Self-generating device based on radiation refrigeration and photo-thermal material

Abstract

The invention belongs to the technical field of new energy and energy conservation, and relates to a self-generating device based on radiation refrigeration and photo-thermal materials, which comprises a greenhouse, a photo-thermal film layer, a radiation cooling film layer and a thermoelectric conversion component, and is characterized in that the thermoelectric conversion component sequentially comprises an upper heat conduction layer, a thermoelectric device and a lower heat conduction layer from top to bottom; the thermoelectric device comprises at least one thermoelectric unit, and each thermoelectric unit comprises a thermoelectric gel electrolyte and electrodes arranged on the two sides of the thermoelectric gel electrolyte. The radiation cooling film serves as the cold end of the thermoelectric conversion assembly, the photo-thermal material serves as the hot end, the generated temperature difference is converted into electromotive force through the thermoelectric gel electrolyte, and then electric energy is generated; the whole thermoelectric power generation device is simple in structure, low in cost and good in cyclic utilization effect, achieves daytime heat collection and all-weather refrigeration, improves the energy utilization efficiency, and can be used as a green and sustainable power supply for supplying power to electronic products.

Description

Technical Field

[0001] The present invention belongs to the field of new energy and energy-saving technology, relates to the comprehensive utilization of thermal energy and electrical energy, and particularly relates to a self-generating device based on radiation refrigeration and photothermal materials. Background Art

[0002] With the decreasing fossil fuels, solar energy has become an important part of human energy. As a clean and renewable energy, solar energy is both a primary energy source and a renewable energy source. It is an ideal alternative to fossil fuels and has been widely used in various fields. As an emerging green and environmentally friendly power generation method, solar thermal power conversion technology has the characteristics of simple structure, no noise, no pollution, etc., and has broad development prospects, but its disadvantage is that it is unstable and requires sunlight to work normally, otherwise it will affect the quality of electricity.

[0003] Radiative cooling technology is a passive cooling technology that consumes no energy and emits no greenhouse gases. It uses materials to spontaneously dissipate their own heat through the atmospheric transparent window with a wavelength of 8-13μm to the cold outer space, and reflects sunlight with a wavelength range of about 0.3-2.5μm back, thereby achieving spontaneous cooling of the surface of buildings or other equipment. This technology is expected to replace the refrigeration system based on air compression, which will have a significant impact on the world's energy structure and global climate change.

[0004] If radiative cooling power generation is combined with solar power generation, it is possible to cool down the solar power generation equipment while also generating some additional electricity, which can provide all-weather power for micro and small devices such as automatic radio receiving devices, automatic weather forecast stations, microwave relay stations and unmanned navigation lights. However, the power generation efficiency of current power generation devices that use temperature difference to generate electricity still has room for further improvement. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of existing radiation refrigeration devices and solar temperature difference power generation systems, and to provide a high-efficiency integrated system that can perform all-weather thermoelectric conversion. A photothermal film is used as the hot end of the thermoelectric device to improve the utilization rate of solar energy; a radiation cooling film with high refrigeration efficiency is used as the cold end, with a simple structure and good recycling effect; the thermoelectric gel with a high Seebeck coefficient has good thermoelectric conversion efficiency.

[0006] The technical solution adopted by the present invention to achieve the above-mentioned purpose is as follows:

[0007] A self-generating device based on radiation cooling and photothermal materials, comprising a photothermal film layer, a radiation cooling film layer and a thermoelectric conversion component, wherein the thermoelectric conversion component comprises an upper heat-conducting layer, a thermoelectric device and a lower heat-conducting layer from top to bottom, wherein the thermoelectric device comprises at least one thermoelectric unit, wherein the thermoelectric unit comprises a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte; wherein the upper heat-conducting layer is arranged adjacent to the photothermal film layer, and the lower heat-conducting layer is arranged adjacent to the radiation cooling film layer. The present invention adopts the technical scheme, and uses the photothermal film as the hot end of the thermoelectric conversion component and the radiation cooling film as the cold end of the thermoelectric conversion component to form a temperature difference at both ends of the thermoelectric conversion component. The temperature difference thus generated is converted into an electromotive force by the thermoelectric unit in the thermoelectric conversion component, thereby generating electric energy; the entire temperature difference power generation device has a simple structure, low cost, good recycling effect, can realize daytime heat collection and all-weather cooling, improve energy utilization efficiency, and can be used as a green and sustainable power source for powering electronic products.

[0008] Preferably, the radiation cooling film of the radiation cooling film layer is a composite film with a reflectivity of not less than 90% in the solar spectrum range and an infrared emissivity of not less than 90% in the atmospheric window; more preferably, the radiation cooling film is composed of organic polymers and inorganic micro-nano particles, and is bonded to one end of the thermoelectric conversion component through thermal conductive silicone grease, and attached to the surface of the lower thermal conductive layer of the thermoelectric conversion component as a cold end. More preferably, the layer thickness of the radiation cooling film layer is 120-170μm.

