Back contact battery, battery assembly and photovoltaic system

Abstract

The invention is suitable for the field of photovoltaic technology, and provides a back contact battery, a battery assembly and a photovoltaic system, the back contact battery comprises a silicon substrate, the silicon substrate comprises a first edge and a second edge; the first main grid is arranged on the back surface of the silicon substrate; the first fine grids and the second fine grids are alternately arranged on the back face at intervals in the first direction; the first polarity bonding pad is arranged on the first main grid and comprises a first bonding pad arranged close to the first edge and a second bonding pad arranged close to the second edge; the first insulation paste is arranged on the back surface and close to the first main grid, and at least covers the part, close to the first main grid, of the second fine grid; the first insulation paste is discontinuously arranged between the first bonding pad and the second bonding pad. The first insulation paste continuously covers the part, located between the first bonding pad and the first edge, of the first main grid and the part, located between the second bonding pad and the second edge, of the first main grid. According to the back contact battery, the warping degree of the battery pieces can be reduced, and the structural stability of the battery is improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a back-contact battery, battery module and photovoltaic system. Background Technology

[0002] A solar cell is a semiconductor device that converts solar energy into electrical energy. Under sunlight, a solar cell generates a photocurrent, which is then output as electricity through electrodes. In recent years, solar cell manufacturing technology has continuously advanced, production costs have decreased, and conversion efficiency has increased. Solar cell power generation has become increasingly widespread and is an important energy source for electricity supply. Solar cells mainly include back-contact cells and bifacial contact cells. Because the positive and negative grid lines of a back-contact cell are located on the back side, the grid lines can avoid shading the front of the cell, significantly improving cell efficiency compared to bifacial contact cells.

[0003] In related technologies, the back side of a back contact battery typically includes two main grids of different polarities and two fine grids of different polarities. The fine grids of the first polarity are connected to the main grids of the first polarity, and the fine grids of the second polarity are connected to the main grids of the second polarity. To prevent the solder ribbons on the main grids from contacting the dissimilar fine grids, insulating adhesive is needed to cover the portion of the dissimilar fine grids near the main grids. However, the insulating adhesive in back contact batteries is usually continuously laid along the length of the main grids, resulting in an excessively long continuous distribution length of the insulating adhesive. During the heating process, such as heating and curing the insulating adhesive after printing and heating and welding the back contact battery to the solder ribbons, the insulating adhesive deforms due to heat, which can easily lead to severe warping of the battery cells, thus affecting the structure of the back contact battery. Summary of the Invention

[0004] This invention provides a back-contact battery, which aims to solve the problem that existing back-contact batteries have insulating adhesive that is continuously arranged along the length of the main grid, which easily leads to severe warping of the battery cells.

[0005] This invention is implemented by providing a back contact battery, comprising: A silicon substrate, the silicon substrate including a first edge and a second edge disposed opposite to each other along a first direction; A first main gate is disposed on the back side of the silicon substrate, and the first main gate extends along the first direction; The first and second fine grids are disposed on the back side, both extending along a second direction, which intersects with the first direction. The first and second fine grids are alternately spaced along the first direction. The first fine grid is connected to the first main grid, and the second fine grid is spaced apart from the first main grid. At least two first polarity pads are disposed on the first main gate, the first polarity pads including a first pad disposed near the first edge and a second pad disposed near the second edge; and A first insulating adhesive is disposed on the back side and near the first main gate, the first insulating adhesive extends along the first direction, and the first insulating adhesive at least covers the portion of the second fine gate near the first main gate; the first insulating adhesive is intermittently disposed between the first pad and the second pad along the first direction, the first insulating adhesive continuously covers the portion of the first main gate located between the first pad and the first edge, and the first insulating adhesive continuously covers the portion of the first main gate located between the second pad and the second edge.

[0006] Preferably, the first insulating adhesive comprises: A first cover portion is disposed around the first polarity pad, the first cover portion at least covering the portion of the second fine gate near the first polarity pad; A second covering portion is located between two adjacent first covering portions, the second covering portion comprising a plurality of first sub-insulating blocks arranged at intervals along the first direction.

[0007] Preferably, the spacing between adjacent first and second fine grids is D, and the spacing between two adjacent first sub-insulating blocks is L, satisfying 0μm < L < (D-150)μm.

[0008] Preferably, the first insulating adhesive comprises: A third cover portion is located between the first pad and the first edge, the third cover portion is continuously disposed along the first direction, and the third cover portion completely covers the portion of the first main gate located between the first pad and the first edge.

[0009] Preferably, the first insulating adhesive comprises: A fourth cover portion is located between the second pad and the second edge, the fourth cover portion is continuously disposed along the first direction, and the fourth cover portion completely covers the portion of the first main gate located between the second pad and the second edge.

[0010] Preferably, the third covering portion is connected to the first covering portion corresponding to the first pad.

[0011] Preferably, the fourth covering portion is connected to the first covering portion corresponding to the second pad.

[0012] Preferably, the first insulating adhesive also covers the portion of the first fine grid near the first main grid.

[0013] Preferably, the first polarity pad further includes: At least one third pad is provided on the first main gate, the third pad being located between the first pad and the second pad.

