Photovoltaic module based on electrochromic material

Abstract

The invention provides a photovoltaic module based on an electrochromic material, which comprises a high-strength transparent protective layer, a transparent conductive layer, an electrochromic layer, a thermal electrolyte layer, an ion storage layer, a photovoltaic active layer and a back plate which are arranged from top to bottom, and is characterized in that a back plate heat dissipation layer is arranged on the back plate; the device further comprises a microcontroller, a temperature sensor and a spectral intensity sensor, the temperature sensor is used for detecting the temperature of the surface of the assembly, the spectral intensity sensor and the temperature sensor are both in electric signal connection with the microcontroller, and the microcontroller is used for voltage regulation. The electrochromic layer is integrated in the photovoltaic module, and according to the surface temperature or spectral intensity of the photovoltaic module, the voltage is adjusted through the microcontroller, so that the electrochromic material is subjected to an electrochemical oxidation-reduction reaction under the action of an electric field, the optical characteristics of the electrochromic material are changed, the light transmittance / reflectivity is regulated and controlled in real time, and then the temperature control effect is achieved; and the stability of the photovoltaic module system is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaics and specifically relates to a photovoltaic component based on electrochromic materials. Background Art

[0002] Photovoltaic panels convert solar energy into usable electricity and are currently the most common way to utilize solar energy. Currently, the conversion efficiency of silicon-based photovoltaics at room temperature (25°C) is approximately 20%. Above 25°C, the output power decreases by approximately 0.3% to 0.5% for every 1°C increase in temperature. Long-term high or low temperatures can accelerate aging or reduce the power generation of components. For photovoltaic panels exposed to direct sunlight, the temperature can rise by up to 40°C, resulting in a relative efficiency drop of approximately 18%. This temperature effect, resulting in a reduction in photoelectric conversion efficiency, can significantly impact the actual production capacity of photovoltaic panels.

[0003] Currently, photovoltaic panel temperature control methods include active cooling and passive heat dissipation. Active cooling includes air cooling, water cooling, and phase change material cooling. Air cooling depends on ambient wind speed. In high temperatures and no wind, heat dissipation efficiency drops sharply, and fan energy consumption may offset power generation gains. In addition, airflow distribution is uneven across the panel surface, easily forming localized high-temperature areas (such as hot spots), which exacerbate battery aging. Water cooling requires the laying of water pipes, water pumps, and a circulation system, resulting in high initial investment (for example, the University of Malta's water cavity cooling technology nearly doubles the cost). It is only suitable for scenarios near water sources (such as offshore photovoltaics) and is difficult to promote in arid areas. Phase change material cooling is prone to failure due to repeated phase changes, requiring regular replacement, which increases operation and maintenance costs.

[0004] Passive cooling module structures provide insufficient heat dissipation. Traditional backsheets have a thermal conductivity of only 0.14W / m·K, far lower than glass (1.04W / m·K), leading to heat accumulation. While double-glass modules improve heat dissipation, they also increase weight and cost.

[0005] Electrochromic materials are functional materials whose optical properties (including reflectivity, transmittance, and absorptivity) undergo stable, reversible changes when driven by an applied electric field or current. This change manifests as a reversible shift in color and transparency. Essentially, the material undergoes an electrochemical redox reaction under the influence of an electric field, altering its chemical structure and triggering changes in its absorption spectrum. While research continues into the application of electrochromic materials in smart windows and display technologies, there are no reports on their application in temperature control for photovoltaic modules. Summary of the Invention

[0006] The purpose of the present invention is to provide a photovoltaic module based on electrochromic materials to solve the technical problems existing in the prior art. The module temperature is controlled by the uninterrupted power supply adjustment reaction of the microcontroller, thereby improving the problem of abnormal high temperature of the module due to long-term illumination.

[0007] To this end, the technical solutions provided by the present invention are as follows:

[0008] A photovoltaic module based on electrochromic materials, comprising a high-strength transparent protective layer, a transparent conductive layer, an electrochromic layer, a thermoelectrolyte layer, an ion storage layer, a photovoltaic active layer and a backplane arranged from top to bottom, wherein the backplane is provided with a backplane heat dissipation layer;

[0009] It also includes a microcontroller, a temperature sensor and a spectral intensity sensor. The temperature sensor is used to detect the temperature of the component surface. The spectral intensity sensor and the temperature sensor are both electrically connected to the microcontroller. After receiving data from the temperature sensor and / or the spectral intensity sensor, the microcontroller adjusts the power voltage generated by the photovoltaic component.

