impression that the electrolyte Seebeck effect is purely a bulk phenomenon. Without enforcing local electroneutrality, we derive S(t) generated by a binary electrolyte with arbitrary ionic valencies subject to a time-dependent thermal gradient. Next, we experimentally measure S(t) for five acids, bases, and salts near titanium electrodes. For the steady state, we find S ≈ 2 mV K-1 for many electrolytes, roughly one order of magnitude larger than the predictions based on literature αi. We fit our expression for S(t) to the experimental data, treating the αi as fit parameters, and also find larger-than-literature values, accordingly.
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Affiliation(s)
- André Luiz Sehnem
- Institute of Physics, University of São Paulo, CEP 05508-090 São Paulo, Brazil
| | - Mathijs Janssen
- Department of Mathematics, Mechanics Division, University of Oslo, N-0851 Oslo, Norway
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15
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Teixeira JS, Costa RS, Pires AL, Pereira AM, Pereira C. Hybrid dual-function thermal energy harvesting and storage technologies: towards self-chargeable flexible/wearable devices. Dalton Trans 2021; 50:9983-10013. [PMID: 34264261 DOI: 10.1039/d1dt01568k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The worldwide energy scarcity arising from the massive consumption of nonrenewable energy sources raised a global awareness of the need for cleaner and affordable energy solutions to mitigate climate change and ensure the world sustainable development. The rise of the Internet of Things and the fast growth of the groundbreaking market of wearable electronics boosted a major quest for self-powered technologies merging energy harvesting and energy storage functionalities to meet the demands of a myriad of market segments, such as healthcare, transportation, defense and sports. Thermoelectric devices are a green energy harvesting solution for wearable electronics since they harness the low-grade waste heat from ubiquitous thermal energy sources and convert it into electrical energy. However, these systems generate electrical energy in an intermittent manner, depend on the local heat release availability and require an additional unit to store energy. Flexible and wearable supercapacitors are a safe and eco-friendly energy storage solution to power wearables, offering advantages of security, longer cycle life, higher power density and faster charging over batteries. However, an additional unit that generates energy or that is able to charge the storage device is required. More recently, a new class of all-in-one thermally-chargeable supercapacitors blossomed to meet the requirements of the next generation of autonomous wearable electronics and ensure an endurable energy supply. This self-chargeable hybrid technology combines the functionalities of thermal energy harvesting and supercapacitive energy storage in a single multitasking device. In this Perspective, the advances in the burgeoning field of all-in-one thermally-chargeable supercapacitors for flexible/wearable applications will be critically examined, ranging from their structure and working principle to the rational design of the composing materials and of tailor-made architectures. It will start by introducing the foundations of single flexible/wearable thermoelectric generators and supercapacitors and will evolve into the pioneering venture of fully-integrated thermal energy harvesting/storage systems. It will end by highlighting the current bottlenecks and future pathways for advancing the development of this sophisticated smart technology.
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Affiliation(s)
- Joana S Teixeira
- REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. and IFIMUP - Instituto de Física de Materiais Avançados, Nanotecnologia e Fotónica, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Rui S Costa
- REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal. and IFIMUP - Instituto de Física de Materiais Avançados, Nanotecnologia e Fotónica, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Ana L Pires
- IFIMUP - Instituto de Física de Materiais Avançados, Nanotecnologia e Fotónica, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - André M Pereira
- IFIMUP - Instituto de Física de Materiais Avançados, Nanotecnologia e Fotónica, Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Clara Pereira
- REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
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16
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Riedl JC, Akhavan Kazemi MA, Cousin F, Dubois E, Fantini S, Loïs S, Perzynski R, Peyre V. Colloidal dispersions of oxide nanoparticles in ionic liquids: elucidating the key parameters. NANOSCALE ADVANCES 2020; 2:1560-1572. [PMID: 36132302 PMCID: PMC9419491 DOI: 10.1039/c9na00564a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/15/2020] [Indexed: 06/12/2023]
Abstract
The combination of ionic liquid and nanoparticle properties is highly appealing for a number of applications. However, thus far there has been limited systematic exploration of colloidal stabilisation in these solvents, which provides an initial direction towards their employment. Here, we present a new and comprehensive study of the key parameters affecting the colloidal stability in dispersions of oxide nanoparticles in ionic liquids. Twelve diverse and representative ionic liquids are used to disperse iron oxide nanoparticles. The liquid interface of these nanoparticles has been carefully tuned in a molecular solvent before transferring into an ionic liquid, without passing through the powder state. Multiscale-characterisation is applied, on both the micro and the nano scale, incorporating both small angle X-ray scattering and dynamic light scattering. The results show the surface charge of the nanoparticles to be a crucial parameter, controlling the layering of the surrounding ionic liquid, and hence producing repulsion allowing efficient counterbalancing of the attractive interactions. For intermediate charges the strength of the repulsion depends on the specific system causing varying levels of aggregation or even none at all. Several samples consist of sufficiently repulsive systems leading to single dispersed nanoparticles, stable in the long term. Thanks to the magnetic properties of the chosen iron oxide nanoparticles, true ferrofluids are produced, appropriate for applications using magnetic fields. The strength and breadth of the observed trends suggests that the key parameters identified here can be generalised to most ionic liquids.
