Grid line, cell and cell string

Abstract

Provided in the present disclosure are a grid line, a cell and a cell string. A grid line structure comprises positive current collection points and negative current collection points which are respectively connected to positive grid lines and negative grid lines on a solar cell, wherein the negative grid lines and the positive grid lines are distributed in an interdigitated manner, the same positive current collection point is connected to several positive grid lines, and the same negative current collection point is connected to several negative grid lines.

Description

grid lines, batteries and battery strings

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese Patent Application No. 202411131355.4, filed on August 17, 2024, entitled "Grid Structure of Battery Cell, Back Contact Battery and Battery String", and Chinese Patent Application No. 202410517131.0, filed on April 26, 2024, entitled "Grid Structure of Battery Cell, Back Contact Battery and Battery String", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure pertains to the field of solar cell technology, and particularly relates to a grid structure for a solar cell, a back contact cell, and a cell string. Background Technology

[0004] A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect. As long as the illuminance meets certain conditions, it can instantly output voltage and generate current when there is a circuit.

[0005] With technological advancements, the back-contact cell structure of solar cells has gradually evolved from MBB (Multi-Busbar) to SMBB (Super Multi-Busbar) and 0BB (O-Busbar, without a main grid). SMBB suffers from unavoidable grid losses, resulting in poor current collection, the presence of bright and dark areas, and severe inter-cell series mismatch. To ensure better current collection, an 0BB structure can be used. However, the dense grid of the 0BB structure necessitates pre-printing soldering material at the welding positions in certain situations to guarantee current collection. This leads to increased soldering material usage and costs, and is also prone to issues such as missed printing causing poor soldering and printing misalignment causing short circuits due to overlapping of irregular grid lines, affecting welding quality and reducing reliability. Summary of the Invention

[0006] This disclosure provides a grid structure for a battery cell, aiming to solve the problems of excessive welding material consumption, frequent printing errors leading to incomplete soldering, and printing misalignment causing short circuits due to overlapping of irregular grid lines in existing battery cell grid structures, which affect welding performance and reliability.

[0007] The present disclosure is implemented as follows: a grid structure for a battery cell includes a positive current collection point and a negative current collection point.

[0008] The battery cell includes a first collection area and a second collection area;

[0009] The first collection area is equipped with a positive current collection point, which is used to connect to the positive grid line on the battery cell.

[0010] The second collection area is equipped with a negative current collection point, which is used to connect to the negative grid line on the battery cell.

[0011] The negative and positive grid lines are arranged in a toothed, intersecting pattern.

[0012] The grid structure also satisfies at least one of the following conditions:

[0013] The same positive current collection point is connected to several positive grid lines, and the same negative current collection point is connected to several negative grid lines;

[0014] The first collection area is provided with a number of positive current collection points, and each positive current collection point in the first collection area is arranged along the first direction. The second collection area is provided with a number of negative current collection points, and each negative current collection point in the second collection area is arranged along the first direction. The first direction forms a preset angle with the direction parallel to the positive grid line.

[0015] Furthermore, the number of positive grid lines connected to the same positive current collection point includes 2-15, or the number of negative grid lines connected to the same negative current collection point includes 2-15, or both the number of positive grid lines connected to the same positive current collection point and the number of negative grid lines connected to the same negative current collection point include 2-15.

[0016] Furthermore, the number of positive grid lines connected to the same positive current collection point includes 4-6, or the number of negative grid lines connected to the same negative current collection point includes 4-6, or the number of positive grid lines connected to the same positive current collection point and the number of negative grid lines connected to the same negative current collection point both include 4-6.

[0017] Furthermore, the positive and negative grid lines are arranged parallel to each other and alternately. 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.

[0018] Furthermore, the positive grid line includes a positive connecting grid line, the negative grid line includes a negative connecting grid line, and the positive current collection points in the parallel direction of the same positive grid line are connected through the same positive connecting grid line, and the negative current collection points in the parallel direction of the same negative grid line are connected through the same negative connecting grid line.

[0019] Furthermore, the battery cell also has positive electrode edge grid lines and negative electrode edge grid lines, which are located on both sides of the positive electrode grid lines and negative electrode grid lines.

[0020] The same positive electrode edge grid line is connected to several positive electrode grid lines, the same negative electrode edge grid line is connected to several negative electrode grid lines, and the positive electrode edge grid line is connected to the positive electrode connecting grid line, and the negative electrode edge grid line is connected to the negative electrode connecting grid line.

[0021] Furthermore, the battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints, and at least one set of positive electrode solder joints are arranged in a straight line with the positive current collection points in the same first collection area, and at least one set of negative electrode solder joints are arranged in a straight line with the negative current collection points in the same second collection area.

[0022] Furthermore, a first welding material layer for connecting with the welding strip is provided at the positive current collection point located on the straight line of the positive electrode solder joint, and a second welding material layer for connecting with the welding strip is provided at the negative current collection point located on the straight line of the negative electrode solder joint.

[0023] Furthermore, the battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. 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. Positive electrode solder joints in the same positive electrode grid line are connected to each other through the same positive electrode connecting grid line, and negative electrode solder joints in the same negative electrode grid line are connected to each other through the same negative electrode connecting grid line.

[0024] Furthermore, the battery cell also has positive electrode edge grid lines and negative electrode edge grid lines, which are located on both sides of the positive electrode grid lines and the negative electrode grid lines, respectively.

[0025] The same positive electrode edge grid line is connected to several positive electrode grid lines, the same negative electrode edge grid line is connected to several negative electrode grid lines, and the positive electrode edge grid line is connected to the positive electrode connecting grid line, and the negative electrode edge grid line is connected to the negative electrode connecting grid line.

[0026] 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 set of positive electrode solder joints and at least one set of negative electrode solder joints;

[0027] Both the first and second collection areas are located within the middle area;

[0028] The positive current collection point and the corresponding positive solder joint within the same first collection area are on the same straight line;

[0029] The negative current collection point and the corresponding negative solder joint in the same second collection area are on the same straight line.

[0030] Furthermore, the battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints, and the first collection area containing at least one positive electrode current collection point and the second collection area containing at least one negative electrode current collection point are both offset from the positive electrode solder joints and the negative electrode solder joints.

[0031] Furthermore, the positive current collection point and the negative current collection point can be square, circular, triangular, or irregular in shape.

