Battery piece and photovoltaic battery
By designing the connection area of the end area on the battery cell to be larger than the connection area of the non-end area, the problem of silver paste reducing the easy desoldering of the battery cell after temperature cycling test is solved, and the reliability of the battery cell is improved.
Patent Information
- Application Number
- CN202411962418.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-11
AI Technical Summary
After the temperature cycle test of the cell with reduced silver paste, the area close to the first pad point and the tail pad point is prone to desoldering with the main gate of the cell due to the concentrated stress of the photovoltaic welding belt, resulting in blackening of the EL detection false welding and excessive power attenuation of the cell, affecting the reliability of the cell.
Design a battery cell, whose end area is larger than the connection area of the non-end area, and ensures that the welding area between the area where the end pad point is located and the photovoltaic welding tape is strengthened.
It effectively avoids the desoldering of the photovoltaic welding tape with the main gate of the battery cell after temperature cycle test, reduces the problem of blackening of EL dummy welding and excessive power attenuation of the battery cell, and improves the reliability of the battery cell.
Smart Images
Figure CN119815995A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a cell sheet and a photovoltaic cell. Background Art
[0002] Silver paste has become one of the main raw materials for photovoltaic cells due to its excellent rheological and conductive properties. With the development of high-efficiency battery technology (such as Topcon and heterojunction batteries), the unit consumption of silver paste is increasing, resulting in an increase in the cost of photovoltaic cells.
[0003] Related technologies reduce the cost of photovoltaic cells by reducing the silver paste consumption. However, after the temperature cycle test, the area near the first pad point and the last pad point of the cell is easily desoldered from the main grid of the cell due to the stress concentration of the photovoltaic ribbon, resulting in EL detection (Electroluminescence, electroluminescence defect detection) and blackening of cold solder joints, excessive power attenuation of the cell, and other problems, affecting the reliability of the cell.
[0004] Accordingly, the art needs a new technical solution to solve the above problems. Summary of the invention
[0005] In order to solve at least one of the above-mentioned problems in the prior art, that is, to solve the problem that after the temperature cycle test of the solar cell with reduced silver paste, the areas near the first pad point and the tail pad point in the solar cell are easily desoldered from the main grid of the solar cell due to the stress concentration of the photovoltaic welding ribbon, resulting in blackening of the EL detection of cold solder joints and excessive power attenuation of the solar cell, thereby affecting the reliability of the solar cell.
[0006] In a first aspect, the present application provides a battery cell, comprising: a plurality of main bus lines, each of which is provided with a plurality of pad points; wherein a connection area of an end region between any end pad point and an adjacent non-end pad point is greater than a connection area of a non-end region between any two adjacent non-end pad points.
[0007] In some embodiments, the battery cell also includes: multiple auxiliary grid lines, which are arranged to intersect with the main grid lines, and a centipede foot is provided at the intersection of each auxiliary grid line and each main grid line; wherein the connection area of the end region is the sum of the area of the end pad point, the area of the main grid line located in the end region, and the area of the centipede foot located in the end region.
[0008] In some embodiments, the connection area of the non-end region is the sum of the area of any one of the non-end pad points in the non-end region, the area of the main grid line located in the non-end region, and the area of the centipede foot located in the non-end region.
[0009] In some embodiments, the centipede foot is a diamond-shaped centipede foot or a trapezoidal centipede foot, wherein in the end area, the length of the diamond-shaped centipede foot or the trapezoidal centipede foot along the main grid line direction ranges from 0.05 mm to 0.09 mm.
[0010] In some embodiments, in the non-end region, the length of the diamond-shaped centipede leg or the trapezoidal centipede leg along the main grid line direction ranges from 0.03 mm to 0.05 mm.
[0011] In some embodiments, the centipede foot is a rectangular centipede foot, wherein in the end area, the width of the rectangular centipede foot along the main grid line direction ranges from 0.05mm to 0.09mm, and the length of the rectangular centipede foot along the secondary grid line direction ranges from 0.08mm to 1.00mm.
[0012] In some embodiments, in the non-end region, the width of the rectangular centipede foot along the main grid line direction ranges from 0.03 mm to 0.05 mm, and the length of the rectangular centipede foot along the secondary grid line direction ranges from 0.06 mm to 0.08 mm.
[0013] In some embodiments, the width of the main grid line in the end region ranges from 20 μm to 50 μm.
[0014] In some embodiments, the width of the main grid line in the non-end region ranges from 10 μm to 15 μm.