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Affiliation(s)
- J C Riedl
- Sorbonne Université, Laboratoire PHENIX 4 place Jussieu, case 51 75005 Paris France
| | - M A Akhavan Kazemi
- Sorbonne Université, Laboratoire PHENIX 4 place Jussieu, case 51 75005 Paris France
| | - F Cousin
- Laboratoire Léon Brillouin, UMR 12, CNRS-CEA, CEA-Saclay 91191 Gif-sur-Yvette France
| | - E Dubois
- Sorbonne Université, Laboratoire PHENIX 4 place Jussieu, case 51 75005 Paris France
| | - S Fantini
- Solvionic SA 195 route d'Espagne, BP1169 31036 Toulouse Cedex 1 France
| | - S Loïs
- Solvionic SA 195 route d'Espagne, BP1169 31036 Toulouse Cedex 1 France
| | - R Perzynski
- Sorbonne Université, Laboratoire PHENIX 4 place Jussieu, case 51 75005 Paris France
| | - V Peyre
- Sorbonne Université, Laboratoire PHENIX 4 place Jussieu, case 51 75005 Paris France
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17
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Fu L, Joly L, Merabia S. Giant Thermoelectric Response of Nanofluidic Systems Driven by Water Excess Enthalpy. PHYSICAL REVIEW LETTERS 2019; 123:138001. [PMID: 31697539 DOI: 10.1103/physrevlett.123.138001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 07/11/2019] [Indexed: 06/10/2023]
Abstract
Nanofluidic systems could in principle be used to produce electricity from waste heat, but current theoretical descriptions predict a rather poor performance as compared to thermoelectric solid materials. Here we investigate the thermoelectric response of NaCl and NaI solutions confined between charged walls, using molecular dynamics simulations. We compute a giant thermoelectric response, 2 orders of magnitude larger than the predictions of standard models. We show that water excess enthalpy-neglected in the standard picture-plays a dominant role in combination with the electro-osmotic mobility of the liquid-solid interface. Accordingly, the thermoelectric response can be boosted using surfaces with large hydrodynamic slip. Overall, the heat harvesting performance of the model systems considered here is comparable to that of the best thermoelectric materials, and the fundamental insight provided by molecular dynamics suggests guidelines to further optimize the performance, opening the way to recycle waste heat using nanofluidic devices.
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Affiliation(s)
- Li Fu
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Laurent Joly
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Samy Merabia
- Univ Lyon, Univ Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
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18
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Salez TJ, Kouyaté M, Filomeno C, Bonetti M, Roger M, Demouchy G, Dubois E, Perzynski R, Cēbers A, Nakamae S. Magnetically enhancing the Seebeck coefficient in ferrofluids. NANOSCALE ADVANCES 2019; 1:2979-2989. [PMID: 36133602 PMCID: PMC9419873 DOI: 10.1039/c9na00109c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/03/2019] [Indexed: 05/22/2023]
Abstract
The influence of the magnetic field on the Seebeck coefficient (Se) was investigated in dilute magnetic nanofluids (ferrofluids) composed of maghemite magnetic nanoparticles dispersed in dimethyl-sulfoxide (DMSO). A 25% increase in the Se value was found when the external magnetic field was applied perpendicularly to the temperature gradient, reminiscent of an increase in the Soret coefficient (S T, concentration gradient) observed in the same fluids. In-depth analysis of experimental data, however, revealed that different mechanisms are responsible for the observed magneto-thermoelectric and -thermodiffusive phenomena. Possible physical and physico-chemical origins leading to the enhancement of the fluids' Seebeck coefficient are discussed.