[0014] Preferably, the number of first fine grids partially covered by each first sub-insulating block is less than or equal to two, and the number of second fine grids partially covered by each first sub-insulating block is less than or equal to two.

[0015] Preferably, each of the first sub-insulating blocks partially covers one of the first fine grids, and each of the first sub-insulating blocks partially covers one of the second fine grids.

[0016] Preferably, the first covering portion and the second covering portion are spaced apart in the first direction.

[0017] Preferred options also include: A second main gate is disposed on the back side of the silicon substrate, the second main gate extends along the first direction, the second main gate and the first main gate are alternately spaced along the second direction, the second fine gate is connected to the second main gate, and the first fine gate is spaced apart from the second main gate; A second insulating adhesive is disposed on the back side and near the second main grid, the second insulating adhesive extends along the first direction, and the second insulating adhesive at least covers the portion of the first fine grid near the second main grid.

[0018] Preferred options also include: At least two second polarity pads are provided on the second main gate, the second polarity pads including a fourth pad disposed near the first edge and a fifth pad disposed near the second edge, the second insulating adhesive being intermittently disposed between the fourth pad and the fifth pad along the first direction.

[0019] Preferably, the second insulating adhesive continuously covers the portion of the second main gate located between the fourth pad and the first edge, and the second insulating adhesive continuously covers the portion of the second main gate located between the fifth pad and the second edge.

[0020] Preferred options also include: A third insulating adhesive connected to the first insulating adhesive, the third insulating adhesive covering the second fine grid and extending toward the second insulating adhesive along the second direction.

[0021] Preferred options also include: A fourth insulating adhesive connected to the second insulating adhesive, the fourth insulating adhesive covering the first fine grid and extending toward the first insulating adhesive along the second direction.

[0022] Preferably, the projection of the fourth insulating adhesive along the first direction overlaps with the projection of the third insulating adhesive along the first direction.

[0023] Preferably, the third insulating adhesive and the second insulating adhesive are spaced apart in the second direction.

[0024] Preferably, the fourth insulating adhesive is spaced apart from the first insulating adhesive in the second direction.

[0025] The present invention also provides a battery assembly including the aforementioned back contact battery.

[0026] The present invention also provides a photovoltaic system including the above-described battery module.

[0027] The present invention provides a back contact battery in which the first insulating adhesive is intermittently arranged between the first and second pads along a first direction. This discontinuous arrangement of the first insulating adhesive along the first direction reduces the length of the continuous distribution of the first insulating adhesive in the first direction, thereby reducing the thermal shrinkage caused by heating the first insulating adhesive. This also reduces the degree of cell warpage that occurs during the heating and curing of the first insulating adhesive after printing and the heating and welding of the back contact battery to the solder strip, ensuring the structural stability of the cell and guaranteeing good electrical performance. Furthermore, the intermittent arrangement of the first insulating adhesive between the first and second pads along the first direction reduces the coverage area of ​​the first insulating adhesive and the amount of material used, thereby reducing production costs.

[0028] Furthermore, the first insulating adhesive continuously covers the portion of the first main grid located between the second pad and the second edge, ensuring continuous coverage of both the portion between the first pad and the first edge, and the portion between the second pad and the second edge. This first insulating adhesive protects the portion of the first main grid near the edge of the cell, preventing it from being broken due to excessive welding temperature and thus ensuring the structural stability of the first main grid. Therefore, the back contact battery of this invention can prevent severe cell warping caused by excessively long continuous distribution of the first insulating adhesive, and also prevent the portion of the first main grid near the edge of the cell from being broken due to excessive welding temperature, effectively ensuring the structural reliability of the back contact battery. Attached Figure Description

[0029] Figure 1 A schematic diagram of the back side of a back-contact battery provided in an embodiment of the present invention; Figure 2 This is a partial schematic diagram of a back contact battery provided in an embodiment of the present invention; Figure 3 for Figure 2 A magnified schematic diagram of part A in the middle; Figure 4 This is another partial schematic diagram of a back contact battery provided in an embodiment of the present invention; Figure 5 for Figure 4 A magnified schematic diagram of part B in the middle. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to 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 the invention, and should not be construed as limiting the invention. Furthermore, it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] In the description of this invention, it should be understood that the terms "upper", "lower", "backlight", "front", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this invention and simplifying the description, and do not 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 invention.

[0032] In this invention, unless otherwise explicitly 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.

[0033] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. 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, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0034] Please refer to Figures 1-3 This invention provides a back contact battery, comprising: Silicon substrate 1, the silicon substrate 1 includes a first edge 11 and a second edge 12 disposed opposite to each other along a first direction Y; A first main gate 2 is disposed on the back side 10 of the silicon substrate 1, and the first main gate 2 extends along the first direction Y; The first fine grid 3 and the second fine grid 4 are provided on the back side 10. The first fine grid 3 and the second fine grid 4 are both extended along the second direction X. The second direction X intersects with the first direction Y. The first fine grid 3 and the second fine grid 4 are alternately spaced along the first direction Y. The first fine grid 3 is connected to the first main grid 2, and the second fine grid 4 is spaced apart from the first main grid 2. At least two first polarity pads 5 are disposed on the first main gate 2, the first polarity pads 5 including a first pad 51 disposed near the first edge 11 and a second pad 52 disposed near the second edge 12; and A first insulating adhesive 6 is disposed on the back side 10 and near the first main gate 2. The first insulating adhesive 6 extends along the first direction Y and at least covers the portion of the second fine gate 4 near the first main gate 2. The first insulating adhesive 6 is disposed intermittently between the first pad 51 and the second pad 52 along the first direction Y. The first insulating adhesive 6 continuously covers the portion of the first main gate 2 located between the first pad 51 and the first edge 11, and continuously covers the portion of the first main gate 2 located between the second pad 52 and the second edge 12.

