Battery assembly, photovoltaic assembly and building

Abstract

The application provides a battery assembly, a photovoltaic assembly and a building, wherein the battery assembly comprises a battery string, the battery string comprises a plurality of solar cells and a conductive assembly, the plurality of solar cells are arranged side by side along a first direction, the conductive assembly is arranged on at least one side of the plurality of solar cells in a thickness direction and comprises a plurality of conductive pieces, at least part of the plurality of conductive pieces are electrically connected to any two adjacent solar cells in the plurality of solar cells along the first direction, wherein the plurality of conductive pieces of the conductive assembly has a first region and a second region, at least one of the first region and the second region is provided with a coating layer, so that at least one of the first region and the second region has a pattern. In this way, the photoelectric conversion efficiency of the patterned photovoltaic assembly is higher.

Description

Technical Field

[0001] This application relates to a battery module, a photovoltaic module, and a building. Background Technology

[0002] A photovoltaic (PV) module is the smallest effective power generation unit in a solar power system, typically comprising multiple cell strings and encapsulation materials for those strings. A single cell string consists of multiple solar cells connected by conductive components such as solder ribbons. The encapsulation materials include glass as the front-facing transparent encapsulation material, an encapsulating film (e.g., EVA (Ethylene Vinyl Acetate Copolymer)) for tightly pressing the cell strings together, a backsheet for supporting the cell strings on the back, and an encapsulation frame (e.g., an aluminum alloy frame).

[0003] To enhance aesthetic appeal and meet diverse application needs, some photovoltaic (PV) modules undergo patterning processing technology, resulting in PV modules with inherent patterns.

[0004] However, the patterns on photovoltaic modules are usually located on the encapsulation glass, which affects light transmission performance, increases optical loss, and reduces photoelectric conversion efficiency. Utility Model Content

[0005] This application aims to provide a patterned battery module, photovoltaic module, and building with higher photoelectric conversion efficiency.

[0006] To achieve the above objectives, the battery assembly provided in this application includes:

[0007] A battery string includes multiple solar cells and a conductive component. The multiple solar cells are arranged side by side along a first direction. The conductive component is disposed on at least one side of the multiple solar cells in the thickness direction and includes multiple conductive elements. At least some of the conductive elements are electrically connected to any two adjacent solar cells along the first direction.

[0008] The conductive component has a first region and a second region, and at least one of the first region and the second region is provided with a coating such that at least one of the first region and the second region has a pattern.

[0009] In some embodiments, the second region is provided with a coating, and the coating of the second region is dark; and / or, the coating is a thermochromic coating.

[0010] In some embodiments, the coating of the second region is black, gray, or dark blue; and / or, only the first region has a pattern, the second region has a coating, and the coating of the second region is dark.

[0011] In some embodiments, both the first region and the second region are provided with a coating, the coating in the first region and the coating in the second region are different colors; and / or, the thickness of the coating is 1~150μm.

[0012] In some embodiments, the coating material is polyimide, SiO2, or a metal oxide; and / or, the first region is distributed in a dotted or linear pattern on the conductive component.

[0013] In some embodiments, the coating material is CuO, VO2, Co3O4, Fe3O4, MnO2, ZnO or WO3.

[0014] In some embodiments, the conductive component is disposed only on one side of the plurality of solar cells in the thickness direction; and / or, the surface of the plurality of solar cells on which the conductive component is disposed has no grid lines.

[0015] In some embodiments, conductive components are disposed only on the back side of multiple solar cells.

[0016] In some embodiments, a current-collecting layer is provided on the back of the solar cell, and a conductive element is electrically connected to the current-collecting layer.

[0017] In some embodiments, the current collection layer is configured as at least one of the following:

[0018] Thickness is 0.5~1μm;

[0019] Width is 1~10μm;

[0020] It contains 75% to 90% silver by mass.

[0021] In some embodiments, the conductive element includes a conductive wire; and / or, the material of the conductive element includes copper, Al-Si alloy, or Zn-Sn alloy.

[0022] In some embodiments, the width of the conductive wire is less than or equal to 0.15 mm.

[0023] In some embodiments, the battery assembly includes a plurality of battery strings arranged in a pattern.

[0024] In addition, the photovoltaic modules provided in this application include the battery modules of any embodiment.

[0025] Furthermore, the building provided in this application includes photovoltaic modules according to any embodiment.

[0026] In some embodiments, the photovoltaic module is installed vertically; and / or, the conductive component of the photovoltaic module is disposed only on one side of the plurality of solar cells, and the side of the photovoltaic module with the conductive component faces the inside of the building.

[0027] Patterns are obtained by applying a coating to at least one of the first and second regions of a plurality of conductive elements used to achieve electrical connections between solar cells in a cell string. Since the coating is attached to the conductive elements that are already present in the cell string, the coating does not add additional light-blocking area and does not affect light transmission performance like patterns applied to encapsulation glass. Therefore, optical loss is less and photoelectric conversion power is higher, which can reduce the optical loss of patterned photovoltaic modules and improve the photoelectric conversion efficiency of patterned photovoltaic modules.

[0028] In addition, by applying a coating to conductive components, the process is relatively simple and does not have high requirements for materials, equipment, or structure, making it easier to promote. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the photovoltaic module in the embodiments of this application.

[0030] Figure 2 for Figure 1 The diagram shows the structure of a single cell string in a photovoltaic module.

[0031] Figure 3 This is a schematic flowchart illustrating the method for preparing the battery assembly in this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. Photovoltaic modules;

[0034] 10. Battery string; 20. Battery assembly;

[0035] 1. Solar cell; 11. Substrate; 12. Front side; 13. Back side; 14. Passivation layer; 15. p+ doped region; 16. n+ doped region; 17. Current collection layer;

[0036] 2. Conductive components;

[0037] 3. Conductive components; 31. Conductive wire;

[0038] 4. First area;

[0039] 5. Second area;

[0040] 6. Coating;

[0041] 7. Pattern;

[0042] X, first direction; Y, second direction; Z, thickness direction. Detailed Implementation

[0043] In this application, unless otherwise stated, "multiple" means at least two, such as two, three or more.

[0044] With the continuous development of the photovoltaic industry, patterning of photovoltaic modules has become a key technology for improving their overall performance and expanding their application scope.

[0045] Patterning photovoltaic (PV) modules can, on the one hand, change the monotonous appearance of traditional PV modules, greatly enhance their aesthetic value, and allow them to better integrate into different architectural styles and environmental scenarios, satisfying people's pursuit of aesthetic and personalized building appearances. On the other hand, patterned PV modules can replace traditional exterior wall materials such as glass curtain walls, marble, tiles, and real stone paint, covering various scenarios such as roof shapes, artistic exterior walls, fences, and soundproof walls. In addition, in some commercial displays and public facilities, they can also attract attention with unique patterns, achieving a fusion of function and display. Therefore, it can also broaden the application scenarios of PV modules and promote their application in scenarios such as building-integrated photovoltaics (BIPV).

[0046] Building integrated photovoltaics (BIPV) is a technology that integrates solar power generation (photovoltaic) products into buildings. It refers to installing photovoltaic modules on the surface of the building envelope to provide electricity, while also replacing some traditional building structures, such as roofs, building facades, and canopies, as functional parts of the building structure.

[0047] However, current photovoltaic module patterning solutions suffer from significant optical efficiency loss and are quite complex and difficult to implement, which hinders the further promotion and application of photovoltaic module patterning technology.

[0048] Specifically, a typical photovoltaic module patterning technology currently involves patterned glass technology. This technology uses enamel and a screen to print patterns onto a glass substrate (i.e., the encapsulation panel of the photovoltaic module), or it involves engraving patterns onto the glass substrate. In this case, the pattern is located on the encapsulation glass, which affects light transmission, causing a 15% to 25% power loss and reducing photoelectric conversion efficiency. Moreover, patterned glass technology, when using printing, has extremely high requirements for enamel selection and printing processes, making it quite difficult. Furthermore, changing the pattern requires customizing the screen and adjusting the process, resulting in long delivery cycles and high costs. When using engraving, the glass needs to be carved, which is difficult and can reduce glass strength, affecting structural reliability. All of these factors restrict the further promotion and application of this patterning technology.

[0049] It is evident that using patterned glass technology to set patterns on the glass used as encapsulation material has the problem of significant optical power loss, as well as high requirements and difficulties. These factors severely restrict the further promotion and application of patterned photovoltaic modules.

[0050] In view of the above situation, in order to facilitate the further promotion and application of patterned photovoltaic modules, this application provides a battery module and its preparation method, a photovoltaic module and a building.

[0051] Figures 1-2 The photovoltaic module and battery string of this application are illustrated by way of example. Figure 3 An exemplary method for preparing the battery assembly of this application is shown.

[0052] See Figure 1 and Figure 2 In this application, the photovoltaic module 100 includes a battery module 20, which in turn includes a battery string 10. The battery string 10 includes a plurality of solar cells 1 and a conductive component 2. The plurality of solar cells 1 are arranged side by side along a first direction X. The conductive component 2 is disposed on at least one side of the plurality of solar cells 1 in the thickness direction Z and includes a plurality of conductive elements 3. These conductive elements 3 are electrically connected to any two adjacent solar cells 1 along the first direction X. The conductive elements 3 of the conductive component 2 have a first region 4 and a second region 5. At least one of the first region 4 and the second region 5 is provided with a coating 6, such that at least one of the first region 4 and the second region 5 has a pattern 7.

[0053] The above scheme divides the multiple conductive elements 3 of the battery string 10 of the battery assembly 20 for realizing electrical connection between solar cells into sections, and sets a coating 6 in at least one of the divided first region 4 and second region 5. The pattern 7 is formed by the difference in the coating setting in the first region 4 and the second region 5, such as the difference in the presence or absence of coating, or the difference in coating properties (such as color). This pattern processing method of setting coating in sections of conductive elements can be called patterned conductive element technology.

[0054] A patterned photovoltaic module 100 is prepared by using a corresponding patterned conductive component technology. Since the coating 6 is attached to the conductive component 3 that is already present in the cell string 10, the coating 6 does not increase the light-shielding area and will not affect the light transmission performance like the pattern set on the encapsulation glass. Therefore, it can improve the light transmission performance, reduce optical loss, and increase the photoelectric conversion power, which is conducive to the further promotion and application of patterned photovoltaic module technology.

[0055] Moreover, using appropriate patterned conductive component technology to fabricate patterned photovoltaic modules 100 not only reduces optical losses and improves photoelectric conversion power, but also has the following advantages:

[0056] Since only the conductive parts 3 connected between the solar cells need to be patterned, and there is no need to engrave the encapsulation glass, the strength of the glass is not reduced, which helps to improve the structural reliability.

[0057] Since only the conductive parts 3 connected between the solar cells need to be patterned without changing the internal structure of the solar cells, damage to the solar cells 1 can be reduced and the structural reliability can be improved.

[0058] The coating 6 can be uniformly and extensively applied to the conductive component 3, which facilitates the preparation of large-area and uniform patterns. This not only helps to further improve the aesthetic performance of the photovoltaic module 100, but also helps to achieve large-scale production and improve production efficiency.