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Affiliation(s)
- Thomas J Salez
- Service de physique de l'état condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France +33 1 6908 8786 +33 1 6908 7538
- École des Ponts ParisTech 6 et 8 avenue Blaise Pascal, Champs-sur-Marne F-77455 Marne-la-Vallée France
| | - Mansour Kouyaté
- Physico-chimie des Electrolytes et Nanosystémes InterfaciauX, Sorbonne Université, CNRS F-75005 Paris France
| | - Cleber Filomeno
- Physico-chimie des Electrolytes et Nanosystémes InterfaciauX, Sorbonne Université, CNRS F-75005 Paris France
- Inst. de Quémica, Complex Fluid Group, Universidade de Brasília Brasília Brazil
| | - Marco Bonetti
- Service de physique de l'état condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France +33 1 6908 8786 +33 1 6908 7538
| | - Michel Roger
- Service de physique de l'état condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France +33 1 6908 8786 +33 1 6908 7538
| | - Gilles Demouchy
- Physico-chimie des Electrolytes et Nanosystémes InterfaciauX, Sorbonne Université, CNRS F-75005 Paris France
- Département de Physique, Université de Cergy Pontoise 33 Boulevard du Port 95011 Cergy-Pontoise Cedex France
| | - Emmanuelle Dubois
- Physico-chimie des Electrolytes et Nanosystémes InterfaciauX, Sorbonne Université, CNRS F-75005 Paris France
| | - Régine Perzynski
- Physico-chimie des Electrolytes et Nanosystémes InterfaciauX, Sorbonne Université, CNRS F-75005 Paris France
| | - Andrejs Cēbers
- MMML Lab, Faculty of Physics and Mathematics, University of Latvia Zellu-8 LV-1002 Riga Latvia
| | - Sawako Nakamae
- Service de physique de l'état condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex France +33 1 6908 8786 +33 1 6908 7538
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19
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Yang Z, Dang F, Zhang C, Sun S, Zhao W, Li X, Liu Y, Chen X. Harvesting Low-Grade Heat via Thermal-Induced Electric Double Layer Redistribution of Nanoporous Graphene Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7713-7719. [PMID: 31122020 DOI: 10.1021/acs.langmuir.9b00646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, a closed thermoelectric cell based on a nanoporous graphene electrode is developed to convert low-grade thermal energy to electric energy. The thermoelectric cell consists of two nanoporous graphene electrodes in contact with the hot and cold ends, respectively, encapsulated in a KCl electrolyte, and the energy is harvested from the redistribution of the electric double layer (EDL) of the graphene electrodes under different temperatures. Because of the large specific surface and conductivity of nanoporous graphene electrodes, the electric voltage is 168.91 mV with the hot-end temperature of 61 °C and cold-end temperature of 26 °C, corresponding to the thermoelectric coefficient of 4.54 mV·°C-1, which is much larger than that of the conventional thermoelectric generator. The specific power output achieves 1.38 mW·g-1 and is also significantly larger than the previous EDL-based thermoelectric generator. System performance with the concentration of the KCl electrolyte is examined. The proposed thermoelectric cell can harvest low-grade waste heat from the ambient environment, which may have potential applications in energy supply, wireless powered devices, outdoor survival, and so forth.
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Affiliation(s)
| | | | | | - Shuocheng Sun
- School of Civil Engineering , Luoyang Institute of Science and Technology , Luoyang 471023 , China
| | - Wei Zhao
- School of Chemical Engineering, Institute of Energy and Chemical Engineering Shaanxi , Northwest University , Xi'an 710069 , China
| | - Ximeng Li
- School of Chemical Engineering, Institute of Energy and Chemical Engineering Shaanxi , Northwest University , Xi'an 710069 , China
| | | | - Xi Chen
- School of Chemical Engineering, Institute of Energy and Chemical Engineering Shaanxi , Northwest University , Xi'an 710069 , China
- Earth Engineering Center, Center for Advanced Materials for Energy and Environment, Department of Earth and Environmental Engineering , Columbia University , New York , New York 10027 , United States
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20
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Janssen M, Bier M. Transient response of an electrolyte to a thermal quench. Phys Rev E 2019; 99:042136. [PMID: 31108728 DOI: 10.1103/physreve.99.042136] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Indexed: 06/09/2023]
Abstract
We study the transient response of an electrolytic cell subject to a small, suddenly applied temperature increase at one of its two bounding electrode surfaces. An inhomogeneous temperature profile then develops, causing, via the Soret effect, ionic rearrangements towards a state of polarized ionic charge density q and local salt density c. For the case of equal cationic and anionic diffusivities, we derive analytical approximations to q,c, and the thermovoltage V_{T} for early (t≪τ_{T}) and late (t≫τ_{T}) times as compared to the relaxation time τ_{T} of the temperature. We challenge the conventional wisdom that the typically large Lewis number, the ratio a/D of thermal to ionic diffusivities, of most liquids implies a quickly reached steady-state temperature profile onto which ions relax slowly. Though true for the evolution of c, it turns out that q (and V_{T}) can respond much faster. Particularly when the cell is much bigger than the Debye length, a significant portion of the transient response of the cell falls in the t≪τ_{T} regime, for which our approximated q (corroborated by numerics) exhibits a density wave that has not been discussed before in this context. For electrolytes with unequal ionic diffusivities, V_{T} exhibits a two-step relaxation process, in agreement with experimental data of Bonetti et al. [J. Chem. Phys. 142, 244708 (2015)JCPSA60021-960610.1063/1.4923199].
