Battery piece

Abstract

The utility model discloses a battery piece, which comprises a substrate, an electrode and a plurality of harpoon structures, and is characterized in that the substrate is provided with a front surface; the electrode comprises a plurality of main grids and a plurality of auxiliary grids which are printed on the front face, the main grids extend in the first direction and are arranged at intervals in the second direction perpendicular to the first direction, preset gaps are formed between the two ends of each main grid and the two side edges, in the first direction, of the front face respectively, and the two ends of each main grid are connected with bonding pads respectively. The plurality of auxiliary grids extend along the second direction and are arranged at intervals along the first direction; the harpoon structures are arranged on the front face and located in the preset gaps, the harpoon structures and the bonding pads are equal in number, each harpoon structure comprises harpoon lines and an extended main grid which are sequentially printed in the first direction, one end of each harpoon line is connected with an auxiliary grid located on the edge of one side of the front face, and the other end of each harpoon line is connected with the extended main grid through the auxiliary grid; one end of the extended main grid away from the harpoon line is connected with the pad. The risk of stress concentration of the battery piece can be reduced, and the production yield of the battery piece is improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery production, and in particular to a battery cell. Background Art

[0002] Solar cells such as monocrystalline silicon solar cells or polycrystalline silicon solar cells can convert solar energy into electrical energy, and the solar cells have the advantages of long service life and high photoelectric conversion efficiency.

[0003] In the related art, a battery cell includes a substrate and a main grid and a sub-grid arranged on the substrate, and a harpoon structure is printed on the edge of the substrate along the extension direction of the main grid. Specifically, as shown in Figure 1, a pad 30 is provided at the end of the main grid 10, and the harpoon structure includes a harpoon line 20, and the end of the harpoon line 20 is overlapped and lapped on the pad 30. However, since the end of the harpoon line 20 is overlapped and lapped on the pad 30, there is a height difference on the surface of the pad 30. Therefore, when the battery cell is tested, cracks or fragments may appear due to local stress concentration in the battery cell, thereby affecting the production yield of the battery cell. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the utility model provides a battery cell, which can reduce the risk of stress concentration in the battery cell, thereby improving the production yield of the battery cell.

[0005] In order to solve the above technical problems, the utility model provides a battery cell, comprising:

[0006] a substrate having a front surface;

[0007] An electrode, wherein the electrode comprises a plurality of main grids and a plurality of auxiliary grids printed on the front surface, wherein the plurality of main grids extend along a first direction and are arranged at intervals along a second direction perpendicular to the first direction, and a preset gap is formed between two ends of each main grid and two sides of the front surface in the first direction, and pads are connected to two ends of each main grid, and the plurality of auxiliary grids extend along the second direction and are arranged at intervals along the first direction;

[0008] A plurality of harpoon structures, wherein the plurality of harpoon structures are all arranged on the front side and located at the preset gap, the number of the plurality of harpoon structures is equal to the number of the plurality of solder pads, the harpoon structure comprises a harpoon line and an extended main grid printed in sequence along the first direction, one end of the harpoon line is connected to the auxiliary grid located at a side edge of the front side, and the other end is connected to the extended main grid, and the end of the extended main grid away from the harpoon line is connected to the solder pad.

[0009] In a possible structure, the harpoon line includes a first harpoon line and a second harpoon line spaced apart along the second direction, the first harpoon line and the second harpoon line extend along the first direction, the auxiliary grid is connected between the ends of the first harpoon line and the second harpoon line facing the pad, and the end of the extended main grid away from the pad is connected to the auxiliary grid between the first harpoon line and the second harpoon line.

[0010] In a possible structure, along the second direction, a distance between the first harpoon line and the second harpoon line is d1, and 1.2 mm≤d1≤1.9 mm.

[0011] In a possible structure, the width of the first harpoon line and the second harpoon line are both D1, 0.025mm≤D1≤0.050mm.

[0012] In a possible structure, along the first direction, the distance between two adjacent sub-grids is d2, and the lengths of the first harpoon line and the second harpoon line are both H1, H1=2d2, or H1=3d2.

