Back contact battery, battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell, a cell assembly and a photovoltaic system. The back contact battery comprises a silicon substrate, a plurality of first polarity fine grids, a plurality of second polarity fine grids, a plurality of first polarity collection grids, a first bonding pad and a second bonding pad, the plurality of first polarity collection grids are positioned between the first polarity fine grids and the second polarity fine grids and are connected with the first polarity fine grids; the first bonding pad is arranged at the joint of the first polarity collection grid and the first polarity fine grid; the second bonding pad is arranged on the second polarity fine grid; wherein the distance between the first polarity collection grid and the second polarity fine grid in the second direction is a first distance, the distance between the first bonding pad and the second bonding pad in the second direction is a second distance, and the ratio of the second distance to the first distance is 1.125-18. Therefore, due to the fact that the ratio of the second interval to the first interval is large, the interval between the first bonding pad and the second bonding pad in the second direction is large, and the risk of short circuit caused by the fact that the distance between the bonding pads with different polarities is too close can be reduced.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a back contact cell, a cell module, and a photovoltaic system. Background Technology

[0002] Solar cell power generation is a sustainable and clean energy source that converts sunlight into electricity using the photovoltaic effect. However, in related technologies, the small distance between pads of different polarities poses a risk of short circuits.

[0003] Therefore, optimizing the distribution design of pads with different polarities to reduce the risk of short circuits has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a back-contact battery, a battery module, and a photovoltaic system, aiming to solve the problem of how to optimize the distribution design of pads with different polarities.

[0005] This application provides a back contact battery, comprising: Silicon substrate; A plurality of first polarity fine gates and a plurality of second polarity fine gates are disposed on the silicon substrate, extending along a first direction and arranged along a second direction; A plurality of first polarity collecting gates are located between the first polarity fine gate and the second polarity fine gate, and are connected to the first polarity fine gate; The first pad is located at the connection between the first polar collection gate and the first polar fine gate; The second pad is located on the second polarity fine gate; Wherein, the distance between the first polar collection gate and the second polar fine gate in the second direction is the first distance, the distance between the first pad and the second pad in the second direction is the second distance, and the ratio of the second distance to the first distance is 1.125-18.

[0006] Furthermore, the first polar collection gate includes a first collection portion and a second collection portion, the first collection portion extends along a first direction, the second collection portion bends from the first collection portion and connects to the first polar fine gate, the first pad is disposed at the connection between the second collection portion and the first polar fine gate, and the first spacing is the spacing between the first collection portion and the second polar fine gate in the second direction.

[0007] Furthermore, the back contact battery includes a second polarity collection grid, which is located between the first polarity fine grid and the second polarity fine grid, and connects to the second polarity fine grid; the second pad is disposed at the connection between the second polarity collection grid and the second polarity fine grid; The distance between the second polar collection gate and the second polar fine gate in the second direction is the third distance, and the ratio of the second distance to the third distance is 1.125-18.

[0008] Furthermore, the second polarity collection gate includes a third collection portion and a fourth collection portion. The third collection portion extends along a first direction, and the fourth collection portion bends from the third collection portion and connects to the second polarity fine gate. The second pad is disposed at the connection between the fourth collection portion and the second polarity fine gate. The third spacing is the spacing between the third collection portion and the first polarity fine gate in the second direction.

[0009] Furthermore, the first spacing is 0.1mm-1.6mm.

[0010] Furthermore, the second spacing is 0.3mm-1.8mm.

[0011] Furthermore, the spacing between the first pad and the second pad in the first direction is 1.5mm-6mm.

[0012] This application provides a battery assembly including any of the back contact batteries described above.

[0013] Furthermore, the battery assembly includes a composite solder strip, which includes a first solder strip, an insulating strip, and a second solder strip. The first solder strip, the insulating strip, and the second solder strip are sequentially connected in contact along a first direction and extend along a second direction. The first solder strip of the composite solder strip is connected to the first pad of the back contact battery, and the second solder strip of the composite solder strip is connected to the second pad of the back contact battery.

