Triboelectricity-thermoelectricity composite cement-based material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of energy conversion, and particularly relates to a triboelectricity-thermoelectricity composite cement-based material and a preparation method and application thereof. The triboelectricity-thermoelectric composite cement-based material comprises a cement-based thermoelectric material and a triboelectricity material which are subpackaged, the cement-based thermoelectric material comprises the following components: a carbon nanomaterial, a nano thermoelectric alloy, a conductive polymer, a carbon nanomaterial dispersing agent, a high-performance water reducing agent, water and cement, the triboelectric material includes a triboelectric polymer and a curing agent. The triboelectricity-thermoelectricity composite cement-based material has high energy conversion efficiency and high electric energy output power, and can be applied to a self-powered cathode protection structure and / or an energy conversion and collection device.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy conversion, and in particular relates to a triboelectric-thermoelectric composite cement-based material and a preparation method and application thereof. Background Art

[0002] Natural energy, such as solar energy, wind energy and geothermal energy, is considered an important alternative to traditional fossil energy due to its clean and renewable characteristics. However, existing natural energy collection systems usually rely on specialized equipment and materials, which limits their scope of application and efficiency. Cement concrete, as a widely used building material, has good mechanical properties and durability, and its surface also has the potential to be used as an energy collection medium. Therefore, how to effectively utilize the structural properties of cement concrete and develop sustainable energy collection solutions has become an urgent problem to be solved.

[0003] At present, most existing cement-based energy conversion and collection devices combine metal or semiconductor materials with cement concrete to form thermoelectric elements, which convert thermal energy into electrical energy. However, due to the limited ambient temperature difference, the thermoelectric conversion efficiency of such materials is low, resulting in insufficient electrical energy output power, which is difficult to meet actual needs. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a triboelectric-thermoelectric composite cement-based material and a preparation method and application thereof. The triboelectric-thermoelectric composite cement-based material has high energy conversion efficiency, high electrical energy output power, and can be used in a self-powered cathodic protection structure and / or an energy conversion collection device.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a triboelectric-thermoelectric composite cement-based material, comprising separately packaged cement-based thermoelectric materials and triboelectric materials;

[0007] The cement-based thermoelectric material comprises the following components by weight:

[0008]

[0009] The Seebeck coefficient of the nano thermoelectric alloy is 100-250 μV / K; the Seebeck coefficient of the conductive polymer is 5-60 μV / K;

[0010] The triboelectric material includes a triboelectric polymer and a curing agent.

[0011] Preferably, the nano thermoelectric alloy includes one or more of nano metal tellurides and solid solutions thereof; the nano metal telluride includes one or more of nano bismuth telluride, nano antimony telluride, nano cadmium telluride and nano tin telluride.

[0012] Preferably, the carbon nanomaterial includes one or more of carbon nanotubes, nano carbon black, graphene, redox graphene and carbon nanofibers.

[0013] Preferably, the conductive polymer includes one or more of polypyrrole, polythiophene, polyaniline and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate.

[0014] Preferably, the triboelectric polymer includes one or more of polydimethylsiloxane, perfluoroethylene-propylene copolymer, polyethylene terephthalate resin and polytetrafluoroethylene.

[0015] Preferably, the mass ratio of the triboelectric polymer to the curing agent is 8 to 12:1.

[0016] Preferably, the carbon nanomaterial dispersant includes one or more of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate and N-methylpyrrolidone.

[0017] The present invention also provides a method for preparing the triboelectric-thermoelectric composite cement-based material described in the above technical solution, comprising the following steps:

[0018] Firstly mixing carbon nanomaterials, nano thermoelectric alloys, conductive polymers, carbon nanomaterial dispersants, high-performance water reducing agents, cement and water to obtain the cement-based thermoelectric material;

[0019] The triboelectric polymer and the curing agent are mixed for a second time to obtain the triboelectric material.

[0020] The present invention also provides the use of the triboelectric-thermoelectric composite cement-based material described in the above technical solution or the triboelectric-thermoelectric composite cement-based material prepared by the preparation method described in the above technical solution in a self-powered cathode protection structure and / or an energy conversion collection device.

[0021] The present invention also provides a self-powered cathode protection structure or energy conversion collection device, comprising a triboelectric component and a cement-based thermoelectric component connected in series and / or in parallel; the triboelectric component comprises a triboelectric layer and a first conductive layer 1 fixed on one side of the triboelectric layer, and a first conductive layer 2 separated from the triboelectric layer; the cement-based thermoelectric component comprises a cement-based thermoelectric fixture and a second conductive layer 1 and a second conductive layer 2 disposed on opposite end surfaces of the cement-based thermoelectric fixture; when connected in series and / or in parallel, the first conductive layer 1, the first conductive layer 2, the second conductive layer 1 and the second conductive layer 2 are connected by wires;

[0022] The material of the triboelectric layer is the triboelectric-thermoelectric composite cement-based material described in the above technical solution or the triboelectric material in the triboelectric-thermoelectric composite cement-based material prepared by the preparation method described in the above technical solution;

[0023] The material of the cement-based thermoelectric fixture is the triboelectric-thermoelectric composite cement-based material described in the above technical solution or the cement-based thermoelectric material in the triboelectric-thermoelectric composite cement-based material prepared by the preparation method described in the above technical solution.