[0013] In a possible structure, the extended main grid crosses multiple sub-grids, and the multiple sub-grids crossed by the extended main grid are all provided with auxiliary reinforcement lines extending along the second direction, the intersection point of the extended main grid and the sub-grid is located in the middle of the auxiliary reinforcement line, and the width of the auxiliary reinforcement line is greater than the width of the sub-grid.

[0014] In a possible structure, the width of the auxiliary reinforcement line decreases from the middle to the end of the auxiliary reinforcement line.

[0015] In a possible structure, the width of the middle portion of the auxiliary reinforcement line is D2, and the width of the end portion is D3, 0.05mm≤D2≤0.08mm, 0.02mm≤D3≤0.04mm.

[0016] In a possible structure, the length of the auxiliary reinforcement line is H2, 1.0mm≤H2≤1.2mm.

[0017] In a possible structure, the extended main grid extends along the first direction, and the width of the extended main grid is D4, 0.025 mm≤D4≤0.030 mm.

[0018] Compared with the prior art, this application has at least the following beneficial effects:

[0019] In the application, since the harpoon structure includes a harpoon line and an extended main grid printed sequentially in a first direction, and the harpoon line is connected to the pad through the extended main grid, it can be seen that the harpoon line in the present application is not directly connected to the pad. Therefore, compared with the solution in the related art that the harpoon structure includes a harpoon line, and the harpoon line is directly overlapped and connected to the pad, the harpoon line in the harpoon structure in the present application is connected to the pad through the extended main grid, thereby avoiding the existence of a height difference on the surface of the pad due to the end of the harpoon line overlapping the pad, thereby avoiding the occurrence of local stress concentration on the battery cell during testing due to the height difference on the surface of the pad, thereby avoiding the occurrence of cracks or breakage of the battery cell due to local stress concentration, thereby improving the production yield of the battery cell.

[0020] In addition, by extending the main grid to replace part of the length of the harpoon wire in the related technology, on the one hand, the area of ​​the front side of the substrate blocked by the harpoon wire can be reduced, thereby improving the light utilization rate of the battery cell. On the other hand, the waste of silver paste materials for printing the harpoon wire is reduced, thereby reducing the production cost of the battery cell. On the other hand, while extending the main grid can provide a stable electrical conduction structure, it can also avoid the risk of cold soldering during the series soldering of the soldering ribbon and the soldering pad due to the harpoon wire overlapping the soldering pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a structural schematic diagram of a harpoon structure in the prior art;

[0023] Figure 2 A schematic diagram of the structure of a battery cell provided in an embodiment of the utility model;

[0024] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0025] Figure 4 for Figure 3 A partial enlarged schematic diagram of point B in the middle;

[0026] Figure 5 for Figure 4 A partial enlarged schematic diagram of point C in the middle;

[0027] Figure 6 for Figure 4 A partial enlarged schematic diagram of middle E;

[0028] Figure 7 for Figure 4 A local enlarged schematic diagram of point D in the middle.

[0029] Description of reference numerals:

[0030] 100-battery cell; 110-substrate; 111-front; 120-electrode; 121-main grid; 122-secondary grid; 130-harpoon structure; 131-harpoon line; 1311-first harpoon line; 1312-second harpoon line; 132-extended main grid; 133-soldering pad; 134-auxiliary reinforcement line. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In the present invention, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0033] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in this utility model can be understood according to specific circumstances.

[0034] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; 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 an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0035] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0036] As described in the background technology of the present application, the battery cell includes a substrate and a main grid and a sub-grid arranged on the substrate, and a harpoon structure is printed on the edge of the substrate along the extension direction of the main grid. Specifically, as shown in Figure 1, a pad 30 is provided at the end of the main grid 10, and the harpoon structure includes a harpoon line 20, and the end of the harpoon line 20 is overlapped and lapped on the pad 30. However, since the end of the harpoon line 20 is overlapped and lapped on the pad 30, there is a height difference on the surface of the pad 30. Therefore, when the battery cell is tested, cracks or fragments may appear due to local stress concentration in the battery cell, thereby affecting the production yield of the battery cell.

