Grid line structure of battery piece, back contact battery and battery string

Abstract

The utility model is applicable to the technical field of solar cells, and provides a grid line structure of a battery piece, a back contact battery and a battery string, the grid line structure comprises a positive electrode current collection point and a negative electrode current collection point, the battery piece comprises a first collection area and a second collection area, the first collection area is provided with the positive electrode current collection point, and the second collection area is provided with the negative electrode current collection point. The first collection area is provided with positive current collection points used for being connected with positive grid lines on a battery piece, the second collection area is provided with negative current collection points used for being connected with negative grid lines on the battery piece, the negative grid lines and the positive grid lines are distributed in a tooth crossing shape, and the same positive current collection point is connected with a plurality of positive grid lines. And the same cathode current collection point is connected with a plurality of cathode grid lines. Current can be better collected through the positive electrode current collecting point and the negative electrode current collecting point, loss caused by the main grid can be effectively reduced, short circuit and pseudo soldering risks are reduced, welding reliability is improved, meanwhile, the using amount of welding materials is reduced, and cost is controlled.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar cells, and in particular relates to a grid line structure of a cell sheet, a back contact cell and a cell string. Background Art

[0002] A solar cell is a device that converts light energy directly into electrical energy through the photoelectric effect. As long as it is exposed to light that meets certain illumination conditions, it can instantly output voltage and generate current in the presence of a circuit.

[0003] With the advancement of technology, the back contact cell structure of solar cells has gradually evolved from MBB (Multi-Busbar) structure to SMBB (Super Multi-Busbar) and 0BB (0-Busbar). Among them, SMBB has inevitable busbar loss, poor current collection effect, the existence of bright and dark areas, and serious inter-cell series mismatch. To ensure the current collection effect, the 0BB structure can be used. However, the fine grid of the 0BB structure is dense. To ensure the current collection effect, in certain cases, welding materials need to be pre-printed at the welding position, resulting in a large amount of welding materials, leading to increased welding material costs. It is also easy to have missing printing resulting in cold solder joints and printing offset causing short circuits of heterogeneous grid lines, affecting the welding effect and low reliability. Utility Model Content

[0004] The present invention provides a grid line structure for a battery cell, aiming to solve the problems of large amount of welding materials used in the welding of existing battery cells without a main grid structure, easy occurrence of missing printing causing cold solder joints and printing offset causing short circuits of heterogeneous grid lines, which affect the welding effect and low reliability.

[0005] The embodiment of the present utility model is implemented as follows: a grid line structure of a battery cell includes a positive current collection point and a negative current collection point;

[0006] The battery sheet includes a first collection area and a second collection area;

[0007] The first collecting area is provided with the positive current collecting point, and the positive current collecting point is used to connect with the positive grid line on the battery cell;

[0008] The second collecting area is provided with the negative current collecting point, and the negative current collecting point is used to connect with the negative grid line on the battery cell;

[0009] The negative electrode grid lines and the positive electrode grid lines are distributed in a tooth-cross shape.

[0010] The same positive current collecting point is connected to a plurality of positive grid lines, and the same negative current collecting point is connected to a plurality of negative grid lines.

[0011] Furthermore, a plurality of positive current collection points are provided in the first collection area, and the positive current collection points in the first collection area are arranged along a first direction, and a plurality of negative current collection points are provided in the second collection area, and the negative current collection points in the second collection area are arranged along the first direction, and a preset angle is formed between the first direction and the direction parallel to the positive grid line.

[0012] Furthermore, the number of positive electrode grid lines connected to the same positive electrode current collecting point, and / or the number of negative electrode grid lines connected to the same negative electrode current collecting point are both 2-15.

[0013] Furthermore, the number of positive electrode grid lines connected to the same positive electrode current collecting point, and / or the number of negative electrode grid lines connected to the same negative electrode current collecting point are both 4-6.

[0014] Furthermore, the positive grid lines and the negative grid lines are parallel to each other and alternately arranged at intervals. In the parallel direction of the positive grid lines, the positive grid lines located on the left and right sides of the positive current collection point are connected to the positive current collection point, and the negative grid lines located on the left and right sides of the negative current collection point are connected to the negative current collection point.

[0015] Furthermore, the positive electrode grid line includes a positive electrode connecting grid line, the negative electrode grid line includes a negative electrode connecting grid line, the positive electrode current collection points in the parallel direction of the same positive electrode grid line are connected by the same positive electrode connecting grid line, and the negative electrode current collection points in the parallel direction of the same negative electrode grid line are connected by the same negative electrode connecting grid line.

[0016] Furthermore, the cell is further provided with a positive electrode edge grid line and a negative electrode edge grid line, and the positive electrode edge grid line and the negative electrode edge grid line are provided on both sides of the positive electrode grid line and the negative electrode grid line.

[0017] The same positive edge grid line is connected to several positive grid lines, the same negative edge grid line is connected to several negative grid lines, the positive edge grid line is connected to the positive connection grid line, and the negative edge grid line is connected to the negative connection grid line.

[0018] Furthermore, the battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and at least one group of positive electrode welding points are arranged on the same straight line with the positive electrode current collection points in the same first collection area, and at least one group of negative electrode welding points are arranged on the same straight line with the negative electrode current collection points in the same second collection area.

[0019] Furthermore, a first welding material layer for connecting to a welding strip is provided on the positive current collecting point located on the straight line where the positive electrode welding point is located, and a second welding material layer for connecting to a welding strip is provided on the negative current collecting point located on the straight line where the negative electrode welding point is located.

[0020] Furthermore, the battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, the positive electrode grid line includes a positive electrode connecting grid line, the negative electrode grid line includes a negative electrode connecting grid line, the positive electrode welding points in the direction parallel to the same positive electrode grid line are connected by the same positive electrode connecting grid line, and the negative electrode welding points in the direction parallel to the same negative electrode grid line are connected by the same negative electrode connecting grid line.

[0021] Furthermore, the cell is further provided with a positive electrode edge grid line and a negative electrode edge grid line, and the positive electrode edge grid line and the negative electrode edge grid line are provided on both sides of the positive electrode grid line and the negative electrode grid line.

[0022] The same positive edge grid line is connected to several positive grid lines, the same negative edge grid line is connected to several negative grid lines, the positive edge grid line is connected to the positive connecting grid line, and the negative edge grid line is connected to the negative connecting grid line.

[0023] Furthermore, the battery cell includes an edge region and a middle region, and both the edge region and the middle region are provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points;

[0024] The first collection area and the second collection area are both arranged in the middle area;

[0025] The positive electrode current collection point and the corresponding positive electrode welding point in the same first collection area are on the same straight line;

[0026] The negative electrode current collecting point and the corresponding negative electrode welding point in the same second collecting area are on the same straight line.

[0027] Furthermore, the battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and the first collecting area containing at least one positive electrode current collecting point and the second collecting area containing at least one negative electrode current collecting point are both staggered with the positive electrode welding points and the negative electrode welding points.

[0028] Furthermore, the positive electrode current collecting points and the negative electrode current collecting points include square, circular, triangular or irregular shapes.