[0059] Since the first region 4 and the second region 5 can be flexibly set, and the setting of the coating 6 can be flexibly changed, such as the outline of the first region 4 and the second region 5, whether the first region 4 and the second region 5 are set with the coating 6, and the material and color of the coating 6, etc., it is convenient to customize according to the usage scenario, meet more diverse patterning needs, and effectively broaden the application scenarios of patterned photovoltaic modules.

[0060] In addition, the corresponding patterned conductive component technology obtains the pattern 7 by setting a coating 6 on at least one of the first region 4 and the second region 5 of the plurality of conductive components 3 used to realize electrical connection between solar cells in the battery string 10. Setting the coating 6 on the conductive component 3 is a relatively simple process with no high requirements on materials, equipment and structure. Therefore, it also has the advantages of low requirements, low difficulty and low cost.

[0061] For example, patterned conductive component technology does not require engraving the glass or printing patterns on the glass substrate using enamel and screen printing, unlike patterned glass technology. Therefore, it does not have the same high requirements for engraving, enamel selection and printing processes. When changing the pattern, there is no need to customize the screen and adjust the process. As a result, the production difficulty is relatively small, the production efficiency is high and the production cost is low.

[0062] For example, patterned conductive component technology does not require changing the structure of solar cells (e.g., it does not require setting special-shaped metal lines on solar cells for splicing patterns), thus not increasing the complexity of solar cell production. It also has lower requirements for splicing different solar cells. In particular, the coating can be applied after multiple cell strings are arranged, which reduces the accuracy requirements for solar cell arrangement. Therefore, the production difficulty is relatively small, the production cost is low, and it can be easily automated for mass production.

[0063] For example, the transparent packaging structure of patterned conductive components does not have special requirements for material selection and structural design (for example, there are no special requirements for the material and structural design of the transparent packaging structure, and there is no need to set a refractive index difference layer for refraction to form a pattern in the transparent packaging mechanism). The technology is relatively easy to implement, so the production difficulty is relatively small and the production cost is relatively low.

[0064] It is evident that patterned conductive component technology also has the advantages of low production requirements, low production difficulty, low production cost, and easy mass production. Correspondingly, the battery string 10, battery module 20, and photovoltaic module 100 prepared based on patterned conductive component technology also have the advantages of low production requirements, low production difficulty, low production cost, and mass production friendliness. Therefore, they are simpler and easier to promote, which is conducive to the further promotion and application of patterned photovoltaic module technology.

[0065] In summary, by partitioning coatings 6 onto multiple conductive elements 3 of conductive components 2 on at least one side of multiple solar cells 1, and patterning multiple conductive elements 3, patterned battery strings 10, battery modules 20, and photovoltaic modules 100 are prepared. This not only results in low power loss, high structural reliability, uniform and aesthetically pleasing patterns, and easy personalization, but also low production requirements, low production difficulty, low production cost, high production efficiency, and mass production friendliness. All of these are conducive to the further promotion and application of patterned photovoltaic module technology, and especially to improving the competitiveness of photovoltaic modules 100 in application scenarios with high appearance requirements, such as building-integrated photovoltaics.

[0066] In this application, only one of the first region 4 and the second region 5 of the plurality of conductive elements 3 may be provided with coating 6, or both may be provided with coating 6, and only one may have pattern 7, or both may have pattern 7.

[0067] When only one of the first region 4 and the second region 5 is coated with coating 6, the two regions can present different visual effects because the other is not coated with coating 6. Therefore, a pattern 7 can be formed in the first region 4 and / or the second region 5 based on the contour at the boundary between the first region 4 and the second region 5. For example, see... Figure 2 In some embodiments, only the second region 5 has the coating 6, while the first region 4 does not. In this case, the first region 4 can be visually distinguished from the second region 5 based on the difference between the color of the conductive element 3 itself and the color of the coating 6 in the second region 5, thus presenting the pattern 7. As another example, in an embodiment not shown, only the first region 4 has the coating 6, while the second region 5 does not. In this case, the first region 4 can be visually distinguished from the second region 5 based on the difference between the color of its coating 6 and the color of the conductive element 3 itself in the second region 5, thus presenting the pattern 7.

[0068] The scheme where only one of the first region 4 and the second region 5 has a coating 6 can be achieved by applying the coating 6 only to the areas in the first region 4 and the second region 5 where the coating 6 is required, while leaving the other region uncoated. Alternatively, it can be achieved by first applying the coating 6 to both the first region 4 and the second region 5, and then removing the coating 6 from the areas where it is not required. The former method eliminates the need to apply the coating 6 to the conductive component 2 and then remove it, thus reducing the number of steps, simplifying the process, and improving production efficiency. The latter method, during the application of the coating 6 to the conductive component 2, does not require distinguishing between the first region 4 and the second region 5, nor does it require precise control of the coating application area. Therefore, it simplifies the coating application process, reduces the requirements for the coating application technology, and, since the coating application process does not require zoning, it can be completed well even before the battery string 10 is prepared. For example, the coating 6 can be applied to the entire conductive component 3 before it is connected to the solar cell 1, ensuring that the entire conductive component 3 has the coating 6, thus achieving the application of the coating 6 to the conductive component 2.

[0069] When both the first region 4 and the second region 5 are coated with a coating 6, different colors of coating 6 can be applied to the first region 4 and the second region 5 to make them visually distinct and present a pattern 7. For example, in some embodiments, a colored coating 6 can be applied to the first region 4, while a monochrome coating 6 can be applied to the second region 5, so that the first region 4 presents a pattern 7, and presents a colored pattern 7, thereby enhancing its aesthetic value.

[0070] The color of coating 6 is not limited and can be any dark or light color. When coating 6 is black, gray, or dark blue, it can not only form the desired pattern 7, but also reduce glare by taking advantage of the strong light absorption of dark colors, thus expanding the application scenarios and making photovoltaic module 100 particularly suitable for vertical installation.

[0071] Glare is understood to refer to visual discomfort caused by abnormal brightness distribution or sudden changes in brightness over time, which can reduce visual clarity and cause eye strain. Vertically installed photovoltaic (PV) modules, often referred to as vertical PV modules, have an installation angle of nearly 90° and offer unique advantages such as bi-directional light reception, efficient land use, and resistance to wind and snow, making them ideal for high-latitude regions, agricultural PV, and transportation infrastructure (such as sound barriers). However, vertical installation generally suffers from significant glare problems. Due to the near-90° installation angle, sunlight at low angles (such as during sunrise and sunset) is easily reflected strongly, potentially causing light pollution, affecting traffic safety (such as near airports and highways), or triggering resident complaints. Therefore, reducing the glare effect of vertical PV modules has become one of the key challenges restricting their widespread application.

[0072] By setting coating 6 to a dark color such as black, gray, or dark blue, the glare effect of patterned photovoltaic modules when vertically installed can be effectively reduced, promoting the widespread application of patterning technology in vertical photovoltaic modules. In particular, among various dark colors, black has the strongest light absorption capacity; therefore, coating 6 can be set to black to better reduce the glare effect. In this application, black includes various shades such as pure black, bluish-black, and dark black.

[0073] The aforementioned dark coating 6 is particularly suitable for areas without pattern 7. For example, in the case where only the first area 4 has pattern 7 and the second area 5 does not, it is particularly suitable to set the dark coating 6 in the second area 5. In this way, the dark coating 6 of the second area 5 without pattern 7 can be used to reduce glare effect and promote the application of photovoltaic module 100 in vertical installation scenarios, while also making it convenient for the first area 4 with pattern 7 to adopt a coating 6 with a color that meets the pattern requirements.

[0074] The coating 6 does not reduce the refractive index of the conductive element 3 in the patterned and unpatterned areas. In other words, the refractive index of the conductive element 3 can remain consistent in the patterned and unpatterned areas, which is beneficial to maintaining consistent light utilization and improving overall power.

[0075] In the foregoing embodiments, the material of coating 6 is not limited. As an example, the material of coating 6 is polyimide, SiO2 (silicon dioxide), or metal oxides (such as manganese dioxide (MnO2), iron(III) oxide (Fe3O4), copper oxide (CuO), VO2 (vanadium dioxide), Co3O4 (cobalt(III) oxide), ZnO (zinc oxide), or WO3 (tungsten trioxide), etc.). When the material of coating 6 is metal oxides such as manganese dioxide (MnO2), iron(III) oxide (Fe3O4), copper oxide (CuO), VO2 (vanadium dioxide), or Co3O4 (cobalt(III) oxide), as well as polyimide or SiO2 (silicon dioxide), coating 6 is black, has strong light absorption capacity, can effectively reduce glare effect, and promote the application of patterning technology in vertical photovoltaic modules. The corresponding black coating 6 can be applied to areas without patterns (e.g., the second area 5) to make the areas without patterns 7 (e.g., the second area 5) appear black while forming the pattern 7, thereby enhancing the aesthetic value of the photovoltaic module 100, reducing glare, and improving the adaptability of the photovoltaic module 100 to vertical installation.

[0076] Furthermore, when the material of coating 6 is CuO, VO2, Co3O4, Fe3O4, MnO2, ZnO, or WO3, coating 6 is a thermochromic coating. A thermochromic coating is a coating that changes color when heated to a preset temperature range. For example, a CuO coating that is originally black can change to red when heated; a VO2 coating that is originally dark blue or black can change to yellowish-brown or golden color upon heating; a Co3O4 coating that is originally dark black can change to grayish-white upon heating; a Fe3O4 coating that is originally black can change to red upon heating; a MnO2 coating that is originally dark black can change to brownish-black or reddish-brown upon heating; a WO3 coating that is originally yellow can change to black upon heating; and a ZnO coating that is originally white can change to yellow upon heating. It can be seen that using CuO, VO2, Co3O4, Fe3O4 or MnO2 to make coating 6 can make coating 6 a thermochromic coating whose original color (i.e., the color before color change) is black; using WO3 to make coating 6 can make coating 6 a thermochromic coating that turns black after color change; using ZnO to make coating 6 can make coating 6 a thermochromic coating that is not black before or after color change.

[0077] The advantage of setting coating 6 as a thermochromic coating is that the corresponding thermochromic coating can be first set in at least one of the first region 4 and the second region 5, and then heat-treated by means of laser heat treatment, etc., to make the corresponding thermochromic coating change color when heated, so as to form pattern 7. This method of setting a thermochromic coating and heat-treating the thermochromic coating to form a pattern is convenient for producing large-area patterns, has high efficiency, and the process of forming the pattern does not produce material residue. There is no need to deal with the residue, and there is no need to worry about the residue affecting the aesthetics and electrical properties of the product. Therefore, it is simpler, cleaner, more efficient and reliable.

[0078] The advantage of setting coating 6 as a thermochromic coating with black as its natural color is that the corresponding thermochromic coating can be applied to areas without patterns (such as the second area 5), ​​so that the areas without patterns are black, reducing the glare effect, and thus making the photovoltaic module 100 more suitable for vertical installation.

[0079] In addition, by setting the coating 6 as a thermochromic coating that turns black after color change, the thermochromic coating can be applied to the conductive component 3, and then the area without a pattern (e.g., the second area 5) can be heat-treated to make the area without a pattern (e.g., the second area 5) turn black, thereby reducing the glare effect and making the photovoltaic module 100 more suitable for vertical installation.