[0015] In a second aspect, the present application provides a photovoltaic cell, which includes the above-mentioned cell sheet and the photovoltaic welding ribbon, and the photovoltaic welding ribbon is connected to the cell sheet through the end region and the non-end region.
[0016] On the premise of adopting the above technical solution, the present application has made a differentiated design for the battery cell, and the connection area of any end region is larger than the connection area of the non-end region. The connection area of the end region refers to the area of the portion in the end region used for connection with the photovoltaic ribbon, and the connection area of the non-end region refers to the area of the portion in the non-end region used for connection with the photovoltaic ribbon. Therefore, the present application increases the welding area between the end region where the end pad point is located and the photovoltaic ribbon. In this way, the welding between the photovoltaic ribbon and the end region is more secure, which can prevent the photovoltaic ribbon connected to the end region from being desoldered from the main grid of the battery cell after the temperature cycle test, avoid problems such as EL cold soldering and blackening, and excessive power attenuation of the battery cell, and is beneficial to improving the reliability of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, in which:
[0018] Figure 1 It is a structural schematic diagram of a battery cell in this application;
[0019] Figure 2 It is a schematic diagram of a partial structure of a battery cell in the present application, wherein in the end region, the diamond-shaped centipede foot is widened;
[0020] Figure 3 is a schematic diagram of a partial structure of a battery cell in the present application, wherein the diamond centipede feet in the end area are widened, and the diamond centipede feet in the non-end area are not widened;
[0021] Figure 4 It is a schematic diagram of a partial structure of a battery cell in the present application, wherein in the end region, the rectangular centipede foot is widened;
[0022] Figure 5 is a schematic diagram of a partial structure of a battery cell in the present application, wherein the rectangular centipede feet in the end area are widened, and the rectangular centipede feet in the non-end area are not widened;
[0023] Figure 6 is a schematic diagram of a local structure of a battery cell in the present application, wherein the main grid line is widened in the end region;
[0024] Figure 7 It is a schematic diagram of a local structure of a battery cell in the present application, wherein the main grid lines in the end region are widened, and the main grid lines in the non-end region are not widened.
[0025] Reference numerals:
[0026] 1. Main grid line; 11. End pad point; 12. Non-end pad point; 15. Centipede foot; 2. Auxiliary grid line. DETAILED DESCRIPTION
[0027] The preferred embodiments of the present application are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios. Such changes in the application scenarios do not deviate from the basic principles of the present application and belong to the scope of protection of the present application.
[0028] In the embodiments of the present application, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present application and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. Moreover, in addition to being used to indicate orientations or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to the specific circumstances.
[0029] It should be noted that, in the description of the preferred embodiment, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection between two components, which cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only, and those skilled in the art can understand the specific meanings of the above terms in the present application according to the specific circumstances.
[0030] Silver paste has become one of the main raw materials for photovoltaic cells due to its excellent rheological and conductive properties. With the development of high-efficiency battery technology (such as Topcon and heterojunction batteries), the unit consumption of silver paste is increasing, which will lead to an increase in the cost of photovoltaic cells.
[0031] Related technologies reduce the cost of photovoltaic cells by reducing the silver paste consumption. However, after the temperature cycle test, the area near the first pad point and the last pad point of the cell is easily desoldered from the main grid of the cell due to the stress concentration of the photovoltaic ribbon, resulting in black solder joints during EL detection and excessive power attenuation of the cell, which affects the reliability of the cell.
[0032] Among them, the unit consumption of silver paste refers to the amount of silver paste required for production per unit area or unit output.
[0033] In photovoltaic cells, pad points refer to the metal contact points on the cell. The main function of these contact points is to connect with the welding ribbon to achieve current conduction.
[0034] The first pad point and the last pad point refer to the pad points located at the beginning and end of the main grid line respectively.
[0035] Temperature cycle test refers to TC test, which is used to evaluate the temperature characteristics and performance of battery cells. TC test simulates the temperature change conditions that may be encountered in actual use by exposing the battery cells to alternating high temperature and low temperature environments to evaluate the performance stability and reliability of the battery cells under these conditions.
[0036] EL testing is a non-destructive testing method used to evaluate the quality and performance of photovoltaic modules. The main purpose of EL testing is to find defects and faults inside photovoltaic modules, which may include cracks, breaks, impurities, poor welding, etc. These defects will affect the performance and life of photovoltaic modules, so timely detection and treatment of these defects is crucial to ensure the quality and reliability of photovoltaic modules. Cold solder joints usually refer to poor connection of solder joints due to some reasons during the welding process, and the surface of the solder joints appears black. This situation may affect the quality and reliability of the welded joints, and thus have an adverse effect on the performance of the entire circuit or product.