[0029] Furthermore, when the positive current collecting point and the negative current collecting point are square, the width of the positive current collecting point and the negative current collecting point are both 0.1 mm to 2 mm.

[0030] Furthermore, when the positive current collecting point and the negative current collecting point are square, the width of the positive current collecting point and the negative current collecting point are both 0.2 mm to 1 mm.

[0031] Furthermore, the shape of the positive current collecting point and / or the negative current collecting point is a wireframe structure with a hollow area, the positive grid line connected to the positive current collecting point passes through the hollow area of ​​the positive current collecting point, and the negative grid line connected to the negative current collecting point passes through the hollow area of ​​the negative current collecting point.

[0032] In a second aspect, the present application further provides a back-contact battery, comprising:

[0033] a cell body having opposite front and back surfaces; and

[0034] The grid line structure of the battery cell as described above is arranged on the back side.

[0035] In a third aspect, the present application also provides a battery string comprising the back-contact battery as described above.

[0036] Furthermore, the battery string further includes a welding ribbon;

[0037] The back of the back-contact battery includes a plurality of first collection areas and a plurality of second collection areas. The first collection area is provided with a plurality of positive current collection points arranged along a first direction. The positive current collection points are used to connect to the positive grid lines on the back of the back-contact battery. The second collection area is provided with a plurality of negative current collection points arranged along the first direction. The negative current collection points are used to connect to the negative grid lines on the back of the back-contact battery. The negative grid lines and the positive grid lines are arranged in a tooth-cross shape, and a preset angle is formed between the first direction and the positive grid lines.

[0038] On the same battery cell, in the first direction, two adjacent positive electrode welding points are welded together by a welding ribbon, and the welding ribbon welded to the positive electrode welding point is also welded to the positive electrode grid line and / or the positive electrode current collection point. Two adjacent negative electrode welding points are welded together by a welding ribbon, and the welding ribbon welded to the negative electrode welding point is also welded to the negative electrode grid line and / or the negative electrode current collection point.

[0039] The beneficial effects of this application are:

[0040] 1) The present application provides a grid line structure for a battery cell including a positive current collecting point and a negative current collecting point, wherein the battery cell includes a first collection area and a second collection area, the first collection area is provided with a positive current collecting point, and the positive current collecting point is used to connect to the positive grid line on the battery cell, the second collection area is provided with a negative current collecting point, and the negative current collecting point is used to connect to the negative grid line on the battery cell, the negative grid lines and the positive grid lines are distributed in a tooth-cross shape, and the same positive current collecting point is connected to several positive grid lines, and the same negative current collecting point is connected to several negative grid lines. By increasing the number of positive and negative current collection points in the region, current can be better collected. Since there is no main grid, the loss caused by the main grid can be effectively reduced. Moreover, when welding to the welding ribbon, the positive and negative current collection points are used to weld to the welding ribbon, increasing the welding contact area, reducing the risk of short circuits and cold welds, and improving welding reliability. At the same time, welding materials only need to be printed on the positive and negative current collection points, rather than on each fine grid, which can effectively reduce the amount of welding materials used and control costs. Moreover, when the positive and negative current collection points are not welded to the welding ribbon, multiple collection paths can be provided for the current to prevent broken grids from affecting current collection.

[0041] 2) The present application provides a grid line structure for a battery cell including positive current collection points and negative current collection points, wherein the battery cell includes a plurality of first collection areas and a plurality of second collection areas, the first collection area being provided with positive current collection points for connecting to the positive grid lines on the battery cell, the second collection area being provided with negative current collection points for connecting to the negative grid lines on the battery cell, the negative grid lines and the positive grid lines being distributed in a tooth-cross pattern, and the same positive current collection point being connected to a plurality of positive grid lines, and the same negative current collection point being connected to a plurality of negative grid lines. By increasing the number of positive and negative current collection points in a region, connecting grid lines, edge grid lines, and connecting grid lines, multiple collection paths are provided for current, enabling better current collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic structural diagram of an embodiment of the grid line structure of a cell provided by the present application, in which the cell edge adopts an 0BB design;

[0043] Figure 2 This is a schematic structural diagram of a grid line structure of a battery cell provided in the present application, in which the current collecting area and the welding point are collinear;

[0044] Figure 3 This is a schematic structural diagram of an embodiment of a grid line structure of a cell provided by the present application, showing a staggered arrangement of the current collecting area and the welding point;

[0045] Figure 4This is a schematic structural diagram of an embodiment of the grid line structure of a battery cell provided by the present application, in which the connection lines of some current collection points are arranged at an angle to the grid lines;

[0046] Figure 5 This is a schematic structural diagram of the arrangement of a partial array of current collection points in one embodiment of the grid line structure of a battery cell provided by the present application;

[0047] Figure 6 This is a schematic diagram of a structure in which current collection points are provided in all areas of a cell in one embodiment of a grid line structure of a cell provided by the present application;

[0048] Figure 7 This is a schematic structural diagram of a grid line structure of a cell provided in the present application, in which a current collection point is provided in a partial area of ​​the cell;

[0049] Figure 8 This is a schematic structural diagram of another embodiment of the grid line structure of the cell provided by the present application, in which a current collection point is provided in a partial area of ​​the cell;

[0050] Figure 9 This is a schematic structural diagram of a concentrated distribution of current collection points in an embodiment of a grid line structure of a battery cell provided in the present application.

[0051] Figure 10 This is a structural schematic diagram of an embodiment of the grid line structure of a battery cell provided in the present application, in which the current collection point adopts a wireframe structure.

[0052] Figure 11 This is a schematic structural diagram of the collinearity of the current collecting area and the welding point in one embodiment of the cell grid line structure provided in the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0054] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as a limitation on the present invention.

[0055] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0056] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0057] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0058] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but a person of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0059] The present application provides a grid line structure of a battery cell including a positive current collecting point and a negative current collecting point, wherein the battery cell includes a first collection area and a second collection area, the first collection area is provided with a positive current collecting point, and the positive current collecting point is used to connect to the positive grid line on the battery cell, the second collection area is provided with a negative current collecting point, and the negative current collecting point is used to connect to the negative grid line on the battery cell, the negative grid lines and the positive grid lines are distributed in a tooth-cross shape, and the same positive current collecting point is connected to several positive grid lines, and the same negative current collecting point is connected to several negative grid lines. By increasing the number of positive and negative current collection points in the region, current can be better collected. Since there is no main grid, the loss caused by the main grid can be effectively reduced. Moreover, when welding to the welding ribbon, the positive and negative current collection points are used to weld to the welding ribbon, increasing the welding contact area, reducing the risk of short circuits and cold welds, and improving welding reliability. At the same time, welding materials only need to be printed on the positive and negative current collection points, rather than on each fine grid, which can effectively reduce the amount of welding materials used and control costs. Moreover, when the positive and negative current collection points are not welded to the welding ribbon, multiple collection paths can be provided for the current to prevent broken grids from affecting current collection.