[0009] Preferably, the organic polymer contains functional groups / bonds such as CO, CN and CY (where Y represents a halogen element, such as F, Cl and Br), has strong absorption due to bending vibration at 7-16 μm, and can be used as an ideal material for radiation cooling, and is more preferably selected from at least one of polyvinylidene fluoride, poly(vinylidene fluoride-co-hexafluoropropylene), polyethylene oxide, polylactic acid, and polytetrafluoroethylene. The inorganic micro-nano particles with a diameter of 10 nm to 100 nm have low solar absorptivity and high solar reflectivity (wide bandgap), and are more preferably selected from at least one of silicon dioxide, titanium dioxide, aluminum oxide, barium sulfate, and calcium carbonate.

[0010] Preferably, the upper heat-conducting layer and the lower heat-conducting layer are thermal grease. More preferably, the thermal grease is selected from commercial thermal grease, more preferably Thermalright TF8 thermal grease, with a thermal conductivity of 13.8 W / (m*K).

[0011] Preferably, the absorbance of the photothermal film layer under the solar absorption spectrum is not less than 90%; more preferably, the preferred layer thickness of the photothermal film layer is 10 to 30 μm; more preferably, the photothermal material of the photothermal film layer is selected from at least one of multi-walled carbon nanotubes, single-layer MXene, graphene, carbon black, copper-zinc particles, carbon fibers, and carbonized lignin nanoparticles.

[0012] Preferably, the thermoelectric gel electrolyte comprises a redox pair with a high Seebeck coefficient, a water-soluble polymer and a conductive polymer, wherein the feed ratio of the redox pair: the water-soluble polymer: the conductive polymer is (5-20): (10-40): (1-10) by mass. Good thermoelectric performance is provided by using a conductive polymer as a conductive matrix and introducing a redox pair with a high Seebeck coefficient, and adding a water-soluble polymer to form a cross-linked conductive network structure, which can maintain a certain shape and has a high degree of flexibility, biocompatibility and excellent mechanical properties. More preferably, the high Seebeck coefficient of the redox pair is not less than 0.6mVK -1 .

[0013] Preferably, the conductive polymer of the thermoelectric gel electrolyte is selected from at least one of polythiophene, polyaniline, polypyrrole, polyacetylene, and polyvinylene, the water-soluble polymer is selected from at least one of polyvinyl alcohol and polyacrylamide, and the redox couple is selected from SO 4 2- and SO 3 2- 、[Fe(CN) 6 ] 3- and [Fe(CN) 6 ] 4- ,I - and I 3 - , Fe 2+ and Fe 3+ At least one of.

[0014] Preferably, the electrode comprises a metal copper sheet.

[0015] Preferably, a greenhouse is arranged above the photothermal film layer, and the greenhouse is composed of a chamber formed by the photothermal film layer and organic glass, and a greenhouse material filled in the chamber. More preferably, the greenhouse material includes at least one of a greenhouse gas and a phase-change heat storage material; more preferably, the greenhouse gas or the phase-change heat storage material includes at least one of carbon dioxide, water vapor, methane, carbon monoxide, ozone, and liquid paraffin. By adding an organic glass shell to the hot-end photothermal film layer, a greenhouse is formed, so that the temperature of the hot end is increased, and the power generation efficiency is further improved.

[0016] Preferably, the self-generating device also includes a heat-insulating bracket for support.

[0017] Preferably, the surface of the thermal insulation bracket is provided with a thermal insulation layer for blocking the heat exchange between the thermal insulation bracket and the thermoelectric conversion component. More preferably, the thermal insulation layer comprises at least one of glass fiber, polyurethane, polystyrene, and aluminum silicate.

[0018] Preferably, the self-generating device based on radiation cooling and photothermal materials described in the present invention comprises: a radiation cooling film layer, a photothermal film layer and a thermoelectric conversion assembly, the thermoelectric conversion assembly comprises an upper heat-conducting layer, a thermoelectric device and a lower heat-conducting layer arranged in sequence from top to bottom, the thermoelectric device is composed of one or more thermoelectric units in parallel or in series, the non-connecting end electrode conductor is in contact with the upper heat-conducting layer, the connecting end electrode conductor is in contact with the lower heat-conducting layer, the thermoelectric unit comprises a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte; the upper heat-conducting layer is in contact with the photothermal film layer, and the lower heat-conducting layer is in contact with the radiation cooling film layer. The self-generating device also comprises a greenhouse arranged above the photothermal film layer and a heat-insulating bracket crossing the thermoelectric conversion assembly.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The present invention is a new type of power generation method that uses solar photovoltaic renewable energy and atmospheric ambient temperature to generate electricity. It does not require electricity or other traditional energy sources, is clean and energy-free. At the same time, the device can form a large temperature difference at both ends of the thermoelectric conversion component to generate a large electromotive force.