[0032] Furthermore, when the positive and negative current collection points are square, the width of both the positive and negative current collection points is 0.1 mm to 2 mm.

[0033] Furthermore, when the positive and negative current collection points are square, the width of both the positive and negative current collection points is 0.2 mm to 1 mm.

[0034] Furthermore, the positive current collection point is a wireframe structure with a hollow region, or the negative current collection point is a wireframe structure with a hollow region, or both the positive and negative current collection points are wireframe structures with hollow regions; the positive grid line connected to the positive current collection point passes through the hollow region of the positive current collection point, and the negative grid line connected to the negative current collection point passes through the hollow region of the negative current collection point.

[0035] Secondly, this application also provides a back contact battery, comprising:

[0036] The main body of the solar cell has a front and a back side; and

[0037] The grid structure of the battery cells, as described above, is located on the back side.

[0038] Thirdly, this application also provides a battery string, including the back contact battery as described above.

[0039] Furthermore, the battery string also includes solder strips;

[0040] The back of the back contact battery includes several first collection areas and several second collection areas. The first collection area is provided with several positive current collection points arranged along a first direction. The positive current collection points are used to connect with the positive grid lines on the back of the back contact battery. The second collection area is provided with several negative current collection points arranged along the first direction. The negative current collection points are used to connect with the negative grid lines on the back of the back contact battery. The negative grid lines and the positive grid lines are distributed in a toothed cross shape. The first direction and the positive grid lines form a preset angle.

[0041] On the same cell, in the first direction, two adjacent positive electrode solder joints are welded together by a solder strip. The solder strip welded to the positive electrode solder joint is also welded to at least one of the positive electrode grid line and the positive electrode current collection point. Two adjacent negative electrode solder joints are welded together by a solder strip. The solder strip welded to the negative electrode solder joint is also welded to the negative electrode grid line, or the solder strip welded to the negative electrode solder joint is also welded to the negative electrode current collection point, or the solder strip welded to the negative electrode solder joint is also welded to both the negative electrode grid line and the negative electrode current collection point.

[0042] The beneficial effects of this application are:

[0043] This application provides a grid structure for a solar cell including a positive current collection point and a negative current collection point. The solar cell includes a first collection region and a second collection region. The first collection region is provided with a positive current collection point for connection to the positive grid line on the solar cell. The second collection region is provided with a negative current collection point for connection to the negative grid line on the solar cell. The negative grid line and the positive grid line are distributed in a toothed cross pattern. The same positive current collection point is connected to several positive grid lines, and the same negative current collection 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 collected more effectively. Since there is no main grid, losses caused by the main grid are effectively reduced. Furthermore, during welding with solder strips, welding is performed through the positive and negative current collection points, increasing the welding contact area, reducing the risk of short circuits and poor solder joints, and improving welding reliability. Simultaneously, welding material only needs to be printed at the positive and negative current collection points, rather than on each individual grid, effectively reducing welding material usage and controlling costs. Moreover, when the positive and negative current collection points are not welded to the solder strip, multiple collection paths can be provided for the current, preventing grid breakage from affecting current collection.

[0044] 2) This application provides a grid structure for a solar cell including positive current collection points and negative current collection points. The solar cell includes several first collection regions and several second collection regions. The first collection regions are provided with positive current collection points for connection to positive grid lines on the solar cell. The second collection regions are provided with negative current collection points for connection to negative grid lines on the solar cell. The negative and positive grid lines are distributed in a toothed pattern, and the same positive current collection point is connected to several positive grid lines, and the same negative current collection point is connected to several negative grid lines. By increasing the number of positive and negative current collection points in each region, connecting grid lines, edge grid lines, and connecting grid lines, multiple collection paths are provided for the current, resulting in better current collection. Attached Figure Description

[0045] Figure 1 is a schematic diagram of the grid structure of the battery cell provided in this application, in which the edge of the battery cell adopts an OBB design.

[0046] Figure 2 is a schematic diagram of the current collection area and the solder joint being collinear in one embodiment of the grid structure of the battery cell provided in this application;

[0047] Figure 3 is a schematic diagram of an embodiment of the grid structure of the battery cell provided in this application, in which the current collection area and the solder joint are misaligned.

[0048] Figure 4 is a schematic diagram of the structure of the grid line structure of the battery cell provided in this application, in which the connection line of some current collection points is set at an angle to the grid line.

[0049] Figure 5 is a schematic diagram of the arrangement of some current collection points in one embodiment of the grid structure of the battery cell provided in this application;

[0050] Figure 6 is a schematic diagram of the structure of the battery cell grid line provided in this application, in which current collection points are provided in the entire area of ​​the battery cell.

[0051] Figure 7 is a schematic diagram of a structure in one embodiment of the grid line structure of the battery cell provided in this application, in which a current collection point is provided in a part of the battery cell.

[0052] Figure 8 is a schematic diagram of a structure in another embodiment of the grid line structure of the battery cell provided in this application, in which a current collection point is provided in a part of the battery cell.

[0053] Figure 9 is a schematic diagram of the concentrated distribution of current collection points in one embodiment of the grid line structure of the battery cell provided in this application.

[0054] Figure 10 is a schematic diagram of a wireframe structure for the current collection point in one embodiment of the grid structure of the battery cell provided in this application.

[0055] Figure 11 is a schematic diagram of the current collection area and solder joint being collinear in one embodiment of the battery cell grid structure provided in this application. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this disclosure and are not intended to limit this disclosure.

[0057] In the description of this disclosure, it should be understood that the terms “length”, “width”, “upper”, “lower”, “left”, “right”, “horizontal”, “top”, “bottom”, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0058] 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 indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0059] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0060] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0061] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0062] This application provides a grid structure for a solar cell including a positive current collection point and a negative current collection point. The solar cell includes a first collection region and a second collection region. The first collection region is provided with a positive current collection point for connection to the positive grid line on the solar cell. The second collection region is provided with a negative current collection point for connection to the negative grid line on the solar cell. The negative grid line and the positive grid line are distributed in a toothed cross pattern. The same positive current collection point is connected to several positive grid lines, and the same negative current collection 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 collected more effectively. Since there is no main grid, losses caused by the main grid are effectively reduced. Furthermore, during welding with solder strips, welding is performed through the positive and negative current collection points, increasing the welding contact area, reducing the risk of short circuits and poor solder joints, and improving welding reliability. Simultaneously, welding material only needs to be printed at the positive and negative current collection points, rather than on each individual grid, effectively reducing welding material usage and controlling costs. Moreover, when the positive and negative current collection points are not welded to the solder strip, multiple collection paths can be provided for the current, preventing grid breakage from affecting current collection.