[0024] The invention provides a triboelectric-thermoelectric composite cement-based material, comprising separately packaged cement-based thermoelectric materials and triboelectric materials; the cement-based thermoelectric material comprises the following components by mass: 0.0005-0.002 parts of carbon nanomaterials, 0.05-0.1 parts of nano thermoelectric alloys, 0.005-0.02 parts of conductive polymers, 0.0001-0.002 parts of carbon nanomaterial dispersants, 0.001-0.015 parts of high-performance water reducers, 0.3-0.6 parts of water, and 1 part of cement; the Seebeck coefficient of the nano thermoelectric alloy is 100-250 μV / K; the Seebeck coefficient of the conductive polymer is 5-60 μV / K; the triboelectric material comprises a triboelectric polymer and a curing agent. The cement-based thermoelectric material of the present invention contains nano thermoelectric alloys, and the nano thermoelectric alloys of the present invention have a high Seebeck coefficient. The added conductive polymer can improve the conductivity and also has a high Seebeck coefficient, which can improve the efficiency of converting thermal energy into electrical energy. When the temperature of one side of the cement-based thermoelectric firmware containing nano thermoelectric alloys and conductive polymers is higher than the other side, the carriers (electrons or holes) inside the thermoelectric alloys and conductive polymers will migrate from the high-temperature side to the low-temperature side, forming a potential difference. When the triboelectric material contacts with materials with different triboelectric properties, due to the triboelectric effect, electrons will transfer between the two, making one surface positively charged and the other surface negatively charged; when the two are separated, due to electrostatic induction, a potential difference will be generated in the external circuit, thereby generating current. While improving the efficiency of thermoelectric conversion, the present invention increases the triboelectric mechanism, improves energy utilization and electrical output power.

[0025] When the triboelectric-thermoelectric composite cement-based material provided by the present invention is used in an energy conversion and collection device, the coupling method of the two energy collection mechanisms of thermoelectricity and triboelectricity is adopted, which effectively improves the overall energy utilization rate, has high output power, and ensures the stable operation of the system under different working conditions. At the same time, the system has strong environmental adaptability and can be unaffected by extreme conditions. For example, in the presence of a temperature difference, the triboelectric material and the cement-based thermoelectric material in the triboelectric-thermoelectric composite cement-based material can achieve a higher energy conversion efficiency under their respective conditions; and in the absence of a significant temperature difference, the triboelectric material can still continuously supply power through mechanical energy conversion.

[0026] When the triboelectric-thermoelectric composite cement-based material provided by the present invention is used in a self-powered cathodic protection structure, the triboelectric-cement-based thermoelectric structure acts as a self-powered device, and simultaneously couples the two self-powered mechanisms of thermoelectricity and triboelectricity, thereby improving the overall energy utilization rate and ensuring the stable operation of the steel bar cathodic protection under different working conditions. The triboelectric-thermoelectric coupling method solves the limitation of a small output voltage of a single temperature difference, and the triboelectric component can continuously power the steel bar cathodic protection by converting mechanical energy into electrical energy when the temperature difference is not obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the application of the triboelectric-cement-based thermoelectric structure as a self-powered cathode protection structure in an application example of the present invention;

[0028] Figure 2 A schematic diagram of the application of the triboelectric-cement-based thermoelectric structure as an energy conversion and collection device in an application example of the present invention;

[0029] Figure 3 is a graph showing the relationship between the output voltage and frequency of the triboelectric layer in the triboelectric component in Application Example 1;

[0030] Figure 4 This is a graph showing the relationship between the output voltage and temperature of the cement-based thermoelectric component in Application Example 1. DETAILED DESCRIPTION

[0031] The present invention provides a triboelectric-thermoelectric composite cement-based material, comprising separately packaged cement-based thermoelectric materials and triboelectric materials;

[0032] The cement-based thermoelectric material comprises the following components by weight:

[0033]

[0034] The Seebeck coefficient of the nano thermoelectric alloy is 100-250 μV / K; the Seebeck coefficient of the conductive polymer is 5-60 μV / K;

[0035] The triboelectric material includes a triboelectric polymer and a curing agent.

[0036] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0037] The triboelectric-thermoelectric composite cement-based material provided by the invention comprises a cement-based thermoelectric material.

[0038] As an embodiment, the cement-based thermoelectric material includes the following components, measured by mass: 0.0005-0.002 parts of carbon nanomaterials, 0.05-0.1 parts of nano thermoelectric alloys, 0.005-0.02 parts of conductive polymers, 0.0001-0.002 parts of carbon nanomaterial dispersants, 0.001-0.015 parts of high-performance water reducers, 0.3-0.6 parts of water, and 1 part of cement.

[0039] As another embodiment, the cement-based thermoelectric material includes the following components: 0.001 to 0.0015 parts of carbon nanomaterials, 0.06 to 0.08 parts of nano thermoelectric alloys, 0.008 to 0.015 parts of conductive polymers, 0.001 to 0.0015 parts of carbon nanomaterial dispersants, 0.006 to 0.01 parts of high-performance water reducers, 0.4 to 0.5 parts of water, and 1 part of cement.