[0060] The present application provides a grid line structure for a battery cell including positive current collection points and negative current collection points, wherein the battery cell includes a plurality of first collection areas and a plurality of second collection areas, the first collection area being provided with positive current collection points, which are used to connect to the positive grid lines on the battery cell, the second collection area being provided with negative current collection points, which are used to connect to the negative grid lines on the battery cell, the negative grid lines and the positive grid lines being distributed in a tooth-cross shape, and the same positive current collection point being connected to a plurality of positive grid lines, and the same negative current collection point being connected to a plurality of negative grid lines. By increasing the positive current collection points and negative current collection points in the region, connecting the grid lines, the edge grid lines, and the connecting grid lines, multiple collection paths are provided for the current, which can better collect the current.

[0061] Example 1

[0062] like Figures 1 to 9 As shown, an embodiment of the present application provides a grid line structure of a battery cell, including a positive current collecting point 100 and a negative current collecting point 200;

[0063] The battery cell 300 includes a first collection area 310 and a second collection area 320;

[0064] The first collecting area 310 is provided with a positive current collecting point 100, which is used to connect to the positive grid line 330 on the battery cell 300;

[0065] The second collection area 320 is provided with a negative current collection point 200, which is used to connect to the negative grid line 340 on the battery cell 300;

[0066] The negative electrode grid lines 340 and the positive electrode grid lines 330 are arranged in a tooth-cross shape.

[0067] The same positive current collecting point 100 is connected to a plurality of positive grid lines 330 , and the same negative current collecting point 200 is connected to a plurality of negative grid lines 340 .

[0068] During implementation, the grid line structure provided by the present application is applied to a battery cell 300 without a main grid, and a number of positive grid lines 330, a number of negative grid lines 340 and a number of PAD points (also known as "pads", "wiring points" or "welding points") are provided on the battery cell 300. Among them, the positive grid lines 330 and the negative grid lines 340 are distributed in a tooth-cross shape, that is, the positive grid lines 330 and the negative grid lines 340 are parallel to each other and alternately arranged at intervals. For example, taking the positive grid lines 330 and the negative grid lines 340 as an example, the positive grid lines 330 and the negative grid lines 340 are parallel to the horizontal plane, and the positive grid lines 330 and the negative grid lines 340 can be regarded as horizontal lines, and there is a negative grid line 340 between two adjacent positive grid lines 330. Similarly, there is a positive grid line 330 between two adjacent negative grid lines 340.

[0069] The PAD points on the battery cell 300 are usually set at the edge of the battery cell 300. For example, when the battery cell 300 is placed vertically to the horizontal plane, the PAD points can be set at the top edge and bottom edge of the battery cell 300 without limitation.

[0070] During implementation, the PAD points on the battery cell 300 are used to connect to the welding ribbon, and the welding ribbon can connect two or more battery cells 300 in series and / or in parallel, which will not be described in detail.

[0071] During implementation, a plurality of first collection areas 310 are provided on the cell 300. Within the first collection areas 310 are a plurality of positive current collection points 100. These positive current collection points 100 are all connected to a plurality of positive grid lines 330, thereby collecting the current from the positive grid lines 330. Similarly, a plurality of second collection areas 320 are also provided on the cell 300. Within the second collection areas 320 are a plurality of negative current collection points 200. These negative current collection points 200 are all connected to a plurality of negative grid lines 340, thereby collecting the current from the negative grid lines 340.

[0072] During implementation, the same positive current collection point 100 is connected to several positive grid lines 330, and the same negative current collection point 200 is connected to several negative grid lines 340. As a result, each positive current collection point 100 can collect the current of multiple positive grid lines 330, and each negative current collection point 200 can collect the current of multiple negative grid lines 340. When any grid line is broken, the broken grid line can still collect current through the corresponding current collection point, providing multiple collection paths for the grid line current, and the current collection is more reliable.

[0073] In some embodiments, the first collection area 310 and the second collection area 320 may be disposed in the entire area of ​​the battery cell 300. Figure 6 Optionally, the first collection area 310 and the second collection area 320 can also be set in a partial area of ​​the battery cell 300, please refer to Figure 7 and Figure 8 As shown, the first collecting area 310 and the second collecting area 320 may also be arranged in the left half or the right half of the battery cell 300 , without limitation.

[0074] In some possible embodiments, the first collection area 310 and the second collection area 320 may be designed to be alternately distributed at intervals, such as Figure 6 Optionally, the first collection area 310 and the second collection area 320 can also be designed to be distributed in blocks on the battery cell 300, for example, Figure 9 As shown, a plurality of first collection areas 310 are arranged on the left half of the battery cell 300 , and a plurality of second collection areas 320 are arranged on the right half of the battery cell 300 , which is not limited thereto.

[0075] In some alternative embodiments, see Figure 1 As shown, a plurality of positive current collection points 100 are provided in the first collection area 310, and the positive current collection points 100 in the first collection area 310 are arranged along the first direction, and a plurality of negative current collection points 200 are provided in the second collection area 320, and the negative current collection points 200 in the second collection area 320 are arranged along the first direction, and a preset angle α is formed between the first direction and the direction parallel to the positive grid line 330.

[0076] In some optional embodiments, the current collection points within the same collection area are arranged along a first direction, and the first direction is arranged at a predetermined angle to the positive electrode grid line 330. In practice, the predetermined angle includes 0 to 180 degrees, such as 30 degrees, 45 degrees, 60 degrees, or 120 degrees, etc., without limitation. In other words, the rows of positive current collection points 100 can be arranged parallel to, perpendicular to, or at other angles to the positive electrode grid line 330. Similarly, the rows of negative current collection points 200 can also be arranged parallel to, perpendicular to, or at other angles to the positive electrode grid line 330, without limitation.

[0077] Optionally, the positive grid lines 330 and the negative grid lines 340 are parallel to each other and alternately arranged at intervals, and each current collection point is connected to the corresponding grid line, that is, in the parallel direction of the positive grid lines 330, the positive grid lines 330 located on the left and right sides of the positive current collection point 100 are all connected to the positive current collection point 100, and the negative grid lines 340 located on the left and right sides of the negative current collection point 200 are all connected to the negative current collection point 200, which will not be elaborated.

[0078] In some embodiments, the battery cell 300 is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and at least one group of positive electrode welding points are arranged on the same straight line with the positive electrode current collection points 100 in the same first collection area 310, and at least one group of negative electrode welding points are arranged on the same straight line with the negative electrode current collection points 200 in the same second collection area 320.

[0079] For example, the battery cell 300 is divided into area A1, area A2, area B1 and area B2. Figure 1 As shown, the A1 region includes two positive electrode welding points hz1, the B2 region includes two positive electrode welding points hz2, the A2 region includes two negative electrode welding points hf1, and the B1 region includes two negative electrode welding points hf2.

[0080] Among them, in the B2 area, several positive current collection points 100 in the first collection area 310 are arranged between the two positive welding points hz2, and are arranged on the same straight line with the two positive welding points hz2, so as to facilitate the subsequent connection of the two positive welding points hz2, the various positive current collection points 100 in the first collection area 310 and the corresponding positive grid lines 330 in the area through welding strips.