[0080] When coating 6 is a thermochromic coating, coating 6 can be applied to conductive element 3 before or after it is connected to battery 1. Specifically, when coating 6 is applied to conductive element 3 before it is connected to battery 1, coating 6 is applied to conductive element 3 before the battery string 10 is fabricated. In this case, since conductive element 3 is not yet fixed to battery 1 and is not constrained or obstructed by battery 1 or other conductive elements 3 or other structures, it is easier to achieve a more efficient and uniform application of coating 6 on conductive element 3. For example, coating 6 can be easily and uniformly applied to the entire conductive element 3.

[0081] The heat treatment of the thermochromic coating can be performed after the battery string 10 is fabricated. This allows for the direct determination of the areas requiring heat treatment on the entire battery string 10 based on the pattern, and enables the simultaneous heat treatment of the coating 6 on all conductive parts 3 within the corresponding heat-treated areas. This approach offers advantages such as large area coverage, high efficiency, and aesthetically pleasing patterns. In particular, the heat treatment of the thermochromic coating can be performed after the battery string 10 is fabricated, and after multiple battery strings 10 are arranged and encapsulated by encapsulating glass. After the battery string 10 is fabricated and multiple battery strings 10 are arranged and encapsulated by the encapsulation glass, the thermochromic coating is then heat-treated. The advantage is that not only can the area requiring heat treatment be more accurately determined according to the pattern of the entire photovoltaic module 10 after the arrangement, but also the coating 6 on more conductive parts 3 can be heat-treated at one time. Moreover, in this case, the heat treatment process is carried out outside the encapsulation glass and through the encapsulation glass. In this way, since the encapsulation glass can meet the basic heat requirements of heat treatment while playing a certain role in heat insulation, it can prevent excessively high temperatures from damaging the structural components of the photovoltaic module. Therefore, it is conducive to achieving a safer heat treatment process. At the same time, since the encapsulation glass is transparent to lasers, it is convenient to perform laser heat treatment on the coating 6, thus achieving a safer laser heat treatment process.

[0082] Furthermore, in the aforementioned embodiments, the thickness of the coating 6 is not limited. Exemplarily, the thickness of the coating 6 is 1~150 μm (micrometers), for example, 1~20 μm, 21~50 μm, 51~100 μm, or 101~150 μm; specifically, for example, 2 μm, 10 μm, 30 μm, 40 μm, 41 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 90 μm, 110 μm, or 120 μm. In this case, the thickness of the coating 6 is suitable, allowing it to firmly adhere to the conductive component 3, forming a clear and aesthetically pleasing pattern 7, while also requiring less material and incurring lower costs. Therefore, it facilitates the formation of a strong and clear pattern at a lower cost, making it easier to promote and apply.

[0083] Furthermore, in the aforementioned embodiments, the distribution of the first region 4 on the conductive component 2 is not limited; it can be distributed in a dotted or linear manner to form more diverse patterns and meet more personalized pattern customization needs.

[0084] In the foregoing embodiments, the conductive component 2 can be disposed on only one side of the multiple solar cells 1 in the thickness direction Z, or on both sides of the multiple solar cells 1 in the thickness direction Z. When the conductive component 2 is disposed on both sides of the solar cell 1 in the thickness direction, both the front side 12 and the back side 13 of the solar cell 1 are provided with the conductive component 2. In this case, the pattern 7 can be achieved by evenly distributing the coating 6 on the conductive component 2 on both sides. When the conductive component 2 is disposed on only one side of the multiple solar cells 1 in the thickness direction Z, the solar cell 1 is provided with the conductive component 2 on only one side. In this case, each conductive element 3 of the conductive component 2 is located on the same side of the multiple solar cells 1. Correspondingly, the pattern is only located on one side, while the other side has no pattern. This can enhance the aesthetic value of the photovoltaic module while reducing changes and impacts on the other side, facilitating normal light transmission on the other side. Furthermore, when the conductive component 2 is only disposed on one side of the thickness direction Z of the plurality of solar cells 1, since each conductive element 3 of the conductive component 2 is located on the same side of the plurality of solar cells 1, and not with one end located on the front side 12 and the other end located on the back side 13 of the adjacent solar cell 1, it is more convenient to set the first region 4 and the second region 5 and the coating 6 located in at least one of the first region 4 and the second region 5 on the conductive element 3 to form a pattern 7.

[0085] As an example where the conductive component 2 is disposed only on one side of the plurality of solar cells 1 in the thickness direction Z, see [reference needed]. Figure 2 The conductive component 2 is only disposed on the back side 13 of multiple solar cells 1. In this case, the conductive component 2 is not disposed on the front side 12 (light-receiving surface) of the solar cell 1, but only on the back side 13 (non-light-receiving surface). In this case, the solar cell 1 is actually a back contact (BC) solar cell.

[0086] Back-contact solar cells are a type of solar cell that integrates all positive and negative metal contacts on the back side. With no grid lines obstructing the front, they can effectively improve photoelectric conversion efficiency, increase the flatness and aesthetics of the solar cell surface, greatly enhance the aesthetic value of photovoltaic modules, and facilitate the perfect integration of photovoltaic modules into building designs, achieving harmonious coexistence between photovoltaic modules and buildings.

[0087] Since the positive and negative electrodes of the back-contact solar cell are both integrated on the back side 13, the conductive components 2 of multiple solar cells in series only need to be set on the back side 13 of the solar cell 1. In this case, all the conductive components 3 of the battery string 10 are located on the same side of the solar cell 1 and are parallel to each other, which makes it easier to set the first area 4, the second area 5 and the coating 6 to form a clear and beautiful pattern.

[0088] See Figure 2In some embodiments, the surfaces of the plurality of solar cells 1 with conductive components 2 are free of grid lines.

[0089] Grid lines are a series of metallic lines located on the surface of a solar cell, primarily serving to collect and transport electrons. Grid lines are typically made of conductive materials such as silver and are printed or deposited onto the substrate surface of the solar cell. When sunlight shines on the substrate, it converts light energy into electrical energy, generating electrons and holes. The role of the grid lines is to quickly guide these electrons to the edges of the solar cell so that they can be collected and utilized by external circuitry.

[0090] A grid line typically consists of a finer grid and a thicker main grid. The grid and main grid intersect, and the grid is connected to a conductive element (such as solder strip) through the main grid to collect and transport electrons outward.

[0091] Traditional solar cells typically have grid lines. However, since the fabrication of grid lines requires silver, solar cells with grid lines have higher silver consumption. Furthermore, with grid lines, there is more lateral current transmission (i.e., transmission along the grid lines in a direction parallel to the surface of the solar cell) before the current flows to the conductive components. This results in a longer transmission path and lower efficiency. At the same time, grid lines also block light to some extent, causing optical loss and affecting light absorption rate and photoelectric conversion efficiency. In addition, grid lines make the surface of the solar cell messy and uneven, affecting the overall aesthetics.

[0092] By eliminating the grid lines, only a current collection layer (or seed layer) needs to be set on the substrate surface, and then the conductive element is placed on the collection layer to form an ohmic contact and achieve electrical connection, thus realizing current collection and transmission. This effectively reduces the silver loss of the grid lines and lowers costs. On the other hand, since the extension direction of the current collection layer is not perpendicular to the extension direction of the conductive element like the fine grid, but consistent with the extension direction of the conductive element, the current can be directly conducted vertically from the current collection layer to the conductive element without first traveling laterally along the fine grid to reach the conductive element. Therefore, it can also change the current collection path of traditional solar cells, avoiding the lateral transmission of current along the grid lines, so that the current no longer needs to travel laterally along the fine grid, but only retains the vertical conduction from the surface of the solar cell to the conductive element, improving the current transmission efficiency. Furthermore, it can also avoid the grid lines blocking sunlight, reducing optical loss and improving light absorption rate and photoelectric conversion efficiency. Moreover, the grid-free design also makes the surface of the solar cell cleaner and more aesthetically pleasing, enhancing the aesthetic value of the photovoltaic module 100 and promoting its application in scenarios with high appearance requirements, such as building-integrated photovoltaics.

[0093] Therefore, by setting the surface of the battery string 10 with the conductive component 2 to a grid-free structure, silver loss can be reduced, lateral current transmission in the grid lines can be avoided, and the grid lines can be prevented from blocking sunlight, thus further reducing costs and improving efficiency. Moreover, the grid-free surface with the conductive component 2 makes the surface with the conductive component 2 cleaner and more aesthetically pleasing, and reduces the visual interference of the grid lines on the patterns on the conductive component 2, thus further improving aesthetics. In addition, compared with the case with grid lines, the conductive part 3 of the conductive component 2 can be thinner and more numerous when there are no grid lines, which makes it easier to set the coating 6 in sections on the conductive part 3 to form a more continuous, clear and beautiful pattern.

[0094] For example, when solar cell 1 is a back-contact solar cell, the conductive component 2 is only disposed on the back side 13 of solar cell 1. In this case, solar cell 1 is configured to have no grid lines on both the front and back sides 13, making solar cell 1 a grid-free back-contact solar cell. The photovoltaic module 100 relies entirely on the conductive component 3 on the back side 13 of solar cell 1 for current transmission, forming a design with no obstruction on the front and a pattern on the back. Therefore, silver consumption is low, efficiency is high, and the pattern is beautiful. In particular, the conductive component 3 of the conductive component 2 on the back side 13 is fine and dense, which facilitates the large-area and uniform application of the coating 6. The pattern 7 obtained after the coating 6 is applied to the conductive component 2 on the back side 13 is not visually disturbed by the grid lines. Therefore, the pattern looks more continuous, clear, and beautiful, with higher aesthetic value.

[0095] The conductive element 3 in the aforementioned embodiments can be a solder strip or a conductive wire 31. The solder strip is relatively thick (typically 0.2~0.28 mm wide) and is generally suitable for solar cells 1 with grid lines. The conductive wire 31 is relatively thin (less than 0.2 mm wide) and is generally suitable for solar cells without grid lines, especially for the aforementioned grid-less back-contact solar cells.

[0096] Since the conductive wires 31 are usually thinner and denser, and are usually only arranged on one side of the solar cell 1, and are parallel to each other, it is easier to set the coating 6 and form the pattern 7. Therefore, photovoltaic modules with conductive wires 31 are particularly suitable for using the patterned conductive component technology of this application to achieve patterning processing, form more continuous, clear and beautiful patterns, and improve aesthetics.

[0097] In some embodiments, the width of the conductive wire 31 is less than or equal to 0.15 mm. For example, the width of the conductive wire 31 is greater than or equal to 1 mm and less than or equal to 0.15 mm, such as 0.15 mm, 0.14 mm, 0.13 mm, 0.12 mm, 0.11 mm, or 0.1 mm. In this case, the conductive wire 31 is thinner and the arrangement is denser. Therefore, it is easier to form a more continuous, clear, and aesthetically pleasing pattern through patterned conductive component technology, thereby improving the aesthetics.

