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CN-122010454-A - Thermoelectric cement-based structural electrolyte, cement-based thermal charging capacitor and preparation method

CN122010454ACN 122010454 ACN122010454 ACN 122010454ACN-122010454-A

Abstract

The invention discloses a thermoelectric cement-based structural electrolyte, a cement-based thermal charging capacitor and a preparation method thereof, wherein the thermoelectric cement-based structural electrolyte comprises a cement matrix, the cement matrix is formed by hardening cement paste uniformly doped with a water-soluble polymer and a two-dimensional MXene material, pores in the cement matrix are filled with an ion donor solution, the mass of the water-soluble polymer is 5% -10% of the mass of the cement, and the mass of the two-dimensional MXene material is 0.01% -0.1% of the mass of the cement. According to the invention, by doping the water-soluble polymer and the two-dimensional MXene material with low doping amount into the cement paste, the pore distribution of the cement matrix is regulated, the mechanical property of the electrolyte with the thermoelectric cement-based structure is maintained or even improved, and the ternary composite system is cooperated to obtain the high Seebeck coefficient and the ion conductivity. The cement-based thermal charging capacitor utilizes the electrolyte with the thermoelectric cement-based structure as an electrolyte layer, and is compounded with the electric double layer capacitor electricity storage electrode, so that good thermal power generation and electricity storage integrated capability is realized under the action of temperature difference.

Inventors

  • ZHANG DONG
  • Shi Muyang

Assignees

  • 同济大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. A thermoelectric cement-based structural electrolyte comprising a cement matrix, characterized in that: the cement matrix is formed by hardening cement paste uniformly doped with a water-soluble polymer and a two-dimensional MXene material, and pores in the cement matrix are filled with an ion donor solution; the mass of the water-soluble polymer is 5% -10% of the mass of cement, and the mass of the two-dimensional MXene material is 0.01% -0.1% of the mass of cement; the compressive strength of the thermoelectric cement-based structural electrolyte is higher than 42.5 MPa, the flexural strength is higher than 8.6 MPa, the absolute value of the Seebeck coefficient is higher than 1.4 mV/K, and the ionic conductivity is higher than 21.1 mS/cm.
  2. 2. The electrolyte of the thermoelectric cement-based structure according to claim 1, wherein the water-soluble polymer is polyacrylamide, the mass of the water-soluble polymer is 6% of the mass of cement, the mass of the two-dimensional MXene material is 0.1% of the mass of cement, the cement is silicate cement, the cement paste has a water cement ratio of 0.4, the compressive strength of the electrolyte of the thermoelectric cement-based structure is higher than 43 MPa, the flexural strength is higher than 9 MPa, the absolute value of a Seebeck coefficient is higher than 3.1 mV/K, and the ionic conductivity is higher than 75 mS/cm.
  3. 3. The thermoelectric cement-based structural electrolyte according to claim 1, wherein the ion donor solution is an aqueous solution of an inorganic ion donor at a concentration of 1M.
  4. 4. A method for preparing a thermoelectric cement-based structural electrolyte, comprising: Firstly, dissolving an initiator, a cross-linking agent and a water-soluble polymer monomer in water, stirring uniformly to obtain a polymer reaction solution, then stirring uniformly the polymer reaction solution and a two-dimensional MXene material to obtain a mixed solution, pouring the cement paste obtained by stirring uniformly the mixed solution and a cement base into a mould, curing, solidifying and demoulding, and finally, vacuum soaking the solidified cement base to adsorb an ion donor solution to obtain the thermoelectric cement base structure electrolyte; The mass of the water-soluble polymer is 5% -10% of the mass of the cement, and the mass of the two-dimensional MXene material is 0.01% -0.1% of the mass of the cement.
  5. 5. The method for preparing the thermoelectric cement-based structural electrolyte according to claim 4, wherein the initiator is ammonium persulfate, the mass of the initiator is 0.45% of the mass of cement, the crosslinking agent is methylene bisacrylamide, the mass of the crosslinking agent is 0.23% of the mass of cement, the mass of the water-soluble polymer monomer is acrylamide, the mass of the water-soluble polymer monomer is 6% of the mass of cement, the mass of the two-dimensional MXene material is 0.1% of the mass of cement, the cement is silicate cement, and the cement paste has a water cement ratio of 0.4.
  6. 6. The method for preparing a thermoelectric cement-based structured electrolyte according to claim 4, wherein the ion donor solution is an aqueous solution of an inorganic ion donor having a concentration of 1M.
  7. 7. A cement-based thermal charge capacitor, which is characterized by comprising an electric double layer capacitor electricity storage positive electrode and an electric double layer capacitor electricity storage negative electrode, wherein the thermoelectric cement-based structural electrolyte according to any one of claims 1 to 3 or the thermoelectric cement-based structural electrolyte prepared by the preparation method according to any one of claims 4 to 6 is used as an electrolyte layer; when the temperature difference exists between the electric double layer capacitor electricity storage positive electrode end and the electric double layer capacitor electricity storage negative electrode end, the directional migration of the electrolyte ions of the thermoelectric cement-based structure is utilized to form a potential difference, so that the conversion of heat energy into electric energy is realized, and the generated electric energy can be stored in a capacitive mode.
  8. 8. The cement-based thermal charge capacitor of claim 7, wherein the positive and negative electric double layer capacitor storage electrodes are loaded with pseudocapacitor electrode material.
  9. 9. A cement-based thermally charged capacitor according to claim 8, wherein said pseudocapacitor electrode material comprises at least one or more battery-type electrode materials including metal oxides, metal hydroxides, conductive polymers or one or more capacitive-type electrode materials including activated carbon, graphene oxide.
  10. 10. The cement-based thermal charging capacitor according to claim 9 is characterized in that the preparation method of the pseudocapacitor electrode material comprises the steps of mixing and pouring a capacitance electrode material, nickel-cobalt layered double hydroxide, a conductive polymer, conductive carbon black and a binder into an organic solvent according to a proportion, mixing and stirring the mixture to form a paste, coating the paste on the surface of a current collector, and drying the paste under pressure, wherein the conductive polymer is one of polyaniline and polypyrrole, and the mass ratio of the conductive polymer to the conductive carbon black to the binder is 7:0.8:0.2:1:1.