[0014] This application provides a photovoltaic system including the battery modules described above.

[0015] The back contact battery of this application embodiment, by setting a first polarity collection gate between the first polarity fine gate and the second polarity fine gate, and placing a first pad at the connection between the first polarity collection gate and the first polarity fine gate, can better conduct the current collected by the first polarity collection gate and the first polarity fine gate. Simultaneously, because the ratio of the distance between the first pad and the second pad located on the second polarity fine gate in the second direction to the distance between the first polarity collection gate and the second polarity fine gate in the first direction is relatively large, the distance between the first pad and the second pad in the second direction is relatively large, thus reducing the risk of short circuits caused by pads of different polarities being too close together. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a back contact battery according to an embodiment of this application; Figure 2This is a partial structural schematic diagram of a back contact battery according to an embodiment of this application; Figure 3 This is a partial structural schematic diagram of a battery assembly according to an embodiment of this application.

[0017] Explanation of key component symbols: 1000-Battery Components; 100 - Back contact cell, 11 - Silicon substrate, 12 - First polar fine grid, 13 - Second polar fine grid, 14 - First polar collection grid, 141 - First collection section, 142 - Second collection section, 15 - First pad, 16 - Second pad, 17 - Second polar collection grid, 171 - Third collection section, 172 - Fourth collection section; 200 - Composite welding strip, 21 - First welding strip, 22 - Insulating strip, 23 - Second welding strip; d1 - first spacing, d2 - second spacing, d3 - third spacing. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0019] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being 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 being 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.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0024] Please see Figure 1 , Figure 2 The back contact battery 100 of this application embodiment includes a silicon substrate 11, a plurality of first polar fine gates 12, a plurality of second polar fine gates 13, a plurality of first polar collection gates 14, a first pad 15 and a second pad 16. A plurality of first polar fine gates 12 and a plurality of second polar fine gates 13 are disposed on a silicon substrate 11, extending along a first direction and arranged along a second direction; a plurality of first polar collection gates 14 are located between the first polar fine gates 12 and the second polar fine gates 13, connecting the first polar fine gates 12; a first pad 15 is disposed at the connection between the first polar collection gate 14 and the first polar fine gate 12; a second pad 16 is disposed on the second polar fine gate 13; wherein, the distance between the first polar collection gate 14 and the second polar fine gate 13 in the second direction is a first distance d1, the distance between the first pad 15 and the second pad 16 in the second direction is a second distance d2, and the ratio of the second distance d2 to the first distance d1 is 1.125-18.

[0025] Thus, by setting the first polarity collection gate 14 between the first polarity fine gate 12 and the second polarity fine gate 13, and placing the first pad 15 at the connection between the first polarity collection gate 14 and the first polarity fine gate 12, the current collected by the first polarity collection gate 14 and the first polarity fine gate 12 can be better discharged. Simultaneously, because the ratio of the distance between the first pad 15 and the second pad 16 located on the second polarity fine gate 13 in the second direction to the distance between the first polarity collection gate 14 and the second polarity fine gate 13 in the first direction is relatively large, the distance between the first pad 15 and the second pad 16 in the second direction is relatively large, thereby reducing the risk of short circuits caused by pads of different polarities being too close together.

[0026] Specifically, the back contact battery 100 can be either a gridless battery or a battery with a grid. This article uses a gridless back contact battery 100 as an example for explanation and illustration.

[0027] It is understandable that the grid of the back contact battery 100 without a main grid in the related technology is relatively dense, and a large number of solder strips are required to collect current, resulting in a relatively small spacing between the solder pads. However, in this application, the ratio of the second spacing d2 to the first spacing d1 is relatively large, which makes the first solder pad 15 and the second solder pad 16 more spaced in the second direction, thus reducing the risk of short circuit caused by solder pads of different polarities being too close together.

[0028] Specifically, the silicon substrate 11 may include a silicon substrate, a first polar doped layer, a second polar doped layer, and a dielectric film layer.