[0098] In the foregoing embodiments, the material of the conductive element 3 is not limited. Exemplarily, in some embodiments, the material of the conductive element 3 includes copper, Al-Si alloy (aluminum-silicon alloy), or Zn-Sn alloy (zinc-tin alloy). For example, in some embodiments, the conductive element 3 includes a conductive wire 31, which is made of copper, Al-Si alloy, or Zn-Sn alloy. Copper, Al-Si alloy, and Zn-Sn alloy all have excellent conductivity, which can effectively improve the electrical performance of the battery string 10, battery module 20, and photovoltaic module 100. When the material of the conductive element 3 includes Al-Si alloy or Zn-Sn alloy, the work function of the conductive element 3 and the thermochromic coating are relatively close, the potential barrier is small or non-existent, and the conductive element 3 is easier to bond with the thermochromic coating. Furthermore, it is less likely to undergo material changes due to hot spots during the heat treatment of the thermochromic coating. Therefore, it is more suitable for situations where the coating 6 is a thermochromic coating and requires heat treatment such as laser heat treatment.

[0099] In the foregoing embodiments, the pattern 7 on a single battery string 10 may be a complete pattern in itself, or it may not constitute a complete pattern on its own, but only be a part of a complete pattern. When the pattern 7 on a single battery string 10 is only a part of a complete pattern, a complete pattern can be formed by splicing multiple battery strings 10. And when the pattern 7 on a single battery string 10 is a complete pattern in itself, multiple battery strings 10 can also be spliced ​​to form a pattern including multiple sub-patterns.

[0100] Therefore, in some embodiments, the battery module 20 includes multiple battery strings 10, whose patterns 7 are arranged together. In this way, the patterns 7 formed by the coating 6 of the multiple battery strings 10 are combined to form a more complete and aesthetically pleasing pattern. At this point, the battery module 20, comprising multiple arranged battery strings 10, can be considered a semi-finished photovoltaic module. It can then undergo component encapsulation processes such as busbarization, stacking, and lamination, as well as conventional component manufacturing methods, to ultimately obtain the finished photovoltaic module.

[0101] As mentioned above, the photovoltaic module 100 provided in the various embodiments of this application is particularly suitable for application in the building field. Therefore, this application also provides a building, which includes the photovoltaic module 100 of any embodiment. The photovoltaic module 100 can be used as a component of the exterior wall or roof of buildings such as houses, or it can also be used as a component of the soundproof wall in places such as airports or overpasses.

[0102] There are no restrictions on the installation method of the photovoltaic module 100 on the building; it can be set according to actual needs. For example, when used as a rooftop, the photovoltaic module 100 can be installed at an angle or horizontally; while when used as an exterior wall or soundproof wall, the photovoltaic module 100 can be installed vertically to form a vertical photovoltaic module. When the photovoltaic module 100 is installed vertically, its second area 5 can be provided with a dark coating 6 to reduce glare.

[0103] When the conductive component 2 of the photovoltaic module 100 is only provided on one side of the multiple solar cells 1, the side of the photovoltaic module 100 with the conductive component 2 can face the inside of the building, such as the interior of a building or the inside of an overpass. In this way, the pattern on the conductive component 2 faces inward, making it easier for people to see and appreciate the pattern. Moreover, it also makes it easier for the side of the photovoltaic module 100 without the pattern to face outward, fully absorb sunlight, and improve optical efficiency.

[0104] In addition, this application also provides a method for preparing a battery module 20, which is used to prepare a battery module 20 according to any embodiment of this application.

[0105] See Figure 3 The method for preparing the battery module 20 provided in this application includes:

[0106] A coating 6 is provided on at least one of the first region 4 and the second region 5 of the conductive component 2 of the battery string 10 of the battery assembly 20, such that at least one of the first region 4 and the second region 5 has a pattern 7.

[0107] The above solution involves dividing a first region 4 and a second region 5 on multiple conductive components 3 of the conductive component 2 of the battery string 10, and setting a coating 6 on at least one of the first region 4 and the second region 5 to form a pattern 7 located in the first region 4 and / or the second region 5. This is a pattern processing solution based on patterned conductive component technology. The corresponding pattern processing solution has low production requirements, low production difficulty, high production efficiency, low production cost, and is mass-producible. Moreover, it has low power loss, uniform and beautiful patterns, and is easy to personalize. Therefore, it is more convenient to promote and apply.

[0108] For example, patterned conductive component technology does not require engraving the glass or printing patterns on the glass substrate using enamel and screen printing, unlike patterned glass technology. Therefore, it does not have the same high requirements for engraving, enamel selection and printing processes. When changing the pattern, there is no need to customize the screen and adjust the process. As a result, the production difficulty is relatively small, the production efficiency is high and the production cost is low.

[0109] For example, patterned conductive component technology does not require changing the structure of solar cells (e.g., no need to set special-shaped metal lines on solar cells), does not increase the production complexity of solar cells, and has lower requirements for splicing between different solar cells. In particular, the coating can be applied after multiple cell strings are arranged, and the requirements for the arrangement accuracy of solar cells are relatively low. Therefore, the production difficulty is relatively small, the production cost is low, and it can be easily automated for mass production.

[0110] For example, the transparent packaging structure of patterned conductive components does not have special requirements for material selection and structural design (for example, there are no special requirements for the materials and structural design of transparent packaging structures), and the technical implementation is relatively simple. Therefore, the production difficulty is relatively small and the production cost is relatively low.

[0111] For example, since the coating 6 is attached to the existing conductive component 3 of the battery string 10, the coating 6 does not add extra light-shielding area and will not affect the light transmission performance like the pattern set on the encapsulation glass. Moreover, the coating 6 can be set on the conductive component 3 in a large area and uniformly to achieve the preparation of a large area and uniform pattern. At the same time, the first region 4 and the second region 5 can be flexibly set, and the setting of the coating 6 can be flexibly changed, which is convenient for personalized customization according to the application scenario. Therefore, it is also beneficial to reduce power loss, improve the uniformity and aesthetics of the pattern, and facilitate personalized customization.

[0112] The method of setting the coating 6 in at least one of the first region 4 and the second region 5 is not limited. For example, the coating 6 can be set in at least one of the first region 4 and the second region 5 by simply adding it, adding it first and then removing it, or adding it first and then heat-treating it to change its color.

[0113] Adding coating 6 is the process of adhering the paint to the target area (at least one of the first area 4 and the second area 5) to form coating 6. The method of adding coating 6 can be varied, including but not limited to spraying, transfer printing and electrostatic adsorption. That is to say, coating 6 can be applied to at least one of the first area 4 and the second area 5 by spraying, transfer printing or electrostatic adsorption.

[0114] Spraying, transfer printing, or electrostatic adsorption methods are relatively simple processes with low equipment costs, and they facilitate the creation of large-area and uniform coatings. Therefore, they are suitable for large-scale production, effectively improving the production efficiency of patterned photovoltaic modules, producing large-area and uniform patterns, and enhancing aesthetic value.

[0115] Furthermore, spraying, transfer printing, or electrostatic adsorption methods allow for flexible adjustment of the paint adhesion area and paint color. Therefore, the coating configuration of the first region 4 and the second region 5 can be easily changed to meet more personalized pattern customization needs. For example, spraying, transfer printing, or electrostatic adsorption methods can easily apply the coating 6 only to the first region 4 or the second region 5, or easily apply the coating 6 to both the first region 4 and the second region 5, making the colors of the coating 6 in the first region 4 and the second region 5 different. Therefore, spraying, transfer printing, or electrostatic adsorption methods are suitable for obtaining the pattern 7 by applying the coating 6 to one of the first region 4 and the second region 5, and also for obtaining the pattern 7 by applying different colored coatings 6 to the first region 4 and the second region 5.

[0116] In some embodiments, during the application of coating 6 in at least one of the first region 4 and the second region 5 by spraying, at least one of the following parameters is used:

[0117] The distance between the nozzle of the spray gun used for spraying paint and the conductive component 3 is 0.05~5cm, for example, 0.1~0.3cm, 0.5~1.5cm or 2~4cm. Specifically, it can be 0.05cm, 0.1cm, 1cm, 1.5cm, 2cm, 2.5cm, 3cm, 3.5cm, 4cm, 4.5cm or 5cm, etc.

[0118] The pressure of the spray gun used for spraying paint is 1~50 bar, for example 1.2~10 bar or 20~40 bar, specifically, it can be 1.2 bar, 2.2 bar, 3 bar, 4 bar, 5 bar, 6 bar, 7 bar, 8 bar, 9 bar or 10 bar, etc.

[0119] The flow rate of the coating is 10~1000 ml / min, for example 20~100 ml / min, 200~500 ml / min or 600~1000 ml / min, specifically, it can be 10 ml / min, 100 ml / min, 200 ml / min, 300 ml / min, 400 ml / min, 500 ml / min, 600 ml / min, 700 ml / min, 800 ml / min, 900 ml / min or 1000 ml / min, etc.

[0120] The atomized particle size of the coating is 0.1~10μm, for example 0.1~6μm or 7~10μm, specifically, it can be 0.1μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.

[0121] Based on at least one of the above parameters, at least one of the following is more suitable: spraying distance, spraying pressure, spraying flow rate, and paint particle size. This is beneficial for spraying the paint to the target area in a more suitable state, resulting in a more uniform paint distribution. This allows for the spraying of clearer, more uniform, and more aesthetically pleasing patterns, making it less likely to cause problems such as pattern blurring and uneven thickness. It also reduces the likelihood of inconsistent flattening of the coating during subsequent lamination, which could affect the aesthetics. Furthermore, it minimizes damage to the battery module 20.

[0122] In some embodiments, applying the coating 6 in at least one of the first region 4 and the second region 5 by a transfer method includes:

[0123] A groove corresponding to at least one of the first region 4 and the second region 5 is machined on the template, and the groove is filled with paint;

[0124] Align the groove with at least one of the first region 4 and the second region 5, and allow the paint in the groove to adhere to at least one of the first region 4 and the second region 5, forming a coating 6 located in at least one of the first region 4 and the second region 5.

[0125] Based on the above steps, the coating 6 can be added to at least one of the first region 4 and the second region 5 by a transfer method.

[0126] Specifically, in some embodiments, during the process of machining grooves on the template corresponding to at least one of the first region 4 and the second region 5, the grooves are engraved with a line width consistent with the width of the conductive element 3. This allows the grooves to be more accurately aligned with the areas in the first region 4 and the second region 5 where the coating 6 needs to be applied, as well as with each conductive element 3 in those areas. This enables the coating 6 to be applied more accurately to at least one of the first region 4 and the second region 5, resulting in a pattern 7 that better meets the requirements.

[0127] In some embodiments, during the process of applying the coating 6 in at least one of the first region 4 and the second region 5 using electrostatic adsorption, at least one of the following parameters is employed:

[0128] The voltage at the electrodes of the spray gun is 5~100kV (kilovolts), for example 5~20 kV, 21~35 kV, 36~50 kV, 60~80kV or 90~100 kV. Specifically, it can be 5 kV, 10 kV, 20 kV, 30 kV, 40 kV, 50 kV, 60 kV, 70 kV, 80 kV, 90 kV or 100 kV, etc.