[0063] This application provides a grid structure for a solar cell including positive and negative current collection points. The solar cell includes several first collection regions and several second collection regions. The first collection regions have positive current collection points for connection to positive grid lines on the solar cell. The second collection regions have negative current collection points for connection to negative grid lines on the solar cell. The negative and positive grid lines are distributed in a toothed pattern, and each positive current collection point connects to several positive grid lines, and each negative current collection point connects to several negative grid lines. By increasing the number of positive and negative current collection points in each region, connecting grid lines, edge grid lines, and connecting grid lines, multiple collection paths are provided for current, resulting in better current collection.

[0064] Example 1

[0065] As shown in Figures 1 to 9, one embodiment of this application provides a grid structure for a battery cell, including a positive current collection point 100 and a negative current collection point 200.

[0066] The battery cell 300 includes a first collection area 310 and a second collection area 320;

[0067] The first collection area 310 is provided with a positive current collection point 100, which is used to connect to the positive grid line 330 on the battery cell 300.

[0068] 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.

[0069] The negative gate line 340 and the positive gate line 330 are arranged in a toothed cross pattern.

[0070] 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.

[0071] In implementation, the grid structure provided in this application is applied to a gridless solar cell 300, which has several positive grid lines 330, several negative grid lines 340, and several PAD points (also called "pads", "connection points", or "solder points"). The positive grid lines 330 and negative grid lines 340 are distributed in a toothed pattern, meaning they are parallel to each other and alternately spaced. For example, if both the positive grid lines 330 and negative grid lines 340 are parallel to a horizontal plane, they can be considered as horizontal lines, with one negative grid line 340 between two adjacent positive grid lines 330, and similarly, one positive grid line 330 between two adjacent negative grid lines 340.

[0072] 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 perpendicular to the horizontal plane, the PAD points can be set at the top edge and bottom edge of the battery cell 300 without limitation.

[0073] In practice, the PAD points on the solar cell 300 are used to connect with the solder ribbon, which can connect two or more solar cells 300 in series and / or in parallel, which will not be elaborated further.

[0074] In implementation, the battery cell 300 is provided with a plurality of first collection regions 310, and a plurality of positive current collection points 100 are provided within the first collection regions 310. These positive current collection points 100 are all connected to a plurality of positive grid lines 330, thereby collecting the current of the positive grid lines 330. Similarly, the battery cell 300 is also provided with a plurality of second collection regions 320, and a plurality of negative current collection points 200 are provided within the second collection regions 320. These negative current collection points 200 are all connected to a plurality of negative grid lines 340, thereby collecting the current of the negative grid lines 340.

[0075] In 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. Thus, 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 breaks, the broken grid line can still collect current through the corresponding current collection point, providing multiple collection paths for the grid line current, making current collection more reliable.

[0076] 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, as shown in FIG6. Optionally, the first collection area 310 and the second collection area 320 may also be disposed in a portion of the battery cell 300, as shown in FIG7 and FIG8. The first collection area 310 and the second collection area 320 may also be disposed in the left half or the right half of the battery cell 300, without limitation.

[0077] In some possible embodiments, the first collection area 310 and the second collection area 320 can be designed to be alternately distributed, as shown in FIG6. 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, as shown in FIG9, 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, without limitation.

[0078] In some optional embodiments, as shown in FIG1, a plurality of positive current collection points 100 are provided in the first collection area 310, and each positive current collection point 100 in the first collection area 310 is arranged along a first direction. A plurality of negative current collection points 200 are provided in the second collection area 320, and each negative current collection point 200 in the second collection area 320 is arranged along a first direction. The first direction forms a preset angle α with the parallel direction of the positive grid line 330.

[0079] In some optional embodiments, the current collection points within the same collection area are arranged along a first direction, which is set at a preset angle to the parallel direction of the positive grid line 330. In implementation, the preset angle includes 0 to 180°, such as 30°, 45°, 60°, or 120°, and is not limited. That is, the rows of positive current collection points 100 can be arranged parallel to, perpendicular to, or at other angles to the positive 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 grid line 330, and are not limited. The parallel direction of the positive grid line 330 can also be understood as the extension direction of the positive grid line 330.

[0080] Optionally, the positive grid line 330 and the negative grid line 340 are arranged parallel to each other and alternately at intervals. Each current collection point is connected to the corresponding grid line. That is, in the parallel direction of the positive grid line 330, the positive grid lines 330 located on both 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 both sides of the negative current collection point 200 are all connected to the negative current collection point 200. This will not be elaborated further.

[0081] In some embodiments, the battery cell 300 is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints, and the at least one set of positive electrode solder joints is arranged in a straight line with the positive current collection point 100 in the same first collection area 310, and the at least one set of negative electrode solder joints is arranged in a straight line with the negative current collection point 200 in the same second collection area 320.

[0082] Taking the cell 300 as an example, which is divided into regions A1, A2, B1 and B2, as shown in Figure 1, region A1 includes two positive electrode solder joints hz1, region B2 includes two positive electrode solder joints hz2, region A2 includes two negative electrode solder joints hf1, and region B1 includes two negative electrode solder joints hf2.

[0083] In region B2, several positive current collection points 100 in the first collection region 310 are arranged between two positive solder joints hz2 and are aligned with the two positive solder joints hz2 on the same straight line, so that the two positive solder joints hz2, each positive current collection point 100 in the first collection region 310 and the corresponding positive grid line 330 in this region can be connected by solder strips.

[0084] In region B1, several negative current collection points 200 in the second collection region 320 are arranged between two negative solder joints hf2 and are aligned with the two negative solder joints hf2 on the same straight line, so that the two negative solder joints hf2, each negative current collection point 200 in the second collection region 320 and the corresponding positive grid line 330 in this region can be connected by solder strips.

