Solar cell piece and photovoltaic module

Abstract

The utility model relates to a solar cell piece and a photovoltaic module, the solar cell piece comprises a substrate and an electrode, the electrode comprises a plurality of positive pole main grids and a plurality of negative pole main grids, each positive pole main grid is connected with a plurality of positive pole fine grids, each negative pole main grid is connected with a plurality of negative pole fine grids, and the positive pole fine grids are connected with the negative pole fine grids. The positive pole fine grids and the negative pole fine grids are alternately arranged along the second direction between the adjacent positive pole main grids and negative pole main grids, each positive pole fine grid is provided with a first insulation paste, each negative pole fine grid is provided with a second insulation paste, and the first insulation paste and the second insulation paste are alternately arranged along the second direction. The projection of the first insulation paste and the projection of the second insulation paste have an overlapped part. According to the solar cell piece and the photovoltaic module, the problem of lap joint short circuit formed between the adjacent positive electrode fine grid and negative electrode fine grid is avoided.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and particularly to a solar cell and a photovoltaic module. Background Art

[0002] With the continuous development of the photovoltaic industry, cost reduction and efficiency improvement have become the development theme of the photovoltaic industry. The back-contact battery is a new type of battery technology that can effectively improve the battery efficiency. Its main feature is that there is no grid line occlusion on the front side of the battery cell, and the positive and negative electrodes of the battery cell are both distributed on the back side of the battery cell. The positive electrode includes a connected positive main grid and positive fine grids, and the negative electrode includes a connected negative main grid and negative fine grids. Among them, the positive fine grids and the negative fine grids are arranged alternately in a finger-like pattern. To avoid short circuits, there should be no overlap between the fine grids and the main grids of opposite-sex electrodes, nor between the fine grids of opposite-sex electrodes.

[0003] In the related art, insulating glue is usually provided at the end of the fine grid to prevent short circuits due to overlap between the fine grids and the main grids of opposite-sex electrodes. However, during the process of forming a photovoltaic module by connecting battery cells with solder tapes, the cut solder tape head or other metal foreign objects entering the photovoltaic module may cause short circuits due to overlap between the fine grids of adjacent opposite-sex electrodes, reducing the finished product yield. Summary of the Invention

[0004] Based on this, it is necessary to provide a solar cell and a photovoltaic module for the problem of how to prevent short circuits due to overlap between the fine grids of opposite-sex electrodes.

[0005] On the one hand, this application provides a solar cell, including a substrate and electrodes. The electrodes include multiple positive main grids and multiple negative main grids. The multiple positive main grids and the multiple negative main grids are alternately arranged on the substrate along a first direction, and each positive main grid and each negative main grid extend along a second direction. The first direction intersects with the second direction;

[0006] Each positive main grid is connected with multiple positive fine grids. The multiple positive fine grids are arranged in parallel along the second direction. There is a first interval between the end of each positive fine grid and the adjacent negative main grid; each negative main grid is connected with multiple negative fine grids. The multiple negative fine grids are arranged in parallel along the second direction. There is a second interval between the end of each negative fine grid and the adjacent positive main grid;

[0007] Among them, between the adjacent positive main grids and the negative main grids, the positive fine grids and the negative fine grids are alternately arranged along the second direction. A first insulating adhesive is provided on each positive fine grid. One end of the first insulating adhesive is located in the first interval, and the other end extends along the direction close to the positive main grid to cover at least a part of the positive fine grid; a second insulating adhesive is provided on each negative fine grid. One end of the second insulating adhesive is located in the second interval, and the other end extends along the direction close to the negative main grid to cover at least a part of the negative fine grid; and along the second direction, the projection of the first insulating adhesive and the projection of the second insulating adhesive have an overlapping part.

[0008] The technical solution will be further described below:

[0009] In one embodiment, one end of the first insulating adhesive close to the positive main grid is spaced from the positive main grid; and / or, one end of the second insulating adhesive close to the negative main grid is spaced from the negative main grid.

[0010] In one embodiment, the length of the first insulating adhesive in the first direction is greater than or equal to half of the distance between the adjacent positive main grid and the negative main grid; and / or, the length of the second insulating adhesive in the first direction is greater than or equal to half of the distance between the adjacent positive main grid and the negative main grid.