[0129] The distance between the spray gun and the conductive component 3 is 5~50cm (cm), for example 5~10cm, 15~30cm or 35~45cm. Specifically, it can be 5cm, 10cm, 15cm, 20cm, 25cm, 30cm, 35cm, 40cm, 45cm or 50cm, etc.

[0130] Based on at least one of the above parameters, at least one of the voltage and the distance between the spray gun and the conductive component 3 during the electrostatic adsorption process is more suitable. This is beneficial for the coating to be adsorbed more evenly and accurately onto the target area of ​​the conductive component 3, reducing defects such as adsorption breakpoints, and obtaining a clearer and more aesthetically pleasing pattern. Specifically, the voltage during the electrostatic adsorption process can decrease as the distance between the spray gun and the conductive component 3 decreases to maintain uniform adsorption.

[0131] As mentioned earlier, in addition to adding the coating 6 to the conductive component 3, the coating 6 can also be applied by first adding and then removing it. Moreover, the method of adding and then removing is particularly suitable for situations where the coating 6 is applied only in one of the first region 4 and the second region 5.

[0132] For example, in some embodiments, applying a coating 6 to at least one of a first region 4 and a second region 5 on a plurality of conductive elements 3 of the conductive component 2 of the battery string 10 includes:

[0133] Coating 6 is applied to the first region 4 and the second region 5;

[0134] Remove the coating 6 from either the first region 4 or the second region 5.

[0135] The above solution involves first adding a coating 6 to both the first region 4 and the second region 5, and then removing the coating 6 from one of the first regions 4 and the second region 5, so that only the other of the first region 4 and the second region 5 has the coating 6, thus forming the pattern 7 located in the first region 4. This method of adding and then removing the coating is relatively simple because the coating addition process does not require distinguishing between the first region 4 and the second region 5.

[0136] The method for removing the coating 6 from the first region 4 or the second region 5 can be varied. As an example, removing the coating 6 from the first region 4 or the second region 5 includes:

[0137] The coating 6 in the first region 4 or the second region 5 is removed by laser film opening.

[0138] Laser patterning is a technique that uses a high-energy laser beam focused to a micron-sized spot to locally melt or vaporize the material surface through thermal effects, forming micropores or specific patterns. The process is relatively simple, the equipment cost is low, and it is easy to prepare large-area and uniform patterns. Therefore, it is also suitable for large-scale production and can effectively improve the production efficiency of patterned photovoltaic modules.

[0139] Specifically, in some embodiments, during the process of removing the coating 6 of the first region 4 or the second region 5 using laser ablation, at least one of the following is employed:

[0140] The laser is an ultraviolet laser;

[0141] The power is 2~80W, for example 10~30 or 40~70 W; specifically, it can be 2 W, 10 W, 20 W, 30 W, 40 W, 50 W, 60 W, 70 W or 80 W, etc.

[0142] The pulse frequency is 50~1000kHz, for example 60~200 kHz, 300~500 kHz or 600~900 kHz; specifically, it can be 50 kHz, 100 kHz, 200 kHz, 300 kHz, 400 kHz, 500 kHz, 600 kHz, 700 kHz, 800 kHz, 900 kHz or 1000 kHz, etc.

[0143] The spot diameter is 5~500μm, for example 10~150μm or 200~450μm; specifically, it can be 5μm, 100μm, 200μm, 300μm, 400μm or 500μm, etc.

[0144] The scanning speed is 100~5000 mm / s, for example 200~800 mm / s, 900~2000 mm / s or 3000~4500 mm / s; specifically, it can be 100 mm / s, 500 mm / s, 1000 mm / s, 1500 mm / s, 2000 mm / s, 2500 mm / s, 3000 mm / s, 3500 mm / s, 4000 mm / s, 4500 mm / s or 5000 mm / s, etc.

[0145] The overlap rate is 0% to 100%, for example, 10% to 50% or 60% to 90%. Specifically, it can be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%, etc.

[0146] Based on at least one of the above, the coating 6 in the area to be removed can be removed more accurately, resulting in a more accurate and aesthetically pleasing pattern.

[0147] In addition to the previously mentioned method of adding coating 6 to the conductive component 3, or adding and then removing coating 6, the coating 6 can also be applied to the conductive component 3 by first adding coating 6 and then heat-treating it. The method of first adding and then heat-treating is suitable for cases where coating 6 is a thermochromic coating.

[0148] When a method of first adding and then heat-treating is adopted, a coating 6 is provided on at least one of the first region 4 and the second region 5 of the multiple conductive elements 3 of the conductive component 2 of the battery string 10 of the battery assembly 20, such that the first region 4 has a pattern 7 including:

[0149] A coating 6 is provided in at least one of the first region 4 and the second region 5;

[0150] Heat treatment is performed on at least one of the coatings 6 in the first region 4 and the second region 5 to change the color of the coatings 6 in the first region 4 and the second region 5, thereby obtaining the pattern 7 in the first region 4.

[0151] The above method involves first setting a coating 6 (thermochromic coating), then heat-treating the coating 6 to change its color, thus obtaining the pattern 7. This method is suitable for preparing patterns over large areas and does not produce slag. Therefore, it is relatively simple, clean, safe, and efficient.

[0152] The heat treatment method may include, but is not limited to, laser heat treatment. When using laser heat treatment to heat the coating 6 in at least one of the first region 4 and the second region 5, at least one of the following parameters may be used:

[0153] The energy density is 0.5~2.5 J / cm², for example, 0.5 J / cm², 0.6 J / cm², 0.7 J / cm², 0.8 J / cm², 0.9 J / cm², 1 J / cm², 1.2 J / cm², 1.5 J / cm², 1.6 J / cm², 1.8 J / cm², 2 J / cm², 2.2 J / cm², 2.4 J / cm², or 2.5 J / cm².

[0154] The pulse width is 50~800 fs, for example, 50 fs, 100 fs, 150 fs, 200 fs, 250 fs, 300 fs, 350 fs, 400 fs, 450 fs, 500 fs, 550 fs, 600 fs, 650 fs, 700 fs, 750 fs or 800 fs;

[0155] The frequency is 1~500 kHz, for example, 1 kHz, 5 kHz, 10 kHz, 20 kHz, 50, 100 kHz, 200 kHz, 250 kHz, 300 kHz, 350 kHz, 400 kHz, 450 kHz or 500 kHz;

[0156] The spot radius is 10~50μm, for example, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm;

[0157] The scanning speed is 0.1~5 mm / s, for example, 0.1 mm / s, 0.2 mm / s, 0.5 mm / s, 0.8 mm / s, 1 mm / s, 1.5 mm / s, 2 mm / s, 2.5 mm / s, 3 mm / s, 3.5 mm / s, 4 mm / s, 4.5 mm / s or 5 mm / s.

[0158] Based on at least one of the above parameters, a more efficient, accurate and uniform heat treatment process can be achieved, resulting in a larger area and a more uniform and aesthetically pleasing pattern.

[0159] In the aforementioned spraying, electrostatic adsorption, and heat treatment processes, only the target areas that need to be treated need to be treated. Areas that do not need to be treated can be further processed by masking or other operations to further reduce the impact of the treatment process on non-target areas. Alternatively, masking or other special operations can be omitted to further simplify the treatment process.

[0160] In the foregoing embodiments, the coating 6 is applied to at least one of the first region 4 and the second region 5 of the plurality of conductive elements 3 of the conductive component 2 of the battery string 10, which can occur after the battery string 10 is manufactured (see [link to previous embodiments]). Figure 3 (or before the battery string 10 is prepared.)

[0161] Since the conductive components 3 have been arranged and fixed after the battery string 10 is prepared, the first region 4 and the second region 5 can be determined more conveniently and accurately according to the pattern. Therefore, it is more convenient and accurate to set the coating 6 and prepare the pattern.

[0162] As an example of applying the coating 6 after the battery string 10 is fabricated, the coating 6 is applied to at least one of the first region 4 and the second region 5 of the plurality of conductive elements 3 of the conductive component 2 of the battery string 10, after the battery string 10 is fabricated and the plurality of battery strings 10 of the battery assembly 20 are arranged. At this time, the battery assembly 20 includes a plurality of battery strings 10, and the coating application process occurs after the battery string 10 is fabricated and the plurality of battery strings 10 of the battery assembly 20 are arranged.

[0163] Since the battery assembly 20 includes multiple battery strings 10, after the battery strings 10 are prepared and the multiple battery strings 10 of the battery assembly 20 are arranged, it is easier to accurately determine and distinguish the first region 4 and the second region 5 according to the complete pattern, and it is easier to set the partition coating for multiple battery strings 10 at one time. Therefore, it is easier to achieve patterning by setting the coating 6, which is more efficient and has a better effect.

[0164] However, as mentioned above, when the coating 6 is applied by first adding and then removing, the coating application process does not need to distinguish between the first region 4 and the second region 5. At the same time, when the coating 6 is applied by first adding and then heat-treating, the coating application process can also not distinguish between the first region 4 and the second region 5, and the coating 6 can be applied directly to both the first region 4 and the second region 5. In these cases, the coating application process is not limited to occurring after the battery string 10 is prepared, but can also occur before the battery string 10 is prepared.

[0165] For example, in some embodiments, when coating 6 is applied using an addition-then-removal method or an addition-then-heat-treatment method, coating 6 is applied in the first region 4 and the second region 5, and applying coating 6 in the first region 4 and the second region 5 includes:

[0166] A coating 6 is provided along the entire length of each conductive component 3 of the conductive component 2;

[0167] Connect each conductive element 3 of the conductive component 2 to the solar cell 1 of the battery string 10 to obtain the battery string 10.

[0168] The above scheme involves adding coating 6 to the first region 4 and the second region 5 before the battery string 10 is fabricated. Specifically, coating 6 is added to the entire length of each conductive element 3 before the conductive element 3 is connected to the solar cell 1. Then, each conductive element 3 with coating 6 is connected to the solar cell 1 of the battery string 10 to form the battery string 10. Since each conductive element 3 has coating 6 before being connected to the solar cell 1 of the battery string 10, after being connected to the solar cell 1 of the battery string 10 to form the battery string 10, both the first region 4 and the second region 5 of the conductive component 2 of the battery string 10 have coating 6, which can easily achieve the desired coating addition process without regional differentiation. In the case of using the method of adding coating first and then heat treatment, the coating 6 added in the corresponding coating addition process without regional differentiation can be the same thermochromic coating. For example, in some embodiments, a VO2 coating or a Co3O4 coating is provided on the entire conductive element 3. When coating 6 is applied using either an addition-then-removal method or an addition-then-heat-treatment method, the coating removal process and the coating heat treatment process can occur after the battery string 10 is fabricated. Since it is easier to accurately determine and distinguish the first region 4 and the second region 5 after the battery string 10 is fabricated, it is easier to remove the coating 6 in the first region 4 or the second region 5, and to perform heat treatment on at least one of the coatings 6 in the first region 4 and the second region 5.