[0085] In some embodiments, a first welding material layer for connecting with the solder strip is provided on the positive current collection point 100 located on the straight line of the positive solder joint, and a second welding material layer for connecting with the solder strip is provided on the negative current collection point 200 located on the straight line of the negative solder joint. This allows the same solder strip to connect solder joints and current collection points of the same polarity arranged on the same straight line. The welding material does not need to cover the entire current collection point, but only needs to ensure that it can be connected with the solder strip. At the same time, it is not necessary to print welding material on each fine grid connected to the current collection point, which can effectively save the amount of welding material used.

[0086] 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 set of positive electrode solder joints and at least one set of negative electrode solder joints.

[0087] The first collection zone 310 and the second collection zone 320 are both located in the middle area;

[0088] The positive current collection point 100 and the corresponding positive solder joint within the same first collection area 310 are on the same straight line;

[0089] The negative current collection point 200 and the corresponding negative solder joint within the same second collection area 320 are on the same straight line.

[0090] For example, the battery cell 300 is divided into an edge region and a middle region. The edge region is close to the edge of the battery cell 300. For example, if the battery cell 300 is square, the edge region can be the region on the battery cell 300 near the two short sides or the region on the battery cell 300 near the two long sides. The middle region is the region located in the middle of the edge region.

[0091] The edge region is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. Similarly, the middle region is also provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. Taking the cell 300 divided into regions A1, A2, B1, and B2 as an example, as shown in Figure 1, region A1 includes two positive electrode solder joints hz1, region B2 includes two positive electrode solder joints hz2, region A2 includes two negative electrode solder joints hf1, and region B1 includes two negative electrode solder joints hf2.

[0092] Each solder joint is connected to the corresponding grid line. For example, the positive grid lines 330 located on both sides of the positive solder joint hz1 are connected to the positive solder joint hz1, and the negative grid lines 340 located on both sides of the negative solder joint hf1 are connected to the negative solder joint hf1. This will not be elaborated further.

[0093] Both regions A1 and A2 are 0BB designs, meaning there are no current collection points in regions A1 and A2. When the cell 300 is soldered to the solder strip, the solder strip corresponding to region A1 is soldered to the two positive electrode solder points hz1, and also to the positive electrode grid line 330 located between the two positive electrode solder points hz1; the solder strip corresponding to region A2 is soldered to the two negative electrode solder points hf1, and also to the negative electrode grid line 340 located between the two negative electrode solder points hf1.

[0094] Since both A1 and A2 regions adopt the 0BB design, they have good current collection performance and can effectively reduce main gate losses.

[0095] In implementation, the first collection area 310 is located in area B2, that is, the first collection area 310 is located between the two positive electrode solder joints hz2. The first collection area 310 is provided with a number of positive electrode current collection points 100. For example, the first collection area 310 can be provided with one, two, three, four or other numbers of positive electrode current collection points 100, without limitation. The arrangement direction of these positive electrode current collection points 100 is perpendicular or substantially perpendicular to the positive electrode grid line 330. That is to say, the two positive electrode solder joints hz2 and the number of positive electrode current collection points 100 are on a straight line.

[0096] When the battery cell 300 is welded to the solder strip, the solder strip corresponding to the B2 area is welded to the two positive electrode solder points hz2, and is also welded to several positive electrode current collection points 100 located between the two positive electrode solder points hz2.

[0097] In implementation, the second collection area 320 is located in area B1, that is, the second collection area 320 is located between the two negative electrode solder joints hf2. The second collection area 320 is provided with a number of negative electrode current collection points 200. For example, the second collection area 320 can be provided with one, two, three, four or other numbers of negative electrode current collection points 200, without limitation. The arrangement direction of these negative electrode current collection points 200 is perpendicular or substantially perpendicular to the positive electrode grid line 330. That is to say, the two negative electrode solder joints hf2 and the number of negative electrode current collection points 200 are on a straight line.

[0098] When the cell 300 is welded to the solder strip, the solder strip corresponding to the B1 area is welded to the two negative electrode solder points hf2, and is also welded to several negative electrode current collection points 200 located between the two negative electrode solder points hf2.

[0099] With the above settings, both B1 and B2 areas adopt a design that includes intermittently distributed current collection points to set up several current collection points. By welding the current collection points to the solder strip, the welding contact area is increased, the risk of short circuit and poor soldering is reduced, and the welding reliability is improved. At the same time, only the positive current collection point 100 and the negative current collection point 200 need to be printed with welding material, instead of printing welding material on each fine grid, which can effectively reduce the amount of welding material used and control costs.

[0100] In some embodiments, multiple A1 and A2 areas can be provided. Similarly, multiple B1 and B2 areas can also be provided. For example, the middle area of ​​the battery cell 300 is provided with two B1 areas and two B2 areas. 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 configuration can be made according to the actual usage and needs, without limitation.

[0101] In some possible embodiments, the battery cell 300 may not adopt an OBB design. Taking the battery cell 300 as divided into regions B11, B12, B21 and B22 as an example, as shown in Figure 2, region B11 includes two positive electrode solder joints hz1, region B12 includes two positive electrode solder joints hz2, region B21 includes two negative electrode solder joints hf1, and region B22 includes two negative electrode solder joints hf2.

[0102] Current collection points are provided in regions B11, B12, B21, and B22. The first collection region 310 is provided in regions B11 and B12, that is, the first collection region 310 is provided between the two positive solder joints hz1 and the two positive solder joints hz2. The second collection region 320 is provided in regions B21 and B22, that is, the second collection region 320 is provided between the two negative solder joints hf1 and the two negative solder joints hf2.

[0103] When the battery cell 300 is welded to the solder strip, the solder strip corresponding to region B11 is welded to two positive electrode solder joints hz1, and also to several positive electrode current collection points 100 located between the two positive electrode solder joints hz1; the solder strip corresponding to region B12 is welded to two positive electrode solder joints hz2, and also to several positive electrode current collection points 100 located between the two positive electrode solder joints hz2; the solder strip corresponding to region B21 is welded to two negative electrode solder joints hf1, and also to several negative electrode current collection points 200 located between the two negative electrode solder joints hf1; the solder strip corresponding to region B22 is welded to two negative electrode solder joints hf2, and also to several negative electrode current collection points 200 located between the two negative electrode solder joints hf2.

[0104] With the above settings, areas B11, B12, B21, and B22 all adopt a design that includes intermittently distributed current collection points. By welding the current collection points to the solder strip, the welding contact area is increased, the risk of short circuits and poor soldering is reduced, and the welding reliability is improved. At the same time, welding material only needs to be printed at the positive current collection point 100 and the negative current collection point 200, instead of printing welding material on each fine grid, which can effectively reduce the amount of welding material used and control costs.

