Photovoltaic module

Abstract

The present application relates to the field of photovoltaics, and provides a photovoltaic module. The photovoltaic module comprises: a cell, the cell comprising a soldering region and a collection region arranged along a first direction, a surface of the cell being provided with a plurality of grid lines arranged along a second direction, each of the grid lines comprising at least two soldering grid lines located in the soldering region and a collection grid line located in the collection region, the soldering grid lines being arranged along the second direction, and each of the at least two soldering grid lines being electrically connected to a same collection grid line; and a connection component, the connection component being located on the cell, the connection component being electrically connected to the plurality of grid lines arranged along the second direction, and the connection component being soldered to each of the soldering grid lines. The photovoltaic module provided in embodiments of the present application can at least reduce power generation loss.

Description

photovoltaic modules Cross-referencing

[0001] This application claims priority to Chinese patent application No. 202411586844.9, entitled "Photovoltaic Module", filed on November 7, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to the photovoltaic field, and in particular to a photovoltaic module. Background Technology

[0003] A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect. A single solar cell cannot generate electricity directly. Several individual cells must be connected in series or parallel using solder strips and then tightly sealed to form a module before use. A solar cell module (also called a solar panel) is the core and most important component of a solar power generation system. The function of a solar cell module is to convert solar energy into electrical energy, which can then be either stored in batteries or used to power loads.

[0004] The main grid and fine grid on a solar cell are key components for ensuring solar energy conversion efficiency. The main grid lines are responsible for collecting solar energy, while the fine grid lines increase light absorption and current transmission. They work together to ensure maximum solar energy absorption and conversion efficiency. The main grid lines, which directly connect to the external leads (i.e., the connecting components), are the thicker parts. The fine grid lines, which collect and transmit current to the main grid lines, are the thinner parts, made into narrow grid lines to overcome the resistance of the diffusion layer.

[0005] However, the grid lines on the front (main grid lines and fine grid lines) block a portion of the silicon wafer, preventing the light energy hitting the grid lines from being converted into electrical energy, resulting in waste. Furthermore, the main component of the paste used to make the grid lines is the expensive precious metal silver, thus raising cost concerns. Based on this, engineers have directly connected more and finer connecting components to the cell grid, concentrating current and achieving cell interconnection, thus eliminating the traditional main grid at the cell level—a "busbar-free" technology. However, many factors still affect the yield of photovoltaic modules and power generation losses, such as the welding quality and yield between the connecting components and the grid. Summary of the Invention

[0006] This application provides a photovoltaic module that at least helps reduce power generation losses.

[0007] According to some embodiments of this application, this application provides a photovoltaic module, including: a solar cell, the solar cell including a welding area and a collection area arranged along a first direction; the surface of the solar cell has a plurality of grid lines arranged along a second direction, each grid line including at least two welding grid lines located in the welding area and a collection grid line located in the collection area, wherein the welding grid lines are arranged along the second direction, and each of the at least two welding grid lines is electrically connected to the same collection grid line; a connecting member, the connecting member being located on the solar cell, the connecting member being electrically connected to the plurality of grid lines arranged along the second direction, and the connecting member being welded to each welding grid line.

[0008] In some embodiments, the width of the welding grid line along the second direction is greater than or equal to the width of the collecting grid line along the second direction.

[0009] In some embodiments, the welding grid includes a first type of grid and a second type of grid, wherein the first type of grid and the collecting grid are composed of burn-through slurry, and the second type of grid is composed of non-burn-through slurry.

[0010] In some embodiments, the welding grid line includes: a first sub-grid line and a second sub-grid line stacked together, the second sub-grid line being located between the connecting member and the first sub-grid line, the first sub-grid line and the second sub-grid line being made of different materials.

[0011] In some embodiments, the battery cell is a back-contact battery cell, and the grid lines include a first grid line of a first conductivity type and a second grid line of a second conductivity type. The first grid line includes a first welding grid line corresponding to a first welding area and a first collection grid line corresponding to a first collection area. The second grid line includes a second welding grid line corresponding to a second welding area and a second collection grid line corresponding to a second collection area. The first welding area and the second collection area are directly opposite each other along a second direction. The battery cell also includes an insulating layer located between the connecting member and the second collection grid line.

[0012] In some embodiments, an insulating layer is located on the first gate line and the second gate line, and the area of ​​the insulating layer corresponding to the first welding area exposes the first welding gate line.

[0013] In some embodiments, at least two first welding grid lines of the same first grid line contact each other to form a pad, and the width of the pad along the second direction is greater than the width of the first collection grid line along the second direction.

[0014] In some embodiments, corresponding to the region of the connecting component, the top surface of the first welding grid line near the insulating layer is higher than the top surface of the first welding grid line away from the insulating layer.

