Enamel-based photovoltaic module and preparation method thereof

Abstract

The present application discloses an enamel-based photovoltaic module and a preparation method thereof, which relates to the technical field of photovoltaic modules. The enamel-based photovoltaic module includes: an enamel plate, a cell and a front plate stacked in sequence; wherein the enamel plate includes: a metal base plate; an enamel layer, the enamel layer is located on the side of the metal base plate facing the cell; the surface of the metal base plate facing the cell is covered with a reflective layer; the enamel layer covers the surface of the reflective layer. The enamel-based photovoltaic module uses an enamel plate as a back plate, and the enamel plate uses a metal base plate. Compared with a back plate made of conventional glass plate material, the enamel plate with a metal base plate has better weather resistance, can increase the service life of the photovoltaic module, and also has greater mechanical strength. It not only has a greater bearing capacity, but also can solve the problem of the greater brittleness of conventional glass back plates and is not easy to break. In addition, compared with a glass back plate, a metal base plate is easier to shape.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic modules, and in particular to an enamel-based photovoltaic module and a preparation method thereof. Background Art

[0002] Globally, countries are actively developing new energy sources to meet the needs of economic development. Most new energy sources are clean, reducing environmental pollution and replacing some conventional energy sources, making them an important path to achieving clean, environmentally friendly, and efficient energy utilization. Solar energy is a mainstream new energy source today, and photovoltaic modules, which convert sunlight into electricity, are a major way to utilize solar energy.

[0003] Currently, most existing photovoltaic modules use glass back panels, which have low mechanical strength and small bearing capacity. Summary of the Invention

[0004] In view of the above problems, this application provides an enamel-based photovoltaic module and its preparation method, which uses an enamel plate with a metal base as the backplane to achieve the purpose of improving the mechanical strength and bearing capacity of the backplane. The specific solution is as follows:

[0005] In a first aspect, the present application provides an enamel-based photovoltaic module, comprising:

[0006] Enamel plates, battery cells and front plates stacked in sequence;

[0007] The enamel plate includes: a metal base plate; an enamel layer, and the enamel layer is located on the side of the metal base plate facing the battery cell.

[0008] Optionally, in the above-mentioned enamel-based photovoltaic module, the surface of the metal base plate facing the solar cells is covered with a reflective layer;

[0009] The enamel layer covers the surface of the reflective layer.

[0010] Optionally, in the above-mentioned enamel-based photovoltaic module, the enamel layer includes a plurality of enamel sub-layers stacked in sequence; and the refraction of two adjacent enamel sub-layers is different.

[0011] Optionally, in the above-mentioned enamel-based photovoltaic module, the enamel layer includes at least one enamel sublayer;

[0012] The surface of the battery cell facing the enamel plate includes the battery positive electrode; the enamel sublayer adjacent to the battery cell is conductive and electrically connected to the battery positive electrode.

[0013] Optionally, in the above-mentioned enamel-based photovoltaic module, the surface of the cell facing the front plate has a negative electrode;

[0014] The metal base plate is insulated from the conductive enamel sublayer; the negative pole of the battery is connected to the metal base plate, and the metal base plate is used for grounding.

[0015] Optionally, in the above-mentioned enamel-based photovoltaic module, the enamel layer includes at least one enamel sublayer;

[0016] The enamel sublayer adjacent to the cell is formed by sintering a glaze coating including a passivation material. During the sintering process, the passivation material can diffuse to the surface of the cell facing the enamel plate to passivate the surface of the cell.

[0017] Optionally, in the above-mentioned enamel-based photovoltaic module, the enamel layer includes at least one enamel sublayer;

[0018] Wherein, at least one enamel sub-layer includes a fluorescent material, and the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light.

[0019] A second aspect of the present application provides a method for preparing any of the above-mentioned enamel-based photovoltaic modules, comprising:

[0020] A glaze coating is formed on one side of the metal base plate using enamel glaze; the surface of the metal base plate is covered with a reflective layer, and the glaze coating is formed on the surface of the reflective layer;

[0021] Laying cells on the surface of the glaze coating;

[0022] The glaze coating is sintered into an enamel layer, and the cell is fixed to the surface of the metal base plate through the enamel layer; wherein the metal base plate and the reflective layer and enamel layer on the surface thereof are constructed into an enamel plate;

[0023] A front plate is arranged on the surface of the battery cell facing away from the enamel plate.

[0024] Optionally, in the above preparation method, the enamel frit comprises: uniformly mixed organic components and inorganic components;

[0025] The organic component includes epoxy resin and polyurethane in a mass ratio of 3:1;

[0026] Inorganic components include: 40wt%~45wt% , 25wt%~30wt% , 8wt%~10wt% and 15wt%~27wt% of auxiliary materials; wherein, the auxiliary materials include: 5wt%~8wt% or , 2wt%~4wt% , 3wt%~5wt% clay, 5wt%~25wt% water.

[0027] Optionally, in the above preparation method, the enamel frit further comprises at least one of a fluorescent material, a passivation material and a nano-conductive material;

[0028] Among them, the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light; the passivation material can diffuse to the surface of the battery cell facing the enamel plate after sintering to passivate the surface of the battery cell; the nano-conductive material can form a conductive channel electrically connected to the positive electrode of the battery cell in the enamel layer after sintering.

[0029] By utilizing the above-described technical solution, the present application provides an enamel-based photovoltaic module and its preparation method, wherein an enamel plate is used as the backplane of the photovoltaic module, and the enamel plate adopts a metal base. Compared with conventional glass backplanes, enamel plates with metal bases have better weather resistance, which can extend the service life of the photovoltaic module. They also have greater mechanical strength, not only providing greater load-bearing capacity, but also solving the problem of the brittleness of conventional glass backplanes, making them less prone to breakage. Furthermore, compared with glass backplanes, metal bases are easier to shape.