[0011] In one embodiment, the length of the overlapping part in the first direction is greater than or equal to 0.3 mm.

[0012] In one embodiment, each positive main grid is further covered with a third insulating adhesive, and each negative main grid is further covered with a fourth insulating adhesive.

[0013] In one embodiment, the first insulating adhesive is connected to the fourth insulating adhesive; and / or, the second insulating adhesive is connected to the third insulating adhesive.

[0014] In one embodiment, the third insulating adhesive and the fourth insulating adhesive are both provided with hollowed-out grooves, and pad points are arranged in the hollowed-out grooves for connecting with solder tapes.

[0015] In one embodiment, the width of the third insulating adhesive in the first direction is greater than the width of the solder tape.

[0016] In one embodiment, the width of the fourth insulating adhesive in the first direction is greater than the width of the solder tape.

[0017] On the other hand, the present application also provides a photovoltaic module, including the above-mentioned solar cell.

[0018] In the above-mentioned solar cell and photovoltaic module, a first insulating adhesive is provided on each positive fine grid, and one end of the first insulating adhesive is located in the first interval, and the other end extends along the direction close to the positive main grid, so as to ensure that the first insulating adhesive can cover at least part of the positive fine grid including the end of the positive fine grid, thereby avoiding the end of the positive fine grid from forming a lap short circuit with the solder tape connected to the negative main grid. Similarly, a second insulating adhesive is provided on each negative fine grid, and one end of the second insulating adhesive is located in the second interval, and the other end extends along the direction close to the negative main grid, so as to ensure that the second insulating adhesive can cover at least part of the negative fine grid including the end of the negative main grid, thereby avoiding the end of the negative fine grid from forming a lap short circuit with the solder tape connected to the positive main grid. In addition, along the second direction, the projection of the first insulating adhesive and the projection of the second insulating adhesive have an overlapping part. In this way, even if a metal foreign object such as a solder head accidentally falls on the solar cell, the metal foreign object cannot simultaneously lap on the exposed sections of the adjacent positive fine grid and the negative fine grid, thereby avoiding the problem of lap short circuit between the adjacent positive fine grid and the negative fine grid. Description of the Drawings

[0019] The drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application.

[0020] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] In addition, the drawings are not drawn to a scale of 1:1, and the relative sizes of the respective elements are only drawn exemplarily in the drawings and not necessarily to the true scale. In the drawings:

[0022] Figure 1 It is a partial enlarged view of a solar cell after hiding the insulating adhesive in an embodiment.

[0023] Figure 2 It is a partial enlarged view of a solar cell in an embodiment.

[0024] Description of the Reference Numerals:

[0025] 10. Substrate; 111. Positive main grid; 112. Negative main grid; 113. Positive fine grid; 1131. First interval; 114. Negative fine grid; 1141. Second interval; 115. Pad point; 21. First insulating glue; 22. Second insulating glue; 23. Third insulating glue; 24. Fourth insulating glue; 231. Hollowed-out groove. Detailed implementation manners

[0026] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0027] In the description of the present application, it should be understood that if such terms as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0028] In addition, if such terms as "first" and "second" appear, these terms are only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0029] In the present application, unless otherwise clearly defined and limited, if such terms as "installed", "connected", "connected to", "fixed" appear, these terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0030] In this application, unless otherwise clearly defined and limited, if there is a description such as a first feature being "on" or "under" a second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0032] An embodiment of this application provides a solar cell, which can specifically be a back contact cell, etc. Specifically, refer to Figure 1 , the solar cell substrate 10 and electrodes of an embodiment. The substrate 10 can be a silicon wafer. The electrodes include multiple positive main grids 111 and multiple negative main grids 112. The positive main grids 111 and the negative main grids 112 are alternately arranged on the substrate 10 along a first direction, and each positive main grid 111 and each negative main grid 112 extend along a second direction. The first direction and the second direction intersect. In this embodiment, the X direction in the figure is the first direction, and the Y direction is the second direction.