[0015] In some embodiments, the spacing between the insulating layer and the first welding gate line is proportional to the thickness of the insulating layer.

[0016] In some embodiments, the thickness of the insulating layer decreases along the second direction and toward the first welding gate line.

[0017] In some embodiments, the second collecting grid line includes two broken grids and a break located between the two broken grids, the break corresponding to the first welding area, the broken grids being located on both sides of the connecting member and insulated from the connecting member. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a schematic diagram of a photovoltaic module according to an embodiment of this application;

[0020] Figure 2 is a top view of a photovoltaic module provided in an embodiment of this application;

[0021] Figure 3 is a partial cross-sectional view of Figure 2;

[0022] Figure 4 is a schematic diagram of four welding grid lines in a photovoltaic module provided in an embodiment of this application;

[0023] Figure 5 is a top view of a welding grid in a photovoltaic module according to an embodiment of this application;

[0024] Figure 6 is a partial cross-sectional view of a photovoltaic module provided in an embodiment of this application;

[0025] Figure 7 is another top view of a welding grid in a photovoltaic module according to an embodiment of this application;

[0026] Figure 8 is a cross-sectional view corresponding to Figure 7;

[0027] Figure 9 is a schematic diagram of a photovoltaic module according to another embodiment of this application;

[0028] Figure 10 is a top view of a photovoltaic module provided in another embodiment of this application;

[0029] Figure 11 is another top view of a photovoltaic module provided in another embodiment of this application;

[0030] Figure 12 is a partial cross-sectional view of Figure 11;

[0031] Figure 13 is another partial cross-sectional view of Figure 11;

[0032] Figure 14 is a partial top view of a photovoltaic module provided in another embodiment of this application. Detailed Implementation

[0033] As can be seen from the background technology, current photovoltaic modules have relatively large power generation losses.

[0034] Analysis revealed that one of the reasons for the current power generation loss is that the mainstream silver electrode is a combination of silver and glass, which has a loose and unstable structure. In addition, the melting point is different from that of copper solder strip. If OBB technology is used, the single-point welding area is reduced by 90%. When subjected to external force or thermal expansion and contraction, the solder strip is easy to detach from the battery cell, resulting in power generation loss.

[0035] This application provides a photovoltaic module that increases the welding area between the connecting component and the solar cell by setting welding grid lines and welding multiple welding grid lines to connecting components. This helps to improve the welding pull force and avoid situations such as poor welding of connecting components and connecting components detaching from solar cells, thereby improving the yield and cell efficiency of the photovoltaic module.

[0036] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0039] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0040] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0041] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0042] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0043] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or it can have another component present in between. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located in between.

[0044] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0045] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0046] Figure 1 is a schematic diagram of a photovoltaic module according to an embodiment of this application; Figure 2 is a top view of a photovoltaic module according to an embodiment of this application; Figure 3 is a partial cross-sectional view of Figure 2. In Figure 2, the connecting component is semi-transparent, and the encapsulant film and cover plate are also transparent, meaning the welding grid lines located beneath the connecting component can be seen through the connecting component. The cross-sectional view in Figure 3 does not show the encapsulant film and cover plate; in reality, the gap between the two welding grid lines is filled with an encapsulant film.

[0047] This application provides a photovoltaic module for reducing power generation losses. Referring to Figures 1 and 2, the photovoltaic module includes: a solar cell 100, which includes a welding area 101 and a collection area 102 arranged along a first direction X. The surface of the solar cell 100 has a plurality of grid lines 110 arranged along a second direction Y. Each grid line 110 includes at least two welding grid lines 111 located in the welding area 101 and a collection grid line 112 located in the collection area 102. The welding grid lines 111 are arranged along the second direction Y, and each of the at least two welding grid lines 111 is electrically connected to the same collection grid line 112. The photovoltaic module includes: a connecting member 120, which is located on the solar cell 100 and electrically connected to the plurality of grid lines 110 arranged along the second direction Y. The connecting member 120 is welded to each welding grid line 111.

[0048] The photovoltaic module provided in this application embodiment includes a solar cell 100 with multiple grid lines 110 arranged along a second direction Y and a connecting component 120 on its surface. The connecting component 120 is welded to each welding grid line 111. The large number of welding grid lines 111, i.e., the large number of welding points between the solar cell 100 and the connecting component 120, increases the welding pull between the solar cell 100 and the connecting component 120, preventing the connecting component 120 from detaching from the solar cell 100, and avoiding poor EL appearance and power generation loss caused by poor soldering. One collecting grid line 112 is electrically connected to multiple welding grid lines 111. Thus, the grid lines on the solar cell can be connected to the connecting component 120 through multiple paths, effectively avoiding power generation loss due to broken grid lines.