[0105] In some possible embodiments, the battery cell 300 is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. The first collection area 310, which includes at least one positive electrode current collection point 100, and the second collection area 320, which includes at least one negative electrode current collection point 200, are both offset from the positive electrode solder joints and the negative electrode solder joints. That is to say, the soldering areas on the battery cell 300 are all designed as 0BB.

[0106] For example, taking the battery cell 300 as having regions A11, A12, A13, A14, B31, B32 and B33, as shown in Figure 3, regions A11 and A13 each include two positive electrode solder joints hz1, regions A12 and A14 each include two negative electrode solder joints hf1, and regions B31, B32 and B33 are each provided with current collection points. Among them, the second collection area 320 is provided in regions B31 and B33, and the first collection area 310 is provided in region B32.

[0107] When the battery cell 300 is welded to the solder strip, the solder strips corresponding to regions A11 and A13 are welded to two positive electrode solder joints hz1, and also to several positive electrode grid lines 330 located between the two positive electrode solder joints hz1; the solder strips corresponding to regions A12 and A14 are welded to two negative electrode solder joints hf1, and also to several negative electrode grid lines 340 located between the two negative electrode solder joints hf1.

[0108] Because zones A11, A12, A13, and A14 employ a 0BB design, current collection is effective, reducing welding losses. Furthermore, the staggered arrangement of zones A11, A12, A13, A14, B31, B32, and B33 allows for connection between the broken grid line and current collection points, as well as other grid lines and solder strips, even if any grid line breaks. This provides multiple collection paths for the grid line current, making current collection more reliable.

[0109] In some possible embodiments, the line connecting the current collection points within the same collection area can also form a certain angle with the positive grid line 330. For example, taking the battery cell 300 as having regions A11, A12, B32, and B33, as shown in Figure 4, region A11 includes two positive electrode solder joints hz1, region A12 includes two negative electrode solder joints hf1, region B32 is provided with a first collection area 310, and region B33 is provided with a second collection area 320. The 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 grid line 330, such as 45° or 55°, etc., without limitation; the 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 grid line 330, such as 135° or 145°, etc., without limitation.

[0110] In some possible embodiments, the current collection points in the collection area can also be arranged in groups. For example, taking the first collection area 310 as an example, based on the grid structure of the battery cell shown in Figure 4, the first collection area 310 located in region B32 is provided with three groups of collection points arranged horizontally. Each group of collection points includes several 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 Figure 5. This is not limited.

[0111] It should be noted that the values ​​and layout designs of the first collection area 310, the second collection area 320, the positive electrode solder joint, the negative electrode solder joint, the positive electrode current collection point 100, the negative electrode current collection point 200, and the various partitions and angles in the above embodiments are illustrative examples of the embodiments of this application, and not specific limitations on this application. In some other embodiments, other quantities or layout designs may be adopted. For example, in some other embodiments, areas A11, A12, A13, A14, B31, B32, and B33 can be set according to requirements. For example, areas A11 and A12 each include two positive electrode solder joints hz1, areas A13 and A14 each include two negative electrode solder joints hf1, or the first collection area 310 is set in areas B31 and B32, and the second collection area 320 is set in area B33, etc., without limitation.

[0112] This application provides a grid structure for a battery cell including a positive current collection point 100 and a negative current collection point 200. The battery cell 300 includes a plurality of first collection regions 310 and a plurality of second collection regions 320. The first collection regions 310 are provided with a plurality of positive current collection points 100 arranged along a first direction. The positive current collection points 100 are used to connect with the positive grid lines 330 on the battery cell 300. The second collection regions 320 are provided with a plurality of negative current collection points 200 arranged along the first direction. The negative current collection 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 toothed cross shape, and the first direction forms a preset angle with the parallel direction of the positive grid lines 330. By increasing the number of positive current collection points 100 and negative current collection points 200 in the region, current can be collected more effectively. Since there is no main grid, the losses caused by the main grid can be effectively reduced. Moreover, when welding with the solder strip, welding is carried out through the positive current collection points 100 and negative current collection points 200, which increases the welding contact area, reduces the risk of short circuits and poor soldering, and improves welding reliability. At the same time, welding material only needs to be printed on the positive current collection points 100 and negative current collection points 200, instead of printing welding material on each fine grid, which can effectively reduce the amount of welding material used and control costs.

[0113] In some embodiments, the positive current collection point 100 and the negative current collection point 200 can be designed as sheet-like structures, and the positive current collection point 100 and the negative current collection point 200 can be designed as square, circular, triangular or irregular shapes, etc., without limitation.

[0114] In some embodiments, the current collection points can be designed to be of uniform size, or they can be designed to be of inconsistent size.

[0115] In some possible embodiments, referring to Figure 10, the positive current collection point 100 and the negative current collection point 200 can be designed as a hollow wire frame surrounded by conductive wires. The hollow area of ​​the wire frame is the solder printing area. The positive gate line 330 connected to the positive current collection point 100 passes through the hollow area of ​​the positive current collection point 100, and the negative gate line 340 connected to the negative current collection point 200 passes through the hollow area of ​​the negative current collection point 200.

[0116] In practice, the conductive wires are made of the same material as the positive grid lines 330 and 340. When printing the positive grid lines 330 and 340 on the battery cell 300, the positive current collection point 100 and the negative current collection point 200 can be printed simultaneously. Typically, the positive current collection point 100 and the negative current collection point 200 can be printed in the aforementioned sheet-like structure to increase the welding area, facilitate welding, and reduce the rate of incomplete soldering. However, printing the positive current collection point 100 and the negative current collection point 200 in the aforementioned wireframe structure can reduce the amount of positive current collection point 100 and negative current collection point 200 used, thus reducing costs.

[0117] In some possible embodiments, when the current collection point is a wireframe structure, the corresponding grid lines can pass through the current collection point. For example, the positive grid line 330 can pass through the positive current collection point 100, and the negative grid line 340 can pass through the negative current collection point 200, which facilitates printing.

[0118] In some embodiments, the solder joints on the battery cell 300 can also adopt the structure of current collection points. For example, the positive electrode solder joint can be the positive electrode current collection point 100, and the negative electrode solder joint can be the negative electrode current collection point 200, which will not be elaborated further.