[0030] Optionally, the reflectivity of the enamel plate can be increased by covering the surface of the metal base plate with a reflective layer, so as to increase the utilization rate of sunlight by the cell and improve the photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0032] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size, without affecting the efficacy and objectives that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0033] Figure 1 A schematic structural diagram of an enamel-based photovoltaic module provided in an embodiment of the present application;

[0034] Figure 2 A schematic structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application;

[0035] Figure 3A schematic structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application;

[0036] Figure 4 A schematic structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application;

[0037] Figure 5 A schematic diagram of a process for preparing an enamel-based photovoltaic module provided in an embodiment of the present application;

[0038] Figure 6 Temperature curves of various photovoltaic modules in a windless test environment provided in the embodiments of this application;

[0039] Figure 7 Temperature curves of various photovoltaic modules in a windy test environment provided in the embodiments of the present application.

[0040] Reference numerals:

[0041] 100 - enamel plate; 101 - battery cell; 102 - front plate; 103 - metal base plate; 104 - enamel layer; 105 - adhesive film; 106 - reflective layer; 107 - enamel sublayer. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments of the present application. Those skilled in the art will know that with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0043] With the rapid development of building-integrated photovoltaic (BIPV) technology, the market demand for photovoltaic modules that combine building envelope functions with efficient power generation performance is growing. Currently, the commonly used technical solutions in the BIPV field mainly include photovoltaic modules using glass backsheets and photovoltaic modules using ordinary organic backsheets.

[0044] The heavy weight of a glass backplane contributes to the weight of the photovoltaic module. Furthermore, glass backplanes are brittle and easily broken, and difficult to shape, making them difficult to adapt to curved structures. Furthermore, glass backplanes are less resistant to inclement weather.

[0045] Ordinary organic backsheets have poor weather resistance and are prone to aging in corrosive environments, affecting the performance and life of photovoltaic modules.

[0046] When photovoltaic modules are used as building components, conventional modules struggle to balance aesthetics with power generation performance, regardless of whether they utilize glass or organic backsheets. Furthermore, glass and organic backsheets place high demands on the installation of the modules, requiring complex external mounting structures, resulting in complex and costly construction.

[0047] In view of this, an embodiment of the present application provides an enamel-based photovoltaic module, which includes:

[0048] Enamel plates, battery cells and front plates stacked in sequence;

[0049] The enamel plate includes: a metal base plate; an enamel layer, and the enamel layer is located on the side of the metal base plate facing the battery cell.

[0050] In the embodiments of this application, a PV module backplane is constructed using a vitreous enamel panel with a metal base. This metal base can be shaped into desired shapes, resolving the issue of conventional glass backplanes being difficult to bend and shape. Furthermore, the metal base offers significant mechanical strength, addressing the weak mechanical strength of conventional glass and organic backplanes.

[0051] In addition, since the metal base plate has greater mechanical strength, greater mechanical strength can be achieved through a smaller thickness, which can reduce the thickness of the back plate, thereby reducing the weight of the back plate and reducing the overall weight of the photovoltaic module.

[0052] Moreover, the enamel layer has good weather resistance. During long-term use, its lifespan is less affected by environmental factors such as temperature, water, oxygen, and acidity and alkalinity, and it is not prone to aging, thus ensuring the service life and performance of photovoltaic modules.

[0053] When photovoltaic modules are used as building components, the metal baseplate can be shaped to the desired shape. This allows the metal baseplate to be shaped to match the building's exterior structure, creating a backplate structure of the desired shape and structure, thus balancing the building's appearance with power generation performance. Furthermore, the metal baseplate can be installed with commonly used metal components in buildings, eliminating the need for complex external structural components, making construction simple and cost-effective.

[0054] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0055] refer to Figure 1 , Figure 1 A schematic structural diagram of an enamel-based photovoltaic module provided in an embodiment of the present application, wherein the enamel-based photovoltaic module includes: an enamel plate 100, a battery cell 101, and a front plate 102 stacked in sequence; wherein the enamel plate 100 includes: a metal base plate 103; an enamel layer 104, and the enamel layer 104 is located on the side of the metal base plate 103 facing the battery cell 101.

[0056] The battery cell 101 can be directly fixed on the surface of the metal base plate 103 based on the enamel layer 104 .

[0057] Alternatively, as Figure 1 As shown, the front panel 102 can be fixed relative to the battery cell 101 by means of an adhesive film 105. The adhesive film 105 can be an EVA adhesive film, which has high light transmittance, strong adhesion and insulation properties, and can ensure perfect packaging and prevent the intrusion of water vapor and oxygen.

[0058] In the enamel-based photovoltaic module provided in the embodiments of the present application, the metal base plate 103 is easily shaped and has high mechanical strength, facilitating the realization of special-shaped designs for the enamel plate 100 and improving the load-bearing capacity of the enamel plate 100. Furthermore, the enamel layer 104 has good weather resistance, which can improve the weather resistance of the enamel plate 100 and the photovoltaic module, thereby enhancing the performance and service life of the photovoltaic module.

[0059] Since the metal base plate 103 has strong mechanical strength and can provide sufficient bearing capacity at a thin thickness, the thickness of the enamel plate 100 can be reduced to reduce its weight, thereby reducing the overall weight of the photovoltaic module.

[0060] When photovoltaic modules are used as building components, the metal base plate 103 can be easily shaped to suit the building's exterior structure, creating a backplate structure with the desired shape and structure, thus achieving a balance between building appearance and power generation performance. Furthermore, the metal base plate 103 can be installed with commonly used metal components in buildings, eliminating the need for complex external structural components, resulting in simple and low-cost construction.

[0061] Optionally, the metal base plate 103 may be a steel plate, an aluminum alloy plate, or a titanium-containing metal plate, etc. The metal base plate 103 made of these materials has greater mechanical strength and can provide sufficient bearing capacity at a thinner thickness.