[0037] In order to solve the technical problems mentioned in the background technology, the utility model provides a battery cell, in which the harpoon structure includes a harpoon line and an extended main grid printed sequentially in a first direction, wherein the harpoon line is connected to the pad through the extended main grid, thereby, the connection between the harpoon line and the pad can be achieved without overlapping the harpoon line on the pad, thereby avoiding the height difference on the surface of the pad due to the end of the harpoon line overlapping the pad, causing layout stress concentration in the battery cell, thereby avoiding the battery cell from cracking or breaking due to local stress concentration, thereby improving the production yield of the battery cell.

[0038] The present application is described in detail below through specific embodiments:

[0039] See also Figure 2 and Figure 3The embodiment of the present application provides a battery cell 100, which includes a substrate 110, an electrode 120 and a plurality of harpoon structures 130, wherein the substrate 110 has a front surface 111; the electrode 120 includes a plurality of main grids 121 and a plurality of auxiliary grids 122 printed on the front surface 111, wherein the plurality of main grids 121 extend along a first direction and are arranged at intervals along a second direction perpendicular to the first direction, wherein two ends of each main grid 121 have a preset gap with two side edges of the front surface 111 in the first direction, and two ends of each main grid 121 are connected to pads 133 respectively, Multiple auxiliary grids 122 extend along the second direction and are arranged at intervals along the first direction; multiple harpoon structures 130 are all arranged on the front side 111 and located at a preset gap, the number of multiple harpoon structures 130 is equal to the number of multiple solder pads 133, the harpoon structure 130 includes a harpoon line 131 and an extended main grid 132 printed sequentially along the first direction, one end of the harpoon line 131 is connected to the auxiliary grid 122 located at a side edge of the front side 111, and the other end is connected to the extended main grid 132 through the auxiliary grid 122, and the end of the extended main grid 132 away from the harpoon line 131 is connected to the solder pad 133.

[0040] The above-mentioned multiple refers to two or more than two. The width of the main grid 121 is greater than the width of the auxiliary grid 122, and the auxiliary grid 122 is first printed on the front surface 111 of the substrate 110, and the main grid 121 is then printed on the front surface 111 of the substrate 110. The specific range of the preset gap between the main grid 121 and the two sides of the front surface 111 in the first direction is not limited, as long as the photoelectric conversion efficiency of the battery cell 100 can be guaranteed.

[0041] In addition, the first direction is Figure 1 The direction indicated by the Y arrow in the figure, the first direction mentioned below refers to the direction indicated by the Y arrow, and the second direction refers to Figure 1 The direction indicated by the X arrow in the figure, and the second direction mentioned below all refer to the direction indicated by the X arrow.

[0042] Since both ends of each main grid 121 are connected to the pads 133 , the number of the pads 133 is twice the number of the main grids 121 . It is worth noting that the pads 133 are disposed on the front surface 111 of the substrate.

[0043] In the present embodiment, since the harpoon structure 130 includes the harpoon line 131 and the extended main grid 132 which are sequentially printed in the first direction, and the harpoon line 131 is connected to the pad 133 through the extended main grid 132, it can be seen that the harpoon line 131 in the present embodiment is not directly connected to the pad 133. Therefore, compared with the solution in the related art that the harpoon structure 130 includes the harpoon line 131, and the harpoon line 131 is directly connected to the pad 133 by lap connection, the harpoon line 131 in the harpoon structure 130 in the present embodiment is By extending the main grid 132 and connecting it with the pad 133, the height difference on the surface of the pad 133 caused by the end of the harpoon line 131 overlapping the pad 133 is avoided, thereby avoiding the occurrence of local stress concentration on the battery cell 100 during the test due to the height difference on the surface of the pad 133, and further avoiding the occurrence of cracks or breakage in the battery cell 100 due to local stress concentration, thereby improving the production yield of the battery cell 100.

[0044] In addition, by extending the main grid 132 to replace a portion of the length of the harpoon wire 131 in the related art, on the one hand, the area of ​​the front side 111 of the substrate 110 blocked by the harpoon wire 131 can be reduced, thereby improving the light utilization rate of the battery cell 100. On the other hand, the waste of silver paste materials for printing the harpoon wire 131 is reduced, thereby reducing the production cost of the battery cell 100. On the other hand, while extending the main grid 132 to provide a stable electrical conduction structure, it can also avoid the risk of cold soldering during the soldering process between the soldering strip and the soldering pad 133 due to the harpoon wire 131 overlapping the soldering pad 133.