[0040] As an embodiment, the carbon nanomaterial includes one or more of carbon nanotubes, nano carbon black, graphene, redox graphene and carbon nanofibers, and in a specific embodiment, carbon nanotubes; the carbon nanotubes include single-walled carbon nanotubes and / or multi-walled carbon nanotubes, and in a specific embodiment, multi-walled carbon nanotubes; the diameter of the carbon nanomaterial is 8 to 15 nm, and in a specific embodiment, it is 8 to 10 nm, and the length is 8 to 14 μm, and in a specific embodiment, it is 10 to 12 μm. The carbon nanomaterial mainly plays a role in improving electrical conductivity. The amount range of the carbon nanomaterial provided by the present invention can improve electrical conductivity, but excessive amount will lead to uneven dispersion and is not conducive to electrical conductivity. Single-walled carbon nanotubes are more effective in improving electrical conductivity, but due to the high preparation cost, multi-walled carbon nanotubes are mostly used in cement-based materials. The diameter and length of single-walled and multi-walled carbon nanotubes will affect their dispersion. Too long or too thin are easy to entangle together, and too short or too thick are prone to agglomeration, which will have an adverse effect on their electrical conductivity.

[0041] As an embodiment, the conductive polymer includes one or more of polypyrrole (PPy), polyaniline (PANI), polythiophene (PTh) and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS), and in a specific embodiment, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate; the weight average molecular weight of the conductive polymer is 10000 to 50000 g / mol, and in a specific embodiment, it is 20000 to 50000 g / mol; the conductive polymer is conductive The polymer is applied in the form of an aqueous solution; the mass concentration of the conductive polymer in the aqueous solution is 1 to 1.7%, and in a specific embodiment, it is 1.3 to 1.7%; when the conductive polymer is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, the mass concentration of poly(3,4-ethylenedioxythiophene) in the aqueous solution of the conductive polymer is 1 to 1.7%, and in a specific embodiment, it is 1 to 1.5%; the Seebeck coefficient of the conductive polymer is 5 to 60 μV / K, and in a specific embodiment, it is 20 to 50 μV / K. The conductive polymer in the present invention can improve the dispersibility of carbon nanomaterials and enhance the conductivity. In PEDOT:PSS, PEDOT plays a conductive role, and PSS plays a role in assisting the dispersion of PEDOT. The poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate provided by the present invention is a finished product solution, wherein the mass concentration of poly(3,4-ethylenedioxythiophene) has the best conductivity within this range.

[0042] As an implementation mode, the nano thermoelectric alloy includes one or more of nano metal telluride and its solid solution, and in a specific embodiment, it is nano metal telluride; the nano metal telluride includes one or more of nano bismuth telluride, nano antimony telluride, nano cadmium telluride and nano tin telluride, and in a specific embodiment, it is nano bismuth telluride; the nano thermoelectric alloy is a powder with an average particle size of 50 to 100 nm, and in a specific embodiment, it is 60 to 80 nm; the Seebeck coefficient of the nano thermoelectric alloy is 100 to 250 μV / K, and in a specific embodiment, it is 180 to 200 μV / K. The nano thermoelectric alloy is used to enhance the potential difference under the action of temperature difference, improve the temperature difference power generation capacity of the material, and improve the thermoelectric performance.

[0043] As an embodiment, the preparation method of the nano-bismuth telluride (Bi2Te3) comprises the following steps: mixing bismuth oxide, tellurium dioxide, an organic solvent, a dispersant and an alkaline solution, and subjecting the obtained mixed solution to a solvothermal reaction to obtain nano-bismuth telluride; the organic solvent is ethylene glycol; the dispersant is polyvinyl pyrrolidone; the mass fraction of polyvinyl pyrrolidone in the mixed solution is 1.0-2.0%, and is 1.6% in a specific embodiment; the molar ratio of bismuth oxide to tellurium dioxide is 1:2.5-3.5, and is 1:3 in a specific embodiment; the total mass of bismuth oxide and tellurium dioxide is 1:2.5-3.5, and is 1:3 in a specific embodiment; the total mass of bismuth oxide and tellurium dioxide is 1:3 of the organic solvent; the mass of the mixed solution is 1:2.5- ... The volume ratio is 1g:(20-150)mL, and in a specific embodiment it is 1g:(50-120)mL; the alkaline solution is a sodium hydroxide solution; the concentration of the sodium hydroxide solution is 1-2mol / L, and in a specific embodiment it is 1mol / L; the total mass of the bismuth oxide and the tellurium dioxide to the volume ratio of the alkaline solution is 1g:(20-150)mL, and in a specific embodiment it is 1g:(50-120)mL; the temperature of the solvent thermal reaction is 200-250°C, and in a specific embodiment it is 210-230°C, and the insulation time is 3-5h, and in a specific embodiment it is 4h.

[0044] As an embodiment, it also includes: after the product obtained by the solvent thermal reaction is cooled to room temperature, the solid obtained by solid-liquid separation is washed, dried and crushed in sequence to obtain bismuth telluride nanopowder; the solid-liquid separation is centrifugation; the centrifugal speed is 3000-12000rpm, 5000-8000rpm in the specific embodiment, the time is 10-30min, 20min in the specific embodiment, the washing is washing with deionized water, anhydrous ethanol and isopropanol in sequence for 2-5 times, 3-4 times in the specific embodiment; the drying temperature is 60-100°C, 60-80°C in the specific embodiment; the drying time is 24-48h, 24-36h in the specific embodiment; the crushing is grinding; the crushing to a particle size of 20-200nm, 50-100nm in the specific embodiment.