[0062] Optionally, the metal substrate 103 has a polyester topcoat layer on the side facing the cell 101. The enamel layer 104 is located on the side of the polyester topcoat layer facing away from the metal substrate 103. The polyester topcoat layer serves as a primer, primarily enhancing the adhesion between the metal substrate 103 and subsequent coatings while also providing basic corrosion protection.

[0063] In the enamel plate 100, the thermal expansion coefficient of the metal base plate 103 is adapted to the thermal expansion coefficient of the enamel layer 104, so that the enamel layer 104 has greater adhesion stability on the surface of the metal base plate 103, avoiding cracking or warping of the enamel layer 104 due to large interlayer stress.

[0064] In the first method, the thermal expansion coefficient of the metal base plate 103 is adapted to the thermal expansion coefficient of the enamel layer 104, including: the thermal expansion coefficient of the metal base plate 103 is equal to or approximately equal to the thermal expansion coefficient of the enamel layer 104. In this way, the interlayer stress between the two can be reduced or even eliminated, and the enamel layer 104 can be effectively prevented from cracking or warping.

[0065] When the thermal expansion coefficient of the metal base plate 103 is equal to or approximately equal to the thermal expansion coefficient of the enamel layer 104, the difference between the thermal expansion coefficient of the metal base plate 103 and the thermal expansion coefficient of the enamel layer 104 does not exceed 1.5×10 -6 / ℃. For example, the metal base plate 103 can be a steel plate, and the thermal expansion coefficient of the steel plate is generally in the range of 11×10 -6 / ℃~12×10 -6 / ℃. The thermal expansion coefficient of enamel materials is generally in the range of 9×10 -6 / ℃~12×10 -6 / ℃.

[0066] When the metal base plate 103 is made of steel plate, not only can the metal base plate 103 and the enamel layer 104 have the same or similar thermal expansion coefficient to reduce or eliminate the interface stress between the two, but the steel plate also has higher mechanical strength and can provide greater bearing capacity with a thinner thickness.

[0067] In the second approach, the thermal expansion coefficient of the metal base plate 103 is adapted to the thermal expansion coefficient of the enamel layer 104. This includes the following: the thermal expansion coefficient of the metal base plate 103 is unequal to that of the enamel layer 104, and the enamel layer 104 comprises multiple, sequentially stacked enamel sublayers, with adjacent enamel sublayers having different thermal expansion coefficients. In this approach, the different thermal expansion coefficients of the metal base plate 103 and the enamel layer 104 create interfacial stress between them. This interfacial stress caused by the different thermal expansion coefficients between the metal base plate 103 and the enamel layer 104 can be distributed across the multiple enamel sublayers of the enamel layer 104, thereby buffering the stress and preventing cracking or warping of the enamel layer 104 and the metal base plate 103.

[0068] Unlike the first approach in which the interfacial stress between the metal base plate 103 and the enamel layer 104 is reduced or eliminated to prevent the enamel layer 104 from cracking or warping due to the interfacial stress, in the second approach, the metal base plate 103 and the enamel layer 104 have different thermal expansion coefficients, and the difference in their thermal expansion coefficients is quite large. Consequently, there is a large interfacial stress at the interface between the two. Without reducing or eliminating the interfacial stress, the interfacial stress is shared by enamel sublayers with different thermal expansion coefficients to buffer the stress.

[0069] In the second method, the thermal expansion coefficient of the multi-layer enamel sublayer can be set to be alternately distributed with the first thermal expansion coefficient and the second thermal expansion coefficient, and the first thermal expansion coefficient and the second thermal expansion coefficient are not equal, that is, the multiple enamel sublayers include enamel sublayers with the first thermal expansion coefficient and enamel sublayers with the second thermal expansion coefficient that are alternately arranged. The multi-layer enamel sublayers with periodically distributed thermal expansion coefficients can more effectively share the interface stress between the metal base plate 103 and the enamel layer 104 due to the different thermal expansion coefficients.

[0070] In a second approach, a gradient of thermal expansion coefficients can be configured for the multiple enamel sublayers. In the direction from the enamel plate 100 toward the front plate 102, the thermal expansion coefficients of each enamel sublayer can decrease sequentially, with the thermal expansion coefficient of the metal base plate 103 being greater than that of the adjacent enamel sublayers. Alternatively, the thermal expansion coefficients of each enamel sublayer can increase sequentially, with the thermal expansion coefficient of the metal base plate 103 being less than that of the adjacent enamel sublayers. In this approach, the multiple enamel sublayers with a gradient of thermal expansion coefficients can more effectively distribute the interfacial stress caused by the different thermal expansion coefficients between the metal base plate 103 and the enamel layer 104.

[0071] When the enamel layer 104 includes multiple enamel sublayers, the enamel layer 104 including the multiple enamel sublayers can be prepared based on a sol-gel method, and the multiple enamel sublayers can be formed with different target parameters. The target parameter can include at least one of a thermal expansion coefficient, a thickness, and a refractive index.

[0072] refer to Figure 2 , Figure 2 This is a schematic structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application. Based on other implementations, Figure 2 In the enamel-based photovoltaic module shown, the surface of the metal base plate 103 facing the solar cell 101 is covered with a reflective layer 106 ; the enamel layer 104 covers the surface of the reflective layer 106 .

[0073] If the surface of the metal base plate 103 has a polyester topcoat layer, the reflective layer 106 is located on the surface of the polyester topcoat layer facing away from the metal base plate 103 .

[0074] When sunlight enters the photovoltaic module from the front panel 102, part of the light will pass through the gaps between the cells 101 or continue to propagate downward through the cells 101. Figure 2 In the manner shown, the reflective layer 106 can reflect part of the light back to the cell 101 , thereby increasing the utilization rate of sunlight by the cell and improving the photoelectric conversion efficiency.