[0037] The present application provides a battery cell and a photovoltaic cell, which can prevent the soldering strip in the area where the end pad point is located from being desoldered from the main grid of the battery cell after a temperature cycle test, avoid problems such as EL cold soldering and blackening, and excessive power attenuation of the battery cell, and is conducive to improving the reliability of the battery cell.
[0038] In a first aspect, the present application provides a battery cell.
[0039] Combination Figure 1 As shown, the battery cell provided in the present application includes a plurality of main grid lines 1.
[0040] A plurality of pad points are arranged on each main grid line 1 .
[0041] Among them, the connection area of the end region between any end pad point 11 and the adjacent non-end pad point 12 is greater than the connection area of the non-end region between any two adjacent non-end pad points 12.
[0042] The connection area of the end region refers to the area of the end region used to connect with the photovoltaic ribbon, and the connection area of the non-end region refers to the area of the non-end region used to connect with the photovoltaic ribbon. Photovoltaic ribbon, also known as tinned copper ribbon or tin-coated copper ribbon, is an important component of photovoltaic modules. Photovoltaic ribbon is used to connect each battery cell to form a series or parallel circuit to ensure that the current can be smoothly transmitted in the battery cell.
[0043] For example, the cell includes a first end pad point located at the first end of the busbar 1 and a second end pad point located at the second end of the busbar 1. The connection area of the end region between the first end pad point and the adjacent non-end pad point 12 is S 1The connection area of the non-end region between the second end pad point and the adjacent non-end pad point 12 is S 2 , the connection area of the non-end region between any two adjacent non-end pad points 12 is S 3 , then S 1 >S 3 And S 2 >S 3 Among them, S 1 With S 2 They may be equal or unequal, and no specific limitation is given here.
[0044] On the premise of adopting the above-mentioned technical solution, the present application has made a differentiated design for the battery cell. The connection area of the end region is larger than the connection area of the non-end region. The present application has increased the welding area between the end region and the photovoltaic welding strip. In this way, the welding of the photovoltaic welding strip and the end region is more firm, which can prevent the photovoltaic welding strip connected to the end region from being desoldered from the main grid of the battery cell after the temperature cycle test, and avoid problems such as EL cold soldering and blackening and excessive power attenuation of the battery cell, which is beneficial to improving the reliability of the battery cell.
[0045] In some embodiments, in combination Figure 1 As shown, the cell also includes a plurality of secondary grid lines 2, and the plurality of secondary grid lines 2 are arranged to intersect with the plurality of main grid lines 1, and a centipede foot 15 is arranged at the intersection of each secondary grid line 2 and each main grid line 1. The connection area of the end region is the sum of the area of the end pad point 11, the area of the main grid line 1 located in the end region, and the area of the centipede foot 15 located in the end region. For example, the end pad point 11 is a rectangle, and the area of the end pad point 11 is the product of the length and width of the end pad point. The area of the main grid line 1 in the end region is the product of the length of the main grid line 1 located in the end region and the width of the main grid line 1. The centipede foot 15 is a rectangular centipede foot, a trapezoidal centipede foot or a diamond-shaped centipede foot. The area of the rectangular centipede foot is equal to the product of the length and width of the rectangular centipede foot; the area of the trapezoidal centipede foot is the sum of the lengths of the upper and lower bases of the trapezoidal centipede foot, multiplied by the height of the trapezoid, and finally divided by 2; the area of the diamond-shaped centipede foot is the product of the lengths of the two diagonals of the diamond-shaped centipede foot, and then divided by 2.
[0046] By setting a centipede foot 15 at the intersection of the main grid line 1 and the auxiliary grid line 2, the centipede foot 15 has multiple small branches, which can increase the contact area between the intersection of the main grid line 1 and the auxiliary grid line 2 and the surface of the battery cell, so that the current can be more effectively collected and conducted during the transmission process, and the current collection efficiency is improved. In addition, the centipede foot 15 increases the connection points between the main grid line 1 and the auxiliary grid line 2 and the battery cell, which helps to improve the overall structural stability of the battery cell. The connection area of the end region is the sum of the area of the end pad point 11, the main grid line 1 located between the end pad point 11 and the non-end pad point 12 adjacent to it, and the centipede foot 15, so that the electric energy can be effectively led out through the photovoltaic welding tape.
