Solar cell and solar cell module

Abstract

The utility model relates to a solar cell and a solar cell module, the solar cell comprises a cell piece and a grid line, the grid line comprises a plurality of auxiliary grid lines arranged in parallel, the plurality of auxiliary grid lines are connected with the cell piece, a welding part is formed on the grid line, the welding part is provided with a welding grid and / or a reinforcing grid, the welding grid is stacked on one side, opposite to the cell piece, of the auxiliary grid lines, and the reinforcing grid is connected with the auxiliary grid lines. According to the solar cell and the solar cell module, the welding performance of the corresponding position of the welding part is improved by using the welding grid and / or the reinforcing grid, the probability of insufficient tension of the welding part of the solar cell is reduced, and the welding reliability is improved; and the resistance of the reinforcing grid and the welding grid is not increased, so that the conversion efficiency of the solar cell is not reduced, and the conversion efficiency is ensured.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a solar cell and a solar cell assembly. Background Art

[0002] Although adopting a technical solution with a thinner main grid or no main grid can reduce the amount of silver paste used and increase the effective illumination area of ​​the solar cell, it requires higher bonding strength and welding resistance in the interconnection area between the solder ribbon and the grid line in the solar cell module to ensure the reliability of the interconnection contact.

[0003] In the related art, when a solar cell adopts a thinner main grid or a main grid-free design, the grid line resistance is large, which easily leads to a decrease in conversion efficiency, and the solar cell has insufficient tension at the welding part, resulting in poor welding reliability. Summary of the invention

[0004] Based on this, the present application provides a solar cell and a solar cell assembly to solve the technical problem of how to ensure the conversion efficiency of the solar cell while increasing the welding reliability.

[0005] In one aspect, the present application provides a solar cell, the solar cell comprising:

[0006] Battery cells;

[0007] The grid line includes a plurality of parallel auxiliary grid lines, each of which is connected to the battery cell. The grid line is formed with a welding portion, and the welding portion is provided with a welding grid and / or a reinforcing grid. The welding grid is stacked on the side of the auxiliary grid line facing away from the battery cell, and the reinforcing grid is stacked between the battery cell and the auxiliary grid line.

[0008] In one embodiment, a plurality of the auxiliary grid lines and the welding parts are disposed on the front side and the back side of the battery cell, and the auxiliary grid lines on at least one side of the battery cell are connected to the welding grid and / or the reinforcing grid.

[0009] In one embodiment, the gate lines include a plurality of main gate lines, the plurality of main gate lines are arranged in parallel, and the main gate lines are vertically connected to the auxiliary gate lines, and the connection position between the main gate lines and the auxiliary gate lines corresponds to the position of the welding portion.

[0010] In one embodiment, the solar cell includes a plurality of connecting wires, and in a direction perpendicular to the secondary grid lines, the connecting wires are vertically connected to at least one of the secondary grid lines located at both ends of the solar cell, and the connection positions of the connecting wires and the secondary grid lines correspond to the positions of the welding portions.

[0011] In one of the embodiments, 20 to 30 connecting lines are arranged at intervals in the extending direction of the secondary grid lines.

[0012] In one of the embodiments, in a direction perpendicular to the secondary grid lines, the connecting line connects 2 to 5 secondary grid lines.

[0013] In one of the embodiments, the conductive paste used for the welding grid and / or the reinforcing grid consists of a conductive phase, a bonding phase and an organic carrier.

[0014] In one embodiment, the material of the welding grid and / or the reinforcing grid is the same as the material of the auxiliary grid line.

[0015] In one embodiment, the width of the secondary grid lines ranges from 0.05 mm to 0.1 mm, the distance between any two adjacent secondary grid lines is the same, and the number of the secondary grid lines is 85 to 185.

[0016] On the other hand, the present application provides a solar cell assembly, comprising a plurality of welding ribbons and the solar cells as described above, wherein the number of the solar cells is at least 2, one end of the plurality of welding ribbons is connected to the front side of one of the solar cells, and the other end is connected to the back side of another solar cell.