[0075] exist Figure 2In the manner shown, the enamel layer 104 may include a plurality of enamel sublayers stacked in sequence; the refractive index of two adjacent enamel sublayers is different. In this manner, the enamel layer 104 may have a higher reflectivity through the plurality of enamel sublayers having different refractive indices, so that light passing through the gaps between the cells 101 or through the cells and incident on the enamel layer 104 can be more reflected back to the cells 101, thereby improving the utilization rate of sunlight by the cells and improving the photoelectric conversion efficiency.

[0076] When the enamel layer 104 includes multiple enamel sub-layers stacked in sequence, and the refractive indexes of two adjacent enamel sub-layers are different, the refractive index of each enamel sub-layer can be gradiently changed, or the refractive index of each enamel sub-layer can be periodically arranged with a first refractive index and a second refractive index to improve the reflectivity of the enamel layer 104. The first refractive index and the second refractive index are not equal.

[0077] If the refractive index of each enamel sublayer is gradually changed, the enamel layer 104 may include three enamel sublayers. In the direction from the enamel plate 100 to the front plate 102, the refractive index of each enamel sublayer may increase successively to achieve a higher reflectivity. For example, the refractive indices of the three enamel sublayers may be 1.65, 1.72, and 1.80, respectively, and the thickness ratio of the three may be 1:1.5:2. This gradient structure can cause constructive interference of incident light at the interface, effectively improving the reflectivity.

[0078] refer to Figure 3 , Figure 3 This is a structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application. Based on other implementations, Figure 3 In the embodiment shown, the enamel layer 104 includes at least one enamel sub-layer 107; wherein, the battery cell 101 faces the side surface of the enamel plate 100 ( Figure 3 The lower surface of the battery cell 101 includes the battery positive electrode; the enamel sublayer 107 adjacent to the battery cell 101 is conductive, and the enamel sublayer 107 is electrically connected to the battery positive electrode.

[0079] exist Figure 3 In the embodiment shown, the enamel layer 104 has three enamel sub-layers 107, at least the top enamel sub-layer 107 is conductive, and the enamel sub-layer 107 is electrically connected to the positive electrode of the battery cell 101. In actual products, the enamel layer 104 can be set to have one or two or more enamel sub-layers 107 according to needs. The embodiment of the present application does not limit the number of enamel sub-layers 107 in the enamel layer 104, and is not limited to Figure 3 The three layers.

[0080] The enamel-based photovoltaic module includes a plurality of interconnected cells 101. A conductive enamel sublayer 107 is provided adjacent to the cells 101 and electrically connected to the cell's positive electrode. This allows the positive electrode of each cell 101 to be directly electrically connected to the underlying conductive enamel sublayer 107. Compared to conventional photovoltaic modules in which the cells 101 are interconnected via grid lines and solder ribbons, this reduces contact resistance and eliminates the need for solder ribbons.

[0081] Optionally, the conductive enamel sublayer 107 has a circuit connection pattern structure for achieving circuit connections between multiple cells 101 in the enamel-based photovoltaic module. The conductive enamel sublayer 107 can be patterned by laser cutting or other methods to form the desired pattern structure. The conductive enamel sublayer 107 is made of an enamel frit containing a conductive material. The conductive material can be Ag nanowires.

[0082] The conductive enamel sublayer 107 is insulated from the metal base plate 103. When the enamel-based photovoltaic module includes a reflective layer 106, the reflective layer 106 can be made of an insulating material. This method can at least achieve insulation isolation between the conductive enamel sublayer 107 and the metal base plate 103 based on the insulating reflective layer 106, without the need for an additional separate insulating isolation layer.

[0083] Alternatively, there is at least one insulating enamel sublayer 107 between the conductive enamel sublayer 107 and the metal base plate 103. This method can achieve insulation isolation between the conductive enamel sublayer 107 and the metal base plate 103 based on the insulating enamel sublayer 107 without the need for an additional separate insulating isolation layer.

[0084] refer to Figure 4 , Figure 4 This is a structural diagram of another enamel-based photovoltaic module provided in an embodiment of the present application. Based on other implementations, Figure 4 In the embodiment shown, the battery cell 101 faces the surface of the front plate 102 ( Figure 4 The upper surface of the middle battery cell 101 has a battery negative electrode; the metal base plate 103 is insulated from the conductive enamel sublayer; the battery negative electrode is connected to the metal base plate 103, and the metal base plate 103 is used for grounding. Figure 4 The dotted line in the figure indicates the connection between the negative electrode of the battery and the metal bottom plate 103.

[0085] Optionally, the negative electrode of the battery can be connected to the metal base plate 103 through a wire, or the negative electrode of the battery can be connected to the component frame, and then connected to the metal base plate 103 through the component frame to achieve grounding.

[0086] exist Figure 4In the illustrated method, based on the conductive properties of the metal base plate 103, it is connected to the negative electrode of the battery cell 101 to achieve a natural grounding design, which can realize a safe and reliable lightweight BIPV design.

[0087] In one embodiment, based on other embodiments, the enamel layer 104 includes at least one enamel sublayer; wherein the enamel sublayer adjacent to the cell 101 is formed by sintering a glaze coating including a passivation material; during the sintering process, the passivation material can diffuse to the surface of the cell 101 facing the enamel plate 100, passivating this surface of the cell 101. This approach allows the enamel sublayer to passivate the surface of the cell 101 facing the enamel plate 100, reducing the low carrier recombination caused by surface defects and improving the photoelectric conversion efficiency of the cell 101.

[0088] The enamel layer 104 includes at least one enamel sublayer. The enamel base layer is formed by sintering the glaze coating. The battery cell 101 and the enamel layer 104 can be fixed synchronously during the sintering process.