[0029] Furthermore, the silicon substrate can be a P-type silicon substrate or an N-type silicon substrate; it can be a monocrystalline silicon substrate or a polycrystalline silicon substrate. No specific form of the silicon substrate is limited here.

[0030] Furthermore, a first polar doped layer and a second polar doped layer are disposed on the silicon substrate. The first polar doped layer and the second polar doped layer have different doping polarities. The two doped layers can be formed by diffusion into the silicon substrate or by deposition of films on the silicon substrate.

[0031] Specifically, the first polar fine gate 12 and the second polar fine gate 13 can be distributed over the entire area of ​​the silicon substrate 11; the first polar fine gate 12 and the second polar fine gate 13 can also be distributed over a portion of the silicon substrate 11. It is understood that areas of the silicon substrate 11 where the first polar fine gate 12 and the second polar fine gate 13 are not distributed may have other fine gates, may have a main gate, or may not have gate lines.

[0032] Specifically, the first polarity fine gate 12 and the second polarity fine gate 13 have different polarities and are spaced apart from each other. The first polarity fine gate 12 is electrically connected to the first polarity doped layer. The second polarity fine gate 13 is electrically connected to the second polarity doped layer.

[0033] Specifically, the number of first polar fine gates 12 can be 1, 2, 3, 4, or other numbers. The number of second polar fine gates 13 can be 1, 2, 3, 4, or other numbers. No limitation is made here. The number of first polar fine gates 12 and the number of second polar fine gates 13 can be the same or different.

[0034] Specifically, the first polar fine gate 12 and the second polar fine gate 13 extending along the first direction means that the overall extending direction of the first polar fine gate 12 and the second polar fine gate 13 is the first direction. This does not represent a limitation on the specific shape of the first polar fine gate 12 and the second polar fine gate 13. In this embodiment, both the first polar fine gate 12 and the second polar fine gate 13 are straight lines, and the extending direction of the first polar fine gate 12 and the second polar fine gate 13, that is, the first direction, is the length direction of the first polar fine gate 12 and the second polar fine gate 13. In other embodiments, the first polar fine gate 12 may also be wavy, zigzag, or other shapes. The second polar fine gate 13 may also be wavy, zigzag, or other shapes. No limitation is made here.

[0035] Specifically, the first polar fine gate 12 and the second polar fine gate 13 are arranged along the second direction, which can be alternating or non-alternating along the second direction; they can be arranged at equal intervals or at unequal intervals along the second direction. No limitation is made here.

[0036] Specifically, the first polarity fine gate 12 and the second polarity fine gate 13 are spaced apart, meaning that a gap is formed between adjacent first polarity fine gates 12 and second polarity fine gates 13. The gap can be filled with an insulating element or it can be an air gap.

[0037] Specifically, the second direction intersects the first direction, meaning the second direction and the first direction do not overlap, are not the same, and are not opposite. In this embodiment, the first direction and the second direction are perpendicular to each other. The first direction and the second direction are parallel to two adjacent long sides of the silicon substrate 11, respectively. It can be understood that in other embodiments, the first direction and the second direction may also form an acute angle or an obtuse angle; the first direction and the second direction may also form an acute angle or an obtuse angle to two adjacent long sides of the silicon substrate 11, respectively. This is not limited here. Please note that "two adjacent long sides" here refers to the sides other than the corners of the silicon substrate 11, not considering the rounded or chamfered arc edges or short sides of the corners of the silicon substrate 11.

[0038] Specifically, a plurality of first polarity collecting gates 14 are located between the first polarity fine gate 12 and the second polarity fine gate 13, and are connected to the first polarity fine gate 12.

[0039] Specifically, the number of first polarity collecting gates 14 is one, two, three, four, or other quantities. The first polarity collecting gates 14 can be arranged at intervals along the first polarity fine gates 12. In this way, by setting up a number of first polarity collecting gates 14, the current collecting capability of the first polarity fine gates 12 is increased.