[0169] Specifically, in cases where the battery assembly 20 comprises multiple battery strings 10, in some embodiments, the removal of the coating 6 from the first region 4 or the second region 5 occurs after the battery strings 10 have been fabricated and arranged. When the battery assembly 20 comprises multiple battery strings 10, it is easier to accurately determine the first region 4 and the second region 5 after the battery strings 10 have been fabricated and arranged, and it is easier to remove the coating 6 from the first region 4 or the second region 5. In particular, the first regions 4 of the multiple battery strings 10 can be combined into a larger area to be coated, thus making it easier to centrally remove the coating 6 from the first regions 4 of the multiple battery strings 10.

[0170] In addition, in cases where the battery assembly 20 includes a plurality of battery strings 10, in some embodiments, the coating 6 of at least one of the first region 4 and the second region 5 is heat-treated after the battery strings 10 are fabricated and the plurality of battery strings 10 of the battery assembly 20 are arranged and encapsulated by encapsulating glass. At this point, the coating heat treatment occurs not only after the battery string 10 is prepared, but also after the battery string 10 is arranged and encapsulated by the encapsulating glass. In this case, since the battery string 10 has been arranged, it can be directly compared with the final pattern of the photovoltaic module to accurately determine the first region 4 and the second region 5, and thus accurately determine the heat treatment area. At the same time, the first region 4 of the multiple battery strings 10 after arrangement can be combined into a larger area to be heat treated. Therefore, it is more convenient to concentrate on heat treating the coating 6 of the multiple battery strings 10 that need heat treatment after arrangement, resulting in higher heat treatment efficiency and better heat treatment effect, and making it easier to obtain a larger area and a more uniform and beautiful photovoltaic module pattern. Moreover, since the battery string 10 after arrangement has been encapsulated by the encapsulating glass, the heat treatment is carried out outside the encapsulating glass and through the encapsulating glass. The encapsulating glass can meet the basic heat requirements of heat treatment while playing a certain role in heat insulation, preventing excessive temperature from damaging the structural components of the photovoltaic module. Therefore, it is conducive to achieving a safer heat treatment process. At the same time, the encapsulating glass is transparent to lasers, so it is convenient to carry out laser heat treatment and achieve a safe laser heat treatment process.

[0171] After the cell strings are arranged and encapsulated by encapsulating glass, the coating is heat-treated, resulting in a photovoltaic module 20 that includes not only multiple cell strings 10 but also encapsulating glass. Following the heat treatment, other conventional module manufacturing processes can be performed to ultimately obtain the photovoltaic module 100.

[0172] As a further improvement to the preparation methods in the foregoing embodiments, the preparation method further includes:

[0173] Before applying a coating 6 to at least one of the first region 4 and the second region 5 of the plurality of conductive elements 3 of the conductive assembly 2 of the battery string 10, the surface of each conductive element 3 is degreased and cleaned.

[0174] Before applying the coating 6, the surfaces of each conductive component 3 are degreased and cleaned. This ensures that the surfaces of each conductive component 3 are cleaner during the coating application process, effectively preventing the conductive component 3 from becoming slippery due to grease or other substances, which could hinder the smooth application of the coating 6. Therefore, this process helps to reduce the difficulty of coating application, accelerate the coating application efficiency, and improve the success rate of coating application.

[0175] The degreasing and cleaning of the surface of each conductive component 3 can occur before or after connecting each conductive component 3 to two adjacent solar cells 1. When the degreasing and cleaning of each conductive component 3 is performed before connecting each conductive component 3 to two adjacent solar cells 1, since each conductive component 3 has not yet been fixed to the solar cell 1, it is easier to clean it thoroughly and achieve a better degreasing and cleaning effect.

[0176] In some embodiments, at least one of the following parameters is used during the degreasing and cleaning process on the surface of the conductive element 3:

[0177] The heating temperature is 20~100℃, for example, 30~50℃ or 70~90℃, specifically, it can be 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃, etc.

[0178] Heating time is 1 to 10 minutes, for example, 1.5 to 5 minutes or 6 to 9 minutes. Specifically, it can be 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, etc.

[0179] The spray pressure is 1~50 bar, for example 1.5~10 bar or 20~45 bar. Specifically, it can be 1 bar, 5 bar, 10 bar, 15 bar, 20 bar, 25 bar, 30 bar, 35 bar, 40 bar, 45 bar or 50 bar, etc.

[0180] The rinsing time is 1 to 10 minutes, for example, 1.5 to 5 minutes or 6 to 9 minutes. Specifically, it can be 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, etc.

[0181] Based on at least one of the above parameters, at least one of the heating temperature, heating time, spray pressure, and rinsing time for degreasing cleaning is more suitable, which can achieve a cleaner degreasing cleaning effect.

[0182] Next, combine Figure 1 and Figure 2 The embodiments shown further illustrate this application.

[0183] Figure 1 The structure of the photovoltaic module 100 in this embodiment is shown.

[0184] like Figure 1As shown, in this embodiment, the photovoltaic module 100 includes a battery module 20, and the battery module 20 includes a plurality of battery strings 10. These plurality of battery strings 10 are arranged side by side along a first direction X and a second direction Y, such that the plurality of battery strings 10 are arranged in a matrix. The first direction X and the second direction Y are perpendicular to each other and are both perpendicular to the thickness direction Z of the photovoltaic module 100 (which is also the thickness direction Z of the battery module 20, the battery strings 10 and the solar cells 1).

[0185] Each battery string 10 has a pattern 7, and the patterns 7 of multiple battery strings 10 are combined to form a complete pattern 7. At this time, the pattern 7 on each battery string 10 is a component of a complete pattern.

[0186] Specifically, Figure 1 The pattern 7 formed by multiple battery strings 10 is a combination of the word "WIFI" and an icon, and the pattern 7 on each battery string 10 is part of the corresponding combination of the word "WIFI" and icon. However, it is easy to understand that the pattern is not limited to this; the battery strings 10 can also form other patterns when put together, and correspondingly, the pattern 7 on each battery string 10 can also be a component of other patterns.

[0187] Based on the pattern formed by combining all the cell strings 10 of the photovoltaic module 100, the photovoltaic module 100 becomes a patterned photovoltaic module.

[0188] Figure 2 The structure of the battery string 10 in this embodiment is further illustrated.

[0189] like Figure 2 As shown, in this embodiment, the battery string 10 includes a plurality of solar cells 1 and a conductive component 2 that connects the plurality of solar cells 1 in series.

[0190] Multiple solar cells 1 are arranged at intervals along a first direction X. Each solar cell 1 is a grid-free back-contact solar cell, including a substrate 11 and a passivation layer 14. The substrate 11 is an n-type silicon substrate, with its two surfaces in the thickness direction Z being a front side 12 and a back side 13, respectively. Neither the front side 12 nor the back side 13 has any grid lines. The front side 12 has a passivation layer 14. The back side 13 has p+ doped regions 15 and n+ doped regions 16 arranged parallel to each other and alternating along a second direction Y. Thus, the p+ doped regions 15 and n+ doped regions 16 are elongated, with their long sides along the first direction X and their short sides along the second direction Y. The passivation layer 14 is a thin oxide film made of materials such as Al2O3 (aluminum oxide), which protects the surface of the solar cell from oxidation damage, improves the efficiency of the solar cell, and reduces energy loss.

[0191] A conductive component 2 is disposed on the back surface 13 of a plurality of solar cells 1 and includes a plurality of conductive wires 31 serving as conductive elements 3. These conductive wires 31 are parallel to each other and laid on the passivation layer 14 of the back surface 13. Each conductive wire 31 extends along a first direction X. All or most of the conductive wires 31 are connected at one end to an electrode of the back surface 13 of one solar cell 1, and at the other end to an electrode of opposite polarity on the back surface 13 of an adjacent solar cell 1, thereby achieving series connection of two adjacent solar cells 1. Figure 2 In the process, most of the conductive wires 31 are electrically connected to two adjacent solar cells 1, while only some of the conductive wires 31 on the first and last solar cells 1 in the first direction X are not connected to two adjacent solar cells 1.

[0192] A current-collecting layer 17 made of low-silver material is also provided between the passivation layer 14 on the back side 13 and the conductive wire 31, so that the conductive wire 31 collects current through the current-collecting layer 17, forming a vertical conductive structure of current-collecting layer 17 + conductive wire 31, reducing lateral current transmission and improving current transmission efficiency. During operation, the current on the solar cell 1 is discharged along the long side direction (i.e., the first direction X) of the elongated n+ or p+ doped region. The current-collecting layer 17 is mainly used to collect the surface current of the solar cell. Its thickness is only about 1 / 10 of that of a conventional fine grid. For example, the thickness of a conventional fine grid is 5~15μm, while in some embodiments, the thickness of the current-collecting layer 17 is 0.5~1μm (e.g., 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, or 1μm, etc.). In addition, its width is also smaller than that of a conventional fine grid. For example, the width of a conventional fine grid is 12~25μm, while in some embodiments, the width of the current-collecting layer 17 is 1~10μm. μm (e.g., 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, etc.), thus significantly reducing the amount of silver paste used. For example, the silver content of conventional gate lines is greater than 90%, while the silver content of the current collection layer 17 is less than 90%. For example, in some embodiments, the silver content (i.e. the mass percentage of silver contained) of the current collection layer 17 is 75% to 90% (e.g., 75%, 78%, 80%, 82%, 85%, 87% or 90%), which can effectively reduce costs.

[0193] Since solar cell 1 is a gridless back-contact solar cell, there are no grid lines on either side, and the positive and negative electrodes are all integrated on the back side 13. Only the back side 13 is provided with a conductive component 2 including multiple conductive wires 31. The conductive wires 31 replace the grid lines (main grid and fine grid) to collect current. Therefore, silver loss can be reduced, photoelectric conversion efficiency can be improved, cost can be reduced and efficiency improved, and the flatness and aesthetics of the solar cell surface can be increased, thus enhancing the aesthetic value of the photovoltaic module.

[0194] In this embodiment, the conductive wire 31 is a flat conductive wire with a flat cross-section and a side length of 0.10~0.15mm, such as 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm or 0.15 mm, etc., and the width (the dimension in the second direction Y) is less than 0.15mm.

[0195] It should be noted that, although Figure 2 Only a small number of relatively thick conductive wires 31 are shown in the illustration, but this is only for clarity. In actual products, there can be more and thinner conductive wires 31. In addition, the cross-sectional shape of the conductive wires 31 is not limited to a flat shape, but can also be other shapes such as circular or extremely thin triangles.

[0196] The conductive wire 31 in this embodiment includes a copper wire, and the welding surface of the copper wire is plated with solder. The solder material is tin, tin-lead alloy, tin-bismuth alloy, or tin-lead-silver alloy. Thus, the conductive wire 31 is a tin-plated conductive wire. The solder can be heated and melted and welded under the assistance of an electric field. In addition to the current-assisted heating generated by the bias voltage, the heating effect can also be enhanced by various other methods between the conductive wire and the current collection layer 17, such as laser heating, heating channels, magnetic coils, or brush heating, etc., without specific limitations.

[0197] When two adjacent solar cells 1 are connected in series, multiple parallel conductive wires 31 are connected to the electrode of one solar cell 1, and at the same time, these conductive wires 31 are connected to the electrode of the other adjacent solar cell 1 with opposite polarity, thus connecting the two adjacent solar cells 1 in series.