[0047] Among them, the main grid line is a relatively wide metal electrode in the photovoltaic cell. It is the main transmission channel for current. The main grid line is responsible for collecting the current generated by the photovoltaic effect from various parts of the battery (such as the auxiliary grid line) for use by the external circuit. The auxiliary grid line is a metal electrode thinner than the main grid line in the photovoltaic cell. They are distributed in various areas of the battery to form a dense current collection network. The auxiliary grid lines play an auxiliary and shunting role. They are responsible for collecting current from all corners of the battery and transmitting it to the main grid line. By setting up the auxiliary grid line, it can be ensured that the current flows to the main line more evenly, avoiding the problem of current congestion or local overheating. In the photovoltaic cell, the current is first conducted from the surface of the cell to the small and dense auxiliary grid lines through the auxiliary grid lines, and then collected to the wider main grid lines through the auxiliary grid lines, and finally transmitted to the photovoltaic welding ribbon through the main grid lines to achieve the series connection between the battery cells.
[0048] Combination Figure 1 As shown, Figure 1 The area a in is the area corresponding to one of the end areas. Taking the first end pad point as an example, the connection area of the end area between the first end pad point and the adjacent non-end pad point 12 is S 1 , the area of the first end pad point is S 11 The area of all main grid lines 1 in the end region is S 12 , the area of all centipede legs 15 located in the end region is S, then S 1 =S 11 +S 12 +S 13 .
[0049] In some embodiments, the connection area of the non-end region is the sum of the area of any non-end pad point 12 in the non-end region, the area of the main grid line 1 located in the non-end region, and the area of the centipede foot 15 located in the non-end region. In this way, electrical energy can be effectively led out through the photovoltaic welding ribbon.
[0050] Combination Figures 1 to 7As shown, region b in the figure is the region corresponding to one of the non-end regions. The connection area of the non-end regions between any two adjacent non-end pad points 12 is S 3 , where the area of a non-end pad point 12 is S 31 The area of the main grid line 1 in the non-end area is S 32 The area of all centipede legs 15 in the non-end region is S 33 , then S 3 =S 31 +S 32 +S 33 .
[0051] For centipede foot 15, this application provides two strengthening methods:
[0052] In the first reinforcement method, combined with Figure 2 and Figure 3 As shown, the centipede foot 15 is a diamond-shaped centipede foot or a trapezoidal centipede foot. In the end area, the length of the diamond-shaped centipede foot along the main grid line 1 ranges from 0.05mm to 0.09mm, or the length of the trapezoidal centipede foot along the main grid line 1 ranges from 0.05mm to 0.09mm. For example, in the end area, the length of the diamond-shaped centipede foot along the main grid line 1 is 0.050mm, 0.055mm, 0.058mm, 0.06mm, 0.065mm, 0.07mm, 0.075mm, 0.080mm, 0.085mm or 0.09mm, etc.; or, in the end area, the length of the trapezoidal centipede foot along the main grid line 1 is 0.050mm, 0.055mm, 0.058mm, 0.06mm, 0.065mm, 0.07mm, 0.075mm, 0.080mm, 0.085mm or 0.09mm, etc. By widening the middle of the diamond-shaped centipede foot or the trapezoidal centipede foot in the end area, the contact area between the centipede foot 15 and the photovoltaic welding strip is effectively increased, which can greatly reduce the broken grid rate and the cold soldering rate caused by stress concentration in the area where the end pad point is located. The use of silver paste is less increased, the shading area is smaller, and the efficiency loss of the battery cell caused by blocking sunlight is reduced, which is beneficial to control costs and ensure the efficiency of the battery panel.
[0053] The following is an explanation based on experimental tests. When the length of the centipede legs along the secondary grid line 2 is constant, when the diagonal of the centipede legs parallel to the main grid line 1 increases from 0.05mm to 0.09mm, the total area of all the centipede legs included in the cell increases by 12.2mm. 2, the silver paste consumption increases by 0.5mg, the shading efficiency is affected by 0.007%, and the broken grid rate and cold soldering rate of the cell are reduced by 50%, reaching a better level. If the diagonal line of the diamond centipede leg parallel to the main grid line 1 continues to increase, then the increase in silver paste consumption, the shading efficiency and the improvement in yield rate are unbalanced.