[0089] Optionally, the passivation material comprises ZAS (ZnO- - ) materials, the component ratio in the ZAS system material is: 20% ZnO, 15% , 65% When sintered at 1100°C~1500°C, the ZAS system material 、 The plasma diffuses to the surface of the cell 101 , forming a 10nm-15nm passivation layer on the surface of the cell 101 , reducing the surface recombination rate from 1000cm / s to 200cm / s, and increasing the open circuit voltage Voc of the cell 101 by 8mV-10mV.

[0090] Based on other embodiments, in one embodiment, the enamel layer 104 includes at least one enamel sublayer; wherein at least one enamel sublayer includes a fluorescent material, and the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light. Optionally, the fluorescent material includes 5wt% of , it can convert 300nm~400nm ultraviolet light into 520nm~580nm yellow-green light (efficiency 78%), thereby improving power generation efficiency.

[0091] Cell 101 can be a silicon solar cell. Silicon solar cells have a low absorption rate for ultraviolet light. Therefore, most of the ultraviolet light in sunlight will transmit downward through cell 101. This ultraviolet light is not only unusable for photoelectric conversion, but also undergoes multiple reflections at the film interfaces in the photovoltaic module, causing structural aging problems in the photovoltaic module. Doping the enamel sublayer with a fluorescent material that can be excited by ultraviolet light and emit visible light not only absorbs ultraviolet light that cannot be effectively utilized by solar cell 101 and converts it into visible light that can be used by cell 101, thereby improving photoelectric conversion efficiency, but also reduces the transmission path of ultraviolet light in the photovoltaic module, reducing the impact of ultraviolet light on the life of the photovoltaic module.

[0092] Based on the above description, it can be seen that the enamel-based photovoltaic provided in the embodiment of the present application uses an enamel plate 100 as the backplane. The enamel plate 100 includes a metal base plate 103 and an enamel layer 104 on its surface. The enamel layer 104 has the advantages of light weight, high weather resistance and strong bonding force, which can reduce the weight of the backplane and improve the weather resistance, stability and reliability of the backplane. The enamel plate 100 can be suitable for curved surface installation and high-corrosion environment, can be integrated into the building, and improve impact resistance.

[0093] The chemical stability of enamel board 100 is better than that of conventional ordinary backboards, and its toughness is better than that of glass backboards. It is suitable for extreme climate environments and can achieve true integration of buildings and photovoltaic modules.

[0094] The enamel layer 104 is prepared by sintering the enamel glaze. The dielectric properties of the enamel layer 104 can be optimized by adjusting the component ratio of the enamel glaze. For example, the dielectric properties of the enamel layer 104 can be optimized by increasing the ratio of the components in the enamel glaze. content, reduce The content of MgO can increase the volume resistivity, thereby optimizing the dielectric properties of the enamel layer 104.

[0095] The enamel layer 104 can be prepared by sol-gel, resulting in a smooth and hydrophobic surface. Surface treatment of the enamel layer 104 can also achieve self-cleaning properties. When enamel-based photovoltaic modules are used as building components, they can improve power generation efficiency while ensuring the building's protective function.

[0096] The enamel panel 100 is 30% lighter than the conventional glass back panel, and the weight per unit area is reduced from 15kg / cm 2 Reduced to 10.5kg / cm 2 By adjusting the thickness of the metal base plate 103 to 0.3 mm, a bending process with a curvature radius less than or equal to 300 mm can be achieved, and the bending strength is maintained above 50 MPa. It has both rigidity and bendability and can be processed into special-shaped building components such as photovoltaic tiles.

[0097] The enamel layer 104 has a dense film structure that can achieve zero water permeability. When tested for 1000 hours in a high humidity environment of 85℃ / 85%RH, the insulation resistance is always greater than 10¹²Ω, far exceeding that of traditional backsheets. Ω performance; after the salt spray test (ASTM B117, 5% NaCl solution, 96h), there was no corrosion or delamination on the component surface, and the performance degradation rate was less than 1%, which is better than the test result of 5% for ordinary backsheets.

[0098] The enamel-based photovoltaic modules provided in the embodiments of this application, when used as building components, can achieve architecturally integrated designs. The enamel sheet 100, serving as the backplane, can be reduced to a thickness of 1.2 mm, with a specific gravity of 2.8 g / cm³. This allows for a minimum bending radius of 800 mm, and after passing a 5000-hour QUV test, a ΔE <3 (minimal color change, exceeding building material standards), making it a perfect fit for BIPV installations on curved surfaces.

[0099] Since the enamel plate 100 uses a metal base plate 103 with high mechanical strength, the enamel-based photovoltaic module can be directly used as a building component, integrating structural support and packaging protection, eliminating the need for traditional backboards and linings. The conductive metal base plate 103 can achieve a built-in natural grounding function, reducing the installation process by 40%, and the installation time of a single enamel-based photovoltaic module is shortened from 15 minutes to 9 minutes; material costs are reduced by 25%, and maintenance costs over 30 years are saved by about 30%.

[0100] The enamel layer 104 can achieve customizable color and gloss by adjusting the enamel glaze component ratio. After ultraviolet aging test (QUV, 340nm, 5000h), the glaze color ΔE value of the enamel layer 104 is less than 1.5, while the ΔE value of the traditional coating backplane is greater than 5. The technical solution of the present application can maintain high color fastness and long-lasting color stability.

[0101] The enamel-based photovoltaic module provided in the embodiment of the present application is prepared based on a sintering process for the enamel plate 100. The high-temperature sintering process makes the surface corrosion-resistant. Accelerated aging experiments show that the power attenuation rate is expected to be less than 8% within 25 years, which is 5% lower than that of conventional products, and the service life is extended to more than 30 years. The enamel glaze component ratio can be adjusted to optimize the enamel dielectric properties. The surface leakage current of the module is less than 5μA, which is 60% lower than that of the existing technology. In the BIPV (building integrated photovoltaic) scenario, the power generation efficiency is increased by 3%-5%, which can achieve the purpose of improving the module life and performance.