[0010] The transparent conductive layer is indium tin oxide, fluorine-doped tin oxide or aluminum-doped zinc oxide.

[0011] The electrochromic layer is made of tungsten trioxide, nickel oxide, titanium oxide, molybdenum oxide and vanadium pentoxide.

[0012] The thermal electrolyte layer is a solid electrolyte or a gel electrolyte.

[0013] The ion storage layer is a WO3 / NiO heterojunction.

[0014] The photovoltaic active layer is a single crystal silicon cell, a polycrystalline silicon cell or an amorphous silicon cell.

[0015] The backplane heat dissipation layer includes a high thermal conductivity material and a radiation cooling coating. The high thermal conductivity material is aluminum nitride or graphene. The radiation cooling coating is randomly stacked and fixed on the surface of the photovoltaic panel. The radiation cooling coating is an inorganic ceramic particle layer, and gaps are formed between the inorganic ceramic particles.

[0016] The inorganic ceramic particle layer is SiO2, TiO2 or Al2O3, and has a particle size of 50-150 nm. The inorganic ceramic particle layer includes various particle sizes.

[0017] The thickness of the transparent conductive layer is 50-100 nm, the thickness of the electrochromic layer is 100-500 nm, the thickness of the thermoelectrolyte layer is 500-5000 nm, and the thickness of the ion storage layer is 100-400 nm.

[0018] The thickness of the radiation cooling coating is 20-120 μm.

[0019] The beneficial effects of the present invention are:

[0020] The present invention integrates an electrochromic layer into a photovoltaic module. According to the surface temperature or spectral intensity of the photovoltaic module, the voltage is adjusted by a microcontroller, causing the electrochromic material to undergo an electrochemical redox reaction under the action of the electric field, thereby changing the optical properties of the electrochromic material, thereby controlling the transmittance / reflectivity in real time, achieving a temperature control effect, and improving the stability of the photovoltaic module system.

[0021] The present invention utilizes the electricity generated by photovoltaic power generation to be stored and supplied back and forth through a low-power battery to apply an external electric field to the color-changing material, thereby eliminating the need for additional power supply equipment and saving energy.

[0022] The present invention achieves cooling of photovoltaic modules through the cooperation of an electrochromic layer and a backplane heat dissipation layer. The high thermal conductivity material of the backplane heat dissipation layer can not only maintain stable performance in a high-temperature environment, but also quickly dissipate heat by radiation. The radiative cooling coating is thin and transparent. Applying it on the photovoltaic glass panel can increase the atmospheric window emissivity of its surface by about 10%, thereby improving the radiative cooling power of the photovoltaic panel and reducing the operating temperature of the photovoltaic panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the invention from the contents disclosed in this specification.

[0025] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the invention may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so as to provide a thorough and complete disclosure of the invention and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings are not intended to limit the invention.

[0026] Unless otherwise specified, the terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have meanings consistent with the context of their relevant fields and should not be interpreted as idealized or overly formal.

[0027] Example 1

[0028] The present invention provides a photovoltaic module based on electrochromic materials, comprising a high-strength transparent protective layer, a transparent conductive layer, an electrochromic layer, a thermoelectrolyte layer, an ion storage layer, a photovoltaic active layer and a backplane arranged from top to bottom, wherein the backplane is provided with a backplane heat dissipation layer;

[0029] It also includes a microcontroller, a temperature sensor and a spectral intensity sensor. The temperature sensor is used to detect the temperature of the component surface. The spectral intensity sensor and the temperature sensor are both electrically connected to the microcontroller. After receiving data from the temperature sensor and / or the spectral intensity sensor, the microcontroller adjusts the power voltage generated by the photovoltaic component.

[0030] The high-strength transparent protective layer is chemically strengthened glass with a thickness of 0.5-1.2mm and a light transmittance greater than 92%. The transparent conductive layer acts as an electrode, applying a regulated voltage to maintain a high light transmittance (85%).

[0031] The electrochromic layer undergoes redox reaction under voltage drive, changing the optical properties, thereby adjusting the transmittance / reflectivity in real time, thereby achieving a temperature control effect;

[0032] The hot electrolyte layer provides H + The ion migration channel supports the electrochromic reaction; during heat absorption, the absorbed heat is used to generate electricity and then provide power to the electric field. The ion storage layer balances the charge and enhances cycle stability; the photovoltaic active layer is the core layer for power generation; and the backplane heat dissipation layer is used to enhance passive heat dissipation.