[0035] In this embodiment of the invention, the first fine gate 3 and the second fine gate 4 have opposite polarities, and the first fine gate 3 has the same polarity as the first main gate 2. The first direction Y and the second direction X can be perpendicular or not perpendicular. Preferably, the first direction Y and the second direction X are perpendicular. There are multiple first fine gates 3 and multiple second fine gates 4, which are alternately arranged on the back surface 10 along the first direction Y. The first fine gate 3 is connected to the first main gate 2, and the second fine gate 4 is disconnected at the position of the first main gate 2, thus spacing the second fine gate 4 from the first main gate 2.

[0036] In this embodiment of the invention, the first insulating adhesive 6 extends along the first direction Y and is located on opposite sides of the first main grid 2 along the second direction X. The first insulating adhesive 6 at least covers the end of the second fine grid 4 near the first main grid 2 to prevent the second fine grid 4 from contacting the solder strip on the first main grid 2 and short-circuiting.

[0037] The first insulating adhesive 6 of the back contact battery provided in this embodiment of the invention is intermittently arranged between the first pad 51 and the second pad 52 along the first direction Y. That is, the first insulating adhesive 6 is not continuously arranged along the first direction Y. The portion of the first insulating adhesive 6 between the first pad 51 and the second pad 52 is discontinuously distributed in the first direction Y. This reduces the length of the first insulating adhesive 6 continuously distributed in the first direction Y, thereby reducing the deformation force generated by the first insulating adhesive 6 when heated and reducing the shrinkage of the first insulating adhesive 6 after heating. This reduces the degree of cell warpage that occurs after the first insulating adhesive 6 is printed and cured, and after the back contact battery is heated and welded to the solder strip, ensuring the structural stability of the cell and guaranteeing good electrical performance of the cell. Moreover, the intermittent arrangement of the first insulating adhesive 6 between the first pad 51 and the second pad 52 along the first direction Y reduces the coverage area of ​​the first insulating adhesive 6 and reduces the amount of material used, thereby reducing production costs.

[0038] Furthermore, since the first pad 51 and the second pad 52 are close to the edge of the battery cell, and the welding temperature of the first pad 51 and the second pad 52 is usually higher than the welding temperature of the pad in the middle of the battery cell, the first insulating adhesive 6 of this embodiment continuously covers the portion of the first main grid 2 located between the first pad 51 and the first edge 11, and continuously covers the portion of the first main grid 2 located between the second pad 52 and the second edge 12. This ensures that the portion of the first main grid 2 located between the first pad 51 and the first edge 11 is continuously covered by the first insulating adhesive 6, and the portion of the first main grid 2 located between the second pad 52 and the second edge 12 is continuously covered by the first insulating adhesive 6. The first insulating adhesive 6 covers and protects the portion of the first main grid 2 near the edge of the battery cell, preventing the first main grid 2 from being broken due to excessive welding temperature, which helps to ensure the structural stability of the first main grid 2. Therefore, the back contact battery of the present invention can prevent the battery cell from warping due to excessively long continuous distribution of the first insulating adhesive 6, and can also prevent the edge of the first main grid 2 near the battery cell from being welded off due to excessively high welding temperature, thus ensuring the structural reliability of the back contact battery.

[0039] The first insulating adhesive 6 is intermittently disposed between the first pad 51 and the second pad 52 along the first direction Y. The specific implementation structure is not limited; it can have only one break, two breaks, or multiple breaks. Preferably, the first insulating adhesive 6 has multiple breaks between the first pad 51 and the second pad 52 along the first direction Y, which can further prevent warping of the battery cell.

[0040] Please refer to the reference. Figure 1 and Figure 2 As an embodiment of the present invention, the first insulating adhesive 6 comprises: A first cover portion 61 is disposed around the first polarity pad 5, and the first cover portion 61 at least covers the portion of the second fine gate 4 near the first polarity pad 5; The second cover 62 is located between two adjacent first cover portions 61. The second cover 62 includes a plurality of first sub-insulating blocks 621 arranged at intervals along the first direction Y.

[0041] In this embodiment, each first polarity pad 5 is provided with a corresponding first covering portion 61, which at least covers both sides of the first polarity pad 5 along the second direction X. That is, the first insulating adhesive 6 is cut out at the position of the first polarity pad 5 to expose the first polarity pad 5 so that the first polarity pad 5 can be soldered to the solder strip. The first covering portion 61 at least covers the end of the second fine gate 4 near the first polarity pad 5 to prevent the end of the second fine gate 4 near the first polarity pad 5 from contacting the solder strip on the first polarity pad 5. Preferably, the first covering portion 61 and the second covering portion 62 also cover the end of the first fine gate 3 near the first main gate 2, and the first insulating adhesive 6 protects the portion of the first fine gate 3 near the first main gate 2 to prevent the first fine gate 3 from being soldered off.