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Affiliation(s)
- Mathijs Janssen
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany
- Institut für Theoretische Physik IV, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Markus Bier
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany
- Institut für Theoretische Physik IV, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
- Fakultät Angewandte Natur- und Geisteswissenschaften, Hochschule für Angewandte Wissenschaften Würzburg-Schweinfurt, Ignaz-Schön-Str. 11, 97421 Schweinfurt, Germany
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21
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Barragán VM, Kristiansen KR, Kjelstrup S. Perspectives on Thermoelectric Energy Conversion in Ion-Exchange Membranes. ENTROPY 2018; 20:e20120905. [PMID: 33266629 PMCID: PMC7512490 DOI: 10.3390/e20120905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/21/2018] [Accepted: 11/22/2018] [Indexed: 11/16/2022]
Abstract
By thermoelectric power generation we mean the creation of electrical power directly from a temperature gradient. Semiconductors have been mainly used for this purpose, but these imply the use of rare and expensive materials. We show in this review that ion-exchange membranes may be interesting alternatives for thermoelectric energy conversion, giving Seebeck coefficients around 1 mV/K. Laboratory cells with Ag|AgCl electrodes can be used to find the transported entropies of the ions in the membrane without making assumptions. Non-equilibrium thermodynamics can be used to compute the Seebeck coefficient of this and other cells, in particular the popular cell with calomel electrodes. We review experimental results in the literature on cells with ion-exchange membranes, document the relatively large Seebeck coefficient, and explain with the help of theory its variation with electrode materials and electrolyte concentration and composition. The impact of the membrane heterogeneity and water content on the transported entropies is documented, and it is concluded that this and other properties should be further investigated, to better understand how all transport properties can serve the purpose of thermoelectric energy conversion.
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Affiliation(s)
- V. María Barragán
- Department of Structure of Matter, Thermal Physics and Electronics; Complutense University of Madrid, 28040 Madrid, Spain
| | - Kim R. Kristiansen
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Signe Kjelstrup
- PoreLab, Department of Chemistry, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
- Correspondence: ; Tel.: +47-918-97079
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22
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Al-Masri D, Dupont M, Yunis R, MacFarlane DR, Pringle JM. The electrochemistry and performance of cobalt-based redox couples for thermoelectrochemical cells. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.03.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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23
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Dupont MF, MacFarlane DR, Pringle JM. Thermo-electrochemical cells for waste heat harvesting - progress and perspectives. Chem Commun (Camb) 2018; 53:6288-6302. [PMID: 28534592 DOI: 10.1039/c7cc02160g] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Thermo-electrochemical cells (also called thermocells) are promising devices for harvesting waste heat for the sustainable production of energy. Research into thermocells has increased significantly in recent years, driven by advantages such as their ability to continuously convert heat into electrical energy without producing emissions or consuming materials. Until relatively recently, the commercial viability of thermocells was limited by their low power output and conversion efficiency. However, there have lately been significant advances in thermocell performance as a result of improvements to the electrode materials, electrolyte and redox chemistry and various features of the cell design. This article overviews these recent developments in thermocell research, including the development of new redox couples, the optimisation of electrolytes for improved power output and high-temperature operation, the design of high surface area electrodes for increased current density and device flexibility, and the optimisation of cell design to further enhance performance.
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Affiliation(s)
- M F Dupont
- ARC Centre of Excellence for Electromaterials Science, Institute for Frontier Materials, Deakin University, Geelong, Australia.