[0045] As an embodiment, the carbon nano material dispersant includes one or more of polyvinyl pyrrolidone (PVP), sodium dodecylbenzene sulfonate (SDBS) and N-methyl pyrrolidone (NMP), and polyvinyl pyrrolidone is used in a specific embodiment. The carbon nano material dispersant in the present invention helps to improve the dispersibility of the carbon nano material in the aqueous solution, and the types and amounts of different dispersants are different. The dispersion effect is best when the mass ratio of the dispersant to the carbon nanotubes is 1:1.

[0046] As an embodiment, the high-performance water reducer includes one or more of a naphthalene-based water reducer, a polycarboxylate water reducer and an aminosulfonate-based water reducer, and in a specific embodiment, a polycarboxylate water reducer. Since the addition of carbon nanomaterials will thicken the cement paste, the addition of polycarboxylate water reducers can reduce the amount of water used, enhance fluidity and promote the dispersion of carbon nanomaterials.

[0047] As an embodiment, the cement includes one or more of Portland cement, aluminate cement, sulphoaluminate cement and ferroaluminate cement, and in the specific embodiment, Portland cement is used. Different types of cement can enhance the early strength, rapid setting or durability of the material.

[0048] As an embodiment, the water includes one or more of tap water, distilled water and deionized water, and in the specific embodiment, deionized water is used. Different water qualities in the present invention can meet the requirements of different preparation environments for water quality.

[0049] The triboelectric-thermoelectric composite cement-based material provided by the invention comprises a triboelectric material.

[0050] As an embodiment, the triboelectric material includes a triboelectric polymer and a curing agent.

[0051] As an embodiment, the triboelectric polymer includes one or more of polydimethylsiloxane (PDMS), perfluoroethylene propylene copolymer (FEP), polyethylene terephthalate resin (PET) and polytetrafluoroethylene (PTFE), and in a specific embodiment, it is polydimethylsiloxane; the weight average molecular weight of the triboelectric polymer is 1000 to 50000 g / mol, and in a specific embodiment, it is 2000 to 5000 g / mol. The triboelectric polymer is used to provide charge and electron transfer.

[0052] As an embodiment, the curing agent includes one or more of a silane coupling agent, benzoyl peroxide and a platinum catalyst, and in a specific embodiment, the curing agent is a platinum catalyst.

[0053] As an implementation mode, the mass ratio of the triboelectric polymer to the curing agent is 8 to 12:1, and in a specific embodiment, it is 10:1.

[0054] The triboelectric-thermoelectric composite cement-based material provided by the present invention realizes multi-source energy collection by combining the triboelectric effect and the thermoelectric effect, makes full use of various energy forms such as temperature difference, vibration and friction in the environment, and significantly improves the efficiency of electric energy output; it has a self-powered function and operates independently without an external power supply, reducing operating costs and improving reliability and environmental adaptability; the material design can adapt to complex environments such as extreme weather and remote areas, provide continuous protection for the steel bars in the concrete, and effectively extend the service life of the structure; at the same time, the design without an external power supply greatly reduces the risk of electric shock and reduces maintenance workload and costs.

[0055] The present invention also provides a method for preparing the triboelectric-thermoelectric composite cement-based material described in the above technical solution, comprising the following steps:

[0056] Firstly mixing carbon nanomaterials, nano thermoelectric alloys, conductive polymers, carbon nanomaterial dispersants, high-performance water reducing agents, cement and water to obtain the cement-based thermoelectric material;

[0057] The triboelectric polymer and the curing agent are mixed for a second time to obtain the triboelectric material.

[0058] The present invention first mixes carbon nano material, nano thermoelectric alloy, conductive polymer, carbon nano material dispersant, high-performance water reducing agent, cement and water to obtain the cement-based thermoelectric material.

[0059] As an embodiment, before the first mixing, the present invention sequentially pre-treats, dries and crushes the carbon nanomaterial; the pre-treatment is to place the carbon nanomaterial in a mixed acid solution for impurity removal; the mixed acid solution includes a mixed solution of nitric acid and sulfuric acid; the mass concentration of the nitric acid is 60-70%, 68% in a specific embodiment; the mass concentration of the sulfuric acid is 60-70%, 65% in a specific embodiment; the volume ratio of the nitric acid to the sulfuric acid is 3-4:1, 3:1 in a specific embodiment; the impurity removal time is 30-90min, 40-60min in a specific embodiment; the drying temperature is 60-100°C, 70-80°C in a specific embodiment; the drying time is 24-48h, 24-36h in a specific embodiment; the crushing is grinding; the crushing to a particle size D50 <25μm, D50 <20μm in a specific embodiment. The present invention removes residual impurities on the surface of the carbon nanomaterial by treating with a mixed acid solution.

[0060] As an embodiment, the first mixing is: dissolving the carbon nano material dispersant in part of water to obtain a carbon nano material dispersant aqueous solution;

[0061] The carbon nanomaterial and the carbon nanomaterial dispersant aqueous solution are mixed and subjected to a first ultrasonic dispersion treatment, the nano thermoelectric alloy is then added and subjected to a second ultrasonic dispersion treatment, and finally a conductive polymer and a polycarboxylate water reducer are added to obtain a nanomaterial dispersion liquid;

[0062] The cement and the remaining water are mixed for a first stirring, and the obtained cement-based material and the nano-material dispersion are mixed for a second stirring to obtain the cement-based thermoelectric material.