[0042] In this embodiment, the portion between two adjacent first covering portions 61 is the second covering portion 62. The second covering portion 62 includes a plurality of first sub-insulating blocks 621 arranged at intervals along the first direction Y. That is, the second covering portion 62 has a discontinuous structure in the first direction Y. The second covering portion 62 is composed of a plurality of first sub-insulating blocks 621, which are arranged at intervals along the first direction Y, so that the first insulating adhesive 6 is broken in multiple places in the first direction Y. The number of first sub-insulating blocks 621 included in the second covering portion 62 is not limited and can be two, three, four or more. Since the second cover portion 62 is a discontinuous structure in the first direction Y, and the second cover portion 62 is intermittent in the first direction Y, the length of the second cover portion 62 continuously distributed in the first direction Y can be reduced, the degree of bending of the battery cell caused by the heating process of the first insulating adhesive 6 can be reduced, the structural stability of the battery cell can be ensured, and the good electrical performance of the battery cell can be guaranteed. Moreover, the second cover portion 62 is intermittent in the first direction Y, which can reduce the coverage area of ​​the first insulating adhesive 6 and reduce the amount of material used in the first insulating adhesive 6, thereby reducing production costs.

[0043] Please refer to the reference. Figure 3 As an embodiment of the present invention, the first sub-insulating block 621 includes a first portion 6211 and a second portion 6212 that are spaced apart from each other along the second direction X. The first portion 6211 is located on the first side of the first main gate 2, and the second portion 6212 is located on the second side of the first main gate 2. The first main gate 2 is exposed in the gap between the first portion 6211 and the second portion 6212.

[0044] In this embodiment, the first sub-insulating block 621 is configured to include a first portion 6211 and a second portion 6212 that are spaced apart from each other along the second direction X, so that the first sub-insulating block 621 does not completely cover the first main grid 2 in the second direction X. This can further reduce the coverage area of ​​the first insulating adhesive 6 and reduce the amount of material used in the first insulating adhesive 6, thereby reducing production costs and facilitating the welding of the first main grid 2 to the welding strip.

[0045] As an embodiment of the present invention, the spacing between adjacent first fine gate 3 and second fine gate 4 is D, and the spacing between two adjacent first sub-insulating blocks 621 is L, satisfying 0μm<L<(D-150)μm.

[0046] In this embodiment, the spacing between adjacent first fine grids 3 and second fine grids 4 is D, that is, the distance between adjacent first fine grids 3 and second fine grids 4 along the first direction Y is D, and the spacing between two adjacent first sub-insulating blocks 621 is L, that is, the distance between two adjacent first sub-insulating blocks 621 along the first direction Y is L; by controlling 0μm < L < (D-150)μm, it is ensured that the second covering part 62 is an intermittent structure in the first direction Y, and the spacing between two adjacent first sub-insulating blocks 621 is avoided to be too large, ensuring that both the first fine grids 3 and second fine grids 4 can be partially covered by the corresponding first sub-insulating blocks 621, preventing the first fine grids 3 from being welded off during the welding process, and preventing the second fine grids 4 from contacting the solder strip and short-circuiting.

[0047] As an embodiment of the present invention, the first insulating adhesive 6 includes: The third cover portion 63 is located between the first pad 51 and the first edge 11. The third cover portion 63 is continuously disposed along the first direction Y, and the third cover portion 63 completely covers the portion of the first main gate 2 located between the first pad 51 and the first edge 11.

[0048] In this embodiment, the third covering portion 63 is continuously arranged along the first direction Y, and the third covering portion 63 completely covers the portion of the first main gate 2 located between the first pad 51 and the first edge 11, so that the portion of the first main gate 2 located between the first pad 51 and the first edge 11 is continuously covered by the third covering portion 63. The third covering portion 63 protects the portion of the first main gate 2 near the first edge 11, preventing the soldering temperature between the solder strip and the first pad 51 from being too high and causing the portion of the first main gate 2 near the first edge 11 to be broken by soldering, which helps to ensure the structural stability of the first main gate 2.

[0049] As an embodiment of the present invention, the first insulating adhesive 6 includes: A fourth cover portion 64 is located between the second pad 52 and the second edge 12. The fourth cover portion 64 is continuously disposed along the first direction Y and completely covers the portion of the first main gate 2 located between the second pad 52 and the second edge 12.

[0050] In this embodiment, the fourth covering portion 64 is continuously arranged along the first direction Y, and the fourth covering portion 64 completely covers the portion of the first main gate 2 located between the second pad 52 and the second edge 12, so that the portion of the first main gate 2 located between the second pad 52 and the second edge 12 is continuously covered by the fourth covering portion 64. The fourth covering portion 64 protects the portion of the first main gate 2 near the second edge 12, preventing the soldering temperature between the solder strip and the second pad 52 from being too high and causing the portion of the first main gate 2 near the second edge 12 to be broken by soldering, which helps to ensure the structural stability of the first main gate 2.

[0051] As an embodiment of the present invention, the third cover portion 63 is connected to the first cover portion 61 corresponding to the first pad 51.