[0021] 2) The use of a dual-effect system of photothermal material heat collection / radiant cooling can achieve daytime heat collection and all-weather cooling, realize the multifunctional, all-weather and cross-seasonal use of the device, and improve the comprehensive energy utilization efficiency.

[0022] 3) Using radiation cooling material as the cold end, it has both refrigeration function and more diverse functions.

[0023] 4) Thermoelectric gel electrolyte thermoelectric devices are used to replace the thermoelectric metal sheets in previous thermoelectric power generation devices, which have a wider range of application scenarios.

[0024] 5) The device is simple, low cost and high efficiency. It can solve the shortcomings of solar absorption refrigeration, such as the inability to operate at night, low efficiency of radiation refrigeration during daytime operation, and high temperature of the cold source. It has a broader market application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the self-generating device described in the present invention; in the figure, 1-photothermal film layer, 2-radiative cooling film layer, 3-thermoelectric device, 4-upper heat conducting layer, 5-lower heat conducting layer, 6-greenhouse, 7-thermal insulation bracket, 8-voltage amplifier, 9-load.

[0026] Figure 2 Schematic diagram of a thermoelectric device unit. DETAILED DESCRIPTION

[0027] In order to better clarify and understand the purpose, process scheme and advantages of the present invention, the technical scheme and implementation method of the present invention are further described clearly, completely and in detail through specific embodiments and in combination with the accompanying drawings. It should be noted that the embodiments described in the present invention are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operating processes are given, but they are only part of the embodiments of the present invention, not all of the embodiments. The specific implementation methods described are limited to explaining and interpreting the present invention, and do not limit the present invention. Based on the embodiments in the present invention, all other implementation methods obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] The experimental methods and conditions used in the following examples are conventional methods and conventional conditions unless otherwise specified. The materials, reagents or instruments used in the examples, unless otherwise specified, can be obtained from commercial sources or prepared by conventional methods. The reaction conditions embodied in the content of the invention of the present invention can achieve the reaction and obtain the product with the expected effect. Due to space limitations, some embodiments are listed below to further illustrate the advantages of the technical solution of the present invention.

[0029] like Figure 1 As shown, in one embodiment of the present invention, a self-generating device based on radiation cooling and photothermal materials is provided, comprising a photothermal film layer 1, a radiation cooling film layer 2 and a thermoelectric conversion component, wherein the thermoelectric conversion component comprises an upper heat conducting layer 4, a thermoelectric device 3 and a lower heat conducting layer 5 arranged from top to bottom. The thermoelectric device 3 comprises at least one thermoelectric unit, such as Figure 2 As shown, the thermoelectric unit includes a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte; the thermoelectric gel electrolyte provides good thermoelectric performance by introducing a redox pair with a high Seebeck coefficient, and adds a water-soluble polymer to form a cross-linked network structure to obtain excellent mechanical properties; the self-generating device also includes a greenhouse 6 arranged above the hot end (photothermal film layer) of the thermoelectric conversion component, and the greenhouse 6 is composed of a photothermal film layer 1 and organic glass, and the size can be selected to be 15cm×5cm×5cm; the self-generating device is also provided with an insulating bracket 7 supporting the thermoelectric conversion component, and the supporting column of the insulating bracket 7 supports the device of the present invention to a certain height, on the one hand to achieve the purpose of heat dissipation, on the other hand to effectively perform radiation heat exchange with the atmospheric window.

[0030] Preferably, the upper and lower surfaces of the hot and cold ends of the thermoelectric conversion component are connected with thermocouples in sequence, so that the temperature and temperature difference of the hot end (photothermal film layer end) and the cold end (radiative cooling film layer end) can be obtained in real time, and the current and voltage generated in the circuit after passing through the voltage amplifier can be measured by a multimeter.

[0031] The method for preparing the thermoelectric gel electrolyte is preferably as follows: dissolve 10 to 40 wt% (mass percentage in the thermoelectric gel electrolyte) of a water-soluble high molecular polymer in 50 to 100 ml of deionized water, and stir at 50 to 100° C. to fully dissolve the material. Then, add 10 to 30 ml of a 0.25M to 2.5M redox couple solution. When the solution becomes transparent, slowly inject 1 to 10 wt% (mass percentage in the thermoelectric gel electrolyte) of a conductive polymer and continue stirring to prepare a thermoelectric gel electrolyte. When the gel solution becomes uniform, it can be customized into the desired shape using different molds.

[0032] Since the radiation cooling film has a high infrared emissivity in the atmospheric window (8-14μm) band, it converts heat into electromagnetic waves of a specific band without inputting any external energy, and directly transfers the heat of the object through the "atmospheric window" to the outer space in the form of radiation, thereby achieving the purpose of cooling and obtaining a lower temperature. Therefore, using functional materials with high emissivity and low solar absorption to reduce the surface temperature can effectively achieve passive radiation cooling, making the cold end of the thermoelectric conversion component lower than the atmospheric environment temperature.