[0054] In some embodiments, in combination Figure 3 As shown, in the non-end area, the length of the diamond-shaped centipede foot or the trapezoidal centipede foot along the main grid line 1 is in the range of 0.03mm to 0.05mm. For example, in the non-end area, the length of the diamond-shaped centipede foot along the main grid line 1 is in the range of 0.03mm, 0.035mm, 0.038mm, 0.04mm, 0.045mm or 0.05mm, etc.; or, the length of the trapezoidal centipede foot along the main grid line 1 is in the range of 0.03mm, 0.035mm, 0.038mm, 0.04mm, 0.045mm or 0.05mm, etc. Figure 3 In the figure, region a is one of the end regions, and region b is one of the non-end regions. It can be clearly seen that the diamond-shaped centipede feet of the end region are widened along the diagonal of the main grid line 1. In this way, the present application has made a differentiated design for the battery cell, and the connection area of the end region is larger than the connection area of the non-end region, which increases the welding area between the end region and the photovoltaic welding strip. In this way, the welding between the photovoltaic welding strip and the end region is more solid, which can prevent the photovoltaic welding strip in the end region from being desoldered from the main grid of the battery cell after the temperature cycle test, avoid problems such as EL cold soldering and blackening, and excessive power attenuation of the battery cell, which is conducive to improving the reliability of the battery cell.
[0055] In the second reinforcement method, combined with Figure 4 and Figure 5 As shown, the centipede foot 15 is a rectangular centipede foot, wherein, in the end region, the value range of the width of the rectangular centipede foot along the main grid line 1 direction is 0.05mm-0.09mm, and the value range of the length of the rectangular centipede foot along the auxiliary grid line 2 direction is 0.08mm-1.00mm. For example, in the end region, the width of the rectangular centipede foot along the main grid line 1 direction is 0.05mm, 0.055mm, 0.058mm, 0.060mm, 0.065mm, 0.069mm, 0.07mm, 0.075mm, 0.08mm, 0.085mm or 0.09mm, etc., and the length of the rectangular centipede foot along the auxiliary grid line 2 direction is 0.08mm, 0.081mm, 0.086mm, 0.089mm, 0.09mm, 0.095mm, 0.097mm or 1.00mm, etc.
[0056] By lengthening and widening the rectangular centipede feet in the end area, the contact area between the rectangular centipede feet and the photovoltaic welding ribbon is effectively increased, which can greatly reduce the broken grid rate and cold soldering rate caused by stress concentration in the end area where the end pad point is located, and can reasonably balance the use of silver paste, shading area and efficiency of the solar panel.
[0057] The following is an explanation based on experimental tests. When the width of the rectangular centipede foot along the main grid line 1 is constant, when the length of the rectangular centipede foot along the secondary grid line 2 increases from 0.8mm to 1.0mm, the total area of all the rectangular centipede feet included in the cell increases by 4mm. 2 , the silver paste consumption increases by 0.3mg, and the shading efficiency is affected by 0.0002%, reaching a good level. If the length of the rectangular centipede foot along the secondary grid line 2 direction continues to increase, the increase in silver paste consumption, the shading efficiency and the improvement in yield rate will be unbalanced.
[0058] In some embodiments, in the non-end region, the width of the rectangular centipede foot along the main grid line 1 is in the range of 0.03mm to 0.05mm, and the length of the rectangular centipede foot along the secondary grid line 2 is in the range of 0.06mm to 0.08mm. For example, in the non-end region, the width of the rectangular centipede foot along the main grid line 1 is 0.03mm, 0.035mm, 0.038mm, 0.040mm, 0.045mm, 0.049mm or 0.05mm, etc., and the length of the rectangular centipede foot along the secondary grid line 2 is 0.06mm, 0.061mm, 0.066mm, 0.069mm, 0.07mm, 0.075mm, 0.077mm or 0.08mm, etc. The rectangular centipede foot is not reinforced in the non-end region, which can not only ensure the performance of the battery cell, but also help reduce the cost of the battery cell.
[0059] It is understandable that when the centipede foot 15 in the end area is a rectangular centipede foot, the centipede foot 15 in the non-end area can be a rectangular centipede foot or a diamond centipede foot, which can be flexibly arranged according to needs.