[0119] In some alternative embodiments, 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 both include 2-15 lines, wherein the number of grid lines in the parallel direction of the same grid line is one.

[0120] In implementation, each current collection point collects current from multiple grid lines. The size of the current collection point depends on the number of grid lines it contains; one current collection point can cover 2-15 grid lines, for example, one current collection point can be connected to 7, 9, or 13 grid lines. Generally, the fewer grid lines a current collection point covers, the higher the amount of welding material used, leading to increased welding material costs; conversely, the more grid lines a current collection point covers, the higher the main grid loss and the lower the module 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. With this setup, experimental data shows that the battery module power loss is only 0.05%-0.1% compared to OBB, while the amount and cost of welding materials can be reduced by approximately 40% to 50%.

[0121] In some optional embodiments, when the positive current collection point 100 and the negative current collection point 200 are square, the width of both the positive current collection point 100 and the negative current collection point 200 is 0.2 mm to 1 mm. The solar cell 300 collects current through grid lines. Therefore, with a fixed area of ​​the solar cell 300, the larger the coverage area of ​​the grid lines, the higher the module efficiency. This means that the positive current collection point 100 and the negative current collection point 200 should be designed to be relatively small. However, if the positive current collection point 100 and the negative current collection point 200 are too small, it will result in a small welding area, leading to risks such as incomplete welding and poor welding. Therefore, the width of both the positive current collection point 100 and the negative current collection point 200 can be 0.2 mm to 1 mm. Preferably, the width of both the positive current collection point 100 and the negative current collection 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 balance module efficiency and welding reliability, and is not limited.

[0122] Example 2

[0123] The difference between this embodiment and Embodiment 1 is that, as shown in Figure 11, the positive gate line 330 includes a positive connecting gate line 331, and the negative gate line 340 includes a negative connecting gate line 341. The positive current collection points 100 in the parallel direction of the same positive gate line 330 are connected through the same positive connecting gate line 331, and the negative current collection points 200 in the parallel direction of the same negative gate line 340 are connected through the same negative connecting gate line 341. That is, each current collection point in the parallel direction of the same gate line is connected through the same gate line.

[0124] In this disclosure, based on connecting multiple grid lines of the same polarity to 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 single grid line, thus 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. For example, in Figure 11, in the two first collection regions 310, regions B11 and B12, the uppermost positive current collection point 100 is connected through a positive connection grid line 331. At this time, the positive current collection point 100 at the uppermost position in region B11 is connected to the positive current collection point 100 on both sides... The positive grid line 330, the positive current collection point 100 at the top of region B11, and the positive current collection point 100 at the top of region B12 are connected to each other, forming a multi-channel collection path between grid lines of the same polarity and current collection points of the same polarity, and between current collection points of the same polarity. This provides more collection paths for grid line current. When a grid line or current collection point has a short circuit or poor soldering, current can still be collected through other paths, improving the reliability of current collection.

[0125] Furthermore, after connecting each current collection point of the same polarity in the parallel direction of the same grid line and the corresponding grid line of each current collection point of the same polarity, when welding with the solder strip, the current collection points in the same collection area can also be connected through the solder strip, so that more grid lines of the same polarity on the cell 300 are connected into a whole, further reducing the risk of short circuit and poor soldering, and improving the reliability of current collection.

[0126] In some alternative embodiments, the positive electrode connection gate line 331 and the negative electrode connection gate line 341 are parallel to each other and alternately spaced.

[0127] In some optional embodiments, the battery cell 300 is further provided with a positive electrode edge grid line 350 and a negative electrode edge grid line 360, both of which are disposed on both sides of the positive electrode grid line 330 and the negative electrode grid line 340.

[0128] The same positive electrode edge grid line 350 is connected to several positive electrode grid lines 330, the same negative electrode edge grid line 360 ​​is connected to several negative electrode grid lines 340, and the positive electrode edge grid line 350 is connected to the positive electrode connecting grid line 331, and the negative electrode edge grid line 360 ​​is connected to the negative electrode connecting grid line 341.

[0129] For example, in Figure 11, the right edge of the battery cell has a negative electrode solder joint hf1 in region B21. Multiple negative electrode grid lines 340 corresponding to the right side of the negative electrode solder joint hf1 are connected to the negative electrode solder joint hf1. Multiple positive electrode grid lines 330 corresponding to the right side of the negative electrode solder joint hf1 are connected through positive electrode edge grid lines 350. At the same time, these positive electrode grid lines 330 can also be connected to the positive electrode current collection point 100 through the positive electrode edge grid lines 350 and the positive electrode connection grid lines 331.

[0130] By coordinating edge grid lines and connecting grid lines of the same polarity, the edge grid lines are fully utilized, effectively improving the current collection efficiency.

[0131] In some optional embodiments, in the first direction, the positive electrode edge grid line 350 and the negative electrode edge grid line 360 ​​are alternately arranged at intervals, and in the parallel direction of the same positive electrode grid line, the positive electrode edge grid line 350 and the negative electrode edge grid line 360 ​​are arranged on both sides of the positive electrode grid line 330, so that in the parallel direction of the same positive electrode grid line, the grid lines on both sides of the edge 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.

[0132] In some embodiments, the battery cell 300 is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. 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. Positive electrode solder joints in the same positive electrode grid line 330 are connected through the same positive electrode connecting grid line 332, and negative electrode solder joints in the same negative electrode grid line 340 are connected through the same negative electrode connecting grid line 342. This constitutes a multi-channel collection path between grid lines and solder joints of the same polarity, and between solder joints of the same polarity, further providing more collection paths for grid line current. When a grid line or solder joint has a short circuit, poor soldering, or other issues, current can still be collected through other paths, improving the reliability of current collection.

[0133] In some embodiments, the battery cell 300 further includes a positive electrode edge grid line 350 and a negative electrode edge grid line 360, which are disposed on both sides of the positive electrode grid line 330 and the negative electrode grid line 340.

[0134] The same positive electrode edge grid line 350 is connected to several positive electrode grid lines 330, the same negative electrode edge grid line 360 ​​is connected to several negative electrode grid lines 340, and the positive electrode edge grid line 350 is connected to the positive electrode connecting grid line 332, and the negative electrode edge grid line 360 ​​is connected to the negative electrode connecting grid line 342.