[0033] The photothermal film formed by the photothermal material is attached to the upper surface of the upper thermal conductive layer 4, and has a high visible light absorption rate and a high photothermal conversion efficiency of 90 to 98%. It converts solar energy into heat and increases the temperature of the substrate surface under sunlight irradiation to achieve the required temperature difference.

[0034] Preferably, the preparation method of the radiation cooling film layer and the photothermal film layer is preferably as follows:

[0035] (1) coating a thermal conductive silicone grease on a carrier and allowing it to stand to form a thermal conductive layer;

[0036] (2) preparing a corresponding precursor solution; wherein:

[0037] The precursor solution of the radiation cooling film is prepared by dissolving an organic polymer in an organic solvent at a temperature of 40 to 80°C, and then adding water at a mass ratio of organic polymer: organic solvent: water = 1:20 to 40:1. The organic solvent is preferably selected from one or a combination of ethyl acetate, acetone, acetonitrile, and N,N-dimethylformamide. Then, 10 to 30 wt% of micro-nano particles are added and stirred vigorously for 4 hours to prepare a uniformly mixed precursor solution;

[0038] The precursor solution of the photothermal film layer includes: dissolving a photothermal material such as MXene or a hydroxylated carbon-based material in water, and obtaining a uniform suspension by stirring and ultrasonication;

[0039] (3) Pour the prepared precursor solution into the material tank and then spray it vertically on the thermal conductive surface. During spraying, the spraying distance of the spray gun is 200-250 cm, the air pressure of the nozzle is 5-6 MPa, and the discharge flow rate of the precursor solution is controlled at 5-6 mLs -1 Maintain a fixed height and spray at a constant speed to ensure uniform coating;

[0040] (4) After spraying, the finished product is placed in a fume hood (25°C) for 4 hours, and then transferred to a forced air oven and kept at 35°C for 2 hours to remove excess moisture; forming a radiation cooling film layer or a photothermal film layer adhered to the thermal conductive layer.

[0041] In one embodiment of the present invention, a greenhouse 6 is further provided above the photothermal material film, which can further increase the temperature of the hot end of the thermoelectric device, thereby increasing the temperature difference. The near-infrared radiation in the solar spectrum can penetrate the glass and reach the inner surface of the greenhouse. The greenhouse gas filled in the greenhouse has a strong near-infrared radiation absorption capacity, and will then transmit the energy upward to the atmosphere in the greenhouse in the form of long-wave radiation. The long-wave radiation cannot penetrate the glass, and a large amount of heat is accumulated in the atmosphere in the greenhouse. The atmosphere inside and outside the greenhouse is blocked by the glass and cannot conduct heat transfer, so that the heat remains in the greenhouse to achieve a heat preservation effect, and through contact and heat exchange with the photothermal film layer, the hot end temperature is further indirectly increased.

[0042] Greenhouse gas can be introduced into the chamber of greenhouse 6 or phase change heat storage material can be added. The greenhouse gas will absorb and release infrared radiation to preserve infrared thermal energy. When the phase change heat storage material reaches the phase change temperature, it will release the phase change latent heat, further aggravating the greenhouse effect caused by light and heat, thereby aggravating the temperature difference.

[0043] In one embodiment of the present invention, a thermal insulation bracket 7 is provided to support the self-generating device. An insulating layer is provided on the surface of the thermal insulation bracket 7, and the thermal insulation bracket 7 crosses the thermoelectric conversion component, which can prevent the heat generated by the hot end of the thermoelectric conversion component from being transferred to the cold end of the radiation cooling film, thereby preventing the cooling efficiency of the cold end from being affected.

[0044] In one embodiment of the present invention, the upper and lower heat-conducting layers are thermally conductive silicone grease, which connects the thermoelectric conversion component and the radiation cooling film and the photothermal material film to ensure that the film does not fall off. The thermally conductive silicone grease is a highly thermally conductive insulating silicone material that almost never solidifies and can maintain a grease state for a long time at a temperature of -50°C to +230°C. It has both excellent electrical insulation and excellent thermal conductivity, and at the same time has stable chemical and physical properties, and is resistant to high and low temperatures, water, ozone, and weather aging.

[0045] The working principle of the device of the present invention is that when the sun is used as a heat source to irradiate sunlight onto the surface of the photothermal film layer 1, the temperature of the hot end will rise rapidly under the action of the greenhouse 6 and the photothermal material film, and the radiation cooling film layer 2 will quickly dissipate heat on the lower surface of the lower heat conductive layer 5 to form a cold end. Due to a certain temperature difference between the upper and lower surfaces of the thermoelectric conversion component 3, a certain potential difference is generated in the loop, that is, current is generated. The greater the temperature difference, the greater the output electrical energy. After amplification by the voltage amplifier 8 through the closed current loop, it can be connected to the load 9.