[0040] Furthermore, the first polarity collecting grid 14 can be arranged at equal intervals along the first polarity fine grid 12, or it can be arranged at non-equal intervals along the first polarity fine grid 12. No limitation is made here.

[0041] Specifically, the first pad 15 is located at the connection between the first polarity collection gate 14 and the first polarity fine gate 12; the second pad 16 is located at the second polarity fine gate 13. That is, the first pad 15 is connected to the connection between the first polarity collection gate 14 and the first polarity fine gate 12, and the second pad 16 is connected to the second polarity fine gate 13.

[0042] Furthermore, the first pad 15 can penetrate the dielectric film layer to contact the first polar doped layer. The first pad 15 and the first polar doped layer can also be isolated by the dielectric film layer. The first pad 15 can be fabricated together with the first polar collection gate 14 and the first polar fine gate 12. Alternatively, the first pad 15 can be fabricated separately from the first polar collection gate 14 and the first polar fine gate 12.

[0043] Furthermore, the second pad 16 can penetrate the dielectric film layer to contact the second polar doped layer. The second pad 16 and the second polar doped layer can also be isolated by the dielectric film layer. The second pad 16 can be fabricated together with the second polar fine gate 13. Alternatively, the second pad 16 and the second polar fine gate 13 can be fabricated separately.

[0044] Specifically, the length of the first pad 15 refers to the dimension of the first pad 15, which can be in the first direction or in the second direction. The length of the first pad 15 can be the same everywhere, different everywhere, or partially the same.

[0045] Furthermore, the length of the first pad 15 is 100μm-2000μm. For example, it can be 100μm, 101μm, 110μm, 150μm, 200μm, 500μm, 800μm, 1000μm, 1800μm, or 2000μm. In this way, the length direction of the first pad 15 is set to be the same as the length extension direction of the solder strip, thereby increasing the contact area between the first pad 15 and the solder strip, thus increasing the stability of the connection.

[0046] Specifically, the size and arrangement of the second pad 16 can be referenced to the first pad 15. It can be the same as the first pad 15 in every way, or different in every way, or partially the same. Further details will not be provided here.

[0047] Specifically, the first pad 15 may include a cutout portion. In this way, while ensuring the coverage area of ​​the first pad 15, the material consumption of the first pad 15 can be reduced, which is beneficial to improving connection stability while reducing manufacturing costs.

[0048] Specifically, the first pad 15 can also be solid. This maximizes the area of ​​the first pad 15. When the solder ribbon connects to the first pad 15, the contact area between the first pad 15 and the solder ribbon can be increased, increasing the tensile force, reducing the risk of the solder ribbon detaching from the back contact battery 10, and improving the connection stability between the back contact battery 10 and the solder ribbon.

[0049] It is understood that the explanation and description of the second pad 16 can be referred to the explanation and description of the first pad 15, and will not be repeated here to avoid redundancy.

[0050] Specifically, the distance between the first polarity collection gate 14 and the second polarity fine gate 13 in the second direction is the first distance d1, the distance between the first pad 15 and the second pad 16 in the second direction is the second distance d2, and the ratio of the second distance d2 to the first distance d1 is 1.125-18.

[0051] Thus, because the first polarity collection gate 14 is disposed between the first polarity fine gate 12 and the second polarity fine gate 13, the ratio of the second spacing d2 to the first spacing d1 is relatively large. Therefore, the first pad 15 and the second pad 16 are spaced relatively far apart in the second direction, which can reduce the risk of short circuits caused by pads of different polarities being too close together.

[0052] Furthermore, the ratio of the second spacing d2 to the first spacing d1 is 3-12. This minimizes the risk of short circuits caused by pads of different polarities being too close together.

[0053] Furthermore, in this embodiment, the ratio of the second spacing d2 to the first spacing d1 is 3. For example, d2 = 1.8 mm, d1 = 0.6 mm. The first polar fine grid 12, the second polar collecting grid 17, the first polar collecting grid 14, and the second polar fine grid 13 are equally spaced.