[0045] In some possible embodiments, see Figure 3 The harpoon line 131 includes a first harpoon line 1311 and a second harpoon line 1312 spaced apart along the second direction, the first harpoon line 1311 and the second harpoon line 1312 extend along the first direction, a secondary grid 122 is connected between the ends of the first harpoon line 1311 and the second harpoon line 1312 facing the pad 133, and one end of the extended main grid 132 away from the pad 133 is connected to the secondary grid 122 between the first harpoon line 1311 and the second harpoon line 1312.

[0046] Since the first harpoon line 1311 and the second harpoon line 1312 both extend along the first direction, the first harpoon line 1311 and the second harpoon line 1312 are parallel and perpendicular to the secondary grid 122. Therefore, when the harpoon line 131 is printed, the length of the first harpoon line 1311 and the second harpoon line 1312 in each harpoon structure 130 and the distance between the two can be ensured to be consistent. Compared with the first harpoon line 1311 and the second harpoon line 1312 both having an angle with the main grid 121, the first harpoon line 1311 and the second harpoon line 1312 in this embodiment have the same shape and high printing efficiency. In addition, the length of the first harpoon line 1311 and the second harpoon line 1312 is shorter, which reduces the waste of silver paste in printing the first harpoon line 1311 and the second harpoon line 1312.

[0047] In addition, in order to ensure the collection of carriers of the first harpoon line 1311 and the second harpoon line 1312, the two ends of the first harpoon line 1311 and the second harpoon line 1312 are respectively connected to two sub-grids 122. Based on this, the ends of the first harpoon line 1311 and the second harpoon line 1312 facing the pad 133 are both connected to a sub-grid 122. In this way, the sub-grid 122 is connected between the ends of the first harpoon line 1311 and the second harpoon line 1312 facing the pad 133, which is beneficial for the carriers in the first harpoon line 1311 and the second harpoon line 1312 to be transferred through the sub-grid 122.

[0048] In some possible embodiments, see Figure 4 , along the second direction, the distance between the first harpoon line 1311 and the second harpoon line 1312 is d1, 1.2mm≤d1≤1.9mm.

[0049] If the spacing between the first harpoon line 1311 and the second harpoon line 1312 is less than 1.2 mm, it means that the spacing between the first harpoon line 1311 and the second harpoon line 1312 is small, which increases the difficulty of printing the first harpoon line 1311 and the second harpoon line 1312, thereby increasing the difficulty of the production process of the battery cell 100. If the spacing between the first harpoon line 1311 and the second harpoon line 1312 is greater than 1.9 mm, it means that the spacing between the first harpoon line 1311 and the second harpoon line 1312 is large. The distance between the first harpoon line 1311 and the second harpoon line 1312 is large, which is not conducive to the collection effect of the first harpoon line 1311 and the second harpoon line 1312 on the carriers, thereby reducing the photoelectric conversion efficiency of the battery cell 100. Based on this, the spacing between the first harpoon line 1311 and the second harpoon line 1312 is between 1.2mm and 1.9mm. In this way, it can avoid excessively increasing the difficulty of the production process of the battery cell 100 and ensure the collection effect of the first harpoon line 1311 and the second harpoon line 1312 on the carriers, thereby improving the photoelectric conversion rate of the battery cell 100.

[0050] For example, the spacing between the first harpoon line 1311 and the second harpoon line 1312 may be 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, etc.

[0051] In some possible embodiments, see Figure 5 The width of the first harpoon line 1311 and the second harpoon line 1312 are both D1, 0.025mm≤D1≤0.050mm.

[0052] The width directions of the first harpoon line 1311 and the second harpoon line 1312 are parallel to the second direction.