[0081] Among them, in the B1 area, several negative current collection points 200 in the second collection area 320 are arranged between the two negative welding points hf2, and are arranged on the same straight line with the two negative welding points hf2, so as to facilitate the subsequent connection of the two negative welding points hf2, the various negative current collection points 200 in the second collection area 320 and the corresponding positive grid lines 330 in the area through welding strips.

[0082] In some embodiments, a first welding material layer for connecting to a welding strip is provided on the positive current collecting point 100 located on the straight line where the positive welding point is located, and a second welding material layer for connecting to a welding strip is provided on the negative current collecting point 200 located on the straight line where the negative welding point is located, so that the same welding strip can connect welding points and current collecting points of the same polarity arranged on the same straight line, and the welding material does not need to cover all the current collecting points, but only needs to ensure that they can be connected to the welding strip. At the same time, there is no need to print welding material on each fine grid connected to the current collecting point, which can effectively save the amount of welding material.

[0083] In some embodiments, the battery cell 300 includes an edge region and a middle region, and both the edge region and the middle region are provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points;

[0084] The first collection area 310 and the second collection area 320 are both arranged in the middle area;

[0085] The positive electrode current collecting point 100 and the corresponding positive electrode welding point in the same first collecting area 310 are on the same straight line;

[0086] The negative electrode current collecting point 200 and the corresponding negative electrode welding point in the same second collecting area 320 are on the same straight line.

[0087] Exemplarily, the battery cell 300 is divided into an edge area and a middle area, wherein the edge area is close to the edge of the battery cell 300. For example, the battery cell 300 is square, and the edge area can be the area close to the short sides on both sides of the battery cell 300, or it can be the area close to the long sides on both sides of the battery cell 300, and the middle area is the area located in the middle of the edge area.

[0088] The edge area is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points. Similarly, the middle area is also provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points. For example, the battery cell 300 is divided into the A1 area, the A2 area, the B1 area and the B2 area. Figure 1 As shown, the A1 region includes two positive electrode welding points hz1, the B2 region includes two positive electrode welding points hz2, the A2 region includes two negative electrode welding points hf1, and the B1 region includes two negative electrode welding points hf2.

[0089] Each welding point is connected to a corresponding gate line. For example, the positive gate lines 330 on both sides of the positive welding point hz1 are connected to the positive welding point hz1, and the negative gate lines 340 on both sides of the negative welding point hf1 are connected to the negative welding point hf1.

[0090] Both areas A1 and A2 have an 0BB design, meaning they lack current collection points. When soldering the cell 300 to the ribbon, the ribbon corresponding to area A1 is welded to the two positive electrode solder points hz1 and the positive gridline 330 located between the two positive solder points hz1. The ribbon corresponding to area A2 is welded to the two negative electrode solder points hf1 and the negative gridline 340 located between the two negative solder points hf1.

[0091] Since both the A1 and A2 areas adopt the 0BB design, the A1 and A2 areas have a good current collection effect and can effectively reduce the main grid loss.

[0092] During implementation, the first collection area 310 is disposed in area B2, i.e., between the two positive electrode welding points hz2. The first collection area 310 is provided with a plurality of positive current collection points 100. For example, the first collection area 310 may be provided with one, two, three, four, or any other number of positive current collection points 100, without limitation. These positive current collection points 100 are arranged perpendicular or substantially perpendicular to the positive electrode grid line 330. In other words, the two positive electrode welding points hz2 and the plurality of positive current collection points 100 are aligned.

[0093] When the battery cell 300 is welded to the welding ribbon, the welding ribbon corresponding to the B2 area is welded to the two positive electrode welding points hz2, and is also welded to a plurality of positive electrode current collecting points 100 located between the two positive electrode welding points hz2.

[0094] In practice, the second collection area 320 is disposed in area B1, that is, between the two negative electrode welding points hf2. The second collection area 320 is provided with a plurality of negative current collection points 200. For example, the second collection area 320 may be provided with one, two, three, four, or any other number of negative current collection points 200, without limitation. These negative current collection points 200 are arranged perpendicular or substantially perpendicular to the positive electrode grid line 330. In other words, the two negative electrode welding points hf2 and the plurality of negative current collection points 200 are aligned.

[0095] When the battery cell 300 is welded to the welding ribbon, the welding ribbon corresponding to the B1 area is welded to the two negative electrode welding points hf2, and is also welded to a plurality of negative electrode current collecting points 200 located between the two negative electrode welding points hf2.

[0096] Through the above settings, both area B1 and area B2 adopt a current collection point design with discontinuous distribution to set up a number of current collection points. The current collection points are welded with the welding strips to increase the welding contact area, reduce the risk of short circuit and cold welding, and improve welding reliability. At the same time, it is only necessary to print welding materials at the positive current collection point 100 and the negative current collection point 200, without the need to print welding materials on each fine grid, which can effectively reduce the amount of welding materials used and control costs.

[0097] In some embodiments, the above-mentioned A1 area and A2 area can be set in multiple numbers. Similarly, there can be multiple B1 areas and B2 areas. For example, two B1 areas and two B2 areas are set in the middle area of ​​the battery cell 300. Each B1 area is provided with a second collection area 320, and each B2 area is provided with a first collection area 310. The specific settings can be made according to actual usage and needs, without limitation.

[0098] In some possible embodiments, the battery cell 300 may not adopt the 0BB design. For example, the battery cell 300 is divided into a B11 area, a B12 area, a B21 area, and a B22 area. Figure 2 As shown, the B11 region includes two positive electrode welding points hz1, the B12 region includes two positive electrode welding points hz2, the B21 region includes two negative electrode welding points hf1, and the B22 region includes two negative electrode welding points hf2.

[0099] Current collection points are set in areas B11, B12, B21 and B22, among which the first collection area 310 is set in areas B11 and B12, that is, the first collection area 310 is set between the two positive electrode welding points hz1, and the first collection area 310 is also set between the two positive electrode welding points hz2; the second collection area 320 is set in areas B21 and B22, that is, the second collection area 320 is set between the two negative electrode welding points hf1, and the first collection area 310 is also set between the two negative electrode welding points hf2.

[0100] When the battery cell 300 is welded to the welding ribbon, the welding ribbon corresponding to the B11 area is welded to the two positive electrode welding points hz1, and is also welded to several positive electrode current collecting points 100 located between the two positive electrode welding points hz1; the welding ribbon corresponding to the B12 area is welded to the two positive electrode welding points hz2, and is also welded to several positive electrode current collecting points 100 located between the two positive electrode welding points hz2; the welding ribbon corresponding to the B21 area is welded to the two negative electrode welding points hf1, and is also welded to several negative electrode current collecting points 200 located between the two negative electrode welding points hf1; the welding ribbon corresponding to the B22 area is welded to the two negative electrode welding points hf2, and is also welded to several negative electrode current collecting points 200 located between the two negative electrode welding points hf2.