[0017] In the solar cell and solar cell assembly described above, the grid line of the solar cell is formed with a welding portion, and the welding portion is provided with a welding grid and / or a reinforcing grid. Among them, the welding grid is stacked on the side of the auxiliary grid line facing away from the battery cell, so that when the solar cell is welded to form a battery string using a welding ribbon, the welding grid can improve the welding performance between the auxiliary grid line and the welding ribbon. The reinforcing grid is stacked between the battery cell and the auxiliary grid line, so that the reinforcing grid can be used to increase the bonding force between the auxiliary grid line and the battery cell. Therefore, whether a welding grid or a reinforcing grid is provided at the corresponding welding portion of the solar cell, the welding performance of the corresponding position of the welding portion can be improved, the probability of insufficient tension in the welding portion of the solar cell can be reduced, and the welding reliability can be improved; and the reinforcing grid and the welding grid will not increase the resistance, so as not to cause the conversion efficiency of the solar cell to decrease, so as to ensure the conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic structural diagram of a solar cell assembly according to one embodiment of the present application.

[0020] Figure 2 It is a schematic structural diagram of a solar cell according to one embodiment of the present application.

[0021] Figure 3 This is a schematic structural diagram of a solar cell according to another embodiment of the present application.

[0022] Figure 4 This is a schematic structural diagram of a solar cell according to another embodiment of the present application.

[0023] Figure 5 Schematic diagram of the grid line structure of a solar cell according to one embodiment of the present application.

[0024] Figure 6 for Figure 5 The schematic diagram of the enlarged local structure of the grid line of the solar cell shown in the circle A.

[0025] Figure 7 A solar cell according to an embodiment of the present application Figure 6 Schematic diagram of the cross-sectional structure of line II.

[0026] Figure 8 This is a schematic diagram of a grid line structure of a solar cell according to another embodiment of the present application.

[0027] Fig. 9 for Figure 8 The schematic diagram of the enlarged local structure of the grid line of the solar cell shown in the circle B.

[0028] Fig.10 A solar cell according to an embodiment of the present application Fig. 9 Schematic diagram of the cross-sectional structure along line II-II.

[0029] Fig.11 This is a schematic cross-sectional structure diagram of a solar cell according to another embodiment of the present application.

[0030] Fig.12 This is a schematic cross-sectional structure diagram of a solar cell according to another embodiment of the present application.

[0031] Fig.13 This is a schematic cross-sectional structure diagram of a solar cell according to another embodiment of the present application.

[0032] Fig.14 This is a schematic cross-sectional structure diagram of a solar cell according to an embodiment of the present application, in which welding grids and reinforcing grids are provided on both the front and back sides of the solar cell.

[0033] Description of reference numerals:

[0034] 10. Welding ribbon; 20. Solar cell; 21. Solar cell; 211. Front; 212. Back; 22. Grid line; 221. Auxiliary grid line; 222. Welding part; 223. Main grid line; 23. Welding grid; 24. Reinforcement grid; 25. Connecting wire. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full 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 violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0036] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0037] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0039] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0040] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0041] Combination Figure 1 As shown, a solar cell assembly provided by one embodiment of the present application includes a plurality of welding ribbons 10 and solar cells 20. The number of solar cells 20 is at least 2, that is, the number of solar cells 20 can be 2 or more than 2. The solar cells 20 are electrically connected to each other through a plurality of welding ribbons 10 to achieve series connection with each other. Specifically, one end of the plurality of welding ribbons 10 is connected to the front side 211 of one of the solar cells 20, and the other end is connected to the back side 212 of another solar cell 20. Among them, the front side 211 of the solar cell 20 is the side of the solar cell 20 facing the sunlight when in use; the backlight of the solar cell 20 is the side of the solar cell 20 facing away from the sunlight when in use.