[0053] If the width of the first harpoon line 1311 and the second harpoon line 1312 is less than 0.025 mm, it means that the width of the first harpoon line 1311 and the second harpoon line 1312 is small, which affects the efficiency of the first harpoon line 1311 and the second harpoon line 1312 in collecting carriers. If the width of the first harpoon line 1311 and the second harpoon line 1312 is greater than 0.050 mm, it means that the width of the first harpoon line 1311 and the second harpoon line 1312 is large. Although it can ensure that the first harpoon line 1311 and the second harpoon line 1312 However, since the first harpoon line 1311 and the second harpoon line 1312 are too wide, the coverage area of ​​the front side 111 of the substrate 110 is increased, which is not conducive to the improvement of the photoelectric conversion efficiency of the battery cell 100. Based on this, the width of the first harpoon line 1311 and the second harpoon line 1312 are both between 0.025mm and 0.050mm. In this way, the carrier collection efficiency of the first harpoon line 1311 and the second harpoon line 1312 can be guaranteed, and the photoelectric conversion efficiency of the battery cell 100 can be improved.

[0054] For example, D1 can be 0.025mm, 0.027mm, 0.029mm, 0.031mm, 0.033mm, 0.045mm, 0.047mm, 0.050mm, etc. The specific values ​​of D1 are only illustrated here and should not be understood as specific limitations on the values ​​of D1. Those skilled in the art should know this.

[0055] There is no limitation on the length of the harpoon line 131. In some possible embodiments, see Figure 5 Along the first direction, the distance between two adjacent auxiliary grids 122 is d2, and the lengths of the first harpoon line 1311 and the second harpoon line 1312 are both H1, H1=2d2, or H1=3d2.

[0056] If H1=d2, it means that the length of the first harpoon line 1311 and the second harpoon line 1312 is too short, so the distance between the main grid 121 and the side of the front side 111 is short. Therefore, during the welding process of the welding strip, it will affect the strength of the edge of the substrate 110 and the production yield of the battery cell 100. If H1>3d2, it means that the length of the first harpoon line 1311 and the second harpoon line 1312 is too long, which not only increases the obstruction of the front side 111 of the substrate 110, but also causes the waste of silver paste materials. Therefore, H1=2d2, or H1=3d2, which can not only ensure the strength of the substrate 110, thereby improving the production yield of the battery cell 100, but also reduce the obstruction of the front side 111 by the first harpoon line 1311 and the second harpoon line 1312, thereby improving the photoelectric conversion efficiency of the battery cell 100, and at the same time avoid the waste of silver paste materials, thereby reducing the production cost of the battery cell 100.

[0057] In some possible embodiments, see Figure 4 The extended main grid 132 crosses multiple sub-grids 122, and auxiliary reinforcement lines 134 extending along the second direction are arranged on the multiple sub-grids 122 crossed by the extended main grid 132. The intersection point of the extended main grid 132 and the sub-grid 122 is located in the middle of the auxiliary reinforcement line 134, and the width of the auxiliary reinforcement line 134 is greater than the width of the sub-grid 122.

[0058] The auxiliary reinforcing line 134 , the harpoon structure 130 and the secondary grid 122 are printed simultaneously. After the auxiliary reinforcing line 134 , the harpoon structure 130 and the secondary grid 122 are printed on the front surface 111 of the substrate 110 , the main grid 121 is printed on the front surface 111 .

[0059] Since the width of the auxiliary grid 122 is relatively small, in order to improve the carrier collection efficiency at the intersection of the auxiliary grid 122 and the extended main grid 132, an auxiliary reinforcement line 134 extending along the second direction is provided on the auxiliary grid 122, and the intersection point of the extended main grid 132 and the auxiliary grid 122 is located in the middle of the auxiliary reinforcement line 134, and the width of the auxiliary reinforcement line 134 is greater than the width of the auxiliary grid 122.

[0060] In addition, optionally, an auxiliary reinforcement line 134 is provided on the end of the auxiliary grid 122 connected to the pad 133, and the width of the auxiliary reinforcement line 134 increases gradually along the direction toward the pad 133. Therefore, when welding the welding strip to the pad 133, it can be prevented that the auxiliary grid 122 is broken due to the excessive width of the auxiliary grid 122 after the surface welding strip deviates.