[0033] Continue to refer to Figure 1 , each positive main grid 111 is connected to multiple positive fine grids 113. The multiple positive fine grids 113 are arranged in parallel along the second direction. There is a first interval 1131 between the end of each positive fine grid 113 and the adjacent negative main grid 112; each negative main grid 112 is connected to multiple negative fine grids 114. The multiple negative fine grids 114 are arranged in parallel along the second direction. There is a second interval 1141 between the end of each negative fine grid 114 and the adjacent positive main grid 111;

[0034] Refer to Figure 2, between the adjacent positive main grid 111 and negative main grid 112, the positive fine grids 113 and negative fine grids 114 are alternately arranged along the second direction. A first insulating adhesive 21 is provided on each positive fine grid 113. One end of the first insulating adhesive 21 is located in the first interval 1131, and the other end extends along the direction close to the positive main grid 111 to cover at least part of the positive fine grid 113; A second insulating adhesive 22 is provided on each negative fine grid 114. One end of the second insulating adhesive 22 is located in the second interval 1141, and the other end extends along the direction close to the negative main grid 112 to cover at least part of the negative fine grid 114; And along the second direction, the projection of the first insulating adhesive 21 and the projection of the second insulating adhesive 22 have an overlapping part.

[0035] In the above solar cell, by providing the first insulating adhesive 21 on each positive fine grid 113 and making one end of the first insulating adhesive 21 located in the first interval 1131 and the other end extending along the direction close to the positive main grid 111, it is ensured that the first insulating adhesive 21 can cover at least part of the positive fine grid 113 including the end of the positive fine grid 113, thereby avoiding the end of the positive fine grid 113 from forming a lap short circuit with the solder strip connected to the negative main grid 112. Similarly, by providing the second insulating adhesive 22 on each negative fine grid 114 and making one end of the second insulating adhesive 22 located in the second interval 1141 and the other end extending along the direction close to the negative main grid 112, it is ensured that the second insulating adhesive 22 can cover at least part of the negative fine grid 114 including the end of the negative main grid 112, thereby avoiding the end of the negative fine grid 114 from forming a lap short circuit with the solder strip connected to the positive main grid 111. In addition, by making the projection of the first insulating adhesive 21 and the projection of the second insulating adhesive 22 have an overlapping part along the second direction, in this way, even if a metal foreign object such as a solder head accidentally falls on the solar cell, the metal foreign object cannot simultaneously be lapped on the exposed sections of the adjacent positive fine grid 113 and negative fine grid 114, thereby avoiding the problem of forming a lap short circuit between the adjacent positive fine grid 113 and negative fine grid 114.

[0036] Continue to refer to Figure 2 , optionally, in an embodiment, the end of the first insulating adhesive 21 close to the positive main grid 111 is spaced from the positive main grid 111, that is, the first insulating adhesive 21 only covers part of the positive fine grid 113 and does not completely cover the positive fine grid 113, thereby saving the amount of the first insulating adhesive 21 while ensuring the avoidance of lap short circuit between the adjacent positive fine grid 113 and negative fine grid 114, and thus saving the material cost. In addition, it also avoids the problem that the solar cell warps severely after the first insulating adhesive 21 cures due to the too large area of the first insulating adhesive 21.

[0037] Similarly, in one embodiment, one end of the second insulating glue 22 close to the negative main grid 112 is spaced from the negative main grid 112, that is, the second insulating glue 22 only covers a part of the negative fine grid 114 and does not completely cover the negative fine grid 114, thereby saving the amount of the second insulating glue 22 while ensuring that adjacent positive fine grids 113 and negative fine grids 114 are prevented from being overlapped and short-circuited, thus saving material costs. In addition, it also avoids the problem that the solar cell sheet warps severely after the second insulating glue 22 is cured due to the too large area of the second insulating glue 22.

[0038] Optionally, the length of the first insulating glue 21 in the first direction is greater than or equal to half of the distance between adjacent positive main grids 111 and negative main grids 112, so as to ensure that the first insulating glue 21 can cover more than half of the length of the positive fine grid 113, strengthening the insulation protection effect on the positive fine grid 113. Similarly, the length of the second insulating glue 22 in the first direction is greater than or equal to half of the distance between adjacent positive main grids 111 and negative main grids 112. In this way, it is ensured that the second insulating glue 22 can cover more than half of the length of the negative fine grid 114, strengthening the insulation protection effect on the negative fine grid 114. In addition, when the lengths of the first insulating glue 21 and the second insulating glue 22 are both greater than half of the distance between the positive main grid 111 and the negative main grid 112, it is ensured that the overlapping part of the first insulating glue 21 and the second insulating glue 22 in the second direction is located at the middle position of the area between the positive main grid 111 and the negative main grid 112, further improving the insulation protection effect.