[0101] Through the above settings, areas B11, B12, B21 and B22 all adopt a current collection point design with discontinuous distribution. By welding the current collection points with the welding strips, the welding contact area is increased, the risk of short circuit and cold welding is reduced, and the welding reliability is improved. At the same time, it is only necessary to print welding materials at the positive current collection point 100 and the negative current collection point 200, without the need to print welding materials on each fine grid, which can effectively reduce the amount of welding materials used and control costs.

[0102] In some possible embodiments, the battery cell 300 is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and the first collection area 310 including at least one positive electrode current collection point 310 and the second collection area 320 including at least one negative electrode current collection point 320 are both staggered with the positive electrode welding points and the negative electrode welding points. That is to say, the welding areas of the welding strips on the battery cell 300 are all designed as 0BB.

[0103] For example, the battery cell 300 includes the A11 area, the A12 area, the A13 area, the A14 area, the B31 area, the B32 area and the B33 area. Figure 3 As shown, area A11 and area A13 each include two positive electrode welding points hz1, area A12 and area A14 each include two negative electrode welding points hf1, and area B31, area B32 and area B33 each have current collection points, wherein the second collection area 320 is set in area B31 and area B33, and the first collection area 310 is set in area B32.

[0104] When the battery cell 300 is welded to the welding ribbon, the welding ribbon corresponding to the A11 area and A13 is welded to the two positive electrode welding points hz1, and is also welded to several positive electrode grid lines 330 located between the two positive electrode welding points hz1; the welding ribbon corresponding to the A12 area and A14 is welded to the two negative electrode welding points hf1, and is also welded to several negative electrode grid lines 340 located between the two negative electrode welding points hf1.

[0105] The 0BB design in areas A11, A12, A13, and A14 improves current collection and reduces welding losses. Furthermore, areas A11, A12, A13, A14, B31, B32, and B33 are staggered. If any gate line breaks, the broken gate line can still connect to the current collection point, other gate lines, and welding ribbons, providing multiple collection paths for the gate line current and ensuring more reliable current collection.

[0106] In some possible embodiments, the connection line of the current collection points in the same collection area may also form a certain angle with the positive electrode grid line 330. For example, taking the battery cell 300 including the A11 area, the A12 area, the B32 area and the B33 area as an example, Figure 4As shown, region A11 includes two positive electrode welding points hz1, region A12 includes two negative electrode welding points hf1, region B32 is provided with a first collection area 310, and region B33 is provided with a second collection area 320. First collection area 310 includes three positive current collection points 100, and the line connecting the center points of these three positive current collection points 100 forms a certain angle with the positive electrode grid line 330, such as 45° or 55°, etc., although this is not limited. Second collection area 320 includes three negative current collection points 200, and the line connecting the center points of these three negative current collection points 200 forms a certain angle with the positive electrode grid line 330, such as 135° or 145°, etc., although this is not limited.

[0107] In some possible embodiments, the current collection points in the collection area may also be arranged in groups. For example, taking the first collection area 310 as an example, Figure 4 Based on the grid line structure of the cell shown, the first collection area 310 located in the B32 area is provided with three groups of collection points arranged horizontally, each group of collection points includes a plurality of positive current collection points 100 arranged vertically, for example, each group of collection points includes three positive current collection points 100 arranged vertically, as shown in FIG. Figure 5 Shown, not limited.

[0108] It should be noted that the values ​​and layout designs of the first collection area 310, the second collection area 320, the positive electrode welding point, the negative electrode welding point, the positive electrode current collection point 100, the negative electrode current collection point 200 and the partitions and angles in the above-mentioned embodiments are examples of the embodiments of the present application, and are not specific limitations on the present application. In some other embodiments, other quantities or layout designs may also be adopted. For example, in some other embodiments, area A11, area A12, area A13, area A14, area B31, area B32 and area B33 may be set according to needs. For example, area A11 and area A12 both include two positive electrode welding points hz1, area A13 and area A14 both include two negative electrode welding points hf1, or the first collection area 310 is set in area B31 and area B32, and the second collection area 320 is set in area B33, etc., without limitation.

[0109] The grid line structure of the battery cell provided in the present application includes a positive current collecting point 100 and a negative current collecting point 200, wherein the battery cell 300 includes a plurality of first collection areas 310 and a plurality of second collection areas 320, the first collection area 310 is provided with a plurality of positive current collecting points 100 arranged along a first direction, the positive current collecting points 100 are used to connect with the positive grid lines 330 on the battery cell 300, the second collection area 320 is provided with a plurality of negative current collecting points 200 arranged along the first direction, the negative current collecting points 200 are used to connect with the negative grid lines 340 on the battery cell 300, the negative grid lines 340 and the positive grid lines 330 are distributed in a tooth-cross shape, and a preset angle is formed between the first direction and the direction parallel to the positive grid lines 330. By increasing the positive current collection points 100 and the negative current collection points 200 in the area, current can be better collected. Since no main grid is set, the loss caused by the main grid can be effectively reduced. Moreover, when welding with the welding strip, the positive current collection points 100 and the negative current collection points 200 are used to weld with the welding strip, thereby increasing the welding contact area, reducing the risk of short circuit and cold welding, and improving welding reliability. At the same time, it is only necessary to print welding materials at the positive current collection points 100 and the negative current collection points 200, without the need to print welding materials on each fine grid, which can effectively reduce the amount of welding materials used and control costs.

[0110] In some embodiments, the positive current collecting point 100 and the negative current collecting point 200 can be designed as a sheet structure, and the positive current collecting point 100 and the negative current collecting point 200 can be designed as a square, circle, triangle or irregular shape, etc., without limitation.

[0111] In some embodiments, the current collecting points may be designed to have uniform sizes, or may be designed to have inconsistent sizes.

[0112] In some possible embodiments, see Figure 10 As shown, the positive current collecting point 100 and the negative current collecting point 200 can be designed to be a hollow wire frame surrounded by conductive wires, and the hollow area in the wire frame is the solder printing area. The positive grid line 330 connected to the positive current collecting point 100 passes through the hollow area of ​​the positive current collecting point 100, and the negative grid line 340 connected to the negative current collecting point 200 passes through the hollow area of ​​the negative current collecting point 200.

[0113] During implementation, the conductive wire is made of the same material as the positive grid lines 330 and the negative grid lines 340. When the positive grid lines 330 and the negative grid lines 340 are printed on the battery cell 300, the positive current collecting points 100 and the negative current collecting points 200 can be printed simultaneously. Typically, the positive current collecting points 100 and the negative current collecting points 200 can be printed into the aforementioned sheet structure, which increases the welding area, facilitates welding, and reduces the rate of false welding. When the positive current collecting points 100 and the negative current collecting points 200 are printed into the aforementioned wireframe structure, the number of positive current collecting points 100 and the negative current collecting points 200 can be reduced, thereby reducing costs.

[0114] In some possible embodiments, when the current collecting point is a wireframe structure, the corresponding grid line can pass through the current collecting point, for example, the positive grid line 330 can pass through the positive current collecting point 100, and the negative grid line 340 can pass through the negative current collecting point 200, to facilitate printing.

