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CN-122028640-A - Wide-temperature-range flexible ion thermoelectric battery and preparation method thereof

CN122028640ACN 122028640 ACN122028640 ACN 122028640ACN-122028640-A

Abstract

The invention discloses a wide-temperature-range flexible ion thermoelectric battery and a preparation method thereof. The wide-temperature-range flexible ion thermoelectric battery provided by the invention has the advantages that the thermal stability of the flexible ion thermoelectric battery in a high-temperature area is improved, the wide-temperature-range flexible ion thermoelectric battery has excellent thermoelectric performance, a feasible path is provided for realizing conversion and collection of heat energy at a higher temperature by utilizing the flexible ion thermoelectric battery, and the wide-temperature-range flexible ion thermoelectric battery has wide application prospects in the fields of sensing monitoring, flexible wearing equipment, refrigeration cooling, heat preservation and heat insulation and the like.

Inventors

  • GAO WAI
  • XU WANQI
  • MENG HAOFEI
  • LU XIN
  • ZHANG CHENGBIN
  • CHEN YONGPING
  • WU SUCHEN

Assignees

  • 东南大学

Dates

Publication Date
20260512
Application Date
20260320

Claims (10)

  1. 1. The wide-temperature-range flexible ion thermoelectric battery comprises thermoelectric hydrogel and an electrode, wherein the thermoelectric hydrogel is obtained by placing a double-network gel matrix in binary redox electrolyte for solvent exchange, and is characterized in that binary redox ions in the binary redox electrolyte comprise first redox and second redox, wherein the first redox is K 3/ 4 Fe(CN) 6 , and the second redox pair is one of (NH 4 ) 3/4 [Fe(CN) 6 ]、Li 3/4 Fe(CN) 6 and Na 3/4 Fe(CN) 6 .
  2. 2. The broad temperature range flexible ion thermoelectric cell of claim 1, wherein the total concentration of redox pair K 3/4 Fe(CN) 6 and redox pair (NH 4 ) 3/4 [Fe(CN) 6 ) in the binary redox ion pair is fixed to 0.2-0.12M.
  3. 3. The wide temperature range flexible ion thermoelectric cell of claim 2, wherein the concentration of the redox couple K 3/4 Fe(CN) 6 is 0.1-0.6M and the concentration of the redox couple (NH 4 ) 3/4 [Fe(CN) 6 ) is 0.1-0.6M.
  4. 4. The wide-temperature-range flexible ion thermoelectric cell according to claim 1, wherein the binary redox electrolyte further comprises water, an organic small molecule additive and a water-soluble metal salt, wherein the organic small molecule additive and the water-soluble metal salt are jointly dispersed in a redox couple aqueous solution formed by a binary redox ion pair and water, the concentration of the organic small molecule additive in the binary redox electrolyte is 0.5-4M, and the concentration of the water-soluble metal salt in the binary redox electrolyte is 0.5-4M.
  5. 5. The flexible ion thermoelectric cell of claim 4 wherein the small organic molecule additive is one or more of the group consisting of guanidine hydrochloride, guanidine carbonate, guanidine phosphate, guanidine sulfate, and guanidine sulfamate.
  6. 6. The broad temperature range flexible ion thermoelectric cell of claim 4 wherein the water soluble metal salt is sodium chloride.
  7. 7. The wide temperature range flexible ion thermoelectric cell according to claim 1, wherein the reaction condition of solvent exchange of the double-network gel matrix in the binary redox electrolyte is that the double-network gel matrix is taken out after being soaked for 1-3 hours under the ambient temperature condition of 85-95 ℃ and then cooled.
  8. 8. The method for preparing the wide temperature range flexible ion thermoelectric battery according to any one of claims 1 to 7, comprising the steps of: preparing a double-network gel matrix: (1) Mixing a first monomer, a first cross-linking agent and a photoinitiator, and performing ultraviolet curing reaction to obtain a single-network gel matrix; (2) Soaking the single-network gel matrix in a mixed solution composed of a second monomer, a second crosslinking agent and a photoinitiator, and performing ultraviolet curing reaction to obtain a double-network gel matrix; preparing thermoelectric hydrogel, namely placing a double-network gel matrix into binary redox electrolyte for solvent exchange to obtain thermoelectric hydrogel; And packaging the electrodes, namely integrating the electrodes on the left side and the right side of the thermoelectric hydrogel, enabling the electrodes on the two sides to be respectively contacted with a cold source and a heat source, and packaging by adopting a flexible packaging material to obtain the wide-temperature-range flexible ion thermoelectric battery.
  9. 9. The broad temperature range flexible ion thermoelectric cell of claim 8, wherein in step (1), the first monomer comprises 2-acrylamide-2-methyl-1-propanesulfonic acid and acrylamide, the first crosslinking agent is N, N' -methylenebisacrylamide, and the photoinitiator is 2-hydroxy-2-methylpropaneketone; The concentration of N, N' -methylenebisacrylamide is 0.002-0.02M, the mass ratio of 2-hydroxy-2-methyl propiophenone to deionized water is 1:200-1:50, the mass ratio of acrylamide to 2-acrylamide-2-methyl-1-propanesulfonic acid is 1:2-1:0.2, and the mass ratio of total monomers to deionized water is 1:10-1:3; In the step (2), the second monomer is acrylamide, the second crosslinking agent is polyethylene glycol diacrylate, the photoinitiator is 2-hydroxy-2-methyl propiophenone, the mass ratio of the acrylamide to deionized water is 1:10-1:6, the concentration of the polyethylene glycol diacrylate is 0.002-0.02M, and the mass fraction of the 2-hydroxy-2-methyl propiophenone is 0.1-1 wt%.
  10. 10. The wide temperature range flexible ion thermoelectric cell of claim 8, wherein the time of the two ultraviolet light curing reactions is 0.4-1 h, and the wavelength of ultraviolet light is 365 nm or 395 nm.