[0063] As an embodiment, the mass ratio of the partial water to the remaining water is 1:1-2, and in a specific embodiment it is 1:1.1-1.5; the temperature of the first ultrasonic dispersion treatment and the second ultrasonic dispersion treatment is independently 18-22°C, and in a specific embodiment it is 20°C, the ultrasonic energy is independently 90-150W / s, and in a specific embodiment it is 90-120W / s, and the time is independently 30-60min, and in a specific embodiment it is 40-60min; during the first ultrasonic dispersion treatment and the second ultrasonic dispersion treatment, the ultrasonic wave is separated by 1s every 5s.

[0064] As an embodiment, the first stirring rate is 100-120 rpm, 120 rpm in a specific embodiment, and the time is 1-2 min, 1 min in a specific embodiment; the second stirring rate is 240-250 rpm, 240 rpm in a specific embodiment, and the time is 3-5 min, 3 min in a specific embodiment.

[0065] The present invention secondly mixes the triboelectric polymer and the curing agent to obtain the triboelectric material.

[0066] As an embodiment, the second mixing is carried out under stirring conditions; the stirring rate is 100-1000rpm, 200-600rpm in a specific embodiment, and the time is 3-5min, 3min in a specific embodiment; after the second mixing, it also includes: degassing the sol obtained by the second mixing; the degassing is to vacuum the sol; the equipment used for the degassing is a vacuum degassing machine; the degassing time is 10-15min, 15min in a specific embodiment.

[0067] The present invention also provides the use of the triboelectric-thermoelectric composite cement-based material described in the above technical solution or the triboelectric-thermoelectric composite cement-based material prepared by the preparation method described in the above technical solution in a self-powered cathode protection structure and / or an energy conversion collection device.

[0068] The present invention also provides a self-powered cathode protection structure or energy conversion collection device, comprising a triboelectric component and a cement-based thermoelectric component connected in series and / or in parallel; the triboelectric component comprises a triboelectric layer and a first conductive layer 1 fixed on one side of the triboelectric layer, and a first conductive layer 2 separated from the triboelectric layer; the cement-based thermoelectric component comprises a cement-based thermoelectric fixture and a second conductive layer 1 and a second conductive layer 2 disposed on opposite end surfaces of the cement-based thermoelectric fixture; when connected in series and / or in parallel, the first conductive layer 1, the first conductive layer 2, the second conductive layer 1 and the second conductive layer 2 are connected by wires;

[0069] The material of the triboelectric layer is the triboelectric material in the triboelectric-thermoelectric composite cement-based material described in the above technical solution;

[0070] The material of the cement-based thermoelectric fixture is the cement-based thermoelectric material in the triboelectric-thermoelectric composite cement-based material described in the above technical solution.

[0071] As an embodiment, the first conductive layer 1 and the first conductive layer 2 are electrode sheets; the electrode sheets are aluminum foil, copper electrode sheets, gold electrode sheets or silver electrode sheets; the cross-sectional areas of the first conductive layer 1 and the first conductive layer 2 are the same as the cross-sectional area of ​​the triboelectric layer; the thickness of the first conductive layer 1 and the first conductive layer 2 is independently 1 to 2 mm, and 1 mm in a specific embodiment; the second conductive layer 1 and the second conductive layer 2 are electrodes; the electrodes are mesh copper mesh electrodes, aluminum electrodes, gold electrodes or silver electrodes; the thickness of the second conductive layer 1 and the second conductive layer 2 is independently 1 to 2 mm, and 1 mm in a specific embodiment. In the present invention, the first conductive layer and the second conductive layer can improve the charge conduction performance, are used to derive charge or transmit current, and are located between the protective layer and the triboelectric layer or cement-based thermoelectric firmware. The first conductive layer 2 transfers the charge generated by triboelectricity to the external circuit.

[0072] As an embodiment, the preparation method of the triboelectric component includes the following steps: the triboelectric material is evenly placed on a reverse mold sprayed with a release agent, and after drying, the mold is demolded to obtain the triboelectric layer, a first conductive layer 1 is fixed on one side of the triboelectric layer, and a first conductive layer 2 separated from the triboelectric layer is provided to obtain the triboelectric component; the release agent is an oily release agent and / or an emulsified oil release agent, and in a specific embodiment, it is silicone oil; the size of the reverse mold is 20-50mm×20-50mm×1-5mm, and in a specific embodiment, it is 40mm×40mm×1mm; the drying temperature is 60-80°C, and in a specific embodiment, it is 65-70°C, and the time is 2-12h, and in a specific embodiment, it is 8-12h; the fixing is carried out with conductive glue.

[0073] The triboelectric layer in the present invention serves as a triboelectric energy conversion module for capturing mechanical energy and converting it into electrical energy.