[0135] By coordinating edge grid lines of the same polarity with connected grid lines, the edge grid lines are fully utilized, effectively improving the current collection efficiency.

[0136] In this disclosure, by coordinating the positive electrode grid line 330 containing the positive electrode connecting grid line 331, the positive electrode current collection point 100, the positive electrode edge grid line 350, and the positive electrode solder joint, and by connecting the positive electrode grid line 330, the positive electrode current collection point 100, and the positive electrode solder joint in the same straight direction with solder ribbon during welding, all positive electrode grid lines on the same cell can be connected through. Similarly, by coordinating the negative electrode grid line 340 containing the negative electrode connecting grid line 341, the negative electrode current collection point 200, the negative electrode edge grid line 360, and the negative electrode solder joint, and by connecting the negative electrode grid line 340, the negative electrode current collection point 200, and the negative electrode solder joint in the same straight direction with solder ribbon during welding, all negative electrode grid lines on the same cell can be connected through. This effectively improves the current collection effect, reduces the risk of short circuits and poor soldering, and reduces series mismatch between cell modules and power loss at the module end.

[0137] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the back contact battery described above can be referred to the corresponding structure and implementation principle in the aforementioned Embodiment 1, and will not be repeated here.

[0138] Example 3

[0139] In some alternative embodiments, this application also provides a back contact battery, comprising:

[0140] The main body of the solar cell has a front and a back side; and

[0141] The grid structure of the battery cells, as described above, is located on the back side.

[0142] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the back contact battery described above can be referred to the corresponding structure and implementation principle in the aforementioned Embodiment 1, and will not be repeated here.

[0143] This application provides a grid structure for a battery cell including a positive current collection point 100 and a negative current collection point 200. The battery cell 300 includes a plurality of first collection regions 310 and a plurality of second collection regions 320. The first collection regions 310 are provided with a plurality of positive current collection points 100 arranged along a first direction. The positive current collection points 100 are used to connect with the positive grid lines 330 on the battery cell 300. The second collection regions 320 are provided with a plurality of negative current collection points 200 arranged along the first direction. The negative current collection 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 toothed cross shape, and the first direction forms a preset angle with the parallel direction of the positive grid lines 330. By increasing the number of positive current collection points 100 and negative current collection points 200 in the region, current can be collected more effectively. Since there is no main grid, the losses caused by the main grid can be effectively reduced. Moreover, when welding with the solder strip, welding is carried out through the positive current collection points 100 and negative current collection points, which increases the welding contact area, reduces the risk of short circuits and poor soldering, and improves welding reliability. At the same time, welding material only needs to be printed on the positive current collection points 100 and negative current collection points 200, instead of printing welding material on each fine grid, which can effectively reduce the amount of welding material used and control costs.

[0144] Example 4

[0145] In some alternative embodiments, this application also provides a battery string, including the back contact battery as described above.

[0146] In implementation, the back of the back contact battery is provided with a positive electrode grid line 330, a negative electrode grid line 340, a positive electrode solder joint, a negative electrode solder joint, a positive electrode current collection point 100, and a negative electrode current collection point 200. The back of the back contact battery includes several first collection areas 310 and several second collection areas 320. Each first collection area 310 has several positive electrode current collection points 100 arranged along a first direction, which are used to connect to the positive electrode grid line 330 on the back of the back contact battery. Each second collection area 320 has several negative electrode current collection points 200 arranged along the first direction, which are used to connect to the negative electrode grid line 340 on the back of the back contact battery. The negative electrode grid line 340 and the positive electrode grid line 330 are distributed in a toothed cross pattern, and the first direction forms a predetermined angle with the parallel direction of the positive electrode grid line 330.

[0147] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the structure and implementation principle of the battery string described above can be referred to the corresponding structure and implementation principle in the aforementioned Embodiments 1 and 2, and will not be repeated here.

[0148] In practice, two adjacent back contact batteries are connected together by welding. On the same cell, in the first direction, two adjacent positive electrode solder points are welded together by a welding strip. The welding strip welded to the positive electrode solder points is also welded to the positive electrode grid line 330 and / or the positive electrode current collection point 100. Two adjacent negative electrode solder points are welded together by a welding strip. The welding strip welded to the negative electrode solder points is also welded to the negative electrode grid line 340 and / or the negative electrode current collection point 200.

[0149] During the welding process, insulating material with irregularly shaped grid lines is first printed onto the back contact cells to prevent short circuits caused by the irregular grid line circuitry during soldering. Then, welding material is printed according to the screen printing plate to facilitate conductivity between the back contact cells and the solder strip. Finally, the solder strip is placed over the welding material to complete the welding between the cells, forming a battery string. Further details regarding the battery string composed of multiple back contact cells and the battery assembly made of materials such as glass, film, backsheet, and frame are omitted.

[0150] This application provides a grid structure for a battery cell including a positive current collection point 100 and a negative current collection point 200. The battery cell 300 includes a plurality of first collection regions 310 and a plurality of second collection regions 320. The first collection regions 310 are provided with a plurality of positive current collection points 100 arranged along a first direction. The positive current collection points 100 are used to connect with the positive grid lines 330 on the battery cell 300. The second collection regions 320 are provided with a plurality of negative current collection points 200 arranged along the first direction. The negative current collection 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 toothed cross shape, and the first direction forms a preset angle with the parallel direction of the positive grid lines 330. By increasing the number of positive current collection points 100 and negative current collection points 200 in the region, current can be collected more effectively. Since there is no main grid, the losses caused by the main grid can be effectively reduced. Moreover, when welding with the solder strip, welding is carried out through the positive current collection points 100 and negative current collection points 200, which increases the welding contact area, reduces the risk of short circuits and poor soldering, and improves welding reliability. At the same time, welding material only needs to be printed on the positive current collection points 100 and negative current collection points 200, instead of printing welding material on each fine grid, which can effectively reduce the amount of welding material used and control costs.

[0151] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A grid structure for a solar cell, comprising a positive current collection point and a negative current collection point; The battery cell includes a first collection area and a second collection area; The first collection area is provided with the positive current collection point, which is used to connect to the positive grid line on the battery cell; The second collection area is provided with the negative current collection point, which is used to connect to the negative grid line on the battery cell; The negative and positive gate lines are arranged in a toothed, intersecting pattern. The grid structure also satisfies at least one of the following conditions: The same positive current collection point is connected to several positive grid lines, and the same negative current collection point is connected to several negative grid lines; The first collection area is provided with a plurality of positive current collection points, and each of the positive current collection points in the first collection area is arranged along a first direction. The second collection area is provided with a plurality of negative current collection points, and each of the negative current collection points in the second collection area is arranged along a first direction. The first direction forms a preset angle with the direction parallel to the positive grid line.