[0102] Enamel-based photovoltaic modules are suitable for scenarios with special requirements on weight and shape, such as BIPV (building integrated photovoltaics), photovoltaic tiles, and automotive photovoltaics. The building integrated structure reduces costs and increases efficiency, and the lightweight and waterproof characteristics significantly save installation and maintenance costs.

[0103] The enamel-based photovoltaic module provided in the embodiment of the present application has better heat dissipation performance. Compared with the conventional double-glass-plate photovoltaic module (both the front plate and the back plate are made of glass plates), the operating temperature of the enamel-based photovoltaic module can be reduced by 3°C to 10°C, and the power generation capacity can be increased by 2% to 3%.

[0104] The effect of reducing the operating temperature of the enamel-based photovoltaic module provided in the embodiment of the present application will be described below in conjunction with specific experimental data.

[0105] refer to Figure 6 and Figure 7 , Figure 6 Temperature curves of various photovoltaic modules in a windless test environment provided in the embodiments of this application; Figure 7 Temperature curves of various photovoltaic modules in a windy test environment provided in the embodiments of the present application. Figure 6 and Figure 7 In the figure, the horizontal axis is the test time in min, and the vertical axis is the operating temperature of the PV module in °C.

[0106] in, Figure 6 and Figure 7 The temperature curves of three photovoltaic modules in a windless test environment and in a windy test environment are shown. The cells in all three photovoltaic modules are heterojunction solar cells. The three photovoltaic modules are the first, second, and third photovoltaic modules. The first photovoltaic module has both a glass front panel and a porcelain enamel back panel. The third photovoltaic module has a plastic front panel and a porcelain enamel back panel. The plastic panels are made of soft plastics, such as ETEE (ethylene tetrafluoroethylene copolymer) or PVDF (polyvinylidene fluoride). These materials offer excellent weather resistance and heat dissipation.

[0107] Figure 6 In the figure, curves L11, L12, and L13 are the temperature curves of the first photovoltaic module, the second photovoltaic module, and the third photovoltaic module in a windless test environment, respectively. Figure 6 As can be seen, the operating temperatures of the first, second, and third PV modules in the windless test environment after 30 minutes were 40.1°C, 34°C, and 32.9°C, respectively. This shows that in the windless test environment, the PV modules with porcelain enamel backsheets (the first and second PV modules) significantly lower their operating temperatures compared to the double-glass PV modules (the third PV module). Furthermore, of the two PV modules with porcelain enamel backsheets, the one with a plastic frontsheet (the third PV module) exhibited the lowest operating temperature.

[0108] Figure 7In the figure, curves L21, L22, and L23 are the temperature curves of the first photovoltaic module, the second photovoltaic module, and the third photovoltaic module in a windy test environment, respectively. Figure 7 As can be seen, the operating temperatures of the first, second, and third PV modules in the windless test environment after 30 minutes were 33.3°C, 30.4°C, and 30°C, respectively. This shows that in windy test environments, the PV modules with porcelain enamel backsheets (the first and second PV modules) significantly lower their operating temperatures compared to the double-glass PV modules (the third PV module). Furthermore, of the two PV modules with porcelain enamel backsheets, the one with a plastic frontsheet (the third PV module) exhibited the lowest operating temperature.

[0109] based on Figure 6 and Figure 7 The experimental data shown in FIG. 4 show that in the enamel-based photovoltaic module provided in the embodiment of the present application, the front plate is preferably made of soft plastic with good heat dissipation properties.

[0110] Based on the enamel-based photovoltaic module provided in the above embodiment, another embodiment of the present application further provides a method for preparing the enamel-based photovoltaic module. The preparation method can be as follows: Figure 5 shown.

[0111] refer to Figure 5 , Figure 5 A schematic flow chart of a method for preparing an enamel-based photovoltaic module provided in an embodiment of the present application, the preparation method comprising:

[0112] Step S11: using enamel glaze to form a glaze coating on one side of the metal base plate 103 .

[0113] Optionally, the surface of the metal base plate 103 may be covered with a reflective layer 106 , and a glaze coating may be formed on the surface of the reflective layer 106 .

[0114] Step S12: laying the cell 101 on the surface of the glaze coating.

[0115] Step S13: Sintering the glaze coating into an enamel layer 104, and fixing the cell 101 on the surface of the metal base plate 103 via the enamel layer 104; wherein the metal base plate 103 and the reflective layer 106 and the enamel layer 104 on its surface constitute the enamel plate 100;

[0116] Step S14 : placing the front plate 102 on the surface of the battery cell 101 facing away from the enamel plate 100 .

[0117] To improve the adhesion stability of the enamel layer 104 formed by the glaze coating on the surface of the metal substrate 103, the metal substrate 103 may be pretreated before the glaze coating is formed. The pretreatment includes cleaning the surface of the metal substrate 103 and / or forming a polyester topcoat layer on the surface of the metal substrate 103 to improve film adhesion. The thickness of the polyester topcoat layer may be 50 μm.

[0118] Optionally, the metal base plate 103 can be a steel plate. The preparation method of the enamel-based photovoltaic module starts with the selection and inspection of the steel plate to ensure that the raw materials meet the standards. In this process, the steel plate needs to be punched and cut, and then sandblasted and derusted to meet the SA2.5 / SSPC10 standards to ensure surface cleanliness and remove impurities. The steel plate is then rolled to ensure that its shape meets the requirements of subsequent use. In order to improve the adhesion of the surface coating, the steel plate can also be degreased and rinsed. Before forming the glaze coating, a layer of polyester topcoat can be sprayed on the surface of the steel plate as a primer to enhance the adhesion of the steel plate to the subsequent coating and improve the basic corrosion protection. The polyester topcoat layer is cured through a drying process to give the steel plate good stability.