[0074] As an embodiment, the preparation method of the cement-based thermoelectric component comprises the following steps: placing a second conductive layer 1 and a second conductive layer 2 at both ends of the mold, then casting the cement-based thermoelectric material and sealing it, demolding it after curing, and curing and drying it in sequence to obtain the cement-based thermoelectric component; the size of the mold is 10-40mm×10-40mm×40-160mm, and in a specific embodiment is 10mm×10mm×40mm; the sealing is covering with a plastic film; the curing is in a closed environment at room temperature Standing; the curing time is 24 to 48 hours, and 24 to 36 hours in the specific embodiment; the curing is carried out in a closed environment at room temperature; the curing time is 3 to 28 days, and 7 to 14 days in the specific embodiment; the drying temperature is 50 to 80°C, and 60 to 70°C in the specific embodiment, and the time is 24 to 48 hours, and 24 to 36 hours in the specific embodiment; the room temperature is 18 to 22°C, and 20°C in the specific embodiment; the relative humidity in the closed environment is 85 to 95%, and 90% in the specific embodiment. The present invention does not specifically limit the shape of the cement-based thermoelectric component, which can be selected according to actual needs. In an embodiment of the present invention, the cement-based thermoelectric component is a P-type component. The cement-based thermoelectric components are connected by copper foil electrodes.

[0075] The cement-based thermoelectric firmware in the present invention is used as a thermoelectric energy conversion module to capture thermal energy and convert it into electrical energy.

[0076] As an embodiment, the triboelectric-cement-based thermoelectric structure further includes: a protective layer; the protective layer is an acrylic plate; the thickness of the protective layer is 0.5 to 2 mm, and in a specific embodiment, it is 1 mm; the protective layer is located outside the triboelectric components and cement-based thermoelectric components connected in series or in parallel. The present invention improves the mechanical strength and corrosion resistance of the triboelectric-cement-based thermoelectric structure through the protective layer, which is located at the outermost layer of the triboelectric-cement-based thermoelectric structure and is mainly used to protect the internal structure and prevent mechanical damage and environmental corrosion.

[0077] As an implementation mode, the protective layer is bonded to the cement-based thermoelectric fixture or the triboelectric component by double-sided tape; the double-sided tape is 3M double-sided tape.

[0078] As an implementation mode, when the triboelectric-thermoelectric composite cement-based material is used in a self-powered cathodic protection structure and / or in a structure, the application method is: the negative electrode of the triboelectric-cement-based thermoelectric structure is connected to the steel bars in the building structure, and the positive electrode is connected to the auxiliary anode; the auxiliary anode is a titanium mesh; and the connection is made with a wire.

[0079] Figure 1Schematic diagram of the application of the triboelectric-cement-based thermoelectric structure as a self-powered cathode protection structure in the application example of the present invention. Figure 1 It can be seen that the present invention connects cement-based thermoelectric components and triboelectric components in parallel as a self-powered cathodic protection structure. The triboelectric-cement-based thermoelectric structure in the present invention supports the integration of multiple cement-based thermoelectric components and triboelectric components in series, parallel or series-parallel, and is suitable for cathodic protection of concrete steel bars in highly corrosive environments such as coastal areas. This material system can be used alone or in conjunction with other external power supply equipment to achieve efficient and reliable cathodic protection effects, effectively extend the service life of concrete structures and reduce maintenance costs.

[0080] As an implementation mode, when the triboelectric-thermoelectric composite cement-based material is used in an energy conversion and collection device, the application method is: connecting the triboelectric-cement-based thermoelectric structure to an external circuit or load to collect energy or provide power to the external load; the connection is: connecting the first conductive layer 1 and the first conductive layer 2 to a rectifier bridge through a wire, and then connecting to an external circuit through a wire; the second conductive layer 1 and the second conductive layer 2 are directly connected to the external circuit through a wire.

[0081] Figure 2 Schematic diagram of the application of the triboelectric-cement-based thermoelectric structure as an energy conversion and collection device in the application example of the present invention. Figure 2 It can be seen that the present invention connects cement-based thermoelectric firmware and triboelectric components in series for application as an energy conversion and collection device. The present invention realizes the effective combination of triboelectric energy collection and thermoelectric energy collection by connecting multiple cement-based thermoelectric firmware and triboelectric components in series, in parallel, or in series-parallel combination. This composite structure can not only be used alone, but also in conjunction with other external power supply equipment to further improve the energy collection efficiency. The triboelectric-thermoelectric composite cement-based material composite triboelectric-thermoelectric multi-source energy collection method provided by the present invention enables the energy collection device prepared therewith to work stably in a variety of environments.

[0082] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0083] Example 1

[0084] 1) The preparation steps of cement-based thermoelectric components are as follows:

[0085] (1) Bismuth telluride (Bi2Te3) was prepared by a solvothermal method: 1.6% polyvinyl pyrrolidone (PVP), Bi2O3 (0.5 mmol), TeO2 (1.5 mmol) and 30 mL 1 mol / L NaOH solution were added to 30 mL ethylene glycol, and the resulting suspension was transferred to an autoclave and kept at 210°C for 4 h for a solvothermal reaction. After cooling to room temperature, the product was collected by centrifugation at a speed of 8000 rpm for 20 min. The solid was washed three times with deionized water, anhydrous ethanol and isopropanol in sequence, dried at 60°C for 24 h, and ground into a powder with an average particle size of 60 nm to obtain bismuth telluride nanopowder;