[0061] In some possible embodiments, see Figure 6 The width of the auxiliary reinforcement line 134 decreases from the middle to the end of the auxiliary reinforcement line 134.

[0062] Therefore, on the one hand, the collection effect of the auxiliary gate 122 on carriers is improved, and on the other hand, the resistance of carrier transfer between the auxiliary gate 122 and the extended main gate 132 is reduced.

[0063] In some possible embodiments, see Figure 6 The width of the middle part of the auxiliary reinforcement line 134 is D2, and the width of the end part is D3, 0.05mm≤D2≤0.08mm, 0.02mm≤D3≤0.04mm.

[0064] If the width of the auxiliary reinforcing line 134 is too large, although it can improve the effect and efficiency of the secondary grid 122 in collecting carriers, due to the excessive width of the auxiliary reinforcing line 134, the coverage area of ​​the front surface 111 of the substrate 110 is increased, which is not conducive to the improvement of the photoelectric conversion efficiency of the battery cell 100. On the contrary, if the width of the auxiliary reinforcing line 134 is too small, although it can reduce the coverage area of ​​the basic front surface 111, it is not conducive to the effect of the secondary grid 122 on carrier collection. Based on this, It is obtained that 0.05mm≤D2≤0.08mm, 0.02mm≤D3≤0.04mm. In this way, it can avoid increasing the coverage area of ​​the front side 111 of the substrate 110 due to the excessive width of the middle part and the end part of the auxiliary reinforcement line 134, thereby improving the photoelectric conversion efficiency of the battery cell 100, and it can also avoid affecting the collection of carriers by the auxiliary grid 122 due to the excessive width of the middle part and the end part of the auxiliary reinforcement line 134, thereby improving the collection effect of the auxiliary grid 122 on the carriers.

[0065] For example, the width of the middle portion of the auxiliary reinforcement line 134 may be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, etc., and the width of the ends of the auxiliary reinforcement line 134 may be 0.02 mm, 0.03 mm, 0.04 mm, etc. It is worth noting that the above values ​​are examples of the width of the middle portion and the width of the ends of the auxiliary reinforcement line 134, and cannot be understood as specific limitations on the width of the middle portion and the width of the ends of the auxiliary reinforcement line 134, which should be known to those skilled in the art.

[0066] In some possible embodiments, see Figure 6 , the length of the auxiliary reinforcement line 134 is H2, 1.0mm≤H2≤1.2mm.

[0067] If the length of the auxiliary reinforcement line 134 is greater than 1.2 mm, it means that the length of the auxiliary reinforcement line 134 is relatively long. On the one hand, it will cause a waste of silver paste materials. On the other hand, it will increase the coverage area of ​​the front side 111 of the substrate 110, which is not conducive to the improvement of the photoelectric conversion rate of the battery cell 100. If the length of the auxiliary reinforcement line 134 is less than 1.0 mm, it means that the length of the auxiliary reinforcement line 134 is relatively short, and the effect of improving the carrier collection of the sub-grid 122 is not significant. Based on this, the length of the auxiliary reinforcement line 134 is made between 1.0 mm and 1.2 mm. In this way, it can avoid the waste of silver paste materials due to the excessive length of the auxiliary reinforcement line 134, thereby reducing the production cost of the battery cell 100, and avoid increasing the coverage area of ​​the front side 111 of the substrate 110, thereby improving the photoelectric conversion rate of the battery cell 100.

[0068] For example, the length of the auxiliary reinforcement line 134 can be 1.0 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm, etc. It is worth noting that the above values ​​are examples of the length of the auxiliary reinforcement line 134 and cannot be understood as a specific limitation on the length of the auxiliary reinforcement line 134, which should be known to those skilled in the art.

[0069] In some possible embodiments, see Figure 7 The extended main grid 132 extends along the first direction, and the width of the extended main grid 132 is D4, 0.025mm≤D4≤0.030mm.