[0046] Example 1

[0047] A self-generating device based on radiation cooling and photothermal materials, comprising a multi-walled carbon nanotube photothermal film layer 1 (film thickness of about 30 μm, absorbance under the solar absorption spectrum close to 97%), a radiation cooling film layer 2 composed of polyethylene oxide and barium sulfate (film thickness of about 160 μm, average pore diameter of about 1.2 μm; solar spectrum reflectivity average 96%) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer to connect the corresponding film and the thermoelectric device, the self-generating device also includes a CO2-filled 2 The greenhouse 6 (size is 15cm×5cm×5cm) and the polyurethane insulation bracket 7, the thermoelectric conversion assembly is composed of an upper heat-conducting layer 4, a thermoelectric device 3, and a lower heat-conducting layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, and any thermoelectric unit includes a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte. The thermoelectric gel electrolyte uses polythiophene as a conductive matrix and polyvinyl alcohol as a conductive network. SO 4 2- and SO 3 2- As redox pairs, 12 pairs of thermoelectric units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0048] Example 2

[0049] A self-generating device based on radiation cooling and photothermal materials, comprising a single-layer MXene photothermal film layer 1 (film thickness of about 20 μm, absorbance under the solar absorption spectrum close to 98%), a radiation cooling film layer 2 composed of polyvinylidene fluoride and aluminum oxide (film thickness of about 156 μm, average pore diameter of about 1.2 μm; average solar spectrum reflectivity of 95%) and a thermoelectric conversion component, thermal conductive silicone grease as a thermal conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size of 15 cm×5 cm×5 cm) filled with water vapor and a glass fiber insulation bracket 7 arranged above the single-layer MXene photothermal film, the thermoelectric conversion component is composed of an upper thermal conductive layer 4, a thermoelectric device 3, and a lower thermal conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte uses polyaniline as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0050] Example 3

[0051] A self-generating device based on radiation cooling and photothermal materials, comprising a graphene photothermal film layer 1 (film thickness of about 25 μm, absorbance under the solar absorption spectrum close to 97%), a radiation cooling film layer 2 composed of poly (vinylidene fluoride-co-hexafluoropropylene) and silicon dioxide (film thickness of about 140 μm, average pore diameter of about 1.2 μm; solar spectrum reflectivity of 96% on average) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer connecting the corresponding film and the thermoelectric conversion component, and the self-generating device also includes The invention comprises an organic glass greenhouse 6 (with a size of 15 cm×5 cm×5 cm) filled with methane and a polystyrene insulation bracket 7 arranged above the graphene photothermal film. The thermoelectric conversion assembly comprises an upper heat-conducting layer 4, a thermoelectric device 3, and a lower heat-conducting layer 5 from top to bottom. The thermoelectric device 3 comprises 12 pairs of thermoelectric units connected in series. Any thermoelectric unit comprises a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte. The thermoelectric gel electrolyte 3 comprises polypyrrole as a conductive matrix and polyacrylamide as a conductive network. - and I 3 - As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0052] Example 4

[0053] A self-generating device based on radiation cooling and photothermal materials, comprising a carbon black photothermal film layer 1 (film thickness of about 17 μm, absorbance under the solar absorption spectrum close to 95%), a radiation cooling film layer 2 composed of polylactic acid and calcium carbonate (film thickness of about 170 μm, average pore diameter of about 1.2 μm; average solar spectrum reflectivity of 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a thermal conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size of 15 cm×5 cm×5 cm) filled with liquid paraffin and an aluminum silicate insulation bracket 7 arranged above the carbon black photothermal film, the thermoelectric conversion component is composed of an upper thermal conductive layer 4, a thermoelectric device 3, and a lower thermal conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyacetylene as a conductive matrix and polyvinyl alcohol as a conductive network, Fe 2+ and Fe 3+ As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0054] Example 5

[0055] A self-generating device based on radiation cooling and photothermal materials, comprising a photothermal film layer 1 composed of copper-zinc particles (film thickness is about 28 μm, and the absorbance under the solar absorption spectrum is close to 97%), a radiation cooling film layer 2 composed of polytetrafluoroethylene and titanium dioxide (film thickness is about 150 μm, average pore diameter is about 1.2 μm; average solar spectrum reflectivity is 95%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size is 15 cm×5 cm×5 cm) filled with ozone and a polyurethane insulation bracket 7 arranged above the copper-zinc photothermal film, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses poly(p-phenylene glycol) as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0056] Example 6

[0057] A self-generating device based on radiation cooling and photothermal materials, comprising a carbon fiber photothermal film layer 1 (film thickness of about 20 μm, absorbance under solar absorption spectrum close to 96%), a radiation cooling film layer 2 composed of polyvinylidene fluoride and aluminum oxide (film thickness of about 156 μm, average pore diameter of about 1.2 μm; solar spectrum reflectivity of 95% on average) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer to connect the corresponding film with the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size of 15 cm×5 cm×5 cm) filled with water vapor arranged above the carbon fiber photothermal film and a glass fiber insulation bracket 7, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyaniline as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0058] Example 7