[0033] Principle of the invention:

[0034] like Figure 1 As shown, the temperature sensor detects the surface temperature of the photovoltaic module in real time, and the spectral intensity sensor detects the spectral intensity in real time. When the temperature sensor detects that the surface temperature of the photovoltaic module exceeds the set value range, or the spectral intensity is weak, the temperature sensor or the spectral intensity sensor sends a signal to the microcontroller, and the microcontroller adjusts the voltage to cause the electrochromic material to undergo an electrochemical redox reaction under the action of the electric field, thereby changing the optical properties of the electrochromic material, thereby adjusting the transmittance / reflectivity in real time, thereby achieving a temperature control effect and balancing the stability of the photovoltaic module system.

[0035] Example 2

[0036] Based on Example 1, this example provides a photovoltaic module based on an electrochromic material, wherein the transparent conductive layer is indium tin oxide, fluorine-doped tin oxide, or aluminum-doped zinc oxide.

[0037] The transparent conductive layer in this embodiment is a metal oxide, and its conductivity mechanism relies primarily on intrinsic defects and impurity defects. Vacancies in the oxygen atom lattice of indium tin oxide (In2O3) lead to oxygen ion inequality, resulting in excess free electrons, which contribute to its conductivity. The addition of high-valent cations (Sn) increases the concentration of free electrons, further enhancing conductivity.

[0038] Example 3

[0039] Based on Example 1, this example provides a photovoltaic module based on an electrochromic material, wherein the electrochromic layer is one of viologen, polypyrrole, polyaniline, tungsten trioxide, nickel oxide, titanium oxide, molybdenum oxide or vanadium pentoxide.

[0040] Electrochromic materials refer to the phenomenon that the optical properties (reflectivity, transmittance, absorptivity, etc.) of the material undergo stable and reversible color changes under the action of an external electric field, which manifests itself as reversible changes in color and transparency.

[0041] Viologens, polypyrroles, and polyaniline are organic electrochromic materials with strong absorption bands in the visible light region. Viologen derivatives are cathodochromic materials. When a negative voltage is applied to them, they undergo a reduction reaction, changing their oxidation state and developing color. The fully oxidized state is stable, mostly appearing pale yellow. The singly oxidized state is color-shifting, with a maximum absorption wavelength in the visible light region. Upon absorbing visible light of a specific wavelength, it exhibits a strong complementary color. The fully reduced state, which has two electrons, has a low molar absorption coefficient and a less pronounced color.

[0042] Example 4

[0043] Based on Example 1, this example provides a photovoltaic module based on an electrochromic material, wherein the thermoelectrolyte layer is a solid electrolyte or a gel electrolyte.

[0044] The hot electrolyte layer provides H + Ion migration channels support the electrochromic reaction; during heat absorption, the absorbed heat is used to generate electricity, which in turn provides power to the electric field. The hot electrolyte layer exhibits regenerative reversibility when energized. In this embodiment, the electrolyte layer utilizes a polyvinyl alcohol (PVA)-phosphoric acid (H3PO4) gel electrolyte. PVA and H3PO4 are dissolved in deionized water at a mass ratio of 1:1, heated and stirred until uniform, and then coated on the surface of the electrochromic layer. Drying forms the electrolyte layer.

[0045] The ion storage layer is a WO3 / NiO heterojunction. The WO3 / NiO heterojunction combines the advantages of tungsten trioxide (WO3, an n-type semiconductor) and nickel oxide (NiO, a p-type semiconductor). The heterojunction creates new electronic states at the interface, broadening the photoresponse range. WO3 typically has a band gap of 2.6-2.8 eV, primarily absorbing ultraviolet and some visible light (blue / violet). NiO has a band gap of approximately 3.0-4.0 eV, also absorbing ultraviolet and some visible light. The energy band alignment formed at the heterojunction interface facilitates the injection of photogenerated electrons from the conduction band of NiO into the conduction band of WO3, and photogenerated holes from the valence band of WO3 into the valence band of NiO. This directional migration further promotes charge separation and improves the efficiency of visible light utilization. The ion storage layer and electrochromic layer can be interchanged.

[0046] The photovoltaic active layer is a single crystal silicon cell, a polycrystalline silicon cell or an amorphous silicon cell.