[0039] See Figure 2 , optionally, in one embodiment, the length L of the overlapping part in the first direction is greater than or equal to 0.3 mm. Specifically, the metal foreign objects that can avoid appearance detection and fall into the photovoltaic module generally have a small volume and a length less than 0.3 mm. By making the length L of the overlapping part greater than or equal to 0.3 mm, it can be fully ensured that after the metal foreign objects fall on the solar cell sheet, they cannot be simultaneously connected to the exposed segments of the adjacent positive fine grid 113 and the negative fine grid 114, thereby avoiding the occurrence of overlapping short circuit.

[0040] See Figure 2 , in one embodiment, each positive main grid 111 is also covered with a third insulating glue 23. Specifically, when the positive main grid 111 is welded to a solder strip (not shown), the welding temperature can reach above 200 °C. If the tin layer of the solder strip reacts with the positive fine grid 113 at high temperature to form an Ag3Sn alloy, it will cause the silver etching and grid breakage phenomenon at the overlapping position of the positive fine grid 113 and the positive main grid 111. By covering the third insulating glue 23 on the positive main grid 111, the third insulating glue 23 can effectively protect the overlapping position of the positive fine grid 113 and the positive main grid 111, avoid the reaction between the tin layer of the solder strip and the positive fine grid 113 at high temperature, and further avoid the silver etching and grid breakage phenomenon of the positive fine grid 113.

[0041] Similarly, each negative main grid 112 is also covered with a fourth insulating glue 24. The fourth insulating glue 24 can effectively protect the overlapping position of the negative fine grid 114 and the negative main grid 112, preventing the tin layer of the solder tape on the negative main grid 112 from reacting with the negative fine grid 114 at high temperatures, thereby avoiding the phenomenon of silver etching and grid breakage of the negative fine grid 114.

[0042] See Figure 2 , the first insulating glue 21 is connected to the fourth insulating glue 24. Exemplarily, the first insulating glue 21 and the fourth insulating glue 24 are integrally formed. In this way, the first insulating glue 21 and the fourth insulating glue 24 can be integrally printed through a single screen plate, simplifying the process and improving production efficiency. Similarly, the second insulating glue 22 is connected to the third insulating glue 23. Exemplarily, the second insulating glue 22 and the third insulating glue 23 are integrally formed. In this way, the second insulating glue 22 and the third insulating glue 23 can be integrally printed through a single screen plate, simplifying the process and improving production efficiency.

[0043] See Figure 2 , in an embodiment, both the third insulating glue 23 and the fourth insulating glue 24 are provided with hollow slots 231, and pad points 115 are arranged in the hollow slots 231. The pad points 115 are used to connect with the solder tape. Exemplarily, the pad points can be silver paste points. When welding the solder tape to the positive main grid 111, the solder tape is arranged above the third insulating glue 23 and welded to the pad point 115 of the positive main grid 111, thereby realizing the electrical connection between the solder tape and the positive main grid 111. Similarly, when welding the solder tape to the negative main grid 112, the solder tape is arranged above the fourth insulating glue 24 and welded to the pad point 115 of the negative main grid 112, thereby realizing the electrical connection between the solder tape and the positive main grid 111. Specifically, both the third insulating glue 23 and the fourth insulating glue 24 are provided with a plurality of hollow slots 231, and the plurality of hollow slots 231 are arranged at intervals along the second direction. Each hollow slot 231 is provided with a pad point 115, thereby enhancing the stability of the solder tape welding.

[0044] Optionally, in an embodiment, the width of the third insulating glue 23 in the first direction is greater than the width of the solder tape, thus ensuring that the solder tape on the positive main grid 111 will not form an overlapping short circuit with the negative fine grid 114. Similarly, the width of the fourth insulating glue 24 in the first direction is greater than the width of the solder tape. In this way, it is ensured that the solder tape on the negative main grid 112 will not form an overlapping short circuit with the negative fine grid 114.