[0049] In some embodiments, the solar cell 100 may be any one of the following, including but not limited to: PERC cell (Passivated Emitter Rear Cell), PERT cell (Passivated Emitter and Rear Totally-diffused cell), TOPCon cell (Tunnel Oxide Passivated Contact), and HIT / HJT cell (Heterojunction Technology).

[0050] In some embodiments, the solar cell 100 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0051] In some embodiments, the solar cell 100 is a whole cell or a sliced ​​cell. A sliced ​​cell refers to a solar cell formed by cutting a complete whole cell. The cutting process includes: laser grooving and cutting (Linear Spectral Clustering, LSC) process and thermal stress cell separation (TMC) process.

[0052] In some embodiments, the sliced ​​battery is a half-cell battery, which can also be understood as a halved battery or a two-piece battery. The function of the halved battery assembly is to increase power generation by reducing resistance loss. The halved battery assembly can optimize the width of the connecting part 120 in the battery. Conventionally, it is necessary to optimize the balance between increasing the width of the connecting part 120 to reduce power generation loss and decreasing the width of the connecting part 120 to reduce shading loss. The halved battery assembly reduces battery loss, so the width of the connecting part 120 can be set to be thinner to reduce shading loss, which is beneficial to improving battery efficiency and power generation. In other embodiments, the sliced ​​battery can be a three-piece battery, a four-piece battery, or an eight-piece battery, etc.

[0053] The welding area 101 refers to the area where the connecting component 120 is welded to the battery cell. In order to ensure that all areas in contact with the connecting component 120 are welding areas 101, the area of ​​the welding area 101 is generally set to be larger than the area of ​​the connecting component 120. Therefore, the width of the connecting component 120 shown in Figure 2 is smaller than the width of the welding area 101.

[0054] The collection area 102 refers to the area on the solar cell other than the welding area 101, which is used to collect and summarize current.

[0055] It should be noted that the welding grid line 111 corresponding to the welding area 101 not only has the function of making alloy contact with the connecting component 120, but also has the function of collecting and summarizing current.

[0056] The welding grid 111 is used to form an alloy contact with the connecting component 120, thereby achieving the purpose of welding. The alloy contact between the welding grid 111 and the connecting component 120 can be formed by welding or lamination.

[0057] In some embodiments, the width of the welding grid line 111 is equal to the width of the collecting grid line 112. This reduces the shading area of ​​the welding grid line 111, thereby improving the photoelectric conversion efficiency of the battery.

[0058] In other embodiments, the width of the welding grid line 111 is greater than the width of the collecting grid line 112. The larger width of the welding grid line 111 results in a larger contact area between the connecting component 120 and the welding grid line 111, thereby improving the alloy contact performance between the connecting component 120 and the welding grid line 111. This improves welding quality and avoids problems such as incomplete soldering and power generation loss caused by the connecting component 120 detaching from the battery cell. Secondly, the larger width of the welding grid line 111 reduces the probability of breakage of the welding grid line 111 due to thermal expansion and contraction of the tin layer on the connecting component 120 during the welding process, thus improving the appearance of the EL (electrode electrode) and reducing power generation loss.

[0059] In some embodiments, the number of welding grid lines 111 can be 2 to 5. A larger number of welding grid lines 111 can result in a larger number of welding points between the connecting component 120 and the battery cell, thereby improving the welding quality between the battery cell and the connecting component 120.

[0060] For example, the number of welding grid lines 111 can be 2, 3, 4 or 5.

[0061] In some embodiments, the shape of the welding grid line 111 can be any one of arc shape, straight line shape, broken line shape or wavy shape.

[0062] Figure 4 shows four schematic diagrams of welding grid lines in a photovoltaic module according to an embodiment of this application.

[0063] Referring to Figure 4, the number and shape of the welding grid lines can be any of those shown in Figure 4 (a to d), and the embodiments of this application do not limit them.

[0064] The width of each welding grid line and the spacing between each welding grid line are not limited in this application, and those skilled in the art can set them according to actual needs.

[0065] Figure 5 is a top view of a welding grid in a photovoltaic module according to an embodiment of this application.

[0066] Referring to Figure 5, in some embodiments, the welding grid line 111 includes a first type grid line 1111 and a second type grid line 1112. The first type grid line 1111 and the collecting grid line 112 are made of burn-through paste, while the second type grid line 1112 is made of non-burn-through paste. Thus, the first type grid line 1111 is used to collect charge carriers and is welded to the connecting component 120. The second type grid line 1112 is used to weld to the connecting component 120 and has better welding pull strength, thereby achieving higher welding quality and lower power generation losses.

[0067] Among them, burn-through paste refers to electrode paste that can burn through the passivation layer of the solar cell and electrically connect with the doped layer, for example, to weld the gate wires to the emitter. Non-burn-through paste refers to electrode paste that cannot burn through the passivation layer.