[0115] In some embodiments, the welding points on the battery cell 300 may also adopt the structure of current collecting points. For example, the positive electrode welding point may be the positive electrode current collecting point 100, and the negative electrode welding point may be the negative electrode current collecting point 200. No further details will be given.

[0116] In some optional embodiments, the number of positive grid lines 330 connected to the same positive current collecting point 100, and / or the number of negative grid lines 340 connected to the same negative current collecting point 200 are both 2-15, wherein the number of grid lines in the same direction parallel to the grid line is one.

[0117] During implementation, each current collection point contains the collection of multiple grid lines. The size of the current collection point depends on the number of grid lines included. One current collection point can cover 2-15 grid lines, for example, one current collection point is connected to 7, 9, or 13 grid lines. Under normal circumstances, the fewer grid lines a current collection point covers, the higher the amount of welding materials used and the higher the cost of welding materials. The more grid lines a current collection point covers, the higher the main grid loss and the lower the component power. Therefore, the number of positive grid lines 330 connected to the same positive current collection point 100 and / or the number of negative grid lines 340 connected to the same negative current collection point 200 can be designed to be 4-6. For example, one current collection point can cover 5 grid lines. Through such a setting, experimental data shows that the power loss of the battery component is only 0.05%-0.1% compared to 0BB, and the amount and cost of welding materials can be reduced by about 40% to 50%.

[0118] In some optional embodiments, when the positive current collecting point 100 and the negative current collecting point 200 are square, the width of the positive current collecting point 100 and the negative current collecting point 200 are both 0.2 mm to 1 mm. The battery cell 300 collects current through the grid line. Therefore, when the area of ​​the battery cell 300 is fixed, the larger the coverage area of ​​the grid line, the higher the component efficiency. That is, the positive current collecting point 100 and the negative current collecting point 200 need to be designed to be smaller. If the positive current collecting point 100 and the negative current collecting point 200 are too small, the welding area will be small and there will be risks such as leaking welding and cold welding. Therefore, the width of the positive current collecting point 100 and the negative current collecting point 200 can be 0.1 mm to 2 mm. Preferably, the width of the positive current collecting point 100 and the negative current collecting point 200 can be 0.2 mm to 1 mm, for example, 0.5 mm, 0.6 mm or 0.8 mm, etc., which can take into account both the component efficiency and welding reliability. There is no limitation.

[0119] Example 2

[0120] The difference between this embodiment and the first embodiment is that, see Figure 11 As shown, the positive electrode grid line 330 includes a positive electrode connecting grid line 331, and the negative electrode grid line 340 includes a negative electrode connecting grid line 341. The positive current collecting points 100 in the parallel direction of the same positive electrode grid line 330 are connected by the same positive electrode connecting grid line 331, and the negative current collecting points 200 in the parallel direction of the same negative electrode grid line 340 are connected by the same negative electrode connecting grid line 341, that is, each current collecting point in the parallel direction of the same grid line is connected by the same grid line.

[0121] In the present invention, on the basis of connecting multiple grid lines of the same polarity at each current collection point, each current collection point of the same polarity in the parallel direction of the same grid line is connected by a grid line, and each current collection point of the same polarity in the parallel direction of the same grid line and the grid lines of the same polarity connected to each current collection point of the same polarity are connected as a whole. For example, Figure 11In the two first collection areas 310 of area B11 and area B12, the top positive current collection point 100 is connected through the positive connection grid line 331. At this time, the positive grid lines 330 on the left and right sides of the top positive current collection point 100 in area B11, the top positive current collection point 100 in area B11, the positive grid lines 330 on the left and right sides of the top positive current collection point 100 in area B12, and the top positive current collection point 100 in area B12 are connected as a whole, forming a multi-channel collection path between the same polarity grid lines and the same polarity current collection points, and between the same polarity current collection points and the same polarity current collection points, further providing more collection paths for the grid line current. When a grid line or a current collection point has a short circuit, cold solder joint, etc., the current can still be collected through other paths, thereby improving the reliability of current collection.

[0122] In addition, after connecting each current collection point of the same polarity in the parallel direction of the same grid line and the corresponding grid lines of the same polarity connected to each current collection point of the same polarity as a whole, when welding with the welding ribbon, the current collection points in the same collection area can also be connected through the welding ribbon, so that more grid lines of the same polarity on the battery cell 300 are connected into a whole, further reducing the risk of short circuit and cold welding, and improving the reliability of current collection.

[0123] In some optional embodiments, the positive electrode connecting grid lines 331 and the negative electrode connecting grid lines 341 are parallel to each other and alternately arranged at intervals.

[0124] In some optional embodiments, the cell 300 is further provided with a positive electrode edge grid line 350 and a negative electrode edge grid line 360, and the positive electrode edge grid line 350 and the negative electrode edge grid line 360 ​​are provided on both sides of the positive electrode grid line 330 and the negative electrode grid line 340.

[0125] The same positive edge grid line 350 is connected to several positive grid lines 330 , the same negative edge grid line 360 ​​is connected to several negative grid lines 340 , and the positive edge grid line 350 is connected to the positive connecting grid line 331 , and the negative edge grid line 360 ​​is connected to the negative connecting grid line 341 .

[0126] For example, in Figure 11 In the figure, a negative electrode welding point hf1 in the B21 area is provided on the right edge of the battery cell. A plurality of negative electrode grid lines 340 corresponding to the right side of the negative electrode welding point hf1 are connected to the negative electrode welding point hf1, and a plurality of positive electrode grid lines 300 corresponding to the right side of the negative electrode welding point hf1 are connected through the positive electrode edge grid line 350. At the same time, these positive electrode grid lines 300 can also be connected to the positive current collection point 100 through the positive electrode edge grid line 350 and the positive electrode connection grid line 331.

[0127] By coordinating the edge grid lines and the connecting grid lines of the same polarity, the edge grid lines are fully utilized to effectively improve the current collection effect.

[0128] In some optional embodiments, in a first direction, the positive edge grid lines 350 and the negative edge grid lines 360 are alternately arranged at intervals, and in a direction parallel to the same positive grid line, the positive edge grid lines 350 and the negative edge grid lines 360 are arranged on both sides of the positive grid line 330, so that in a direction parallel to the same positive grid line, the grid lines on both edges of the battery cell 300 can collect current through the cooperation of the edge grid lines and the connecting grid lines, thereby improving the current collection effect.

[0129] In some embodiments, the cell 300 is provided with at least one set of positive electrode welding points and at least one set of negative electrode welding points. The positive electrode grid line 330 includes a positive electrode connecting grid line 332, and the negative electrode grid line 340 includes a negative electrode connecting grid line 342. The positive electrode welding points parallel to the same positive electrode grid line 330 are connected by the same positive electrode connecting grid line 332, and the negative electrode welding points parallel to the same negative electrode grid line 340 are connected by the same negative electrode connecting grid line 342. This forms a multi-channel collection path between grid lines and welding points of the same polarity, and between welding points of the same polarity, further providing more collection paths for grid line current. When a grid line or a welding point has a short circuit or a cold solder joint, current can still be collected through other paths, thereby improving the reliability of current collection.