Description

Thermoelectric cement-based structural electrolyte, cement-based thermal charging capacitor and preparation method Technical Field The invention relates to the technical field of thermoelectric cement-based structure electrolytes, in particular to a two-dimensional MXene material modified thermoelectric cement-based structure electrolyte, a cement-based thermal charging capacitor and a preparation method. Background The construction operation stage is accompanied by the dissipation of a large amount of low-grade heat energy which is not effectively utilized, such as indoor and outdoor day-night temperature difference (5-20K), condensation waste heat of an air conditioning system, radiation heat exchange of an enclosure structure and the like. The widely distributed environmental temperature difference and waste heat are effectively collected and converted into electric energy for storage and utilization, and the electric energy is a key way for reducing the energy consumption outside the building and realizing the green low-carbon development of urban and rural construction. In the prior art, cement-based thermal charging capacitors with thermoelectric conversion and electric energy storage integrated are not found. The first type of prior art (as in the patent publication CN121517237 a) is directed to the development of pure thermoelectric conversion "no-store only" cement-based materials, which can only function as generators, but it is difficult to achieve storage of electrical energy. The second prior art (such as the patent with publication number CN118430985A, CN120441267A, CN120933081 a) is directed to developing a "store-only-not-send" type cement-based supercapacitor for purely chemical energy storage, which is a purely passive energy storage device, and can only meet the energy storage requirement. Traditional cement-based energy devices are limited by functional singleness, and cannot achieve both efficient conversion and real-time storage of energy. The Ca 2+、OH-、K+、Na+ plasma in the pore solution after cement hydration is utilized to directionally migrate under the drive of temperature difference, so that voltage is generated, but the Seebeck coefficient of the pure cement matrix is very low, and low-grade waste heat is difficult to utilize. At present, carbon-based materials such as carbon nanotubes, nano carbon black, nano graphene and the like are studied to improve the thermoelectric effect (such as publication number ES2908123A 2), but the materials have high carbon content, an electronic path is easy to form inside, the materials cannot be used as an electrolyte, and the stability of a bearing structure is insufficient when the materials are used as an energy storage electrode. Therefore, it is of great importance to develop a cement-based thermal charging capacitor that has a stable bearing structure and is capable of efficiently achieving thermoelectric conversion and electric energy storage as a whole. Disclosure of Invention Aiming at the problems existing in the prior art, one of the purposes of the invention is to provide a thermoelectric cement-based structural electrolyte and a preparation method thereof, wherein a low-doping amount of water-soluble polymer and two-dimensional MXene material are doped in cement paste, so that on one hand, the pore distribution of a cement matrix is regulated, and the mechanical properties of the thermoelectric cement-based structural electrolyte are maintained or even improved, and on the other hand, the water-soluble polymer, the two-dimensional MXene material and an ion donor solution ternary composite system in cement pores are cooperated to obtain high Seebeck coefficient and ion conductivity. The invention further aims to provide a cement-based thermal charging capacitor, which utilizes the electrolyte with the thermoelectric cement-based structure as an electrolyte layer and is compounded with an electric double layer capacitor electricity storage electrode, so that better thermal power generation and electricity storage integrated capability is realized under the action of temperature difference. In order to achieve the above purpose, in a first aspect, the invention provides a thermoelectric cement-based structural electrolyte, which comprises a cement matrix, wherein the cement matrix is formed by hardening cement paste uniformly doped with a water-soluble polymer and a two-dimensional MXene material, pores in the cement matrix are filled with an ion donor solution, the mass of the water-soluble polymer is 5% -10% of that of the cement, the mass of the two-dimensional MXene material is 0.01% -0.1% of that of the cement, the compressive strength of the thermoelectric cement-based structural electrolyte is higher than 42.5 MPa, the flexural strength is higher than 8.6 MPa, the absolute value of a Seebeck coefficient is higher than 1.4 mV/K, and the ionic conductivity is higher than 21.1 mS/cm. The two-dimensional MXene material is herein a