[0068] It should be noted that the first type of grid line 1111 and the collecting grid line 112 can be integrally formed grid lines. The first type of grid line 1111 and the collecting grid line 112 can be printed in the same printing process, and then the second type of grid line 1112 can be printed in another printing process. In some embodiments, the first type of grid line, the collecting grid line and the second type of grid line can also be printed separately.

[0069] Figure 6 is a partial cross-sectional view of a photovoltaic module provided in an embodiment of this application.

[0070] In some embodiments, referring to FIG6, the welding grid line 111 includes: a first sub-grid line 131 and a second sub-grid line 132 stacked together, the second sub-grid line 132 being located between the connecting member 120 and the first sub-grid line 131, and the first sub-grid line 131 and the second sub-grid line 132 being made of different materials. By setting the first sub-grid line 131 and the second sub-grid line 132 to be stacked together, and the first sub-grid line 131 and the second sub-grid line 132 being made of different materials, the first sub-grid line 131 can be set to burn through the passivation layer and contact the doped layer, thereby collecting charge carriers and thus having a large photoelectric conversion efficiency; while the second sub-grid line 132 located above the first sub-grid line 131 is used to weld to the connecting member 120. The second sub-grid line 132 and the connecting member 120 have good compatibility in the molten state, thus having good welding quality and high welding pull force, avoiding the power generation loss problem caused by the separation of the connecting member 120 from the cell 100.

[0071] For example, the material of the first sub-gate line 131 can be silver-aluminum, and the material of the second sub-gate line 132 can be silver. As another example, the material of the first sub-gate line 131 can be silver-aluminum, and the material of the second sub-gate line 132 can be solder paste.

[0072] It should be noted that the fact that the height of the first sub-grid line 131 in Figure 6 is the same as the height of the collecting grid line 112 is only for illustration. In practice, the surface of the first sub-grid line 131 can be lower than the surface of the collecting grid line 112 or flush with the surface of the first sub-grid line 131, and the height of the first sub-grid line 131 can even be higher than the height of the collecting grid line 112.

[0073] Figure 7 is another top view of the welding grid lines in a photovoltaic module according to an embodiment of this application; Figure 8 is a cross-sectional view corresponding to Figure 7.

[0074] In some embodiments, at least two welding grid lines 111 of the same first grid line contact each other to form a pad 113, and the width of the pad 113 along the second direction is greater than the width of the collecting grid line 112 along the second direction. Thus, an electrical connection is achieved between the pad 113 and the connecting member 120. Compared to a single grid line, the width of the pad 113 is larger, thereby avoiding grid line breakage and insufficient welding pull, thus improving welding quality.

[0075] In addition, compared with multiple welding grid lines 111, the working window of the pad 113 is larger, which reduces the process difficulty of the cell and improves the accuracy and precision, thereby improving the yield and aesthetics of the photovoltaic module.

[0076] The connecting component 120 is used to interconnect the solar cells 100 and to collect current for transmission to external components of the photovoltaic module. The connecting component 120 includes busbars and interconnecting strips. The busbars are used to connect the photovoltaic cell string and the junction box, and the interconnecting strips are used to connect the first solar cell and the second solar cell.

[0077] In some embodiments, the connecting component 120 has a core-encased structure, comprising a conductive layer and a solder layer covering the surface of the conductive layer. The conductive layer is the primary conductive transport layer of the connecting component 120; therefore, the lower the resistivity of the conductive layer, the smaller the electrical loss of the connecting component 120, and the better the battery efficiency and power generation. The conductive layer is made of conductive materials with good conductivity, such as copper, nickel, gold, or silver, or alloy materials with low resistivity.

[0078] In some embodiments, the solder layer can be plated or coated on the surface of the conductive layer. Specifically, special processes such as electroplating, vacuum deposition, spraying, or hot-dip coating can be used to uniformly coat the source material of the solder layer around the conductive layer according to a certain composition ratio and thickness. The main function of the solder layer is to ensure the solderability of the connecting component 120 and to firmly weld the connecting component 120 to the grid structure of the battery cell 100, thereby providing good current conduction.

[0079] In some embodiments, the solder layer is made of a metal or alloy with a lower melting point than the conductive layer, such as a tin alloy. Tin alloys may include tin-zinc alloys, tin-bismuth alloys, or tin-indium alloys. Tin is used as a soldering material because of its low melting point and good affinity with metals such as copper, resulting in a strong weld. The lead in tin-lead alloys can lower the melting point of the solder strip, and tin and lead can form a eutectic point with a melting point of 183°C, exhibiting good welding and performance characteristics.