[0047] Specific working process:

[0048] The temperature sensor detects the surface temperature of the photovoltaic module in real time. When the temperature sensor detects that the surface temperature of the photovoltaic module exceeds the set value range, it sends a signal to the microcontroller. The microcontroller adjusts the voltage of the electrochromic layer to 1.5-3V, causing the electrochromic material to undergo an electrochemical redox reaction under the action of the electric field and change color, thereby changing the optical properties of the electrochromic material, increasing the reflectivity in the infrared band, reducing the temperature of the photovoltaic module by 5-10℃, and improving the stability of the system;

[0049] During this process, the hot electrolyte layer absorbs heat, and the absorbed heat is used to collect heat to generate electricity and then supply power to provide an electric field for electrochromism.

[0050] Because red light is more abundant in the morning and evening, and blue light is stronger at noon, a spectral intensity sensor can be used to monitor spectral intensity in real time to improve daily efficiency. When the spectral intensity is weak, the sensor sends a signal to the microcontroller, which adjusts the voltage to change the color of the electrochromic material to dynamically match the peak of the solar spectrum and increase the light transmittance during that period. For example, low voltage (0.5-1.5V) enhances blue light absorption, while high voltage (1.5-3V) expands red light response.

[0051] Example 5

[0052] Based on Example 1, this embodiment provides a photovoltaic module based on electrochromic materials, wherein the backplane heat dissipation layer includes a high thermal conductivity material and a radiation cooling coating, wherein the high thermal conductivity material is aluminum nitride or graphene, and the radiation cooling coating is randomly stacked and fixed on the surface of the photovoltaic panel, and the radiation cooling coating is an inorganic ceramic particle layer, and gaps are formed between the inorganic ceramic particles.

[0053] The inorganic ceramic particle layer is SiO2, TiO2 or Al2O3, and has a particle size of 50-150 nm. The inorganic ceramic particle layer includes various particle sizes.

[0054] The high thermal conductivity material of the back-dissipating heat sink can not only maintain stable performance in high-temperature environments, but also quickly dissipate heat through radiation; the radiative cooling coating is thin and transparent. Applying it on the photovoltaic glass panel can increase the atmospheric window emissivity of its surface by about 10%, thereby improving the radiative cooling power of the photovoltaic panel and reducing the operating temperature of the photovoltaic panel.

[0055] In this embodiment, the high thermal conductivity material may be graphene, with a thermal conductivity as high as 5000 W / mK.

[0056] The thickness of the transparent conductive layer is 50-100 nm, the thickness of the electrochromic layer is 100-500 nm, the thickness of the thermoelectrolyte layer is 500-10000 nm, and the thickness of the ion storage layer is 100-400 nm.

[0057] The thickness of the radiation cooling coating is 20-120 μm.

[0058] Depending on the differences in light intensity and temperature in different regions, the thickness of the transparent conductive layer, electrochromic layer, thermoelectrolyte layer, ion storage layer, photovoltaic active layer and backplane heat dissipation layer will vary, especially the thickness of the thermoelectrolyte layer. The stronger the light, the more intense the reaction. The thermoelectrolyte layer required for the reaction to release and absorb heat needs to be synchronously and proportionally matched.

[0059] In order to verify the effect of the present invention, four 600W photovoltaic modules based on electrochromic materials were prepared, and the data before and after the temperature drop were simulated. The data were compared with the existing 600W photovoltaic modules (control group). The results are shown in Table 1. The ambient temperature is 25℃, the light intensity is 1000W / m 2 Power generation data simulation is carried out under these conditions.

[0060] Table 1 Power generation simulation data

[0061]

[0062] In order to highlight the improved effect of the present invention, a comparison is made between photovoltaic modules before and after the improvement.

[0063] Table 2 Power generation efficiency ratio

[0064]

[0065] Preparation process: The transparent conductive layer, electrochromic layer, thermoelectrolyte layer, ion storage layer, and photovoltaic active layer are stacked on a high-strength transparent protective layer. The high-strength transparent protective layer is on the upper layer (front) of the photovoltaic active layer, the backplane is on the lower layer (back) of the photovoltaic active layer, and the backplane heat dissipation layer is coated on the backplane.

[0066] In this embodiment, the high-strength transparent protective layer is chemically strengthened glass, 0.5-1.2mm thick, with a transmittance greater than 92%. The transparent conductive layer is indium tin oxide, the electrochromic layer is tungsten trioxide, the thermoelectrolyte layer is a polyvinyl alcohol (PVA)-phosphoric acid (H3PO4) gel electrolyte, the ion storage layer is a WO3 / NiO heterojunction, and the photovoltaic active layer is a single-crystalline silicon cell. From top to bottom, the structure consists of glass, transparent conductive layer, electrochromic layer, thermoelectrolyte layer, ion storage layer, photovoltaic active layer, backplane, and backplane heat dissipation layer.