[0086] (2) 0.1 g of multi-walled carbon nanotubes (CNTs) with a diameter of 8 to 15 nm and a length of 8 to 14 μm were subjected to impurity removal in a mixed acid solution (60 wt% nitric acid and 65 wt% sulfuric acid in a volume ratio of 3:1) for 60 min, dried at 70°C for 24 h, and then ground to a D50 of <20 μm. The mixture was added to a total of 18 mL of an aqueous solution containing 0.1 g of SDBS, and then subjected to ultrasonic dispersion treatment at 20°C with an ultrasonic energy of 90 W / s for 60 min. The ultrasonic dispersion treatment was performed with an interval of 1 s for every 5 s of ultrasonic treatment. Then, 10 g of CNTs with an average particle size of 10 μm were added to the obtained CNT dispersion. 60nm bismuth telluride nanopowder (Seebeck coefficient is 200μV / K), and then ultrasonically dispersed at 20°C with 90W / s ultrasonic energy for 30min, the ultrasonic dispersion treatment is 1s interval every 5s of ultrasound, and finally a CNT mixed nano bismuth telluride dispersion is formed, and then 2mL of 1wt% poly (3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) aqueous solution (weight average molecular weight is 30000g / mol, Seebeck coefficient is 50μV / K) and 0.1g polycarboxylic acid water reducer are added thereto to obtain a nano material dispersion, which is set aside;

[0087] (3) adding 100 g of silicate cement and 20 mL of water into a slurry stirring pot, stirring at a low speed of 120 rpm for 1 min, then adding the above nanomaterial dispersion and stirring at a high speed of 240 rpm for 3 min to obtain a cement-based thermoelectric material;

[0088] (4) placing mesh copper mesh electrodes with a thickness of 1 mm at 10 mm from the ends of the prism mold of length, width and height = 10 mm × 10 mm × 40 mm as the second conductive layer 1 and the second conductive layer 2, respectively, casting the above-mentioned cement-based thermoelectric material with an electrode spacing of 30 mm, vibrating and smoothing, forming, and then covering with a plastic film, and standing in a sealed environment with a temperature of 20° C. and a relative humidity of 90% for 24 hours before demolding, and then continuing to cure for 7 days, and drying at 60° C. for 24 hours to obtain a cement-based thermoelectric component;

[0089] 2) The preparation steps of the triboelectric component are as follows:

[0090] (1) Pour polydimethylsiloxane (PDMS, weight average molecular weight 40000 g / mol) and curing agent (platinum catalyst) into a container at a mass ratio of 10:1, and stir at 600 rpm for 3 min to prepare PDMS sol;

[0091] (2) pouring the PDMS sol into a vacuum degassing machine and removing bubbles in the sol by vacuuming for 15 min until there are no more bubbles in the sol;

[0092] (3) Spray a layer of release agent (silicone oil) evenly on a mold with a size of 40 mm × 40 mm × 1 mm, pour the degassed PDMS sol evenly on the mold, and then put it in an oven and dry it at 70 ° C for 12 h until the PDMS sol is completely cured, and then demold it to obtain a triboelectric layer;

[0093] (4) Use scissors to cut an aluminum foil with a thickness of 1 mm into the same size as the triboelectric layer, and then use conductive glue to fix the aluminum foil on one side of the triboelectric layer as the first conductive layer 1, ensuring that the aluminum foil is in close contact with the triboelectric layer, and set another aluminum foil of the same size as the first conductive layer 2 separated from the triboelectric layer to obtain the triboelectric component.

[0094] Example 2

[0095] The difference from Example 1 is that PEDOT:PSS is replaced by PTh, and the remaining steps are the same as Example 1.

[0096] Example 3

[0097] The difference from Example 1 is that PDMS is replaced by PET, and the remaining steps are the same as Example 1.

[0098] Comparative Example 1

[0099] The difference from Example 1 is that the triboelectric component is removed and only the cement-based thermoelectric component is retained, and the remaining steps are the same as Example 1.

[0100] Comparative Example 2

[0101] The difference from Example 1 is that the cement-based thermoelectric component is removed and only the triboelectric component is retained, and the remaining steps are the same as Example 1.

[0102] Application Example 1

[0103] like Figure 1 As shown, the preparation of the triboelectric-cement-based thermoelectric structure is as follows:

[0104] (1) Fixing the aluminum foil and the triboelectric layer prepared in Example 1 in the triboelectric assembly with a fixture to ensure that they remain parallel during contact and separation, and then connecting the first conductive layer 1 and the first conductive layer 2 (aluminum foil) to an external circuit or load through a rectifier bridge with a wire, and monitoring the output voltage and current with an oscilloscope;

[0105] (2) One end of the cement-based thermoelectric component prepared in Example 1 was placed on the surface of a water bath for heating, and a heat sink was placed on the other end to maintain it near room temperature. The copper mesh was connected to a voltmeter to test the temperature difference between the two ends of the cement-based thermoelectric component;

[0106] (3) The triboelectric component prepared in Example 1 and the cement-based thermoelectric component were connected in series to form a triboelectric-thermoelectric module, and the positive and negative electrodes after the series connection were connected to the steel working electrode and the titanium mesh electrode containing 3.5 wt% NaCl concrete pore solution, respectively. The attenuation value of the depolarization potential, the stable value of the polarization resistance, and the corrosion current density were tested and calculated using an electrochemical workstation, which were 634 mV, 171.6 kΩ·cm, and 0.58 μA / cm, respectively. 2 .