[0052] In this embodiment, the first covering portion 61 corresponding to the first pad 51 is a first covering portion 61 disposed around the first pad 51, and the third covering portion 63 is connected to the first covering portion 61 corresponding to the first pad 51. That is, the first covering portion 61 and the first covering portion 61 corresponding to the first pad 51 are continuously disposed, which can better cover and protect the portion of the first main gate 2 located between the first pad 51 and the first edge 11, and prevent the first main gate 2 from being broken during the soldering process.

[0053] As an embodiment of the present invention, the fourth cover portion 64 is connected to the first cover portion 61 corresponding to the second pad 52.

[0054] In this embodiment, the first covering portion 61 corresponding to the second pad 52 is a first covering portion 61 disposed around the second pad 52. The fourth covering portion 64 is connected to the first covering portion 61 corresponding to the second pad 52. That is, the fourth covering portion 64 and the first covering portion 61 corresponding to the second pad 52 are continuously disposed, which can better cover and protect the portion of the first main gate 2 located between the second pad 52 and the second edge 12, and prevent the first main gate 2 from being broken during the soldering process.

[0055] As an embodiment of the present invention, the first insulating adhesive 6 also covers the portion of the first fine grid 3 near the first main grid 2.

[0056] In this embodiment, the first insulating adhesive 6 covers the end of the first fine grid 3 near the first main grid 2. The first insulating adhesive 6 can be used to cover the part of the first fine grid 3 near the first main grid 2, and the first insulating adhesive 6 protects the part of the first fine grid 3 near the first main grid 2 to prevent the first fine grid 3 from being soldered off.

[0057] As an embodiment of the present invention, the first polarity pad 5 further includes: At least one third pad 53 is provided on the first main gate 2, and the third pad 53 is located between the first pad 51 and the second pad 52.

[0058] In this embodiment, the specific number of third pads 53 between the first pad 51 and the second pad 52 is not limited. Figure 2 Only one third pad 53 is shown in the diagram. Each third pad 53 is provided with a first cover portion 61, which surrounds the third pad 53. The portion between the first cover portion 61 corresponding to the first pad 51 and the first cover portion 61 corresponding to the third pad 53 is a second cover portion 62. The portion between the first cover portion 61 corresponding to the second pad 52 and the first cover portion 61 corresponding to the third pad 53 is also a second cover portion 62. The portion between the first cover portions 61 corresponding to adjacent third pads 53 is also a second cover portion 62. Each second cover portion 62 includes a plurality of first sub-insulating blocks 621 arranged sequentially at intervals along the first direction Y.

[0059] As an embodiment of the present invention, the number of first sub-insulating blocks 621 partially covering the first fine grid 3 is less than or equal to two, and the number of second fine grids 4 partially covering the first sub-insulating blocks 621 is less than or equal to two.

[0060] In this embodiment, the number of first sub-insulating blocks 621 partially covering the first fine grid 3 is less than or equal to two. This can be understood as each first sub-insulating block 621 corresponding to a number of first fine grid 3 covered by less than or equal to two, and each first sub-insulating block 621 only covers a portion of the corresponding first fine grid 3 near the first main grid 2. Similarly, each first sub-insulating block 621 partially covers the second fine grid 4 by less than or equal to two, and each first sub-insulating block 621 only covers a portion of the corresponding second fine grid 4 near the first main grid 2. Controlling the number of first sub-insulating blocks 621 partially covering the first fine grid 3 to be less than or equal to two, and the number of first sub-insulating blocks 621 partially covering the second fine grid 4 to be less than or equal to two, avoids excessive length of the first sub-insulating blocks 621 along the first direction Y, which can further reduce the warping deformation of the battery cell caused by the heating of the first insulating adhesive 6.

[0061] As an embodiment of the present invention, each first sub-insulating block 621 is partially covered by a first fine grid 3, and each first sub-insulating block 621 is partially covered by a second fine grid 4.

[0062] In this embodiment, each first sub-insulating block 621 covers a portion of a first fine grid 3 near the first main grid 2, and each first sub-insulating block 621 covers a portion of a second fine grid 4 near the first main grid 2. Since each first sub-insulating block 621 only partially covers a first fine grid 3 and each first sub-insulating block 621 only partially covers a second fine grid 4, the length of the first sub-insulating block 621 along the first direction Y is avoided to be too long. This can further reduce the degree of cell warping and deformation, and ensure that the ends of the first fine grid 3 and the second fine grid 4 near the first main grid 2 are covered by the first sub-insulating block 621, preventing the first fine grid 3 from being welded off and preventing the second fine grid 4 from short-circuiting due to contact with the solder strip.

[0063] As an embodiment of the present invention, the first covering portion 61 and the second covering portion 62 are spaced apart in the first direction Y.

[0064] In this embodiment, the first covering part 61 and the second covering part 62 are spaced apart in the first direction Y, that is, the first covering part 61 and the second covering part 62 are not continuous, which can further reduce the degree of warping deformation of the battery cell and reduce the amount of material used in the first insulating adhesive 6.