[0119] To improve the reflectivity of the enamel plate 100 and reflect incident sunlight back toward the cell 101, thereby increasing sunlight utilization, a reflective layer 106 may be formed on the pre-treated surface of the metal base plate 103. The reflective layer 106 may include alternating layers of TiO2 and SiO2. The reflective layer 106 may be formed using a sol-gel method.

[0120] The thickness of TiO2 film and SiO2 film is , which can make the reflective layer 106 have a higher reflectivity at the peak efficiency wavelength, with the reflectivity reaching more than 92%, further improving the power generation efficiency of the battery cell 101. is the peak efficiency wavelength of the cell 101, and n is the refractive index.

[0121] The peak efficiency wavelength is the wavelength band within the absorption wavelength range of cell 101 that exhibits the maximum photoelectric conversion response. For example, if cell 101 is a silicon solar cell, its absorption wavelength range for photoelectric conversion is 300nm to 1200nm, with 600nm to 1100nm (visible to near-infrared) being the core wavelength range for photoelectric conversion. Silicon solar cells exhibit the maximum photoelectric conversion response at the peak efficiency wavelength, typically between 800nm ​​and 900nm.

[0122] by Taking 800nm ​​as an example, the refractive index n of the TiO2 film is 2.2, so the film thickness is 800 / (4×2.5)=80nm; the refractive index n of the SiO2 film is 1.45, so the film thickness is 800 / (4×1.45)≈138nm.

[0123] After pre-treatment of the metal base plate 103, a glaze coating is formed on the surface thereof. The glaze layer can be formed by electrostatic spraying. The enamel used to prepare the glaze coating includes a uniform mixture of organic components and inorganic components.

[0124] The organic components include thermosetting resins, including epoxy resin and polyurethane, with a mass ratio of 3:1. The material layer formed by mixing the thermosetting resin with the inorganic components can form a dense film structure, which can form a stable thin film contact with the underlying film layer (polyester topcoat layer or reflective layer 106) and provide a good bonding interface for the enamel layer 104 formed by subsequent sintering.

[0125] Optionally, the organic component also includes an organic curing agent (such as an amine or isocyanate). The organic curing agent reacts with active groups (such as epoxy and hydroxyl groups) in the resin material, causing the oil coating to form a three-dimensional network structure after preheating, thereby curing the glaze coating. The polyester topcoat layer on the surface of the metal base plate 103, the reflective layer 106, and the cured glaze coating form a composite film system, which is then sintered to form the glaze coating into an enamel layer.

[0126] Inorganic components include: 40wt%~45wt% , 25wt%~30wt% , 8wt%~10wt% and 15wt%~27wt% of auxiliary materials; wherein, the auxiliary materials include: 5wt%~8wt% or , 2wt%~4wt% , 3wt%~5wt% clay, 5wt%~25wt% water.

[0127] Alternatively, when the total amount of auxiliary materials is 27 wt%, the typical ratio of each component can be: The content is 6wt%, The content of glaze is 3wt%, clay content is 4wt%, and water content is wt% (the mass of water after drying is not included in the final glaze composition). These auxiliary materials work together with the main ingredients to ensure that the glaze has suitable process properties and the quality of the final product.

[0128] In auxiliary materials, or As a co-solvent, it can lower the melting point of the glaze coating. It is used to enhance the chemical stability of the enamel layer 104. Clay (primarily kaolin) acts as a suspending agent to prevent the enamel frit from settling. Water acts as a solvent and evaporates during the sintering process.

[0129] The enamel glaze formed by the inorganic component material provided in the embodiment of the present application can form a selectively light-transmitting enamel layer 104, so that the enamel layer 104 has high light transmittance and high absorption rate for the non-absorbed light of the cell 101. The component ratio can make the enamel layer 104 have a transmittance of more than 85% in the 550nm visible light band. Experimental data show that When the content is 9wt%, the transmittance of the enamel layer 104 in the 550nm visible light band is 87.3%. / The composition ratio of the above components can make the enamel layer 104 have a high selective absorption capacity for ultraviolet light / infrared light. The enamel glaze formed by the inorganic components with the above composition ratio can form an enamel layer 104 with high light transmittance, making the transmittance of the enamel layer 104 greater than 85%. Laboratory test data shows that when When the content is 9wt%, the transmittance of the enamel layer 104 at a wavelength of 550nm reaches 87.3%. The higher transmittance can enable each film layer in the enamel plate 100 to achieve a higher reflectivity based on the film layer interface, so as to reflect the incident sunlight back to the battery cell 101, thereby improving the utilization rate of sunlight by the battery cell 101 and improving the power generation efficiency.

[0130] Optionally, the enamel glaze also includes at least one of a fluorescent material, a passivation material and a nano-conductive material; wherein the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light; the passivation material can diffuse to the surface of the battery cell 101 facing the enamel plate 100 after sintering, and passivate the surface of the battery cell 101; the nano-conductive material can form a conductive path electrically connected to the positive electrode of the battery cell 101 in the enamel layer 104 after sintering.

[0131] Fluorescent materials include , which can be excited by ultraviolet light to emit visible light.

[0132] The passivation material includes a ZAS system material. During the sintering of the glaze coating to form the enamel layer 104, the ZAS system material 、 The plasma diffuses to the surface of the battery cell 101 , forming a passivation layer on the surface of the battery cell 101 .

[0133] The nanoconductive material includes Ag nanowires. Ag nanowires are uniformly mixed into the enamel frit at a concentration of 8.7 wt%. After sintering, the enamel coating forms a conductive enamel sublayer. The Ag nanowires can form a conductive network within the enamel sublayer, forming vertical conductive vias that connect to the positive electrode of the upper battery cell. The spacing between the vertical conductive vias can be 500 μm. The sheet resistance of the conductive enamel sublayer is less than 5 ohms per square. Optionally, the thickness of the conductive enamel sublayer can be 100 μm or another thickness.