[0130] In some embodiments, the cell 300 further includes a positive edge grid line 350 and a negative edge grid line 360 ​​, which are disposed on both sides of the positive grid line 330 and the negative grid line 340 .

[0131] The same positive edge grid line 350 is connected to several positive grid lines 330 , the same negative edge grid line 360 ​​is connected to several negative grid lines 340 , and the positive edge grid line 350 is connected to the positive connecting grid line 332 , and the negative edge grid line 360 ​​is connected to the negative connecting grid line 342 .

[0132] By coordinating the edge grid lines and the connecting grid lines of the same polarity, the edge grid lines are fully utilized to effectively improve the current collection effect.

[0133] In the present invention, by coordinating the positive electrode grid line 330 containing the positive electrode connecting grid line 331, the positive electrode current collecting point 100, the positive electrode edge grid line 350, and the positive electrode welding point, and connecting the positive electrode grid line 330, the positive electrode current collecting point 100 and the positive electrode welding point in the same straight line direction through the welding strip during welding, all the positive polarity grid lines on the same battery cell can be connected through, and by coordinating the negative electrode grid line 340 containing the negative electrode connecting grid line 341, the negative electrode current collecting point 200, the negative electrode edge grid line 360, and the negative electrode welding point, and connecting the negative electrode grid line 340, the negative electrode current collecting point 200 and the negative electrode welding point in the same straight line direction through the welding strip during welding, all the negative polarity grid lines on the same battery cell can be connected through, effectively improving the current collection effect, reducing the risk of short circuit and cold welding, and reducing the series mismatch between battery component slices and the power loss at the component end.

[0134] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the back-contact battery described above can refer to the corresponding structure and implementation principle in the aforementioned embodiment 1, and will not be repeated here.

[0135] Example 3

[0136] In some optional embodiments, the present application further provides a back-contact battery, comprising:

[0137] a cell body having opposite front and back surfaces; and

[0138] The grid line structure of the battery cell as described above is arranged on the back side.

[0139] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the back-contact battery described above can refer to the corresponding structure and implementation principle in the aforementioned embodiment 1, and will not be repeated here.

[0140] The grid line structure of the battery cell provided in the present application includes a positive current collecting point 100 and a negative current collecting point 200, wherein the battery cell 300 includes a plurality of first collection areas 310 and a plurality of second collection areas 320, the first collection area 310 is provided with a plurality of positive current collecting points 100 arranged along a first direction, the positive current collecting points 100 are used to connect with the positive grid lines 330 on the battery cell 300, the second collection area 320 is provided with a plurality of negative current collecting points 200 arranged along the first direction, the negative current collecting points 200 are used to connect with the negative grid lines 340 on the battery cell 300, the negative grid lines 340 and the positive grid lines 330 are distributed in a tooth-cross shape, and a preset angle is formed between the first direction and the direction parallel to the positive grid lines 330. By increasing the positive current collection points 100 and the negative current collection points 200 in the area, current can be better collected. Since no main grid is set, the loss caused by the main grid can be effectively reduced. Moreover, when welding with the welding strip, the positive current collection points 100 and the negative current collection points are used to weld with the welding strip, thereby increasing the welding contact area, reducing the risk of short circuit and cold welding, and improving welding reliability. At the same time, it is only necessary to print welding materials at the positive current collection points 100 and the negative current collection points 200, without the need to print welding materials on each fine grid, which can effectively reduce the amount of welding materials used and control costs.

[0141] Example 4

[0142] In some optional embodiments, the present application also provides a battery string, comprising the back-contact battery as described above.

[0143] During implementation, the back side of the back-contact battery is provided with positive electrode grid lines 330, negative electrode grid lines 340, positive electrode welding points, negative electrode welding points, positive electrode current collection points 100, and negative electrode current collection points 200. Specifically, the back side of the back-contact battery includes a plurality of first collection areas 310 and a plurality of second collection areas 320. The first collection areas 310 are provided with a plurality of positive electrode current collection points 100 arranged along a first direction. The positive electrode current collection points 100 are used to connect to the positive electrode grid lines 330 on the back side of the back-contact battery. The second collection areas 320 are provided with a plurality of negative electrode current collection points 200 arranged along the first direction. The negative electrode current collection points 200 are used to connect to the negative electrode grid lines 340 on the back side of the back-contact battery. The negative electrode grid lines 340 and the positive electrode grid lines 330 are arranged in a tooth-cross pattern, and a preset angle is formed between the first direction and the direction parallel to the positive electrode grid lines 330.

[0144] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the battery string described above can refer to the corresponding structures and implementation principles in the aforementioned embodiments one and two, and will not be repeated here.

[0145] During implementation, two adjacent back-contact batteries are connected together by welding. On the same battery cell, in the first direction, two adjacent positive electrode welding points are welded together by a welding strip, and the welding strip welded to the positive electrode welding point is also welded to the positive electrode grid line 330 and / or the positive electrode current collecting point 100. Two adjacent negative electrode welding points are welded together by a welding strip, and the welding strip welded to the negative electrode welding point is also welded to the negative electrode grid line 340 and / or the negative electrode current collecting point 200.

[0146] During the welding process, an insulating material for the opposite-sex grid lines is first printed on the back-contact cell to prevent short circuits caused by the opposite-sex grid lines during the ribbon welding process. Then, soldering material is screen-printed to provide electrical continuity between the back-contact cell and the ribbon. Finally, the ribbon is placed over the soldering material to complete the welding between the cells and form a battery string. Furthermore, the battery assembly consisting of multiple back-contact cells and materials such as glass, film, backplane, and frame will not be described in detail.

[0147] The grid line structure of the battery cell provided in the present application includes a positive current collecting point 100 and a negative current collecting point 200, wherein the battery cell 300 includes a plurality of first collection areas 310 and a plurality of second collection areas 320, the first collection area 310 is provided with a plurality of positive current collecting points 100 arranged along a first direction, the positive current collecting points 100 are used to connect with the positive grid lines 330 on the battery cell 300, the second collection area 320 is provided with a plurality of negative current collecting points 200 arranged along the first direction, the negative current collecting points 200 are used to connect with the negative grid lines 340 on the battery cell 300, the negative grid lines 340 and the positive grid lines 330 are distributed in a tooth-cross shape, and a preset angle is formed between the first direction and the direction parallel to the positive grid lines 330. By increasing the positive current collection points 100 and the negative current collection points 200 in the area, current can be better collected. Since no main grid is set, the loss caused by the main grid can be effectively reduced. Moreover, when welding with the welding strip, the positive current collection points 100 and the negative current collection points 200 are used to weld with the welding strip, thereby increasing the welding contact area, reducing the risk of short circuit and cold welding, and improving welding reliability. At the same time, it is only necessary to print welding materials at the positive current collection points 100 and the negative current collection points 200, without the need to print welding materials on each fine grid, which can effectively reduce the amount of welding materials used and control costs.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A grid line structure of a battery cell, characterized in that: including a positive current collecting point and a negative current collecting point; The battery sheet includes a first collection area and a second collection area; The first collecting area is provided with the positive current collecting point, and the positive current collecting point is used to connect with the positive grid line on the battery cell; The second collecting area is provided with the negative current collecting point, and the negative current collecting point is used to connect with the negative grid line on the battery cell; The negative electrode grid lines and the positive electrode grid lines are distributed in a tooth-cross shape. The same positive current collecting point is connected to a plurality of positive grid lines, and the same negative current collecting point is connected to a plurality of negative grid lines.