[0054] This results in a uniform distribution of grid lines on the battery surface and good collection performance. Simultaneously, the large spacing between the first pad 15 and the second pad 16 in the second direction reduces the risk of short circuits caused by pads of different polarities being too close together. In some other embodiments, the ratio of the second spacing d2 to the first spacing d1 can be other values. For example, d2 = 1.8 mm, d1 = 0.1 mm, and the ratio of d2 to d1 is 18. Or, d2 = 1.8 mm, d1 = 1.6 mm, and the ratio of d2 to d1 is 1.125. No limitation is imposed here.

[0055] Please see Figure 1 , Figure 2 In some embodiments, the first polar collection gate 14 includes a first collection portion 141 and a second collection portion 142. The first collection portion 141 extends along a first direction, and the second collection portion 142 bends from the first collection portion 141 and connects to the first polar fine gate 12. A first pad 15 is disposed at the connection between the second collection portion 142 and the first polar fine gate 12. The first spacing d1 is the spacing between the first collection portion 141 and the second polar fine gate 13 in a second direction. The first collection portion 141 is electrically connected to a first polar doped layer.

[0056] Thus, because a first collecting portion 141 is provided between the first polarity fine gate 12 and the second polarity fine gate 13, and a second collecting portion 142 bends from the first collecting portion 141 and connects to the first polarity fine gate 12, with the first pad 15 located at the connection between the second collecting portion 142 and the first polarity fine gate 12, the current collected by the second collecting portion 142 and the first polarity fine gate 12 can be better discharged. Simultaneously, because the ratio of the distance between the first pad 15 and the second pad 16 located on the second polarity fine gate 13 in the second direction to the distance between the first collecting portion 141 and the second polarity fine gate 13 in the second direction is relatively large, the distance between the first pad 15 and the second pad 16 in the second direction is larger, which reduces the risk of short circuits caused by pads of different polarities being too close together.

[0057] Specifically, the first collecting section 141 is electrically connected to the first polar doped layer. The second collecting section 142 can be directly electrically connected to the first polar doped layer, increasing the current extraction efficiency. The second collecting section 142 can also be connected to the first collecting section 141, and is separated from the second polar doped layer by a dielectric film layer, thus serving as a connection. No further limitations are specified here.

[0058] In this embodiment, both the first collecting section 141 and the second collecting section 142 are linear. The extending direction of the first collecting section 141, i.e., the first direction, is the length direction of the first polar fine grid and the second polar fine grid. The extending direction of the second collecting section 142, i.e., the second direction, is the length direction of the second collecting section 142, or the width direction of the first polar fine grid 12 and the second polar fine grid 13. In other embodiments, the first collecting section 141 and the second collecting section 142 may also be wavy, zigzag, or other shapes. No limitation is made here.

[0059] Please see Figure 1 , Figure 2 In some embodiments, a second polarity collection gate 17 is located between the first polarity fine gate 12 and the second polarity fine gate 13, and is connected to the second polarity fine gate 13; a second pad 16 is provided at the connection between the second polarity collection gate 17 and the second polarity fine gate 13; wherein, the distance between the second polarity collection gate 17 and the first polarity fine gate 12 in the second direction is a third distance d3, and the ratio of the second distance d2 to the third distance d3 is 1.125-18.

[0060] Thus, by providing a second polarity collection gate 17 between the first polarity fine gate 12 and the second polarity fine gate 13, and by placing the second pad 16 at the connection between the second polarity collection gate 17 and the second polarity fine gate 13, the current collected by the second collection section 142 and the second polarity fine gate 13 can be better discharged. Simultaneously, because the ratio of the distance between the second pad 16 and the first pad 15 on the first polarity fine gate 12 in the second direction to the distance between the second polarity collection gate 17 and the first polarity fine gate 12 in the second direction is relatively large, the distance between the first pad 15 and the second pad 16 in the second direction is larger, reducing the risk of short circuits caused by pads of different polarities being too close together.

[0061] Specifically, the second polarity collection gate 17 can be disposed opposite to the first polarity collection gate 14. This makes the grid line distribution on the surface of the back contact battery 100 more uniform, and the magnitude of the current collected and discharged by the first pad 15 and the second pad 16 is more uniform.