[0065] Please refer to the reference. Figure 1 , Figure 4 and Figure 5 As one embodiment of the present invention, it further includes: A second main gate 7 is disposed on the back side 10 of the silicon substrate 1. The second main gate 7 extends along the first direction Y. The second main gate 7 and the first main gate 2 are alternately spaced along the second direction X. The second fine gate 4 is connected to the second main gate 7. The first fine gate 3 is spaced apart from the second main gate 7. A second insulating adhesive 8 is disposed on the back side 10 and near the second main grid 7. The second insulating adhesive 8 extends along the first direction Y and at least covers the portion of the first fine grid 3 near the second main grid 7.

[0066] In this embodiment, the second main gate 7 has the opposite polarity to the first main gate 2, the second main gate 7 has the same polarity as the second fine gate 4, and the first main gate 2 has the same polarity as the first fine gate 3. The second insulating adhesive 8 at least covers the end of the first fine gate 3 near the second main gate 7 to prevent the first fine gate 3 from contacting the solder strip on the second main gate 7 and causing a short circuit.

[0067] As one embodiment of the present invention, it also includes: At least two second polarity pads 9 are provided on the second main gate 7. The second polarity pads 9 include a fourth pad 91 provided near the first edge 11 and a fifth pad 92 provided near the second edge 12. The second insulating adhesive 8 is intermittently provided between the fourth pad 91 and the fifth pad 92 along the first direction Y.

[0068] In this embodiment, the second insulating adhesive 8 is intermittently arranged between the fourth pad 91 and the fifth pad 92 along the first direction Y. That is, the portion of the second insulating adhesive 8 located between the first pad 51 and the second pad 52 is disconnected in the first direction Y. This can reduce the length of the second insulating adhesive 8 continuously distributed in the first direction Y, and further reduce the degree of cell warping that occurs during the heating and curing of the second insulating adhesive 8 and the heating and welding of the back contact battery with the solder strip, thereby ensuring the structural stability of the cell and guaranteeing good electrical performance of the cell.

[0069] As an embodiment of the present invention, the second insulating adhesive 8 continuously covers the portion of the second main gate 7 located between the fourth pad 91 and the first edge 11, and the second insulating adhesive 8 continuously covers the portion of the second main gate 7 located between the fifth pad 92 and the second edge 12.

[0070] In this embodiment, the second insulating adhesive 8 continuously covers the portion of the second main grid 7 located between the fourth pad 91 and the first edge 11, and the second insulating adhesive 8 continuously covers the portion of the second main grid 7 located between the fifth pad 92 and the second edge 12. The second insulating adhesive 8 covers and protects the portion of the second main grid 7 near the edge of the battery cell, preventing the second main grid 7 from being broken due to excessive welding temperature, which helps to ensure the structural stability of the second main grid 7.

[0071] As one embodiment of the present invention, it also includes: A third insulating adhesive 13 is connected to the first insulating adhesive 6, the third insulating adhesive 13 covers the second fine grid 4 and extends along the second direction X toward the second insulating adhesive 8.

[0072] In this embodiment, the third insulating adhesive 13 covers and protects the portion of the second fine gate 4 that is away from the first main gate 2, which can prevent short circuits between the second fine gate 4 and the first fine gate 3, especially preventing short circuits caused by solder paste falling between the second fine gate 4 and the first fine gate 3 during the soldering process. The third insulating adhesive 13 may cover only a portion of the second fine gate 4 or completely cover the second fine gate 4.

[0073] As one embodiment of the present invention, it also includes: A fourth insulating adhesive 14 is connected to the second insulating adhesive 8, the fourth insulating adhesive 14 covers the first fine grid 3 and extends along the second direction X toward the first insulating adhesive 6.

[0074] In this embodiment, the fourth insulating adhesive 14 covers and protects the portion of the first fine gate 3 that is away from the first main gate 2, further preventing solder paste from falling onto the first fine gate 3 during the soldering process and causing a short circuit between the second fine gate 4 and the first fine gate 3. The fourth insulating adhesive 14 may cover a portion of the first fine gate 3, or it may completely cover the first fine gate 3.

[0075] As an embodiment of the present invention, the projection of the fourth insulating adhesive 14 along the first direction Y overlaps with the projection of the third insulating adhesive 13 along the first direction Y.

[0076] In this embodiment, the projection of the fourth insulating adhesive 14 along the first direction Y overlaps with the projection of the third insulating adhesive 13 along the first direction Y. Even if solder paste falls into any area between the second fine gate 4 and the first fine gate 3 during the soldering process, it will not cause a short circuit between the second fine gate 4 and the first fine gate 3, which can improve the reliability of the insulation between the second fine gate 4 and the first fine gate 3.

[0077] As an embodiment of the present invention, the third insulating adhesive 13 and the second insulating adhesive 8 are spaced apart in the second direction X.

[0078] In this embodiment, the third insulating adhesive 13 and the second insulating adhesive 8 are spaced apart in the second direction X, that is, there is a gap between the third insulating adhesive 13 and the second insulating adhesive 8, which can reduce the amount of insulating adhesive used and reduce costs.

[0079] As an embodiment of the present invention, the fourth insulating adhesive 14 and the first insulating adhesive 6 are spaced apart in the second direction X.

[0080] In this embodiment, the fourth insulating adhesive 14 and the first insulating adhesive 6 are spaced apart in the second direction X, that is, there is a gap between the fourth insulating adhesive 14 and the first insulating adhesive 6, which can reduce the amount of insulating adhesive used and reduce costs.