[0080] The embodiments disclosed in this application use other metallic elements to replace lead or add other elements, such as bismuth, to the tin-lead alloy. The use of bismuth can lower the melting point temperature and reduce surface tension. The melting point of the tin-bismuth alloy can be lowered to 129°C, meeting the requirements for low-temperature welding. In this way, the stress caused by thermal expansion and contraction of the connecting component 120 is reduced, lowering the risk and probability of grid breakage in the weld grid 111.

[0081] In some embodiments, the solder layer contains flux, which refers to a chemical substance that helps and promotes the soldering process while providing protection and preventing oxidation. Flux includes inorganic flux, organic flux, and resin flux. It is understood that the flux has a lower melting point than the solder layer and increases the fluidity of the molten solder layer to facilitate good alloying between the solder layer and the grid structure.

[0082] In some embodiments, the cross-sectional shape of the connecting component 120 along a section perpendicular to the first direction Y is circular. Circular solder strips do not have orientation or alignment issues, and are easier to mass-produce.

[0083] In some embodiments, the cross-sectional shape of the connecting member 120 can be triangular or any other arbitrary shape to increase the contact area between the solder strip and the grid structure and reduce the problem of alignment misalignment between the connecting member 120 and the grid structure.

[0084] In some embodiments, the surface of the connecting member 120 away from the solar cell has a reflective layer located on the outer side of the solder layer away from the conductive layer and the solar cell. The reflective layer is used to mitigate electrical losses caused by the area of ​​the connecting member 120 obstructing the solar cell.

[0085] In some embodiments, the outer surface of the solder layer has reflective grooves, which are recessed grooves or channels in the direction of the solder layer toward the conductive layer. Sunlight is reflected onto the solar cell through the sidewalls of the reflective grooves, thereby improving the utilization rate of sunlight.

[0086] In some embodiments, continuing to refer to FIG1, the photovoltaic module further includes a battery string, which is composed of a plurality of battery cells in the above embodiments connected by a connecting member 120, wherein the connecting member 120 is used to connect adjacent battery cells 100 in series.

[0087] In some embodiments, the battery cell includes a first battery cell and a second battery cell. A connecting member 120 connects a first electrode of the first battery cell to a second electrode of an adjacent second battery cell, or a connecting member 120 connects a second electrode of the first battery cell to a first electrode of an adjacent second battery cell. The first electrode is either a positive electrode or a negative electrode, and the second electrode is either a positive electrode or a negative electrode.

[0088] In some embodiments, referring to FIG1, the front sides of the first and second battery cells face the same side, and the back sides of the first and second battery cells face the same side, or in other words, the first electrodes of all battery cells 100 face the same side, and the second electrodes of all battery cells 100 face the same side. In this case, the connecting member 120 needs to naturally extend from the front side of the battery cell to the back side of the adjacent battery cell so that the connecting member 120 connects the first electrode and the second electrode of the adjacent battery cell.

[0089] In other embodiments, the first and second battery cells are arranged in the order of first surface, second surface, first surface, and second surface, so the connecting component will not be bent and the connecting component directly connects the first electrode of the first battery cell and the second electrode of the adjacent second battery cell.

[0090] In Figure 1, adjacent solar cells 100 are spaced apart to provide electrical insulation between them. In other embodiments, there are no gaps between adjacent solar cells; the cells are stacked together.

[0091] Referring again to Figure 1, the photovoltaic module further includes: an encapsulating film 11, which covers the surface of the cell strings and fills the gaps between the cell strings. The photovoltaic module also includes: a cover plate 12, which covers the side of the encapsulating film 11 away from the cell strings.

[0092] The materials of the film 11 include organic encapsulation films such as EVA, POE, or PVB.

[0093] In some embodiments, the glass transition temperature of the encapsulant film 11 is -70 to -10°C. The glass transition temperature of the encapsulant film is used to ensure that the encapsulant film can be in a molten state during the lamination process to fill the gaps in the photovoltaic module and improve the yield of the photovoltaic module.

[0094] In some embodiments, the melting point of the adhesive film and the melting point of the connecting member 120 can be set according to actual needs. When the melting point of the adhesive film 11 is greater than that of the connecting member 120, the connecting member 120 can be alloyed before the adhesive film 11 reaches a molten state, which can effectively prevent the molten adhesive film 11 from immersing into the welding grid lines 111 and the connecting member 120 and from pushing the connecting member 120 to cause it to shift. When the melting point of the adhesive film 11 is less than that of the connecting member 120, the lamination temperature can be set to be lower, thereby improving the thermal stress on the solar cell 100 and increasing the yield of the photovoltaic module.

[0095] In some embodiments, the cover plate 12 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 12 away from the adhesive film 11 can be an uneven surface, thereby increasing the utilization rate of incident light. The cover plate 12 includes a first cover plate and a second cover plate, the first cover plate facing the front of the battery cell and the second cover plate facing the back of the battery cell.