[0059] A self-generating device based on radiation cooling and photothermal materials, comprising a single-layer MXene photothermal film layer 1 (film thickness of about 20 μm, absorbance under the solar absorption spectrum close to 98%), a radiation cooling film layer 2 composed of polylactic acid and calcium carbonate (film thickness of about 170 μm, average pore diameter of about 1.2 μm; average solar spectrum reflectivity of 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a thermal conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size of 15 cm×5 cm×5 cm) filled with methane and an aluminum silicate insulation bracket 7 arranged above the single-layer MXene photothermal film, the thermoelectric conversion component is composed of an upper thermal conductive layer 4, a thermoelectric device 3, and a lower thermal conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyacetylene as a conductive matrix, polyvinyl alcohol as a conductive network, Fe 2+ and Fe 3+ As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0060] Example 8

[0061] A self-generating device based on radiation cooling and photothermal materials, comprising a carbonized lignin nanoparticle photothermal film layer 1 (film thickness of about 23 μm, absorbance under solar absorption spectrum close to 94%), a radiation cooling film layer 2 composed of polytetrafluoroethylene and titanium dioxide (film thickness of about 150 μm, average pore diameter of about 1.2 μm; average solar spectrum reflectivity of 95%) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size of 15 cm×5 cm×5 cm) filled with carbon dioxide arranged above the carbonized lignin nanoparticles and a polyurethane insulation bracket 7, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses poly(p-phenylene glycol) as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0062] Example 9

[0063] A self-generating device based on radiation cooling and photothermal materials, comprising a single-layer MXene photothermal film layer 1 (film thickness of about 20 μm, absorbance under the solar absorption spectrum close to 98%), a radiation cooling film layer 2 composed of poly (vinylidene fluoride-co-hexafluoropropylene) and silicon dioxide (film thickness of about 150 μm, average pore diameter of about 1.2 μm; solar spectrum reflectivity of 96% on average) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer connecting the corresponding film and the thermoelectric conversion component, the self-generating device also includes a device A methane-filled organic glass greenhouse 6 (15 cm × 5 cm × 5 cm in size) and a polystyrene insulation bracket 7 are placed above the single-layer MXene photothermal film. The thermoelectric conversion assembly is composed of an upper thermal conductive layer 4, a thermoelectric device 3, and a lower thermal conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, and any thermoelectric unit includes a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte. The thermoelectric gel electrolyte 3 uses polyaniline as a conductive matrix and polyacrylamide as a conductive network. [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0064] Example 10

[0065] A self-generating device based on radiation cooling and photothermal materials, comprising a carbon black photothermal film layer 1 (film thickness of about 17 μm, absorbance under the solar absorption spectrum close to 95%), a radiation cooling film layer 2 composed of polyethylene oxide and barium sulfate (film thickness of about 160 μm, average pore diameter of about 1.2 μm; solar spectrum reflectivity average 96%) and a thermoelectric conversion component, thermal conductive silicone grease as a heat conductive layer connecting the corresponding film and the thermoelectric conversion component, the self-generating device also includes a carbon black photothermal film filled with CO 2 The organic glass greenhouse 6 (size is 15cm×5cm×5cm) and the polyurethane insulation bracket 7, the thermoelectric conversion assembly is composed of an upper heat-conducting layer 4, a thermoelectric device 3, and a lower heat-conducting layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, each of which includes a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte. The thermoelectric gel electrolyte 3 uses polyacetylene as a conductive matrix and polyvinyl alcohol as a conductive network. Fe 2+ and Fe 3+ As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 1 is only the presence or absence of the organic glass greenhouse 6.

[0068] A self-generating device based on radiation cooling and photothermal materials comprises a multi-walled carbon nanotube photothermal film layer 1 (film thickness is about 30 μm, and absorbance under solar absorption spectrum is close to 97%), a radiation cooling film layer 2 composed of polyethylene oxide and barium sulfate (film thickness is about 160 μm, average pore diameter is about 1.2 μm; average solar spectrum reflectance is 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also comprises a polyurethane insulation bracket 7, and the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 comprises 12 pairs of thermoelectric units connected in series, any thermoelectric unit comprises a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 comprises polythiophene as a conductive matrix, polyvinyl alcohol as a conductive network, SO 4 2- and SO 3 2- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0069] Comparative Example 2

[0070] The difference between Comparative Example 2 and Example 2 is only the presence or absence of the organic glass greenhouse 6.

[0071] A self-generating device based on radiation cooling and photothermal materials, comprising a single-layer MXene photothermal film layer 1 (film thickness of about 20 μm, absorbance under the solar absorption spectrum close to 98%), a radiation cooling film layer 2 composed of polyvinylidene fluoride and aluminum oxide (film thickness of about 156 μm, average pore diameter of about 1.2 μm; average solar spectrum reflectivity of 95%) and a thermoelectric conversion component, thermal conductive silicone grease as a thermal conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes a glass fiber insulation bracket 7, the thermoelectric conversion component is composed of an upper thermal conductive layer 4, a thermoelectric device 3, and a lower thermal conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyaniline as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0072] Comparative Example 3

[0073] The difference between Comparative Example 3 and Example 3 is only the presence or absence of the photothermal film layer 1.