[0060] In some embodiments, in combination Figure 6 As shown, the width of the main grid line 1 in the end region ranges from 20μm to 50μm. For example, the width of the main grid line 1 in the end region is 20μm, 25μm, 27μm, 29μm, 30μm, 35μm, 38μm, 40μm, 43μm, 45μm or 50μm, etc. By increasing the width of the main grid line 1 in the end region, the contact area between the main grid line 1 and the photovoltaic welding strip is effectively increased, which can greatly reduce the broken grid rate and the cold welding rate caused by stress concentration in the end region, and can reasonably balance the use of silver paste, the shading area and the efficiency of the solar panel.
[0061] In some embodiments, the width of the busbar 1 in the non-end region is in the range of 10 μm to 15 μm. For example, the width of the busbar 1 in the non-end region is 10 μm, 11 μm, 12 μm, 12 μm, μm or 15 μm, etc. The width of the busbar 1 is not increased in the non-end region, which can ensure the performance of the cell and reduce the cost of the cell.
[0062] In a second aspect, the present application provides a photovoltaic cell.
[0063] The photovoltaic cell provided in the present application comprises a cell sheet and a photovoltaic welding ribbon according to any one of the above embodiments, and the photovoltaic welding ribbon is connected to the cell sheet through an end region and a non-end region.
[0064] Under the premise of adopting the above technical solution, the present application has carried out a differentiated design for the cell of the photovoltaic cell, the connection area of the end region is larger than the connection area of the non-end region, and the present application has increased the welding area between the end region and the photovoltaic welding strip. In this way, the welding of the photovoltaic welding strip and the end region is more solid, which can prevent the welding strip in the end region from being desoldered from the main grid of the cell after the temperature cycle test, avoid the problems of EL cold soldering and blackening, and excessive power attenuation of the cell, which is conducive to improving the reliability of the photovoltaic cell.
[0065] So far, the technical solutions of the present application have been described in conjunction with the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific implementations. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.
Claims
1. A battery cell, characterized in that: The battery cell comprises: A plurality of main grid lines (1), each main grid line (1) being provided with a plurality of pad points; Among them, the connection area of the end region between any end pad point (11) and the adjacent non-end pad point (12) is greater than the connection area of the non-end region between any two adjacent non-end pad points (12).
2. The battery cell according to claim 1, characterized in that: The battery cell also includes: A plurality of auxiliary grid lines (2) are arranged to intersect with the main grid line (1), and a centipede foot (15) is arranged at the intersection of the auxiliary grid line (2) and the main grid line (1); The connection area of the end region is the sum of the area of the end pad point (11), the area of the main grid line (1) located in the end region, and the area of the centipede foot (15) located in the end region.
3. The battery cell according to claim 2, characterized in that: The connection area of the non-end region is the sum of the area of any one of the non-end pad points (12) in the non-end region, the area of the main grid line (1) located in the non-end region, and the area of the centipede foot (15) located in the non-end region.
4. The battery cell according to claim 2, characterized in that: The centipede foot (15) is a diamond-shaped centipede foot or a trapezoidal centipede foot, wherein in the end region, the length of the diamond-shaped centipede foot or the trapezoidal centipede foot along the main grid line (1) is in the range of 0.05 mm to 0.09 mm.
5. The battery cell according to claim 4, characterized in that: In the non-end region, the length of the diamond-shaped centipede leg or the trapezoidal centipede leg along the direction of the main grid line (1) ranges from 0.03 mm to 0.05 mm.
6. The battery cell according to claim 2, characterized in that: The centipede foot (15) is a rectangular centipede foot, wherein in the end area, the width of the rectangular centipede foot along the main grid line (1) is in the range of 0.05mm to 0.09mm, and the length of the rectangular centipede foot along the secondary grid line (2) is in the range of 0.08mm to 1.00mm.
7. The battery cell according to claim 6, characterized in that: In the non-end area, the width of the rectangular centipede foot along the main grid line (1) is in the range of 0.03mm to 0.05mm, and the length of the rectangular centipede foot along the secondary grid line (2) is in the range of 0.06mm to 0.08mm.
8. The battery cell according to any one of claims 1 to 7, characterized in that: The width of the main grid line (1) in the end region ranges from 20 μm to 50 μm.
9. The battery cell according to any one of claims 1 to 7, characterized in that: The width of the main grid line (1) in the non-end region ranges from 10 μm to 15 μm.
10. A photovoltaic cell, characterized in that: The photovoltaic cell comprises the cell sheet according to any one of claims 1 to 9 and a photovoltaic welding ribbon, wherein the photovoltaic welding ribbon is connected to the cell sheet through the end region and the non-end region.