[0045] Optionally, in an embodiment, the first insulating glue 21, the second insulating glue 22, the third insulating glue 23, and the fourth insulating glue 24 are all epoxy resin insulating glues.

[0046] Another embodiment of the present application further provides a photovoltaic module, including the solar cell of any of the above embodiments. Specifically, the number of solar cells is multiple, and the multiple solar cells are connected in series or in parallel through solder tapes.

[0047] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0048] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A solar cell sheet, characterized in that: Comprising a substrate (10) and an electrode, the electrode comprising a plurality of positive electrode main grids (111) and a plurality of negative electrode main grids (112), the positive electrode main grids (111) and the negative electrode main grids (112) being alternately arranged on the substrate (10) along a first direction, and each of the positive electrode main grids (111) and each of the negative electrode main grids (112) extending along a second direction, the first direction being arranged to intersect with the second direction; Each of the positive electrode main grids (111) is connected to a plurality of positive electrode fine grids (113), the plurality of positive electrode fine grids (113) are arranged in parallel along the second direction, and the end of each of the positive electrode fine grids (113) has a first interval (1131) with the adjacent negative electrode main grid (112); each of the negative electrode main grids (112) is connected to a plurality of negative electrode fine grids (114), the plurality of negative electrode fine grids (114) are arranged in parallel along the second direction, and the end of each of the negative electrode fine grids (114) has a second interval (1141) with the adjacent positive electrode main grid (111); Wherein, between the adjacent positive electrode main grid (111) and the negative electrode main grid (112), the positive electrode fine grid (113) and the negative electrode fine grid (114) are alternately arranged along the second direction, each of the positive electrode fine grids (113) is provided with a first insulating glue (21), one end of the first insulating glue (21) is located in the first gap (1131), and the other end of the first insulating glue (21) extends in a direction close to the positive electrode main grid (111) to cover at least part of the positive electrode fine grid (113); each of the negative electrode fine grids (114) is provided with a second insulating glue (22), one end of the second insulating glue (22) is located in the second gap (1141), and the other end of the second insulating glue (22) extends in a direction close to the negative electrode main grid (112) to cover at least part of the negative electrode fine grid (114); and along the second direction, the projection of the first insulating glue (21) and the projection of the second insulating glue (22) have an overlapping part.

2. The solar cell sheet according to claim 1, characterized in that: An end of the first insulating glue (21) close to the positive electrode main grid (111) is spaced apart from the positive electrode main grid (111); and / or an end of the second insulating glue (22) close to the negative electrode main grid (112) is spaced apart from the negative electrode main grid (112).

3. The solar cell sheet according to claim 1, characterized in that: The length of the first insulating glue (21) in the first direction is greater than or equal to half of the distance between the adjacent positive electrode main grid (111) and the negative electrode main grid (112); and / or the length of the second insulating glue (22) in the first direction is greater than or equal to half of the distance between the adjacent positive electrode main grid (111) and the negative electrode main grid (112).

4. The solar cell sheet according to claim 1, characterized in that: A length of the overlapping portion in the first direction is greater than or equal to 0.3 mm.

5. The solar cell sheet according to claim 1, characterized in that: Each of the positive electrode main grids (111) is also covered with a third insulating glue (23), and each of the negative electrode main grids (112) is also covered with a fourth insulating glue (24).

6. The solar cell sheet according to claim 5, characterized in that: The first insulating adhesive (21) is connected to the fourth insulating adhesive (24); and / or the second insulating adhesive (22) is connected to the third insulating adhesive (23).

7. The solar cell sheet according to claim 5, characterized in that: The third insulating adhesive (23) and the fourth insulating adhesive (24) are both provided with hollow grooves (231), and pad points (115) are provided in the hollow grooves (231), and the pad points (115) are used to be connected to welding strips.

8. The solar cell sheet according to claim 7, characterized in that: The width of the third insulating glue (23) in the first direction is greater than the width of the welding strip.

9. The solar cell sheet according to claim 7, characterized in that: The width of the fourth insulating adhesive (24) in the first direction is greater than the width of the welding strip.

10. A photovoltaic module, characterized in that: A solar cell sheet comprising any one of claims 1 to 9.

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