[0081] As an embodiment of the present invention, the second insulating adhesive 8 includes: A fifth cover portion 81 is disposed around the second polarity pad 9, and the fifth cover portion 81 covers at least the end of the first fine gate 3 near the second polarity pad 9; The sixth cover 82 is located between two adjacent fifth cover portions 81. The sixth cover 82 includes a plurality of second sub-insulating blocks 821 that are sequentially spaced along the first direction Y.

[0082] In this embodiment, each second polarity pad 9 is provided with a corresponding fifth covering portion 81. The fifth covering portion 81 covers at least both sides of the second polarity pad 9 along the second direction X. This can also be understood as the second insulating adhesive 8 being hollowed out at the position of the second polarity pad 9 to expose the second polarity pad 9 for soldering with the solder strip. Specifically, the second insulating adhesive 8 covers at least the end of the first fine gate 3 near the second polarity pad 9 to prevent the end of the first fine gate 3 near the second polarity pad 9 from contacting the solder strip on the second polarity pad 9. Preferably, the second insulating adhesive 8 also covers the end of the second fine gate 4 near the second main gate 7, which can be used to cover the end of the second fine gate 4 near the second main gate 7 to prevent the second fine gate 4 from being soldered off.

[0083] As an embodiment of the present invention, the second insulating adhesive 8 includes: The seventh cover portion 83 is located between the fourth pad 91 and the first edge 11. The seventh cover portion 83 is continuously disposed along the first direction Y and completely covers the portion of the second main gate 7 located between the fourth pad 91 and the first edge 11.

[0084] In this embodiment, the seventh covering portion 83 is continuously arranged along the first direction Y, and the seventh covering portion 83 completely covers the portion of the second main gate 7 located between the fourth pad 91 and the first edge 11, so that the portion of the second main gate 7 located between the fourth pad 91 and the first edge 11 is continuously covered by the seventh covering portion 83. The seventh covering portion 83 protects the portion of the second main gate 7 near the first edge 11, preventing the second main gate 7 from being broken due to excessively high welding temperature between the solder strip and the fourth pad 91, which helps to ensure the structural stability of the second main gate 7.

[0085] As an embodiment of the present invention, the second insulating adhesive 8 includes: An eighth cover portion 84 is located between the fifth pad 92 and the second edge 12. The eighth cover portion 84 is continuously arranged along the first direction Y, and the eighth cover portion 84 completely covers the portion of the second main gate 7 located between the fifth pad 92 and the second edge 12. The eighth cover portion 84 continuously covers the portion of the second main gate 7 located between the fifth pad 92 and the second edge 12. The eighth cover portion 84 covers and protects the portion of the second main gate 7 near the second edge 12, preventing the solder strip from being welded to the fifth pad 92 at excessively high temperatures, which would cause the second main gate 7 to break. This helps to ensure the structural stability of the second main gate 7.

[0086] As an embodiment of the present invention, the second polarity pad 9 further includes: At least one sixth pad 93 is provided on the second main gate 7, the sixth pad 93 being located between the fourth pad 91 and the fifth pad 92.

[0087] In this embodiment, the specific number of sixth pads 93 is not limited. Figure 4 Only one sixth pad 93 is shown in the diagram. The sixth cover portion 82 has a similar structure to the second cover portion 62, and includes a plurality of second sub-insulating blocks 821 arranged at intervals along the first direction Y, such that the sixth cover portion 82 is discontinuously arranged in the first direction Y. Figure 5 As shown, each second sub-insulating block 821 includes a third portion 8211 and a fourth portion 8212 that are spaced apart from each other along the second direction X. This can reduce the coverage area of ​​the second insulating adhesive 8 and reduce the amount of material used in the second insulating adhesive 8, thereby reducing production costs. Moreover, it is advantageous that the second main grid 7 is exposed in the gap between the third portion 8211 and the fourth portion 8212 so that the second main grid 7 can be welded to the welding strip.

[0088] This invention also provides a battery assembly including the back contact battery described in the above embodiments. It should be noted that this battery assembly has the same or similar beneficial effects as the back contact battery, and the related aspects between the two can be referred to each other; to avoid repetition, they will not be repeated here.

[0089] In this embodiment, multiple back-contact batteries in the battery assembly can be connected in series to form a battery string, thereby achieving series current output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0090] It is understood that in such embodiments, the battery assembly may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back surfaces of the back-contact battery, the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0091] Photovoltaic glass can be applied to the encapsulating film on the front side of the back contact battery. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the back contact battery while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the back contact battery together, providing sealing, insulation, and waterproofing / moisture protection for the battery.

[0092] The backsheet can be attached to the adhesive film on the back side of the back contact cell. The backsheet protects and supports the back contact cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice depends on the specific circumstances and is not limited here. The backsheet, back contact cell, adhesive film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0093] This invention also provides a photovoltaic system, which includes the battery module described in the above embodiments. It should be noted that this photovoltaic system has the same or similar beneficial effects as the back-contact battery described above, and the related aspects between the two can be referred to each other; to avoid repetition, they will not be repeated here.