[0107] Based on the fact that the triboelectric-cement-based thermoelectric structure can cause a large negative shift in the steel bar potential, a large polarization resistance, and a low corrosion current, it is shown that it can provide good protection against steel bar corrosion.

[0108] Application Example 2

[0109] like Figure 2 As shown, the cement-based thermoelectric component and the friction electric component in Example 1 are assembled in series, specifically: the protective layer (acrylic plate), the second conductive layer 2, the cement-based thermoelectric fixture, the second conductive layer 1, and the protective layer (acrylic plate) are bonded with 3M double-sided tape in order, the first conductive layer 2 and the protective layer (acrylic plate) are bonded with 3M double-sided tape, and the friction electric layer, the first conductive layer 1 and the protective layer (acrylic plate) are bonded with 3M double-sided tape in order, including two P-type cement-based thermoelectric fixtures connected with copper foil electrodes, the first conductive layer 1 and the first conductive layer 2 are connected to the rectifier bridge through a wire, and then connected to the external circuit through a wire; the second conductive layer 1 and the second conductive layer 2 are directly connected to the external circuit through a wire for energy collection.

[0110] Performance Testing

[0111] (1) Figure 3 The relationship between the output voltage and frequency of the triboelectric layer in the triboelectric component in Application Example 1. As can be seen from the figure, the maximum output AC voltage of the triboelectric layer using PDMS as the triboelectric polymer is 120V at a frequency of 2Hz.

[0112] (2) Figure 4The relationship between the output voltage and temperature of the cement-based thermoelectric component in Application Example 1 is shown in the figure. As can be seen from the figure, the maximum output voltage is 36mV when the temperature difference is 60°C.

[0113] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A triboelectric-thermoelectric composite cement-based material, characterized in that: Includes packaged cement-based thermoelectric materials and triboelectric materials; The cement-based thermoelectric material comprises the following components by weight: The Seebeck coefficient of the nano thermoelectric alloy is 100-250 μV / K; the Seebeck coefficient of the conductive polymer is 5-60 μV / K; The triboelectric material includes a triboelectric polymer and a curing agent.

2. The triboelectric-thermoelectric composite cement-based material according to claim 1, characterized in that: The nano thermoelectric alloy includes one or more of nano metal telluride and solid solutions thereof; the nano metal telluride includes one or more of nano bismuth telluride, nano antimony telluride, nano cadmium telluride and nano tin telluride.

3. The triboelectric-thermoelectric composite cement-based material according to claim 1, characterized in that: The carbon nanomaterial includes one or more of carbon nanotubes, nano carbon black, graphene, redox graphene and carbon nanofibers.

4. The triboelectric-thermoelectric composite cement-based material according to claim 1, characterized in that: The conductive polymer includes one or more of polypyrrole, polythiophene, polyaniline and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate.

5. The triboelectric-thermoelectric composite cement-based material according to claim 1, characterized in that: The triboelectric polymer includes one or more of polydimethylsiloxane, perfluoroethylene propylene copolymer, polyethylene terephthalate resin and polytetrafluoroethylene.

6. The triboelectric-thermoelectric composite cement-based material according to claim 1 or 5, characterized in that: The mass ratio of the triboelectric polymer to the curing agent is 8 to 12:

1.

7. The triboelectric-thermoelectric composite cement-based material according to claim 1, characterized in that: The carbon nanomaterial dispersant includes one or more of polyvinyl pyrrolidone, sodium dodecylbenzene sulfonate and N-methyl pyrrolidone.

8. The method for preparing the triboelectric-thermoelectric composite cement-based material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Firstly mixing carbon nanomaterials, nano thermoelectric alloys, conductive polymers, carbon nanomaterial dispersants, high-performance water reducing agents, cement and water to obtain the cement-based thermoelectric material; The triboelectric polymer and the curing agent are mixed for a second time to obtain the triboelectric material.

9. Use of the triboelectric-thermoelectric composite cement-based material according to any one of claims 1 to 7 or the triboelectric-thermoelectric composite cement-based material prepared by the preparation method according to claim 8 in a self-powered cathode protection structure and / or an energy conversion collection device.

10. A self-powered cathodic protection structure or energy conversion collection device, characterized in that: It comprises a triboelectric component and a cement-based thermoelectric component connected in series and / or in parallel; the triboelectric component comprises a triboelectric layer and a first conductive layer 1 fixed on one side of the triboelectric layer, and a first conductive layer 2 separated from the triboelectric layer; the cement-based thermoelectric component comprises a cement-based thermoelectric fixture and a second conductive layer 1 and a second conductive layer 2 disposed on opposite end surfaces of the cement-based thermoelectric fixture; when connected in series and / or in parallel, the first conductive layer 1, the first conductive layer 2, the second conductive layer 1 and the second conductive layer 2 are connected by wires; The material of the triboelectric layer is the triboelectric material in the triboelectric-thermoelectric composite cement-based material according to any one of claims 1 to 7 or the triboelectric material in the triboelectric-thermoelectric composite cement-based material prepared by the preparation method according to claim 8; The material of the cement-based thermoelectric fixture is the triboelectric-thermoelectric composite cement-based material described in any one of claims 1 to 7 or the cement-based thermoelectric material in the triboelectric-thermoelectric composite cement-based material prepared by the preparation method described in claim 8.

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