[0042] Combination Figure 2 As shown, the solar cell 20 includes a cell 21 and a grid line 22. The grid line 22 includes a plurality of parallel auxiliary grid lines 221, and the plurality of auxiliary grid lines 221 are connected to the cell 21. The grid line 22 is formed with a welding portion 222. The welding portion 222 may be located at the connection position between the auxiliary grid line 221 and the cell 21, or may be located at the connection position between the welding strip 10 and the grid line 22.

[0043] For example, combined with Figure 3 As shown, the gate line 22 includes a plurality of main gate lines 223 , which are arranged in parallel and vertically connected to the auxiliary gate lines 221 , and the connection position between the main gate lines 223 and the auxiliary gate lines 221 corresponds to the position of the welding portion 222 .

[0044] For example, combining Figure 4 As shown, in some embodiments, the solar cell 20 includes a plurality of connecting wires 25, and in a direction perpendicular to the secondary grid lines 221, the connecting wires 25 are vertically connected to at least one secondary grid line 221 located at both ends of the battery cell 21, and the connection position between the connecting wires 25 and the secondary grid lines 221 corresponds to the position of the welding portion 222.

[0045] Combination Figures 5 to 7 As shown, the welding portion 222 is provided with a welding grid 23, which is stacked on the side of the secondary grid line 221 facing away from the cell 21. When the solar cells 20 are welded to form a cell string using the welding ribbon 10, the welding grid 23 can improve the welding performance between the secondary grid line 221 and the welding ribbon 10.

[0046] Combination Figures 8 to 10 As shown, the welding portion 222 is provided with a reinforcing grid 24, and the reinforcing grid 24 is stacked between the battery cell 21 and the auxiliary grid line 221. In this embodiment, the reinforcing grid 24 can increase the bonding force between the auxiliary grid line 221 and the battery cell 21.

[0047] It should be noted that, in some embodiments, the solar cell 20 may be provided with both a welding grid 23 and a reinforcing grid 24. Fig.11 As shown, the welding portion 222 is provided with a welding grid 23 and a reinforcing grid 24 . The reinforcing grid 24 is stacked between the battery cell 21 and the auxiliary grid line 221 . The welding grid 23 is stacked on the side of the auxiliary grid line 221 facing away from the battery cell 21 .

[0048] In the solar cell 20 of the embodiment of the present application, the welding portion 222 of the grid line 22 is provided with a welding grid 23 and / or a reinforcing grid 24, wherein the reinforcing grid 24 can increase the bonding force between the secondary grid line 221 and the cell 21, and the welding grid 23 can improve the welding performance between the secondary grid line 221 and the welding ribbon 10. Therefore, whether the welding grid 23 or the reinforcing grid 24 is provided corresponding to the welding portion 222 in the solar cell 20, the welding performance of the corresponding position of the welding portion 222 can be improved, the probability of insufficient tension in the welding portion 222 of the solar cell 20 can be reduced, and the welding reliability can be improved; and the welding grid 23 and the reinforcing grid 24 will not increase the resistance, so as not to cause the conversion efficiency of the solar cell 20 to decrease, so as to ensure the conversion efficiency.

[0049] It should be noted that when the solar cells 20 are welded to form a cell string using the welding ribbons 10 , a plurality of welding ribbons 10 are connected to the welding portions 222 on the cell sheets 21 .

[0050] exist Fig.10 and Fig.11 In the cross-sectional structure of the solar cell 20 shown, only one side of the solar cell 21 is provided with a secondary grid line 221 and a welding grid 23 and / or a reinforcing grid 24 connected to the secondary grid line 221 .

[0051] In some embodiments, the front side 211 and the back side 212 of the cell 21 are both provided with a plurality of secondary grid lines 221 and welding portions 222. In this embodiment, the secondary grid lines 221 on at least one side of the cell 21 are connected to welding grids 23 and / or reinforcing grids 24.