[0134] Optionally, to improve the heat dissipation performance of the enamel layer 104, the inorganic material composition also includes 3wt% to 5wt% WO3, achieving self-heating. The emissivity reaches 0.92 in the 8μm to 14μm band. This method can reduce the operating temperature of the enamel-based photovoltaic module by 5°C to 8°C through radiative cooling. Experimental data shows that the average temperature rise during midday is 6.2°C lower than that of conventional modules.

[0135] High-temperature sintering is a key manufacturing process for the enamel plate 100. Sintering the composite film system on the surface of the metal base plate 103 at 1100°C to 1500°C creates a metallurgical bond between the composite film system and the metal base plate 103, enhancing the plate's weather resistance and corrosion resistance, effectively protecting it from UV rays and wind and sand erosion.

[0136] The enamel plate 100, as the outer structure of the photovoltaic module, provides super strong protection for the enamel-based photovoltaic module, and is also conducive to achieving a higher photoelectric conversion rate for the enamel-based photovoltaic module.

[0137] Each layer of material in a ceramic enamel photovoltaic module undergoes a rigorous, standardized process, including cleaning, stacking, lamination, shaping, and sealing, to ensure the module's stability and reliability over long-term use. After surface treatment, the cells 101 in the module are connected in series and parallel to precisely match output requirements, ultimately resulting in higher conversion efficiency and a longer lifespan for the entire module.

[0138] The various embodiments in the specification of this application are described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other. The embodiments provided in the embodiments of this application can be combined with each other if there is no contradiction.

[0139] It should be noted that in the description of this application, it should be understood that the description of the drawings and embodiments is illustrative rather than restrictive. The same figure numbers throughout the embodiments of the specification identify the same structure. In addition, for the purpose of understanding and ease of description, the drawings may exaggerate the thickness of some layers, films, panels, regions, etc. It is also understood that when an element such as a layer, film, region or substrate is referred to as "on" another element, the element may be directly on the other element or there may be an intermediate element. In addition, "on" refers to positioning an element on or below another element, but does not essentially mean positioning on the upper side of another element according to the direction of gravity.

[0140] The terms "upper," "lower," "top," "bottom," "inner," "outer," and the like, indicating positions or locations, are based on the positions or locations shown in the accompanying drawings and are intended solely to facilitate and simplify the description of this application. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally located component.

[0141] It should also be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the article or device comprising the aforementioned elements.

[0142] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An enamel-based photovoltaic module, characterized in that: include: Enamel plates, battery cells and front plates stacked in sequence; The enamel plate includes: a metal base plate; an enamel layer, wherein the enamel layer is located on a side of the metal base plate facing the battery cell; The surface of the metal base plate facing the battery cell is covered with a reflective layer; The enamel layer covers the surface of the reflective layer; The enamel layer includes at least one enamel sublayer; wherein, the surface of the battery cell facing the enamel plate includes a battery positive electrode; the enamel sublayer adjacent to the battery cell is conductive and electrically connected to the battery positive electrode.

2. The enamel-based photovoltaic module according to claim 1, characterized in that: The thermal expansion coefficient of the metal base plate is adapted to the thermal expansion coefficient of the enamel layer.

3. The enamel-based photovoltaic module according to claim 1 or 2, characterized in that: The enamel layer includes multiple enamel sub-layers stacked in sequence; the refraction of two adjacent enamel sub-layers is different.

4. The enamel-based photovoltaic module according to claim 1, characterized in that: The surface of the battery sheet facing the front plate has a negative electrode; The metal base plate is insulated from the conductive enamel sublayer; the negative electrode of the battery is connected to the metal base plate, and the metal base plate is used for grounding.

5. The enamel-based photovoltaic module according to claim 1 or 2, characterized in that: The enamel layer includes at least one enamel sublayer; The enamel sublayer adjacent to the cell is formed by sintering a glaze coating including a passivation material; during the sintering process, the passivation material can diffuse to the surface of the cell facing the enamel plate to passivate the surface of the cell.

6. The enamel-based photovoltaic module according to claim 1 or 2, characterized in that: The enamel layer includes at least one enamel sublayer; Wherein, at least one of the enamel sub-layers includes a fluorescent material, and the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light.

7. A method for preparing an enamel-based photovoltaic module according to any one of claims 1 to 6, characterized in that: include: Using enamel glaze, a glaze coating is formed on one side of the metal base plate; The surface of the metal base plate is covered with a reflective layer, and the glaze coating is formed on the surface of the reflective layer; Laying a battery cell on the surface of the glaze coating; Sintering the glaze coating into an enamel layer, and fixing the cell on the surface of the metal base plate through the enamel layer; wherein the metal base plate and the reflective layer and the enamel layer on the surface thereof are constructed into an enamel plate; A front plate is arranged on a surface of the battery cell facing away from the enamel plate.

8. The preparation method according to claim 7, characterized in that The enamel glaze comprises: uniformly mixed organic components and inorganic components; The organic component includes epoxy resin and polyurethane in a mass ratio of 3:1; The inorganic components include: 40wt%~45wt% , 25wt%~30wt% , 8wt%~10wt% and 15wt%~27wt% of auxiliary materials; wherein, the auxiliary materials include: 5wt%~8wt% or , 2wt%~4wt% , 3wt%~5wt% clay, 5wt%~25wt% water.

9. The preparation method according to claim 7 or 8, characterized in that The enamel material further includes at least one of a fluorescent material, a passivation material and a nano-conductive material; Among them, the fluorescent material can emit visible light fluorescence based on the excitation of ultraviolet light; the passivation material can diffuse to the surface of the battery cell facing the enamel plate after sintering, and passivate the surface of the battery cell; the nano-conductive material can form a conductive channel electrically connected to the positive electrode of the battery cell in the enamel layer after sintering.

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