[0070] If the width of the extended main grid 132 is less than 0.025 mm, it means that the width of the extended main grid 132 is too narrow, which affects the collection of carriers by the extended main grid 132 on the one hand, and on the other hand, in the process of welding the welding strip and the welding pad 133, if the welding strip deviates, the risk of the extended main grid 132 being broken will be caused due to the fact that the extended main grid 132 is too narrow. If the width of the extended main grid 132 is greater than 0.030 mm, it means that the width of the extended main grid 132 is too wide. Although it can improve the collection of carriers by the extended main grid 132, However, since the extended main grid 132 is too wide, the coverage area of ​​the extended main grid 132 on the front side 111 of the substrate 110 will increase, thereby affecting the improvement of the photoelectric conversion rate of the battery cell 100. Based on this, the width of the extended main grid 132 is made between 0.025mm and 0.030mm. In this way, it can avoid affecting the collection of carriers by the extended main grid 132 due to the narrow width of the extended main grid 132, and can also avoid affecting the improvement of the photoelectric conversion rate of the battery cell 100 due to the extended main grid 132 being too wide.

[0071] For example, the width of the extended main grid 132 may be 0.025 mm, 0.026 mm, 0.027 mm, 0.028 mm, 0.029 mm, 0.030 mm, etc. It should be noted that the above values ​​are examples of the width of the extended main grid 132 and cannot be understood as specific limitations on the width of the extended main grid 132, which should be known to those skilled in the art.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A battery cell, characterized in that: include: a substrate having a front surface; An electrode, wherein the electrode comprises a plurality of main grids and a plurality of auxiliary grids printed on the front surface, wherein the plurality of main grids extend along a first direction and are arranged at intervals along a second direction perpendicular to the first direction, and a preset gap is formed between two ends of each main grid and two sides of the front surface in the first direction, and pads are connected to two ends of each main grid, and the plurality of auxiliary grids extend along the second direction and are arranged at intervals along the first direction; A plurality of harpoon structures, wherein the plurality of harpoon structures are all arranged on the front side and located at the preset gap, the number of the plurality of harpoon structures is equal to the number of the plurality of solder pads, the harpoon structure comprises a harpoon line and an extended main grid printed in sequence along the first direction, one end of the harpoon line is connected to the auxiliary grid located at a side edge of the front side, and the other end is connected to the extended main grid, and the end of the extended main grid away from the harpoon line is connected to the solder pad.

2. The battery cell according to claim 1, characterized in that: The harpoon line includes a first harpoon line and a second harpoon line spaced apart along the second direction, the first harpoon line and the second harpoon line extend along the first direction, the auxiliary grid is connected between the ends of the first harpoon line and the second harpoon line facing the pad, and the end of the extended main grid away from the pad is connected to the auxiliary grid between the first harpoon line and the second harpoon line.

3. The battery cell according to claim 2, characterized in that: Along the second direction, the distance between the first harpoon line and the second harpoon line is d1, 1.2mm≤d1≤1.9mm.

4. The battery cell according to claim 2, characterized in that: The width of the first harpoon line and the second harpoon line are both D1, 0.025mm≤D1≤0.050mm.

5. The battery cell according to claim 2, characterized in that: Along the first direction, the distance between two adjacent sub-grids is d2, and the lengths of the first harpoon line and the second harpoon line are both H1, H1=2d2, or H1=3d2.

6. The battery cell according to claim 2, characterized in that: The extended main grid crosses the plurality of sub-grids, and the plurality of sub-grids crossed by the extended main grid are all provided with auxiliary reinforcement lines extending along the second direction, the intersection point of the extended main grid and the sub-grid is located in the middle of the auxiliary reinforcement line, and the width of the auxiliary reinforcement line is greater than the width of the sub-grid.

7. The battery cell according to claim 6, characterized in that: The width of the auxiliary reinforcement line decreases from the middle portion to the end portion of the auxiliary reinforcement line.

8. The battery cell according to claim 7, characterized in that: The width of the auxiliary reinforcement line in the middle is D2, and the width of the end is D3, 0.05mm≤D2≤0.08mm, 0.02mm≤D3≤0.04mm.

9. The battery cell according to claim 6, characterized in that: The length of the auxiliary reinforcement line is H2, 1.0mm≤H2≤1.2mm.

10. The battery cell according to claim 2, characterized in that: The extended main grid extends along the first direction, and the width of the extended main grid is D4, 0.025 mm≤D4≤0.030 mm.

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