2. The grid line structure of the battery cell according to claim 1, wherein: A plurality of positive current collection points are provided in the first collection area, and the positive current collection points in the first collection area are arranged along a first direction. A plurality of negative current collection points are provided in the second collection area, and the negative current collection points in the second collection area are arranged along the first direction. A preset angle is formed between the first direction and the direction parallel to the positive grid line.

3. The grid line structure of the battery cell according to claim 1, wherein: The number of the positive electrode grid lines connected to the same positive electrode current collecting point, and / or the number of the negative electrode grid lines connected to the same negative electrode current collecting point are both 2-15.

4. The grid line structure of the battery cell according to claim 3, wherein: The number of the positive electrode grid lines connected to the same positive electrode current collecting point, and / or the number of the negative electrode grid lines connected to the same negative electrode current collecting point are both 4-6.

5. The grid line structure of the battery cell according to claim 1, wherein: The positive grid lines and the negative grid lines are parallel to each other and alternately arranged at intervals. In the parallel direction of the positive grid lines, the positive grid lines located on the left and right sides of the positive current collection point are connected to the positive current collection point, and the negative grid lines located on the left and right sides of the negative current collection point are connected to the negative current collection point.

6. The grid line structure of the battery cell according to claim 1, wherein: The positive electrode grid line includes a positive electrode connecting grid line, and the negative electrode grid line includes a negative electrode connecting grid line. The positive current collection points in the direction parallel to the same positive electrode grid line are connected through the same positive electrode connecting grid line, and the negative current collection points in the direction parallel to the same negative electrode grid line are connected through the same negative electrode connecting grid line.

7. The grid line structure of the battery cell according to claim 6, wherein: The cell is further provided with a positive electrode edge grid line and a negative electrode edge grid line, wherein the positive electrode edge grid line and the negative electrode edge grid line are provided on both sides of the positive electrode grid line and the negative electrode grid line. The same positive edge grid line is connected to several positive grid lines, the same negative edge grid line is connected to several negative grid lines, the positive edge grid line is connected to the positive connection grid line, and the negative edge grid line is connected to the negative connection grid line.

8. The grid line structure of a battery cell according to claim 1, wherein: The battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and at least one group of positive electrode welding points are arranged on the same straight line with the positive electrode current collection points in the same first collection area, and at least one group of negative electrode welding points are arranged on the same straight line with the negative electrode current collection points in the same second collection area.

9. The grid line structure of the battery cell according to claim 8, characterized in that: A first welding material layer for connecting to a welding strip is provided on the positive current collecting point located on the straight line where the positive welding point is located, and a second welding material layer for connecting to a welding strip is provided on the negative current collecting point located on the straight line where the negative welding point is located.

10. The grid line structure of a solar cell according to claim 1, wherein: The battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points. The positive electrode grid line includes a positive electrode connecting grid line, and the negative electrode grid line includes a negative electrode connecting grid line. The positive electrode welding points in a direction parallel to the same positive electrode grid line are connected by the same positive electrode connecting grid line, and the negative electrode welding points in a direction parallel to the same negative electrode grid line are connected by the same negative electrode connecting grid line.

11. The grid line structure of the battery cell according to claim 10, wherein: The cell is further provided with a positive electrode edge grid line and a negative electrode edge grid line, wherein the positive electrode edge grid line and the negative electrode edge grid line are provided on both sides of the positive electrode grid line and the negative electrode grid line. The same positive edge grid line is connected to several positive grid lines, the same negative edge grid line is connected to several negative grid lines, the positive edge grid line is connected to the positive connecting grid line, and the negative edge grid line is connected to the negative connecting grid line.

12. The grid line structure of a solar cell according to claim 1, wherein: The battery cell comprises an edge region and a middle region, wherein both the edge region and the middle region are provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points; The first collection area and the second collection area are both arranged in the middle area; The positive electrode current collecting point and the corresponding positive electrode welding point in the same first collecting area are on the same straight line; The negative electrode current collecting point and the corresponding negative electrode welding point in the same second collecting area are on the same straight line.

13. The grid line structure of a solar cell according to claim 1, wherein: The battery cell is provided with at least one group of positive electrode welding points and at least one group of negative electrode welding points, and the first collection area containing at least one positive electrode current collecting point and the second collection area containing at least one negative electrode current collecting point are both staggered with the positive electrode welding points and the negative electrode welding points.

14. The grid line structure of a solar cell according to claim 1, wherein: The positive electrode current collecting point and the negative electrode current collecting point are in the shape of a square, a circle, a triangle or an irregular shape.

15. The grid line structure of the battery cell according to claim 14, wherein: When the positive current collecting point and the negative current collecting point are square, the widths of the positive current collecting point and the negative current collecting point are both 0.1 mm to 2 mm.

16. The grid line structure of a battery cell according to claim 14, wherein: When the positive current collecting point and the negative current collecting point are square, the widths of the positive current collecting point and the negative current collecting point are both 0.2 mm to 1 mm.

17. The grid line structure of a solar cell according to claim 1, wherein: The shape of the positive current collecting point and / or the negative current collecting point is a wireframe structure with a hollow area, the positive grid line connected to the positive current collecting point passes through the hollow area of ​​the positive current collecting point, and the negative grid line connected to the negative current collecting point passes through the hollow area of ​​the negative current collecting point.

18. A back contact battery, characterized in that: include: A battery cell body having a front side and a back side facing each other; as well as The grid line structure of the cell according to any one of claims 1 to 17 is arranged on the back surface.

19. A battery string, characterized in that: Comprising a back contact cell as described in claim 18.

20. The battery string according to claim 19, wherein: The battery string also includes a welding ribbon: The back side of the back-contact battery includes a plurality of first collection areas and a plurality of second collection areas, wherein the first collection area is provided with a plurality of positive current collection points arranged along a first direction, and the positive current collection points are used to connect to the positive grid lines on the back side of the back-contact battery; the second collection area is provided with a plurality of negative current collection points arranged along the first direction, and the negative current collection points are used to connect to the negative grid lines on the back side of the back-contact battery, the negative grid lines and the positive grid lines are distributed in a tooth-cross shape, and a preset angle is formed between the first direction and the direction parallel to the positive grid lines; On the same battery cell, in the first direction, two adjacent positive electrode welding points are welded together by a welding ribbon, and the welding ribbon welded to the positive electrode welding point is also welded to the positive electrode grid line and / or the positive electrode current collection point. Two adjacent negative electrode welding points are welded together by a welding ribbon, and the welding ribbon welded to the negative electrode welding point is also welded to the negative electrode grid line and / or the negative electrode current collection point.

Images