[0052] Combination Figure 12 to Figure 14 As shown, in Fig.12 In the cross-sectional structure of the solar cell 20 shown, a reinforcing grid 24 is provided on both the front side 211 of the cell 21 and the back side 212 of the cell 21, wherein the reinforcing grid 24 located on the front side 211 of the cell 21 is stacked between the auxiliary grid line 221 located on the front side 211 and the cell 21, and the reinforcing grid 24 located on the back side 212 of the cell 21 is stacked between the auxiliary grid line 221 located on the back side 212 and the cell 21.

[0053] exist Fig.13 In the cross-sectional structure of the solar cell 20 shown, a welding grid 23 is provided on both the front side 211 of the cell 21 and the back side 212 of the cell 21, wherein the welding grid 23 located on the front side 211 of the cell 21 is stacked on the side of the auxiliary grid line 221 located on the front side 211 facing away from the cell 21, and the welding grid 23 located on the back side 212 of the cell 21 is stacked on the side of the auxiliary grid line 221 located on the back side 212 facing away from the cell 21.

[0054] Accordingly, in Fig.14 In the cross-sectional structure of the solar cell 20 shown, the front side 211 of the cell 21 and the front side 211 of the cell 21 are both provided with a welding grid 23 and a reinforcing grid 24, thereby, not only can the reinforcing grid 24 be used to improve the bonding force between the auxiliary grid line 221 on the corresponding side and the cell 21, but the welding grid 23 can also be used to increase the welding reliability between the auxiliary grid line 221 on the corresponding side and the welding strip 10.

[0055] It should be noted that when the solar cells 20 are connected to form a battery string using multiple welding ribbons 10, one end of the multiple welding ribbons 10 is connected to the welding portion 222 on the front side 211 of one of the solar cells 20, and the other end is connected to the welding portion 222 on the back side 212 of another solar cell 20, so that the solar cells 20 are connected in series using multiple welding ribbons 10. After the solar cells 20 are connected to form a battery string using the welding ribbons 10 through an interconnection process, the solar cell module can be manufactured through operations such as layout, stacking, lamination and testing. The manufacturing steps of the solar cell module will not be described in detail here.

[0056] In the embodiment where the solar cell 20 includes a plurality of connecting wires 25, the number of the connecting wires 25 can be configured according to actual needs. For example, 20 to 30 connecting wires 25 are arranged at intervals in the extending direction of the secondary grid lines 221. Specifically, the number of the connecting wires 25 can be 20, 23, 25, 26, 27, 29, or 30, and the number of the connecting wires 25 is not limited here.

[0057] In some embodiments, the connection line 25 connects 2 to 5 secondary grid lines 221 in a direction perpendicular to the secondary grid lines 221. Specifically, the connection line 25 may connect 2, 3, 4 or 5 secondary grid lines 221.

[0058] In some embodiments, the conductive paste used for the welding grid 23 and / or the reinforcing grid 24 is composed of a conductive phase, a bonding phase, and an organic carrier, so as to obtain good corrosion resistance and welding performance.

[0059] It should be noted that the conductive paste can use silver powder as the conductive phase. Silver has good electrical conductivity and stable chemical properties. In contrast, copper has unstable chemical properties and is prone to oxidation, which increases resistance. Therefore, the conductive paste uses silver powder as the conductive phase to reduce the probability of oxidation and increased resistance. The binding phase can be glass oxide, and the organic carrier can be an organic resin solvent. In some embodiments, the conductive paste can be a mixture of silver powder, glass oxide and organic resin solvent, which is stirred and rolled to form a uniform paste.

[0060] The material of the welding grid 23 and / or the reinforcing grid 24 is the same as that of the auxiliary grid line 221. Therefore, when the grid line 22, welding grid 23 or reinforcing grid 24 and other structures are formed on the surface of the battery cell 21 by printing, the same material can reduce the frequency of replacing the conductive paste, thereby improving processing efficiency.