[0062] Furthermore, the second polarity collection gate 17 can be arranged alternately and parallel to the first polarity collection gate 14 between the first polarity fine gate 12 and the second polarity fine gate 13. In this way, the second polarity collection gate 17 and the first polarity collection gate 14 can be staggered and mutually avoid each other, and are distributed as evenly as possible between the first polarity fine gate 12 and the second polarity fine gate 13, so that the current collected and discharged by the first pad 15 and the second pad 16 is maximized.

[0063] It is understood that the range of the ratio between the second spacing d2 and the third spacing d3 can be set with reference to the range of the ratio between the second spacing d2 and the first spacing d1; the same explanation and effect will not be repeated here. In some other embodiments, the range of the ratio between the second spacing d2 and the third spacing d3 may not be set with reference to the ratio between the second spacing d2 and the first spacing d1. No limitation is made here.

[0064] Please see Figure 1 , Figure 2 In some embodiments, the second polarity collection gate 17 includes a third collection portion 171 and a fourth collection portion 172. The third collection portion 171 extends along a first direction, and the fourth collection portion 172 bends from the third collection portion 171 and connects to the second polarity fine gate 13. A second pad 16 is disposed at the connection between the fourth collection portion 172 and the second polarity fine gate 13. The third spacing d3 is the spacing between the third collection portion 171 and the first polarity fine gate 12 in a second direction. The third collection portion 171 is electrically connected to the second polarity doped layer.

[0065] Thus, by providing a third collecting section 171 between the first polarity fine gate 12 and the second polarity fine gate 13, and bending the fourth collecting section 172 from the third collecting section 171 to connect to the second polarity fine gate 13, and placing the second pad 16 at the connection between the fourth collecting section 172 and the second polarity fine gate 13, the current collected by the third collecting section 171 and the second polarity fine gate 13 can be better discharged. Simultaneously, because the ratio of the distance between the second pad 16 and the first pad 15 on the first polarity fine gate 12 in the second direction to the distance between the third collecting section 171 and the first polarity fine gate 12 in the second direction is relatively large, the distance between the first pad 15 and the second pad 16 in the second direction is relatively large, thus reducing the risk of short circuits caused by pads of different polarities being too close together.

[0066] Specifically, the third collection section 171 and the fourth collection section 172 can be arranged opposite to the first collection section 141 and the second collection section 142.

[0067] Furthermore, the bending direction of the second collecting section 142 from the first collecting section 141 is opposite to the bending direction of the fourth collecting section 172 from the third collecting section 171. The first collecting section 141 and the third collecting section 171 are arranged alternately. In this way, the first collecting section 141 and the third collecting section 171 are staggered and avoid each other, and are distributed as evenly as possible between the first polarity fine gate 12 and the second polarity fine gate 13, so that the current collected and discharged by the first pad 15 and the second pad 16 is most efficient.

[0068] Furthermore, the first polar fine gate 12, the third collection portion 171, the first collection portion 141, and the second polar fine gate 13 are arranged sequentially in a forward-facing interval. In this way, the arrangement of the first polar fine gate 12, the third collection portion 171, the first collection portion 141, and the second polar fine gate 13 is the same as the arrangement of the first polar doped layer and the second polar doped layer on the silicon substrate, and the connection method is simple and reliable.

[0069] Furthermore, the first polar fine gate 12, the third collecting section 171, the first collecting section 141, and the second polar fine gate 13 are arranged in a reverse-spaced manner. That is, the second polar fine gate 13, the first collecting section 141, the third collecting section 171, and the first polar fine gate 12 are arranged in a reverse-spaced manner. The reverse-spaced arrangement can be referred to as the forward-spaced arrangement, and the relevant explanations and effects will not be repeated.