Description

Wide-temperature-range flexible ion thermoelectric battery and preparation method thereof Technical Field The invention belongs to the technical field of thermoelectric energy conversion, and particularly relates to a wide-temperature-range flexible ion thermoelectric battery and a preparation method thereof. Background Low-grade heat energy with abundant reserves is widely distributed in social production and human activities, and development of efficient collection strategies thereof is a key to advancing sustainable energy technology and powering wearable or distributed electronic systems. Thermoelectric technology capable of directly converting heat energy into electric energy has wide application prospect due to the advantages of compact structure, no moving parts, long service life and the like. In existing thermoelectric technology, quasi-solid state thermochemical batteries (QSTs) are a promising solution due to their low cost, mechanical flexibility, and high seebeck coefficient resulting from entropy driven redox reactions. The key to high performance QSTs is that the redox couple (e.g., [ Fe (CN) 6]3-/4- ion pair) has a large entropy change (ΔS r c). To enhance this effect, recent research breakthroughs have utilized chaotropic cations (e.g., guanidine ions Gdm +) to induce [ Fe (CN) 6]4- to form thermosensitive crystals, which in turn build up a steep concentration gradient through dynamic crystallization precipitation-dissolution equilibrium, raising the seebeck coefficient S i of thermochemical batteries from about 1.4 mVK -1 to above 3.7 mVK -1. However, such supramolecular assemblies with large entropy increase are maintained by means of fragile non-covalent interactions, resulting in thermal instability. Thermodynamic dissociation of the formed thermosensitive crystals at high temperatures (> 55 ℃) can disrupt the build up of concentration gradients, thereby impairing thermoelectric performance. Thus, achieving thermodynamic ion conditioning is a critical but unresolved issue in advancing the thermoelectric performance of flexible ion thermoelectric cells at high temperatures. Disclosure of Invention The invention aims to provide a wide-temperature-range flexible ion thermoelectric battery and a preparation method thereof, aiming at the defects of the prior art, and the working temperature range of the thermo-chemical battery for realizing continuous, stable and efficient thermoelectric conversion is widened. The technical scheme adopted by the invention is as follows: a wide-temperature-range flexible ion thermoelectric battery comprises thermoelectric hydrogel and a platinum wire electrode, wherein the thermoelectric hydrogel comprises a double-network gel matrix and binary redox electrolyte; the double-network gel matrix is prepared by a sequential network method; the binary redox electrolyte comprises a binary redox ion pair, water, an organic micromolecular additive and water-soluble metal salt; the thermoelectric hydrogel is obtained by soaking a double-network gel matrix in binary redox electrolyte. According to the wide-temperature-range flexible ion thermoelectric battery based on the double-network gel and the binary redox pair, the solvation shell layer of [ Fe (CN) 6]4- ] is reconfigured by utilizing ammonium cations (NH 4+), the lattice energy is improved through enhanced ion association, the upper limit of the tolerance temperature of a crystalline structure is effectively improved, and the system and the double-network hydrogel are cooperatively integrated. Finally, the prepared flexible ion thermoelectric battery realizes decoupling of thermal responsiveness and structural stability, and realizes efficient and stable thermoelectric performance output in a wide temperature range of 25-90 ℃. The total concentration of redox pair K 3/4Fe(CN)6 and redox pair (NH 4)3/4[Fe(CN)6) in the binary redox ion pair is fixed at 0.2-0.12M. The concentration of the redox couple K 3/4Fe(CN)6 is 0.1-0.6M, and the concentration of the redox couple (NH 4)3/4[Fe(CN)6) is 0.1-0.6M. 4. The wide-temperature-range flexible ion thermoelectric cell according to claim 1, wherein the binary redox electrolyte further comprises water, an organic small molecule additive and a water-soluble metal salt, wherein the organic small molecule additive and the water-soluble metal salt are jointly dispersed in a redox couple aqueous solution formed by a binary redox ion pair and water, the concentration of the organic small molecule additive in the binary redox electrolyte is 0.5-4M, and the concentration of the water-soluble metal salt in the binary redox electrolyte is 0.5-4M. The preparation method of the thermoelectric hydrogel provided by the invention comprises the steps of placing a double-network gel matrix in binary redox electrolyte for solvent exchange to obtain the thermoelectric hydrogel. In the preparation method of the thermoelectric hydrogel, the preparation method of the double-network gel comprises