[0061] In some embodiments, the width of the secondary grid line 221 ranges from 0.05 mm to 0.1 mm. The width of the secondary grid line 221 can specifically be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm or 0.1 mm. In this embodiment, the width of the secondary grid line 221 is appropriate, the secondary grid line 221 is not too wide to increase the effective illumination area of ​​the solar cell 20, and the secondary grid line 221 is not too narrow to reduce the conductivity.

[0062] It should be noted that the distance between any two adjacent secondary grid lines 221 is the same, and the number of the secondary grid lines 221 is 85-185. The number of the secondary grid lines 221 can be 85, 90, 95, 105, 125, 135, 155, 165 or 185 to meet the production needs of solar cells 20 of corresponding specifications. The number of the secondary grid lines 221 and the width of the secondary grid lines 221 are not limited here.

[0063] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0064] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the inventive concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A solar cell (20), characterized in that: The solar cell (20) comprises: Battery cell (21); A grid line (22) comprises a plurality of secondary grid lines (221) arranged in parallel, the plurality of secondary grid lines (221) being connected to the battery cell (21), the grid line (22) forming a welding portion (222), the welding portion (222) being provided with a welding grid (23) and / or a reinforcing grid (24), the welding grid (23) being stacked on a side of the secondary grid line (221) facing away from the battery cell (21), and the reinforcing grid (24) being stacked between the battery cell (21) and the secondary grid line (221).

2. The solar cell (20) according to claim 1, characterized in that: A plurality of auxiliary grid lines (221) and welding portions (222) are provided on the front side (211) of the battery cell (21) and the back side (212) of the battery cell (21); the auxiliary grid lines (221) on at least one side of the battery cell (21) are connected to the welding grid (23) and / or the reinforcing grid (24).

3. The solar cell (20) according to claim 1 or 2, characterized in that: The grid lines (22) comprise a plurality of main grid lines (223), the plurality of main grid lines (223) are arranged in parallel, the main grid lines (223) are vertically connected to the auxiliary grid lines (221), and the connection position between the main grid lines (223) and the auxiliary grid lines (221) corresponds to the position of the welding portion (222).

4. The solar cell (20) according to claim 1 or 2, characterized in that: The solar cell (20) comprises a plurality of connection lines (25), wherein in a direction perpendicular to the secondary grid lines (221), the connection lines (25) are vertically connected to at least one of the secondary grid lines (221) located at both ends of the cell sheet (21), and the connection positions of the connection lines (25) and the secondary grid lines (221) correspond to the positions of the welding portions (222).

5. The solar cell (20) according to claim 4, characterized in that: 20 to 30 connecting lines (25) are arranged at intervals in the extension direction of the secondary grid lines (221).

6. The solar cell (20) according to claim 4, characterized in that: In a direction perpendicular to the secondary grid lines (221), the connection line (25) connects 2 to 5 secondary grid lines (221).

7. The solar cell (20) according to claim 1, characterized in that: The conductive paste used in the welding grid (23) and / or the reinforcing grid (24) consists of a conductive phase, a bonding phase and an organic carrier.

8. The solar cell (20) according to claim 7, characterized in that: The material of the welding grid (23) and / or the reinforcing grid (24) is the same as the material of the auxiliary grid line (221).

9. The solar cell (20) according to claim 1, characterized in that: The width of the secondary grid lines (221) ranges from 0.05 mm to 0.1 mm, the distance between any two adjacent secondary grid lines (221) is the same, and the number of the secondary grid lines (221) is 85 to 185.

10. A solar cell assembly, characterized in that: It comprises a plurality of welding strips (10) and a solar cell (20) as claimed in any one of claims 1 to 9, wherein the number of the solar cells (20) is at least 2, one end of the plurality of welding strips (10) is connected to the front side (211) of one of the solar cells (20), and the other end is connected to the back side (212) of another solar cell (20).

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