[0096] The photovoltaic module provided in this application embodiment includes a solar cell surface comprising multiple grid lines arranged along a second direction and a connecting component 120. The connecting component 120 is welded to each welding grid line 111. The large number of welding grid lines 111, i.e., the large number of welding points between the solar cell and the connecting component 120, increases the welding pull between the solar cell and the connecting component 120, preventing the connecting component 120 from detaching from the solar cell and avoiding poor EL appearance and power generation loss caused by incomplete soldering. One collection grid line 112 is electrically connected to multiple welding grid lines 111. Thus, the grid lines on the solar cell can be connected to the connecting component 120 through multiple paths, effectively avoiding power generation loss due to broken grid lines.

[0097] Accordingly, another embodiment of this application also provides a battery cell, which differs from the above embodiment in that the battery cell in the above embodiment is a non-back contact battery cell, that is, one side of the battery cell has a grid line of a certain type of conductivity, while another embodiment of this application provides a back contact battery cell, one side of the battery cell has a first grid line of a first type of conductivity and a second grid line of a second type of conductivity. The parts that are the same as or corresponding to the above embodiment will not be described in detail here.

[0098] Figure 9 is a structural schematic diagram of a photovoltaic module according to another embodiment of this application; Figure 10 is a top view of a photovoltaic module according to another embodiment of this application.

[0099] Another embodiment of this application provides a photovoltaic module for reducing power generation losses. Referring to Figures 9 and 10, the photovoltaic module includes: a solar cell 200, the solar cell 200 including a welding area and a collection area arranged along a first direction X.

[0100] In some embodiments, the solar cell 200 is a back-contact solar cell, such as an interdigitated back contact (IBC) crystalline silicon solar cell. An IBC cell is a back-junction back-contact solar cell structure in which the positive and negative metal electrodes are arranged in an interdigitated manner on the back surface of the cell. Its PN junction and electrodes are located on the back of the cell, that is, the electrodes of the emitter region and the base region of the IBC cell are both on the back, and there is no grid line obstruction on the front, which can improve the photoelectric conversion performance of the cell.

[0101] Referring to Figure 10, the welding area may include a first welding area 2011 and a second welding area 2012, and the collection area may include a first collection area 2021 and a second collection area 2022.

[0102] The surface of the cell 200 has a plurality of grid lines arranged along a second direction. Each grid line includes at least two welding grid lines located in a welding area and a collection grid line located in a collection area. The welding grid lines are arranged along the second direction, and each of the at least two welding grid lines is electrically connected to the same collection grid line.

[0103] In some embodiments, referring to FIG10, the gate line includes a first gate line 240 of a first conductivity type and a second gate line 250 of a second conductivity type. The first gate line 240 includes a first welding gate line 241 corresponding to the first welding area 2011 and a first collection gate line 242 corresponding to the first collection area. The second gate line 250 includes a second welding gate line 251 corresponding to the second welding area 2012 and a second collection gate line 252 corresponding to the second collection area 2022. The first welding area 2011 and the second collection area 2022 are directly opposite each other along the second direction Y, and the second welding area 2012 and the first collection area 2021 are directly opposite each other along the second direction Y.

[0104] Referring to Figure 10, the photovoltaic module includes a connecting component located on the solar cell. The connecting component includes a first connecting component 221 and a second connecting component 222. The first connecting component 221 is electrically connected to a plurality of first grid lines 240 arranged along the second direction Y, and the first connecting component 221 is welded to each of the first welding grid lines 241. The second connecting component 222 is electrically connected to a plurality of second grid lines 250 arranged along the second direction Y, and the second connecting component 222 is welded to each of the second welding grid lines 251.

[0105] Referring again to Figure 10, the photovoltaic module further includes: an insulating layer 260, which is located between the first connecting member 221 and the second collecting grid line 252. The insulating layer 260 is located between the second connecting member 222 and the first collecting grid line 242.

[0106] In some embodiments, the insulating layer 260 is an independent adhesive block, corresponding to the space between the first connecting member 221 and the second collecting grid line 252 and between the second connecting member 222 and the first collecting grid line 242, thereby reducing the amount of insulating layer 260 used and reducing manufacturing costs.

[0107] The dimensions, length, and thickness of the insulating layer 260 in this embodiment are not limited. It is only necessary to ensure electrical insulation between the corresponding first connecting component 221 and the second collecting grid line 252, and electrical insulation between the second connecting component 222 and the first collecting grid line 242.

[0108] In some embodiments, the insulating layer 260 not only covers the first welding area 2011, but also extends beyond the first welding area 2011 and extends to a portion of the width of the first collection area 2021. The width extending to the first collection area 2021 is 0.5mm to 2.5mm. This reduces the difficulty of serial soldering and effectively avoids the risk of short circuits.