[0074] A self-generating device based on radiation cooling and photothermal materials, comprising a radiation cooling film layer 2 composed of poly(vinylidene fluoride-co-hexafluoropropylene) and silicon dioxide (film thickness is about 140 μm, average pore diameter is about 1.2 μm; average solar spectrum reflectivity is 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size is 15 cm×5 cm×5 cm) filled with methane and arranged above the original photothermal film and a polystyrene insulation bracket 7, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polypyrrole as a conductive matrix and polyacrylamide as a conductive network, I - and I 3 - As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0075] Comparative Example 4

[0076] The difference between Comparative Example 4 and Example 4 is only the presence or absence of the photothermal film layer 1.

[0077] A self-generating device based on radiation cooling and photothermal materials, comprising a radiation cooling film layer 2 composed of polylactic acid and calcium carbonate (film thickness is about 170 μm, average pore diameter is about 1.2 μm; average solar spectrum reflectivity is 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size is 15 cm×5 cm×5 cm) filled with liquid paraffin and an aluminum silicate insulation bracket 7 arranged above the original photothermal film, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyacetylene as a conductive matrix, polyvinyl alcohol as a conductive network, Fe 2+ and Fe 3+ As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0078] Comparative Example 5

[0079] The difference between Comparative Example 5 and Example 5 is only the presence or absence of the radiation cooling film 2.

[0080] A self-generating device based on radiative cooling and photothermal materials, comprising a photothermal film layer 1 composed of copper-zinc particles (film thickness is about 28 μm, and absorbance under the solar absorption spectrum is close to 97%) and a thermoelectric conversion component, wherein thermal conductive silicone grease is used as a heat-conducting layer to connect the corresponding film and the thermoelectric conversion component, and the self-generating device also comprises an organic glass greenhouse 6 (with a size of 15 cm×5 cm×5 cm) filled with ozone and a polyurethane thermal insulation bracket 7 arranged above the copper-zinc photothermal film, wherein the thermoelectric conversion component is composed of an upper heat-conducting layer 4, a thermoelectric device 3, and a lower heat-conducting layer 5 from top to bottom; the thermoelectric device 3 comprises 12 pairs of thermoelectric units connected in series, wherein any thermoelectric unit comprises a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte, wherein the thermoelectric gel electrolyte 3 comprises poly(p-phenylene glycol) as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0081] Comparative Example 6

[0082] The difference between Comparative Example 6 and Example 6 is only the presence or absence of the radiation cooling film 2.

[0083] A self-generating device based on radiation cooling and photothermal materials, comprising a carbon fiber photothermal film layer 1 (film thickness is about 20 μm, and absorbance under the solar absorption spectrum is close to 96%) and a thermoelectric conversion component, thermal conductive silicone grease is used as a heat conductive layer to connect the corresponding film and the thermoelectric conversion component, the self-generating device also includes an organic glass greenhouse 6 (size is 15 cm×5 cm×5 cm) filled with water vapor and a glass fiber thermal insulation bracket 7 arranged above the carbon fiber photothermal film, the thermoelectric conversion component is composed of an upper heat conductive layer 4, a thermoelectric device 3, and a lower heat conductive layer 5 from top to bottom; the thermoelectric device 3 includes 12 pairs of thermoelectric units connected in series, any thermoelectric unit includes a thermoelectric gel electrolyte, and electrodes arranged on both sides of the thermoelectric gel electrolyte, the thermoelectric gel electrolyte 3 uses polyaniline as a conductive matrix and polyacrylamide as a conductive network, [FeCN 6 ] 3- and [FeCN 6 ] 4- As redox pairs, 12 pairs of thermoelectric integrated units are connected in series to output voltage signals, and the closed current loop can be connected to a load 9 after being amplified by a voltage amplifier 8 .

[0084] The thermoelectric gel electrolyte designed in each embodiment of the present invention takes a rectangular structure as an example, with an effective length of 2 cm, a width of 2 cm, and a thickness of 2 mm. The metal copper sheet is connected to the two ends of the thermoelectric gel electrolyte as an electrode. Fluke 15B+ is used to measure the resistance of the left and right ends of the thermoelectric gel electrolyte. The low-voltage power supply and temperature patrol meter YGX-300V-3A control the temperature difference between the left and right ends of the sample. Test conditions: Time: 10:30 am to 14:30 pm on September 17, 2024, location: Moganshan Campus of Zhejiang University of Technology, sunny weather, average solar irradiance 1560W / m 2 , air temperature 25.2 ~ 34.1 ℃, relative humidity 75%, the measured temperature difference and integrated thermoelectric power performance are shown in Table 1:

[0085] Table 1 Summary of performance of various embodiments and comparative examples

[0086]

[0087]

[0088] From the above comparison, it can be seen that the corresponding temperature difference and the output power of the integrated thermoelectric element of Comparative Examples 1 and 2 of the present invention are significantly better than those of Comparative Examples 3-6, which proves that the device of the present invention can form a larger temperature difference at both ends of the thermoelectric conversion component, generate a larger electromotive force, and have low cost and high efficiency; at the same time, on this basis, the embodiment of the present invention is equipped with a greenhouse, which can further significantly form a larger temperature difference and further improve the output power of the integrated thermoelectric element on the basis of Comparative Examples 1 and 2, and therefore has more significant advantages.

