Solvent effect on the Seebeck coefficient of Fe<sup>2+</sup>/Fe<sup>3+</sup> hydrogel thermogalvanic cells

Liu, Yang; Qi, Zhang; Odunmbaku, George Omololu; He, Yongjie; Zheng, Yu; Chen, Shanshan; Zhou, Yongli; Li, Jing; Li, Meng; Sun, Kuan

doi:10.1039/d1ta10508f

Cited by 37 publications

(19 citation statements)

References 41 publications

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“…The O v -WO 3 /TGC/S v -ZIS system demonstrated a photocatalytically enhanced thermopower of 8.2 mV K –1 versus that of other reported TGCs (Fig. 2F and table S2) ( 1 , 2 , 8 , 9 , 15 , 16 , 18 , 19 , 28 – 42 ). The normalized power density of 8.5 mW m –2 K –2 also exceeded that of other TGCs.…”

Section: Thermoelectric Performancementioning

confidence: 74%

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

Wang

Zhang

et al. 2023

Science

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High-performance thermogalvanic cells have the potential to convert thermal energy into electricity, but their effectiveness is limited by the low concentration difference of redox ions. We report an in situ photocatalytically enhanced redox reaction that generates hydrogen and oxygen to realize a continuous concentration gradient of redox ions in thermogalvanic devices. A linear relation between thermopower and hydrogen production rate was established as an essential design principle for devices. The system exhibited a thermopower of 8.2 millivolts per kelvin and a solar-to-hydrogen efficiency of up to 0.4%. A large-area generator (112 square centimeters) consisting of 36 units yielded an open-circuit voltage of 4.4 volts and a power of 20.1 milliwatts, as well 0.5 millimoles of hydrogen and 0.2 millimoles of oxygen after 6 hours of outdoor operation.

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Section: Thermoelectric Performancementioning

confidence: 74%

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

Wang

Zhang

et al. 2023

Science

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“…A larger difference of 0.3 Å in R 1st is also observed, so that the valence change due to redox reactions of Fe 3+ /Fe 2+ pairs would result in a larger solvation structure change, which is consistent with the measured higher α values. 21 The coordination number of acetone in the first solvation shell of Fe 3+ and Fe 2+ is 8.4 and 7.8 respectively. Such non-integer coordination number is a result of solvation shell fluctuations, which is commonly observed in MD simulations.…”

Section: Analysis Of Solvation Structurementioning

confidence: 98%

“…Electrolytes based on Co 3+ /Co 2+ redox pairs in ionic liquids or organic solvents also showed an α of 2.2 mV/K, higher than typical aqueous transition metal redox pairs. 18,19 Kim et al 20 and Liu et al 21 discovered that adding organic solvents to aqueous Fe(CN) 6 3À /Fe(CN) 6…”

Section: Introductionmentioning

confidence: 99%

Effect of solvation shell structure on thermopower of liquid redox pairs

Chen

Huang

Liu

et al. 2023

EcoMat

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Developing redox electrolytes with high thermopower is the key to making efficient thermogalvanic batteries for harvesting low‐grade heat. This work applies molecular dynamics simulations to predict the thermopower (i.e. thermogalvanic temperature coefficient) of the redox pairs Fe(CN)63−/Fe(CN)64− and Fe3+/Fe2+, showing excellent agreement with experimental values. We showed that of the Fe3+/Fe2+ redox pair can be increased from 1.70.4 mV/K to 3.80.5 mV/K with the increased acetone to water fraction. We discovered a significant change in the variance of solvent dipole orientation between Fe3+ and Fe2+, which can serve as a microscopic indicator for large . In mixed acetone‐water solvent, of Fe3+/Fe2+ showed a rapid increase at high acetone fractions, due to the intercalation of acetone molecules into the first solvation shell of the Fe2+ at high acetone fractions. Our discovery provides insights into how solvation shell order can be engineered to develop electrolytes with high .image

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“…TE generators vary based on the materials used for charge separation. For example, electronic TE generators use semiconductors [ 33 ] or conducting polymers [ 34 , 35 ], while ionic TE generators use liquid electrolytes [ 36 ], hydrogels [ 37 , 38 , 39 ], and ion gels [ 40 ]. As noted at the beginning, TEGs have the potential to directly convert a temperature difference into an electric potential difference through the thermoelectric (TE) effect, and vice versa, [ 5 ] which could be modeled as the Peltier effect, the Seebeck effect, and the Thomas Johann effect, depending on the actual working conditions [ 41 ].…”

Section: Introductionmentioning

confidence: 99%

Hybrid Photovoltaic/Thermoelectric Systems for Round-the-Clock Energy Harvesting

Zhang

Gao

2022

Molecules

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Due to their emission-free operation and high efficiency, photovoltaic cells (PVCs) have been one of the candidates for next-generation “green” power generators. However, PVCs require prolonged exposure to sunlight to work, resulting in elevated temperatures and worsened performances. To overcome this shortcoming, photovoltaic–thermal collector (PVT) systems are used to cool down PVCs, leaving the waste heat unrecovered. Fortunately, the development of thermoelectric generators (TEGs) provides a way to directly convert temperature gradients into electricity. The PVC–TEG hybrid system not only solves the problem of overheated solar cells but also improves the overall power output. In this review, we first discuss the basic principle of PVCs and TEGs, as well as the principle and basic configuration of the hybrid system. Then, the optimization of the hybrid system, including internal and external aspects, is elaborated. Furthermore, we compare the economic evaluation and power output of PVC and hybrid systems. Finally, a further outlook on the hybrid system is offered.

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Solvent effect on the Seebeck coefficient of Fe²⁺/Fe³⁺ hydrogel thermogalvanic cells

Abstract: The Seebeck coefficient of Fe2+/3+ thermogalvanic cells is inversely proportional to the donor number of organic solvent additives, which cause rearrangement of the Fe2+/3+ solvent shell.

Cited by 37 publications

References 41 publications

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

Effect of solvation shell structure on thermopower of liquid redox pairs

Hybrid Photovoltaic/Thermoelectric Systems for Round-the-Clock Energy Harvesting

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Solvent effect on the Seebeck coefficient of Fe2+/Fe3+ hydrogel thermogalvanic cells

Abstract: The Seebeck coefficient of Fe2+/3+ thermogalvanic cells is inversely proportional to the donor number of organic solvent additives, which cause rearrangement of the Fe2+/3+ solvent shell.

Cited by 37 publications

References 41 publications

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

Effect of solvation shell structure on thermopower of liquid redox pairs

Hybrid Photovoltaic/Thermoelectric Systems for Round-the-Clock Energy Harvesting

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Product

Resources

About

Solvent effect on the Seebeck coefficient of Fe²⁺/Fe³⁺ hydrogel thermogalvanic cells