[0109] For example, the width of the insulating layer 260 extending to the first collection area 2021 is 0.5mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm or 2.5mm.

[0110] Similarly, the insulating layer 260 not only covers the second welding area 2012, but also extends to the second collection area 2022, and the extension width is 0.5mm to 2.5mm.

[0111] Figure 11 is another top view of a photovoltaic module provided in another embodiment of this application; Figure 12 is a partial cross-sectional view of Figure 11; Figure 13 is another partial cross-sectional view of Figure 11.

[0112] In some embodiments, referring to FIG11, an insulating layer 260 is located on the first gate line 240 and the second gate line 250. The insulating layer 260 has a cutout area 261, which corresponds to the first welding area 2011 and exposes the first welding gate line 241. The cutout area also corresponds to the second welding area 2012, and the cutout area 261 exposes the second welding gate line 251. In this way, by setting an entire insulating layer 260 and setting the cutout area 261 in the corresponding area, the electrical connection between the first connecting component 221 and the first welding gate line 241, and the electrical connection between the second connecting component 222 and the second welding gate line 251 are realized. This reduces the difficulty of printing each insulating layer block individually and the alignment requirements, thereby reducing the process difficulty.

[0113] In some embodiments, the insulating layer 260 covers the first soldering area 2011 and extends beyond the first soldering area 2011 into a first collection area 2021 with a width of 0.5mm to 2.5mm; another insulating layer 260 covers the second soldering area 2012 and extends beyond the second soldering area 2012 into a second collection area 2022 with a width of 0.5mm to 2.5mm. This reduces the difficulty of serial soldering and effectively avoids the risk of short circuits.

[0114] In some embodiments, at least two first welding grid lines 241 of the same first grid line 240 contact each other to form a pad, and the width of the pad along the second direction is greater than the width of the first collecting grid line 242 along the second direction Y. Thus, electrical connection is achieved through the pad and the connecting component. Compared to a single grid line, the wider pad avoids grid line breakage and insufficient welding pull, thereby improving welding quality. Furthermore, compared to multiple welding grid lines, the pad has a larger operable window, reducing the manufacturing difficulty of the solar cells and improving accuracy and precision, thereby improving the yield and aesthetics of the photovoltaic module.

[0115] Similarly, in some embodiments, at least two second welding gate lines 251 of the same second gate line 250 contact each other to form a pad, and the width of the pad along the second direction is greater than the width of the second collection gate line 252 along the second direction Y.

[0116] In some embodiments, referring to FIG13, corresponding to the region of the connecting member, the top surface of the first welding gate line 241 near the insulating layer 260 is higher than the top surface of the first welding gate line 241 away from the insulating layer 260, that is, the height h1 of the first welding gate line 241 near the insulating layer 260 can be greater than the height h2 of the first welding gate line 241 away from the insulating layer 260. From FIG12 and FIG13, it can be seen that because the height h1 of the first welding gate line 241 near the insulating layer 260 is slightly higher, the contact area between the first connecting member 221 and the top surface of the first welding gate line 241 near the insulating layer 260 is increased, thereby improving welding quality and increasing welding pull strength.

[0117] In some embodiments, the width of the first welding gate line 241 near the insulating layer 260 may be greater than the width of the first welding gate line 241 away from the insulating layer 260.

[0118] In some embodiments, the spacing between the insulating layer 260 and the first welding gate line 241 is proportional to the thickness of the insulating layer 260. That is, a larger insulating layer 260 results in a larger spacing between the insulating layer 260 and the first welding gate line 241, and a larger area of ​​the cutout region, allowing the first connecting member 221 to undergo greater spatial deformation and a larger contact area between the connecting member and the first welding gate line 241. Conversely, a smaller insulating layer 260 results in a smaller spacing between the insulating layer 260 and the first welding gate line 241, and a smaller area of ​​the cutout region.

[0119] In some embodiments, the thickness of the insulating layer 260 decreases along the second direction Y and toward the first welding gate line 241. Thus, the first connecting member 221 can be welded to the first welding gate line 241 along the thickness variation of the insulating layer 260, thereby increasing the welding area and avoiding incomplete soldering.

[0120] Figure 14 is a partial top view of a photovoltaic module provided in another embodiment of this application.

[0121] In some embodiments, the first collecting grid line 242 includes two first broken grids 206 and a first break 205 located between the two first broken grids 206. The first break 205 corresponds to the second welding area 2012. The first broken grids 206 are located on both sides of the second connecting member and are insulated from the second connecting member.

[0122] The second collecting grid line 252 includes two broken grids 204 and a break 203 located between the two broken grids 204. The break 203 corresponds to the first welding area 2011. The broken grids 204 are located on both sides of the first connecting component and are insulated from the first connecting component.