[0067] The preparation process of the inorganic ceramic particle layer (radiative cooling coating) of the backplane heat dissipation layer is as follows:

[0068] Step 1) Inorganic nano-ceramic particles (SiO2) of various particle sizes are stirred in ethanol to obtain a nano-ceramic particle hydrosol;

[0069] Step 2) adding a film-forming agent and a leveling agent to the nano-ceramic particle hydrosol and stirring to obtain a nano-ceramic coating;

[0070] Step 3) Spray or scrape the nano-ceramic coating on the glass to form an inorganic radiative cooling coating after drying.

[0071] In the photovoltaic module of the color-changing material, the thickness of the transparent conductive layer is 60nm, the thickness of the electrochromic layer is 400nm, the thickness of the thermoelectrolyte layer is 3500nm, the thickness of the ion storage layer is 400nm, and the thickness of the radiation cooling coating is 180μm.

[0072] As shown in Table 1, a 10°C temperature reduction in a simulated 600W optical module generates approximately 0.013-0.017 kWh of additional electricity per hour. As installed capacity increases, the value of sustainable development is enormous.

[0073] The present invention achieves cooling of photovoltaic modules through the cooperation of an electrochromic layer and a backplane heat dissipation layer. The high thermal conductivity material of the backplane heat dissipation layer can not only maintain stable performance in a high-temperature environment, but also quickly dissipate heat by radiation. The radiative cooling coating is thin and transparent. Applying it on the photovoltaic glass panel can increase the atmospheric window emissivity of its surface by about 10%, thereby improving the radiative cooling power of the photovoltaic panel and reducing the operating temperature of the photovoltaic panel.

[0074] The above examples are merely illustrative of the invention and do not constitute a limitation on the scope of protection of the invention. Any design that is identical or similar to the invention falls within the scope of protection of the invention.

Claims

1. A photovoltaic module based on an electrochromic material, characterized by: The invention comprises a high-strength transparent protective layer, a transparent conductive layer, an electrochromic layer, a thermoelectrolyte layer, an ion storage layer, a photovoltaic active layer and a back plate arranged from top to bottom, wherein the back plate is provided with a back plate heat dissipation layer; It also includes a microcontroller, a temperature sensor and a spectral intensity sensor. The temperature sensor is used to detect the temperature of the component surface. The spectral intensity sensor and the temperature sensor are both electrically connected to the microcontroller. After receiving data from the temperature sensor and / or the spectral intensity sensor, the microcontroller adjusts the power voltage generated by the photovoltaic component.

2. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The transparent conductive layer is indium tin oxide, fluorine-doped tin oxide or aluminum-doped zinc oxide.

3. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The electrochromic layer is one of tungsten trioxide, nickel oxide, titanium oxide, molybdenum oxide or vanadium pentoxide.

4. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The thermal electrolyte layer is a solid electrolyte or a gel electrolyte.

5. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The ion storage layer is a WO3 / NiO heterojunction.

6. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The photovoltaic active layer is a single crystal silicon cell, a polycrystalline silicon cell or an amorphous silicon cell.

7. The photovoltaic module based on electrochromic material according to claim 1, characterized in that: The backplane heat dissipation layer includes a high thermal conductivity material and a radiation cooling coating. The high thermal conductivity material is aluminum nitride or graphene. The radiation cooling coating is randomly stacked and fixed on the surface of the photovoltaic panel. The radiation cooling coating is an inorganic ceramic particle layer, and gaps are formed between the inorganic ceramic particles.

8. The photovoltaic module based on electrochromic material according to claim 7, characterized in that: The inorganic ceramic particle layer is SiO2, TiO2 or Al2O3, and has a particle size of 50-150 nm. The inorganic ceramic particle layer includes various particle sizes.

9. A photovoltaic module based on an electrochromic material according to any one of claims 1 to 8, characterized in that: The thickness of the transparent conductive layer is 50-100 nm, the thickness of the electrochromic layer is 100-500 nm, the thickness of the thermoelectrolyte layer is 500-5000 nm, and the thickness of the ion storage layer is 100-400 nm.

10. The photovoltaic module based on electrochromic material according to claim 8, characterized in that: The thickness of the radiation cooling coating is 20-120 μm.

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