[0198] During the distribution of conductive wires, the electrodes on each strip-shaped n+ and p+ doped region of the solar cell 1 are connected by conductive wires 31. In this embodiment, a low-silver-content current collection layer 17 is first laid on the preset conductive wire positions by screen printing, and ohmic contacts are formed by drying and sintering. Then, the conductive wires 31 are arranged first, and the first solar cell is aligned with it. The second solar cell is rotated 180 degrees and aligned with the conductive wires 31, so that the N-region and P-region of the second solar cell are opposite to those of the first solar cell, which facilitates the connection of the N-region and P-region of the two solar cells to form a series connection. The subsequent solar cells are also arranged in this manner. Then, the excess conductive wire segments are cut off, so that these solar cells 1 form a series circuit, which becomes a battery string 10.

[0199] After each battery string 10 is prepared, they can be arranged to form a battery module 20, which is a semi-finished photovoltaic module. Then, the module encapsulation processes such as current merging, stacking and lamination are carried out to obtain the photovoltaic module 100.

[0200] As mentioned above, the photovoltaic module 100 in this embodiment is a patterned photovoltaic module. In order to form the pattern of the photovoltaic module 100, the conductive wires 31 of the battery module 20 are patterned in this embodiment.

[0201] Specifically, in combination Figure 1 and Figure 2 As can be seen, in this embodiment, the patterning of the conductive wires 31 of the battery assembly 20 is performed by applying a coating 6 to a portion of the conductive wires 31 of the battery assembly 20 according to the desired complete pattern.

[0202] More specifically, in this embodiment, firstly, patterned areas and non-patterned areas are determined on the battery assembly 20 according to the desired complete pattern. Then, coating 6 is applied to the non-patterned portions of the conductive wires 31 of the battery assembly 20 using methods such as spraying, transfer printing, electrostatic adsorption, and laser film opening. This ensures that only the conductive wires 31 in the non-patterned areas have the coating 6, while the conductive wires 31 in the patterned areas do not. As a result, the conductive wires 31 in the patterned areas exhibit their own silver-white color, while the conductive wires 31 in the non-patterned areas exhibit the color of the non-silver-white coating 6. Thus, the conductive wires 31 in the patterned and non-patterned areas exhibit different colors, and the desired pattern is formed in the patterned areas.

[0203] The patterned and unpatterned areas of the battery module 20 correspond to the first area 4 and the second area 5 of the multiple conductive wires 31 of each battery string 10, respectively. In other words, the first areas 4 of all the battery strings 10 of the photovoltaic module 100 together constitute the patterned area, and the second areas 5 of all the battery strings 10 together constitute the unpatterned area. Therefore, as... Figure 2 As shown, the non-patterned areas are provided with coating 6, while the patterned areas are not provided with coating 6. This means that the second region 5 of the multiple conductive wires 31 of each battery string 10 is provided with coating 6, while the first region 4 is not provided with coating 6, but has a pattern 7 as part of the complete pattern.

[0204] As can be seen, this embodiment uses patterned conductive wire technology to achieve patterning of the photovoltaic module 100. The corresponding technology divides the multiple battery strings 10 into patterned and non-patterned areas, and applies a coating 6 to the conductive wires 31 in the non-patterned areas. This results in each battery string 10 having multiple conductive wires 31 divided into a first area 4 corresponding to the patterned area of ​​the photovoltaic module (i.e., the patterned area) and a second area 5 corresponding to the non-patterned area of ​​the photovoltaic module. Only the conductive wires 31 in the second area 5 have the coating 6, while the conductive wires 31 in the first area 4 do not have the coating 6. This forms a pattern 7 located in the first area 4 of each battery string 10, which serves as part of the complete pattern, and the complete pattern required for the photovoltaic module obtained by combining multiple battery strings 10.

[0205] Since the patterning process can be completed by simply setting the coating 6 on the conductive wire 31 to obtain the desired pattern, and the setting process of the coating 6 is relatively simple, with no high requirements for materials, equipment and structure, and large-area and uniform coating can be easily set, the production requirements are low, the production difficulty is small, the production efficiency is high, the production cost is low, and it is easy to mass produce.

[0206] Moreover, since the desired pattern can be obtained simply by setting the coating 6 on the conductive wire 31, there is no need to change the internal structure of the solar cell or set the pattern on the encapsulation glass. Therefore, damage to the solar cell and optical loss can be reduced, which is beneficial to improving the structural reliability and efficiency of the photovoltaic module 100.

[0207] Furthermore, this embodiment achieves patterning by coating 6 onto the conductive wires 31 of the gridless back-contact solar cell. Since the gridless back-contact solar cell has no grids on both the front and back sides, and the conductive wires 31 located only on the back side 13 are fine and dense, it is easier to set the coating 6 and to obtain a clear, coherent and beautiful pattern based on the coating 6. This can form a back-contact photovoltaic module with an unobstructed front and a clear and beautiful outline graphic effect on the back, thereby improving the adaptability of the photovoltaic module to the photovoltaic building integration scenario.

[0208] Moreover, the coating application in this embodiment occurs after the battery string 10 is prepared and arranged. It is convenient to accurately determine the areas that need to be coated (patterned areas) and the areas that do not need to be coated (non-patterned areas) based on the complete pattern of the photovoltaic module. The area where the coating is applied is relatively large. Therefore, it is more convenient, accurate and efficient to apply the coating 6 to obtain a more beautiful and satisfactory complete pattern.

[0209] Furthermore, in this embodiment, the coating is only applied to the second region 5 and not to the first region 4. Therefore, less coating material is required, the cost is lower, and the coating application process is simpler and more efficient. This is beneficial for further reducing the production cost of patterned photovoltaic modules, improving the production efficiency of patterned photovoltaic modules, and further promoting the application of patterned photovoltaic modules.

[0210] like Figure 2 As shown, in this embodiment, the coating 6 is black. This not only makes the color of the second region 5 different from the color of the first region 4 (or the color of the non-patterned region different from the color of the patterned region), thus forming a pattern, but also allows the second region 5 to take advantage of the strong light absorption of black to reduce glare and improve the adaptability of the photovoltaic module to vertical installation.

[0211] Since coating 6 is black, the process of applying coating 6 can also be called a blackening process. This blackening process reduces glare.

[0212] It is evident that this embodiment, based on the patterning process of setting a coating 6 on the conductive wire 31, is not only simple and efficient, easy to mass-produce, but also produces beautiful patterns with less glare and high aesthetic value.

[0213] The coating 6 can be set by spraying, transfer printing, electrostatic adsorption and laser film opening. The following will explain the four methods of spraying, transfer printing, electrostatic adsorption and laser film opening respectively.

[0214] Spraying method

[0215] See Figure 3 When using a spray coating method, the photovoltaic module manufacturing process can proceed as follows: first, the cell strings are prepared and arranged; then, the coating is applied; and finally, module encapsulation processes such as busbar assembly, stacking, and lamination, along with conventional module manufacturing, are carried out. The coating application occurs after the cell strings have been prepared and arranged.

[0216] In the battery string fabrication process, high-purity monocrystalline silicon wafers are first selected. After removing surface impurities with acid and alkali solutions, P-type and N-type semiconductor regions are formed on the back surface of the silicon wafer through diffusion and other processes to construct the emitter and back field. Then, a pyramid structure is formed on the surface of the silicon wafer through texturing to increase the light absorption area. Next, a passivation layer, such as silicon dioxide or silicon nitride film, is deposited on the surface of the silicon wafer to reduce the surface recombination rate and reduce carrier loss. Then, a low-silver-content paste is uniformly printed on the surface of the solar cell using screen printing technology to form an extremely thin current collection layer 17. Afterward, using high-precision welding equipment, conductive wires 31 with copper as the substrate and solder paste on the surface are vertically welded to the current collection layer 17. Multiple parallel conductive wires 31 are connected to the electrodes of one solar cell 1. At the same time, these conductive wires 31 are connected to the electrodes of adjacent solar cells 1 with opposite polarities, so that the current on the solar cell 1 is led out along the long side of the strip-shaped n+ or p+ doped region. Finally, the excess conductive wire segments are cut off to form a battery string 10.

[0217] Specifically, the battery string fabrication process can be as follows:

[0218] An N-type silicon wafer with a resistivity of 20 Ω cm and a thickness of 150 μm was texturized. The wafer was then loaded into an LPCVD (Low Pressure Chemical Vapor Deposition) quartz boat (also known as quartz glass, a laboratory and industrial device made of high-purity quartz material) and a boron source was introduced to complete the boron diffusion process. At this point, a P+ emitter / BSG (Borosilicate glass) was formed on the silicon wafer surface. (Glass, borosilicate glass); The BSG film layer reserved for the N-region and Gap region on the back is etched away using a 45W green laser; then, a polishing process is performed in an alkaline KOH solution, forming polished surfaces in both the N-region and Gap region, while the P-region remains unaffected due to the protection of the surface BSG; subsequently, the dried silicon wafer is placed in a quartz boat, heated to 600℃ under low pressure, and 2000 sccm of oxygen is introduced to grow a SiO2 layer of approximately 1.5 nm. Silane is then introduced to grow a 250 nm thick i-Poly Si. The temperature is then increased, and a phosphorus source is introduced to complete the phosphorus diffusion process. At this point, the N-region has a three-layer structure of SiO2 / N+ Poly Si (N-type doped silicon layer) / PSG (Phosphosilicate Glass), and the P-region has a P+ / BSG / N+ Poly The structure is a four-layer Si / PSG structure. Then, the PSG above the P region and the PSG above the Gap are etched away using a 30W green laser, and the front PSG is etched away using a 5% HF etching solution. After that, a texturing process is performed to remove the N+Poly Si above the P region, and the front and back Gap regions are textured. The PSG outside the N region and the BSG mask layer on the surface of the P region are removed using a 10% HF solution.

[0219] Al2O3 coating was applied to the front side of the silicon wafer. Trimethylaluminum and water were introduced at 250°C to grow 6nm thick Al2O3 layers on both sides. Then, in a plasma-enhanced chemical vapor deposition (PECVD) system, silane and ammonia were introduced at 540°C to complete the deposition of SiNx thin films on both sides, with a thickness of 75nm.

[0220] By screen printing, a current collection layer 17 with low silver content (e.g., the solid content of silver in the paste is 75%~90%) is laid on the preset conductive wire positions, and ohmic contacts are formed by drying and sintering. This makes the current collection layer 17 laid in strip shape on the preset conductive wire 31 positions, with the extension direction consistent with the conductive wire 31. Then, the conductive wires 31 are arranged first, and solder is plated on the welding surface of the conductive wires 31 to form tin-plated conductive wires. The first solar cell 1 is aligned with it, and the second solar cell 1 is rotated 180 degrees and aligned with the conductive wire 31 to ensure that it is connected in series with the first solar cell 1. The subsequent solar cells are arranged in this manner. After that, the excess conductive wire segments are cut off to form a battery string 10.

[0221] After the battery strings are prepared, they are arranged. This arrangement process involves arranging the battery strings 10 according to a preset order and position. The arranged battery strings 10 together form a semi-finished component, namely the battery module 20.

[0222] Next, the battery assembly 20 is patterned. The patterning process is as follows:

[0223] Plan the spraying path according to the graphical design scheme.