[0094] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0095] In the description of this specification, references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0096] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A back-contact battery, characterized in that, include: A silicon substrate, the silicon substrate including a first edge and a second edge disposed opposite to each other along a first direction; A first main gate is disposed on the back side of the silicon substrate, and the first main gate extends along the first direction; The first and second fine grids are disposed on the back side, both extending along a second direction, which intersects with the first direction. The first and second fine grids are alternately spaced along the first direction. The first fine grid is connected to the first main grid, and the second fine grid is spaced apart from the first main grid. At least two first polarity pads are disposed on the first main gate, the first polarity pads including a first pad disposed near the first edge and a second pad disposed near the second edge; and A first insulating adhesive is disposed on the back side and near the first main gate, the first insulating adhesive extends along the first direction, and the first insulating adhesive at least covers the portion of the second fine gate near the first main gate; the first insulating adhesive is intermittently disposed between the first pad and the second pad along the first direction, the first insulating adhesive continuously covers the portion of the first main gate located between the first pad and the first edge, and the first insulating adhesive continuously covers the portion of the first main gate located between the second pad and the second edge.

2. The back contact battery according to claim 1, characterized in that, The first insulating adhesive includes: A first cover portion is disposed around the first polarity pad, the first cover portion at least covering the portion of the second fine gate near the first polarity pad; A second covering portion is located between two adjacent first covering portions, the second covering portion comprising a plurality of first sub-insulating blocks arranged at intervals along the first direction.

3. The back contact battery according to claim 2, characterized in that, The spacing between adjacent first and second fine grids is D, and the spacing between two adjacent first sub-insulating blocks is L, satisfying 0μm < L < (D - 150)μm.

4. The back contact battery according to claim 2, characterized in that, The first insulating adhesive includes: A third cover portion is located between the first pad and the first edge, the third cover portion is continuously disposed along the first direction, and the third cover portion completely covers the portion of the first main gate located between the first pad and the first edge.

5. The back contact battery according to claim 2, characterized in that, The first insulating adhesive includes: A fourth cover portion is located between the second pad and the second edge, the fourth cover portion is continuously disposed along the first direction, and the fourth cover portion completely covers the portion of the first main gate located between the second pad and the second edge.

6. The back contact battery according to claim 4, characterized in that, The third cover portion is connected to the first cover portion corresponding to the first pad.

7. The back contact battery according to claim 5, characterized in that, The fourth cover portion is connected to the first cover portion corresponding to the second pad.

8. The back contact battery according to claim 1, characterized in that, The first insulating adhesive also covers the portion of the first fine grid near the first main grid.

9. The back contact battery according to claim 1, characterized in that, The first polarity pad also includes: At least one third pad is provided on the first main gate, the third pad being located between the first pad and the second pad.

10. The back contact battery according to claim 2, characterized in that, Each of the first sub-insulating blocks partially covers the first fine grid in a number of less than or equal to two, and each of the first sub-insulating blocks partially covers the second fine grid in a number of less than or equal to two.

11. The back contact battery according to claim 10, characterized in that, Each of the first sub-insulating blocks partially covers one of the first fine grids, and each of the first sub-insulating blocks partially covers one of the second fine grids.

12. The back contact battery according to claim 2, characterized in that, The first covering portion and the second covering portion are spaced apart in the first direction.

13. The back contact battery according to any one of claims 1 to 12, characterized in that, Also includes: A second main grid is disposed on the back side, the second main grid extends along the first direction, the second main grid and the first main grid are alternately spaced along the second direction, the second fine grid is connected to the second main grid, and the first fine grid is spaced apart from the second main grid; A second insulating adhesive is disposed on the back side and near the second main grid, the second insulating adhesive extends along the first direction, and the second insulating adhesive at least covers the portion of the first fine grid near the second main grid.

14. The back contact battery according to claim 13, characterized in that, Also includes: At least two second polarity pads are provided on the second main gate, the second polarity pads including a fourth pad disposed near the first edge and a fifth pad disposed near the second edge, the second insulating adhesive being intermittently disposed between the fourth pad and the fifth pad along the first direction.

15. The back contact battery according to claim 14, characterized in that, The second insulating adhesive continuously covers the portion of the second main gate located between the fourth pad and the first edge, and the second insulating adhesive continuously covers the portion of the second main gate located between the fifth pad and the second edge.

16. The back contact battery according to claim 13, characterized in that, Also includes: A third insulating adhesive connected to the first insulating adhesive, the third insulating adhesive covering the second fine grid and extending toward the second insulating adhesive along the second direction.

17. The back contact battery according to claim 16, characterized in that, Also includes: A fourth insulating adhesive connected to the second insulating adhesive, the fourth insulating adhesive covering the first fine grid and extending toward the first insulating adhesive along the second direction.

18. The back contact battery according to claim 17, characterized in that, The projection of the fourth insulating adhesive along the first direction overlaps with the projection of the third insulating adhesive along the first direction.

19. The back contact battery according to claim 16, characterized in that, The third insulating adhesive and the second insulating adhesive are spaced apart in the second direction.

20. The back contact battery according to claim 17, characterized in that, The fourth insulating adhesive is spaced apart from the first insulating adhesive in the second direction.

21. A battery assembly, characterized in that, Including the back contact battery as described in any one of claims 1 to 20.

22. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 21.

Images