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24
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Jia H, Ju Z, Tao X, Yao X, Wang Y. P-N Conversion in a Water-Ionic Liquid Binary System for Nonredox Thermocapacitive Converters. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7600-7605. [PMID: 28700242 DOI: 10.1021/acs.langmuir.7b00746] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An intriguing p-n conversion of thermoelectric property was observed in a water-ionic liquid ([EMIm][Ac]) binary system with precise control over water content. The highest p-type and n-type Seebeck coefficient were optimized at water-[EMIm][Ac] molar ratio of 2:1 and 4:1, respectively. DFT calculation illustrates that a configuration of solvent separation ion pairs is preferred at the water-[EMIm][Ac] molar ratio of 4:1, leading to the p-n conversion through weakening interaction between anion clusters and gold electrodes. Furthermore, p-n thermocapacitive converters were integrated to enhance the output Seebeck voltages. This work opens up new perspectives for harvesting low grade heat with the use of fluidic materials.
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Affiliation(s)
- Hanyu Jia
- Department of Chemistry, Renmin University of China , 100872, Beijing, China
| | - Zhaoyang Ju
- Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences , 100190, Beijing, China
| | - Xinglei Tao
- Department of Chemistry, Renmin University of China , 100872, Beijing, China
| | - Xiaoqian Yao
- Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences , 100190, Beijing, China
| | - Yapei Wang
- Department of Chemistry, Renmin University of China , 100872, Beijing, China
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25
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Stout RF, Khair AS. Diffuse charge dynamics in ionic thermoelectrochemical systems. Phys Rev E 2017; 96:022604. [PMID: 28950449 DOI: 10.1103/physreve.96.022604] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Indexed: 04/27/2023]
Abstract
Thermoelectrics are increasingly being studied as promising electrical generators in the ongoing search for alternative energy sources. In particular, recent experimental work has examined thermoelectric materials containing ionic charge carriers; however, the majority of mathematical modeling has been focused on their steady-state behavior. Here, we determine the time scales over which the diffuse charge dynamics in ionic thermoelectrochemical systems occur by analyzing the simplest model thermoelectric cell: a binary electrolyte between two parallel, blocking electrodes. We consider the application of a temperature gradient across the device while the electrodes remain electrically isolated from each other. This results in a net voltage, called the thermovoltage, via the Seebeck effect. At the same time, the Soret effect results in migration of the ions toward the cold electrode. The charge dynamics are described mathematically by the Poisson-Nernst-Planck equations for dilute solutions, in which the ion flux is driven by electromigration, Brownian diffusion, and thermal diffusion under a temperature gradient. The temperature evolves according to the heat equation. This nonlinear set of equations is linearized in the (experimentally relevant) limit of a "weak" temperature gradient. From this, we show that the time scale on which the thermovoltage develops is the Debye time, 1/Dκ^{2}, where D is the Brownian diffusion coefficient of both ion species, and κ^{-1} is the Debye length. However, the concentration gradient due to the Soret effect develops on the bulk diffusion time, L^{2}/D, where L is the distance between the electrodes. For thin diffuse layers, which is the condition under which most real devices operate, the Debye time is orders of magnitude less than the diffusion time. Therefore, rather surprisingly, the majority of ion motion occurs after the steady thermovoltage has developed. Moreover, the dynamics are independent of the thermal diffusion coefficients, which simply set the magnitude of the steady-state thermovoltage.
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Affiliation(s)
- Robert F Stout
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Aditya S Khair
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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26
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Anari EHB, Romano M, Teh WX, Black JJ, Jiang E, Chen J, To TQ, Panchompoo J, Aldous L. Substituted ferrocenes and iodine as synergistic thermoelectrochemical heat harvesting redox couples in ionic liquids. Chem Commun (Camb) 2016; 52:745-8. [PMID: 26563939 DOI: 10.1039/c5cc05889a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combining ferrocene and iodine results in enhanced thermoelectrochemical (or thermogalvanic) waste heat harvesting abilities, for both the Seebeck coefficient and the overall power output. All systems displayed a mixture of ferrocene, ferrocenium, iodine and triiodide. The observed enhancement correlates with lower electron-density on the ferrocene; the synergistic improvement observed for mixtures of substituted ferrocenes and iodine is attributed to the formation of charge-transfer complexes. Combining dibutanoylferrocene and iodine resulted in the highest Seebeck coefficient of 1.67 mV K(-1).
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Affiliation(s)
- E H B Anari
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - M Romano
- Intelligent Polymer Research Institute, Innovation Campus, University of Wollongong, Wollongong, NSW 2522, Australia
| | - W X Teh
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - J J Black
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - E Jiang
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - J Chen
- Intelligent Polymer Research Institute, Innovation Campus, University of Wollongong, Wollongong, NSW 2522, Australia
| | - T Q To
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - J Panchompoo
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
| | - L Aldous
- School of Chemistry, UNSW Australia, Sydney, NSW 2052, Australia.
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