[0123] In some embodiments, continuing to refer to FIG9, the photovoltaic module further includes a battery string, which is composed of a plurality of battery cells as described in the above embodiments through connecting members, wherein the connecting members are used to connect adjacent battery cells in series.

[0124] In some embodiments, the battery cell includes a first battery cell and a second battery cell. A connecting member 220 connects a first welding grid line 241 of the first battery cell to a second welding grid line 251 of an adjacent second battery cell, or a connecting member 220 connects a second welding grid line 251 of the first battery cell to a first welding grid line 241 of an adjacent second battery cell.

[0125] Referring again to Figure 9, the photovoltaic module further includes: an encapsulating film 21, which covers the surface of the cell strings and fills the gaps between the cell strings. The photovoltaic module also includes: a cover plate 22, which covers the side of the encapsulating film 21 away from the cell strings.

[0126] The photovoltaic module provided in this application embodiment includes a solar cell surface comprising a plurality of first grid lines 240, first connecting components 221, and second connecting components 222 arranged along a second direction. The first connecting components 221 are welded to each of the first welding grid lines 241, and the second connecting components 222 are electrically connected to the second welding grid lines 251. By electrically connecting the first welding grid lines 241 to the first connecting components 221 and welding the second welding grid lines 251 to the second connecting components 222, and by having a large number of first welding grid lines 241 and second welding grid lines 251, the number of welding points between the solar cell and the first connecting components 221 and the number of welding points between the solar cell and the second connecting components 222 is increased. This improves the welding pull between the solar cell and the connecting components, preventing the connecting components from detaching from the solar cell, and avoiding poor EL appearance and power generation loss caused by incomplete soldering. A first collection grid line 242 is electrically connected to multiple first welding grid lines 241. In this way, the first grid lines on the solar cell can be connected to the first connecting component 221 through multiple paths, effectively avoiding power generation loss caused by grid breakage.

[0127] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, comprising: A battery cell, the battery cell including a welding area and a collection area arranged along a first direction; The surface of the battery cell has a plurality of grid lines arranged along a second direction. Each grid line includes at least two welding grid lines located in the welding area and a collection grid line located in the collection area. The welding grid lines are arranged along the second direction, and each of the at least two welding grid lines is electrically connected to the same collection grid line. A connecting component is located on the battery cell and is electrically connected to a plurality of grid lines arranged along the second direction, and is welded to each of the welding grid lines.

2. The photovoltaic module according to claim 1, wherein, The width of the welding grid line along the second direction is greater than or equal to the width of the collecting grid line along the second direction.

3. The photovoltaic module according to claim 1, wherein, The welding grid includes a first type of grid and a second type of grid. The first type of grid and the collecting grid are made of burn-through slurry, and the second type of grid is made of non-burn-through slurry.

4. The photovoltaic module according to claim 1 or 3, wherein, The welding grid line includes: a first sub-grid line and a second sub-grid line stacked together, the second sub-grid line being located between the connecting component and the first sub-grid line, the first sub-grid line and the second sub-grid line being made of different materials.

5. The photovoltaic module according to claim 1, wherein, The battery cell is a back-contact battery cell. The grid lines include a first grid line of a first conductivity type and a second grid line of a second conductivity type. The first grid line includes a first welding grid line corresponding to a first welding area and a first collection grid line corresponding to a first collection area. The second grid line includes a second welding grid line corresponding to a second welding area and a second collection grid line corresponding to a second collection area. The first welding area and the second collection area are directly opposite each other along the second direction. The second welding area and the first collection area are directly opposite each other along the second direction. It also includes an insulating layer located between the connecting member and the second collection grid line.

6. The photovoltaic module according to claim 5, wherein, The insulating layer is located on the first gate line and the second gate line, and the area of ​​the insulating layer corresponding to the first welding area exposes the first welding gate line.

7. The photovoltaic module according to claim 5 or 6, wherein, At least two of the first welding gate lines of the same first gate line contact each other to form a pad, and the width of the pad along the second direction is greater than the width of the first collection gate line along the second direction.

8. The photovoltaic module according to claim 5 or 6, wherein, In the region corresponding to the connecting component, the top surface of the first welding grid line near the insulating layer is higher than the top surface of the first welding grid line away from the insulating layer.

9. The photovoltaic module according to claim 6, wherein, The spacing between the insulating layer and the first welding grid line is proportional to the thickness of the insulating layer.

10. The photovoltaic module according to claim 6, wherein, The thickness of the insulating layer decreases along the second direction and toward the first weld grid line.

11. The photovoltaic module according to claim 6, wherein, The second collecting grid line includes two broken grids and a break located between the two broken grids. The break corresponds to the first welding area. The broken grids are located on both sides of the connecting component and are insulated from the connecting component.

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