[0224] The battery assembly 20 is fixed on the spraying workbench, the spraying equipment is started, and the nozzle of the spraying equipment moves along the preset path to evenly spray the atomized paint onto the conductive wire 31 in the non-patterned area, so that the conductive wire 31 in the non-patterned area is provided with a coating 6.

[0225] After the coating is completed, the components are sent to the drying equipment to dry quickly, completing the patterning process.

[0226] During the above-mentioned spraying process, according to the graphic requirements, a paint with corresponding optical, electrical or decorative properties can be selected and adjusted to a suitable viscosity and solid content. The spraying pressure, flow rate and atomization degree of the spray gun or nozzle can be adjusted. For example, the height of the nozzle from the conductive wire 31 can be controlled to be 0.2 cm, the spray gun pressure to be 1.5 bar, the paint flow rate to be 200 mL / min, and the atomized particle size to be 5 μm, so that the paint can be sprayed in a more suitable form.

[0227] Transfer method

[0228] When using the transfer printing method, the photovoltaic module manufacturing process can proceed with cell string preparation and layout first, followed by coating application, and then module encapsulation processes such as busbar assembly, stacking, and lamination, as well as conventional module manufacturing. Coating application also occurs after cell string preparation and layout are completed.

[0229] In the coating process, a flexible polymer template, such as metal or PDMS (Polydimethylsiloxane), is used. Grooves corresponding to the non-patterned areas are etched on the template, and the line width on the template is consistent with the width of the conductive wires. This allows the template grooves to be precisely aligned with all the conductive wires in the non-patterned areas. Black liquid paint is filled into the template grooves, and the template is made to adhere to the surface of the solar cell to ensure accurate positioning of the conductive wires (error < ±5 μm). The paint is rapidly cured by pressure or temperature assistance, and then the template is slowly separated, leaving the coating 6 on the surface of the conductive wires 31.

[0230] In order to facilitate the coating to adhere to the surface of the conductive wire, the conductive wire 31 can be pre-treated before laying it during the battery string preparation process. The conductive wire 31 is degreased and cleaned by an ultrasonic cleaner, with a heating temperature of 60°C and a heating time of 3 min. The high-pressure spray system is used to rinse for 2 min at a pressure of 2 bar, and then it is dried before the conductive wire welding process is carried out.

[0231] electrostatic adsorption

[0232] The principle of electrostatic adsorption is that when a charged object approaches an uncharged object, due to electrostatic induction, the side of the uncharged object that is close to the charged object will induce a charge of opposite polarity, thus producing an adsorption phenomenon due to the attraction between opposite charges.

[0233] See Figure 3 When using electrostatic adsorption, the photovoltaic module manufacturing process can proceed with cell string preparation and layout first, followed by coating application, and then module encapsulation processes such as busbar assembly, stacking, and lamination, as well as conventional module fabrication. Coating application occurs after cell string preparation and layout are complete.

[0234] During the coating process, powder coating is supplied to the spray gun via a powder pump. The spray gun electrode generates corona discharge at a voltage of 60 kV. The spray gun is 15 cm away from the conductive wire, causing the conductive wire 31 in the powder coating and non-patterned areas to induce charges of opposite polarity. For example, the powder coating is negatively charged, and the conductive wire 31 in the non-patterned areas is positively charged. The conductive wire 31 attracts the powder to adhere, forming a uniform coating 6 with a thickness of approximately 50 μm. The coating is then cured in a hot air circulating curing oven at 150 °C for 10 min to ensure the pattern is firmly established.

[0235] In order to facilitate the coating to adhere to the surface of the conductive wire, the conductive wire 31 can be pre-treated before laying it during the battery string preparation process. The conductive wire 31 can be degreased and cleaned by an ultrasonic cleaner, with a heating temperature of 60°C and a heating time of 3 min, a high-pressure spray system pressure of 2 bar, and a rinsing time of 2 min. Then it can be dried before the conductive wire welding process is carried out.

[0236] Laser film opening

[0237] See Figure 3 When using laser film-opening, the coating process no longer occurs after the battery string is prepared, but before it is prepared. However, the coating area process still occurs after the battery string is prepared and the layout is completed.

[0238] Specifically, in the battery string preparation process, conductive wires 31 with a coating 6 on their surface are directly laid out; then, the components are arranged, and the back of the arranged battery components 20 is completely black; then, a laser device is used, and the laser parameters are adjusted according to the coating material and the type of copper substrate. An ultraviolet laser with a power of 20 W, a pulse frequency of 150 kHz, a spot diameter of 100 μm, a scanning speed of 1000 mm / s, and an overlap rate of 50% is used to open the pattern area. The laser beam scans along the set path and peels off the coating 6 of the pattern area layer by layer. At the same time, compressed air is used to blow away the residue, exposing the silver-white color of the conductive wire itself, so that only the non-pattern areas retain the coating 6, thereby forming the outline pattern.

[0239] It is evident that regardless of spraying, transfer printing, electrostatic adsorption, or laser film-forming methods, coating settings can be easily implemented in non-patterned areas, completing the pattern processing process based on patterned conductive wire technology. Spraying, transfer printing, electrostatic adsorption, and laser film-forming are all more suitable for application after the battery string arrangement is completed but before lamination, because after this process, the coating 6 can be added or removed over a large area without obstruction by the encapsulation material. When pattern processing is performed after the battery string arrangement is completed but before lamination, the battery assembly 20 includes multiple battery strings 10 but does not include the encapsulation glass.

[0240] Of course, this embodiment is only illustrated by the case where the non-patterned area has color based on the coating 6, while the patterned area has no coating and no color. However, it is not limited to this. For example, in other embodiments, both the non-patterned area and the patterned area may have the coating 6, but the coating 6 of the patterned area and the non-patterned area may have different colors. In this way, the color of the patterned area is no longer limited to the color of the conductive wire itself, and the pattern is more beautiful.

[0241] When both patterned and non-patterned areas have coating 6, the aforementioned spraying, transfer, electrostatic adsorption, and heat treatment methods are more suitable for setting the coating 6, because these three methods can easily set coatings of different colors in the patterned and non-patterned areas. Specifically, spraying, transfer, and electrostatic adsorption methods can directly set different colored coatings 6 in the patterned and non-patterned areas to obtain different colored coatings 6. The heat treatment method, on the other hand, can first set the same coating 6 in both patterned and non-patterned areas, and then heat-treat either the patterned or non-patterned area coating 6 to change its color, thus obtaining different colored coatings 6 in the patterned and non-patterned areas.

[0242] This section presents an example based on a heat treatment method, in which both patterned and non-patterned areas have a coating 6, but the colors of the coating 6 differ between the patterned and non-patterned areas.

[0243] Al-Si alloy or Zn-Sn alloy is selected as the conductive wire material to make conductive wire 31. The entire surface of conductive wire 31 is coated with a thermochromic VO2 or Co3O4 coating. Then, the conductive wire 31 coated with thermochromic coating is connected to the gridless back contact battery to prepare battery string 10. After the battery string 10 is prepared, the module encapsulation process such as module layout, bus, stacking, and lamination is carried out. After lamination is completed and the layout battery string 10 is encapsulated by encapsulation glass, the semi-finished module (i.e., battery module 20) is subjected to laser heat treatment. A femtosecond laser is selected with an energy density of 1 J / cm² (joules per square centimeter), a pulse width of 60 fs (femtosecond), a frequency of 100 kHz (kilohertz), a spot radius of 30 μm, and a scanning speed of 2 mm / s. The pattern area is subjected to laser heat treatment. The laser beam scans along the set path, causing the coating 6 on the surface of the conductive wire 31 in the pattern area to undergo phase change and color change due to high temperature, forming an outline pattern. The remaining conventional photovoltaic module manufacturing processes are then performed to finally produce photovoltaic module 100. The produced photovoltaic module 100 has no grid lines on the front side, resulting in high light transmittance, while its back side has no grid lines but has a pattern. The pattern is located in the patterned area on the back side, while the non-patterned area on the back side is black, which can reduce glare.

[0244] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery assembly (20) characterized by, include: A battery string (10) includes a plurality of solar cells (1) and a conductive component (2). The plurality of solar cells (1) are arranged side by side along a first direction (X). The conductive component (2) is disposed on at least one side of the plurality of solar cells (1) in the thickness direction (Z) and includes a plurality of conductive elements (3). At least some of the conductive elements (3) are electrically connected to any two adjacent solar cells (1) along the first direction (X). The conductive component (2) has a plurality of conductive elements (3) having a first region (4) and a second region (5), at least one of the first region (4) and the second region (5) having a coating (6) such that at least one of the first region (4) and the second region (5) has a pattern (7).

2. The battery assembly (20) according to claim 1, characterized in that, The battery assembly (20) is configured as at least one of the following: The coating (6) is dark in color; The coating (6) is a thermochromic coating; Both the first region (4) and the second region (5) are provided with a coating (6), and the coating (6) of the first region (4) and the coating (6) of the second region (5) are different in color; The thickness of the coating (6) is 1~150μm.

3. The battery assembly (20) of claim 2, characterized in that, The coating (6) is black, gray or dark blue; and / or, only the first region (4) of the first region (4) and the second region (5) has a pattern (7), the second region (5) has a coating (6), and the coating (6) of the second region (5) is dark.

4. The battery assembly (20) according to any one of claims 1-3, characterized in that, The battery assembly (20) is configured as at least one of the following: The material of the coating (6) is polyimide, SiO2 or metal oxide; The first region (4) is distributed in a dotted or linear pattern on the conductive component (2); The conductive element (3) includes a conductive wire (31); The material of the conductive component (3) includes copper, Al-Si alloy or Zn-Sn alloy; The conductive component (2) is disposed only on one side of the plurality of solar cells (1) in the thickness direction (Z); The surfaces of the plurality of solar cells (1) having the conductive components (2) are free of grid lines; The battery assembly (20) includes multiple battery strings (10) arranged in a pattern (7).

5. The battery assembly (20) of claim 4, characterized in that, The battery assembly (20) is configured as at least one of the following: The material of the coating (6) is CuO, VO2, Co3O4, Fe3O4, MnO2, ZnO or WO3; The width of the conductive wire (31) is less than or equal to 0.15 mm; The conductive component (2) is disposed only on the back (13) of the plurality of solar cells (1).

6. The battery assembly (20) of claim 5, characterized by The back side (13) of the solar cell (1) is provided with a current collection layer (17), and the conductive element (3) is electrically connected to the current collection layer (17).

7. The battery assembly (20) of claim 6, characterized by The current collection layer (17) is constructed as at least one of the following: Thickness is 0.5~1μm; Width is 1~10μm.

8. A photovoltaic module (100), characterized in that Includes the battery assembly (20) as described in any one of claims 1-7.

9. A building, characterized in that Includes the photovoltaic module (100) as described in claim 8.

10. The building of claim 9, wherein, The photovoltaic module (100) is installed vertically; and / or, the conductive component (2) of the photovoltaic module (100) is disposed only on one side of the plurality of solar cells (1), and the side of the photovoltaic module (100) with the conductive component (2) faces the inside of the building.

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