2. The grid line structure of the battery cell as described in claim 1, wherein, The number of positive grid lines connected to the same positive current collection point includes 2-15, or the number of negative grid lines connected to the same negative current collection point includes 2-15, or the number of both positive grid lines connected to the same positive current collection point and negative grid lines connected to the same negative current collection point includes 2-15.

3. The grid line structure of the battery cell as described in claim 2, wherein, The number of positive grid lines connected to the same positive current collection point includes 4-6, or the number of negative grid lines connected to the same negative current collection point includes 4-6, or the number of both positive grid lines connected to the same positive current collection point and negative grid lines connected to the same negative current collection point includes 4-6.

4. The grid line structure of the battery cell as described in claim 1, wherein, The positive grid line and the negative grid line are arranged parallel to each other and alternately. In the parallel direction of the positive grid line, the positive grid lines located on the left and right sides of the positive current collection point are all 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 all connected to the negative current collection point.

5. The grid line structure of the battery cell as described in claim 1, wherein, The positive grid line includes a positive connecting grid line, and the negative grid line includes a negative connecting grid line. Positive current collection points in the parallel direction of the same positive grid line are connected through the same positive connecting grid line, and negative current collection points in the parallel direction of the same negative grid line are connected through the same negative connecting grid line.

6. The grid line structure of the battery cell as described in claim 5, wherein, The battery cell also has positive electrode edge grid lines and negative electrode edge grid lines, which are located on both sides of the positive electrode grid lines and the negative electrode grid lines, respectively. The same positive electrode edge gate line is connected to several positive electrode gate lines, the same negative electrode edge gate line is connected to several negative electrode gate lines, and the positive electrode edge gate line is connected to the positive electrode connecting gate line, and the negative electrode edge gate line is connected to the negative electrode connecting gate line.

7. The grid line structure of the solar cell as described in claim 1, wherein, The battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints, and at least one set of positive electrode solder joints are arranged in a straight line with the positive current collection point in the same first collection area, and at least one set of negative electrode solder joints are arranged in a straight line with the negative current collection point in the same second collection area.

8. The grid line structure of the battery cell as described in claim 7, wherein, A first welding material layer for connecting with the welding strip is provided at the positive current collection point located on the straight line of the positive electrode solder joint, and a second welding material layer for connecting with the welding strip is provided at the negative current collection point located on the straight line of the negative electrode solder joint.

9. The grid line structure of the solar cell as described in claim 1, wherein, The battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. 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. Positive electrode solder joints in the same positive electrode grid line are connected to each other through the same positive electrode connecting grid line, and negative electrode solder joints in the same negative electrode grid line are connected to each other through the same negative electrode connecting grid line.

10. The grid line structure of the solar cell as described in claim 9, wherein, The battery cell also has positive electrode edge grid lines and negative electrode edge grid lines, which are located on both sides of the positive electrode grid lines and the negative electrode grid lines, respectively. The same positive electrode edge gate line is connected to several positive electrode gate lines, the same negative electrode edge gate line is connected to several negative electrode gate lines, and the positive electrode edge gate line is connected to the positive electrode connecting gate line, and the negative electrode edge gate line is connected to the negative electrode connecting gate line.

11. The grid line structure of the solar cell as described in claim 1, wherein, 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 set of positive electrode solder joints and at least one set of negative electrode solder joints. Both the first collection area and the second collection area are located within the intermediate area; The positive current collection point and the corresponding positive solder joint within the same first collection area are on the same straight line; The negative current collection point and the corresponding negative solder joint within the same second collection area are on the same straight line.

12. The grid line structure of the solar cell as described in claim 1, wherein, The battery cell is provided with at least one set of positive electrode solder joints and at least one set of negative electrode solder joints. The first collection area containing at least one positive electrode current collection point and the second collection area containing at least one negative electrode current collection point are both offset from the positive electrode solder joints and the negative electrode solder joints.

13. The grid line structure of the solar cell as described in claim 1, wherein, The positive current collection point and the negative current collection point are square, circular, triangular or irregular in shape.

14. The grid line structure of the solar cell as described in claim 13, wherein, When the positive current collection point and the negative current collection point are square, the width of both the positive current collection point and the negative current collection point is 0.1mm to 2mm.

15. The grid line structure of the solar cell as described in claim 13, wherein, When the positive current collection point and the negative current collection point are square, the width of both the positive current collection point and the negative current collection point is 0.2mm to 1mm.

16. The grid line structure of the solar cell as described in claim 1, wherein, The positive current collection point is a wireframe structure with a hollow region, or the negative current collection point is a wireframe structure with a hollow region, or both the positive current collection point and the negative current collection point are wireframe structures with hollow regions. The positive grid line connected to the positive current collection point passes through the hollow region of the positive current collection point, and the negative grid line connected to the negative current collection point passes through the hollow region of the negative current collection point.

17. A back-contact battery, comprising: A battery cell body, the battery cell body having a front and a back side; as well as The grid structure of the battery cell as described in any one of claims 1 to 16 is disposed on the back side.

18. A battery string comprising the back contact battery as claimed in claim 17.

19. The battery string as claimed in claim 18, wherein: The battery string also includes solder strips: The back of the back contact battery includes a plurality of first collection areas and a plurality of second collection areas. The first collection areas are 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 areas are 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 distributed in a toothed cross shape. The first direction and the parallel direction of the positive grid lines form a preset angle. On the same battery cell, in a first direction, two adjacent positive electrode solder joints are welded together by a solder strip. The solder strip welded to the positive electrode solder joint is also welded to at least one of the positive electrode grid line and the positive electrode current collection point. Two adjacent negative electrode solder joints are welded together by a solder strip. The solder strip welded to the negative electrode solder joint is also welded to the negative electrode grid line, or the solder strip welded to the negative electrode solder joint is also welded to the negative electrode current collection point, or the solder strip welded to the negative electrode solder joint is also welded to both the negative electrode grid line and the negative electrode current collection point.

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