[0089] In addition, the performance of some embodiments of the present invention and comparative examples under the condition of no heat source at night was also tested. The test conditions were: time from 19:30 to 22:30 on September 17, 2024, location was Moganshan Campus of Zhejiang University of Technology, weather was a little cloudy, temperature was 28.1-32.0°C, average relative humidity was about 80%, and the measured temperature difference and integrated thermoelectric power performance were shown in Table 2:

[0090] Table 2 Summary of the performance of each embodiment and comparative example under the condition of no heat source at night

[0091]

[0092]

[0093] From the above comparison, it can be seen that in the absence of a heat source, the various embodiments of the present invention can maintain a temperature difference between 14.5 and 24.0°C, and the output power is between 0.76 and 1.71 μW. Since no greenhouse is set up for Comparative Examples 1 and 2, the temperature difference between the hot end and the cold end is about 2°C, and the output power of the integrated thermoelectric element is extremely weak. For Comparative Examples 3 and 4, a greenhouse is set up to store and preserve the solar heat obtained during the day, and the radiation cooling film can further reduce the temperature of the cold end, so a temperature difference of about 6°C can be maintained and a weak power can be output. For Comparative Examples 5 and 6, although there is a greenhouse to store heat but no radiation cooling film, the temperature difference is about 3°C, and only extremely weak power can be output.

[0094] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A self-generating device based on radiation cooling and photothermal materials, characterized in that: The invention comprises a photothermal film layer (1), a radiation cooling film layer (2) and a thermoelectric conversion component, wherein the thermoelectric conversion component comprises, from top to bottom, an upper heat-conducting layer (4), a thermoelectric device (3) and a lower heat-conducting layer (5), wherein the thermoelectric device (3) comprises at least one thermoelectric unit, and the thermoelectric unit comprises a thermoelectric gel electrolyte and electrodes arranged on both sides of the thermoelectric gel electrolyte; the upper heat-conducting layer (4) is arranged adjacent to the photothermal film layer (1), and the lower heat-conducting layer (5) is arranged adjacent to the radiation cooling film layer (2).

2. According to claim 1, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The radiation cooling film is a composite film with a reflectivity of not less than 90% in the solar spectrum range and an infrared emissivity of not less than 90% in the atmospheric window.

3. According to claim 2, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The layer thickness of the radiation cooling film layer (2) is 120-170 μm.

4. According to claim 2, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The radiation cooling film is composed of organic polymers and inorganic micro-nano particles; the organic polymer is selected from at least one of polyvinylidene fluoride, poly(vinylidene fluoride-co-hexafluoropropylene), polyethylene oxide, polylactic acid, and polytetrafluoroethylene, and the inorganic micro-nano particles are selected from at least one of silicon dioxide, titanium dioxide, aluminum oxide, barium sulfate, and calcium carbonate.

5. According to claim 1, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The absorbance of the photothermal film layer (1) under the solar absorption spectrum is not less than 90%.

6. According to claim 5, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The photothermal film layer (1) has a thickness of 10 to 30 μm.

7. According to claim 5, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The photothermal material of the photothermal film layer (1) is selected from at least one of multi-walled carbon nanotubes, single-layer MXene, graphene, carbon black, copper-zinc particles, carbon fibers, and carbonized lignin nanoparticles.

8. According to claim 1, a self-generating device based on radiation cooling and photothermal materials is characterized in that: The thermoelectric gel electrolyte comprises a redox pair with a high Seebeck coefficient, a water-soluble high molecular polymer and a conductive polymer.

9. The self-generating device based on radiation cooling and photothermal materials according to claim 8, characterized in that: The conductive polymer is selected from at least one of polythiophene, polyaniline, polypyrrole, polyacetylene and poly(p-phenylene). The water-soluble polymer is selected from at least one of polyvinyl alcohol and polyacrylamide. The redox pair is selected from SO4 2- and SO3 2- , [Fe(CN)6] 3- and [Fe(CN)6] 4- ,I - and I3 - , Fe 2+ and Fe 3+ At least one of.

10. The self-generating device based on radiation cooling and photothermal materials according to claim 1, characterized in that: A greenhouse (6) is arranged above the photothermal film layer (1), and the greenhouse (6) is composed of a chamber formed by the photothermal film layer (1) and organic glass, and a greenhouse material filled in the chamber.

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