[0070] This ensures that the fine grid and collecting sections are evenly distributed on the battery surface, thereby improving the rationality of the grid line layout on the battery surface and maximizing the efficiency of current collection and discharge. In some other embodiments, the third collecting section 171 and the fourth collecting section 172 may not be disposed opposite to the first collecting section 141 and the second collecting section 142, which is not limited here.

[0071] Furthermore, in this embodiment, both the third collecting section 171 and the fourth collecting section 172 are linear. The extending direction of the third collecting section 171, i.e., the first direction, is also the length direction of the first polar fine grid 12 and the second polar fine grid 13. The extending direction of the fourth collecting section 172, i.e., the second direction, is also the length direction of the second collecting section 142, or the width direction of the first polar fine grid 12 and the second polar fine grid 13. In other embodiments, the first collecting section 141 and the second collecting section 142 may also be wavy, zigzag, or other shapes. No limitation is made here.

[0072] Specifically, in some embodiments, the first collecting section 141 may include multiple spaced first collecting grids, which are connected to the first polarity grid 12 via the second collecting section 142. The third collecting section 171 may also include multiple spaced second collecting grids, which are connected to the second polarity grid 13 via the fourth collecting section 172. The first and second collecting grids are arranged alternately. In this case, the first spacing d1 is the distance between the first collecting grid closest to the second polarity grid 13 in the first collecting section 141 and the second polarity grid 13 in the second direction, and the third spacing d3 is the distance between the second collecting grid closest to the first polarity grid 12 in the third collecting section 171 and the first polarity grid 12 in the second direction.

[0073] In this way, while increasing the current collection area, the ratio of the distance between the second pad 16 and the first pad 15 located on the first polarity fine gate 12 in the second direction to the distance between the third collection portion 171 and the first polarity fine gate 12 in the second direction is further increased. This further increases the distance between the first pad 15 and the second pad 16 in the second direction, thereby reducing the risk of short circuits caused by pads of different polarities being too close together.

[0074] Specifically, the number of the first collecting grids can be 1, 2, 3, 4, or other numbers. The number of the second collecting grids can also be 1, 2, 3, 4, or other numbers. No limitation is made here. The number of the first collecting grids can be the same as or different from the number of the second collecting grids.

[0075] Specifically, in this embodiment, both the first and second collecting grids are straight lines, and the extending direction of the first and second collecting grids, i.e., the first direction, is the length direction of the first and second collecting grids. In other embodiments, the first collecting grid may also be wavy, zigzag, or other shapes. The second collecting grid may also be wavy, zigzag, or other shapes. No limitation is made here.

[0076] Specifically, the lengths of the first and second collecting grids can be the same or different. They can be partially the same or partially different. They can be completely the same or completely different. No limitation is made here.

[0077] Please see Figure 2 In some embodiments, the first spacing d1 is 0.1mm-1.6mm.

[0078] This ensures that the spacing between the first polarity collecting grid 14 and the second polarity fine grid 13 in the second direction is within a suitable range. This reduces the risk of short circuits caused by easy contact between grid lines of different polarities due to an excessively small first spacing d1, and also reduces the deterioration of the current conduction effect from the battery due to an excessively large first spacing d1.

[0079] Furthermore, the first spacing d1 can be 0.1mm-0.6mm. This further ensures that the spacing between the first polarity collecting grid 14 and the second polarity fine grid 13 in the second direction is within a favorable range, thus reducing the risk of short circuits caused by contact between grid lines of different polarities. Simultaneously, it ensures better current extraction from the battery.

[0080] Specifically, the first spacing d1 can be 0.6mm. In this way, the risk of short circuits caused by grid lines of different polarities coming into contact is minimized, while the current is discharged from the battery most effectively.

[0081] It is understood that the setting of the third spacing d3 can be the same as that of the first spacing d1. Therefore, its specific explanation and effect will not be elaborated further. In some other embodiments, the setting of the third spacing d3 may also be different from that of the first spacing d1. This is not limited here.

[0082] Please see Figure 2 In some embodiments, the second spacing d2 is 0.3mm-1.8mm. That is, the spacing between the first pad 15 and the second pad 16 in the second direction is 0.3mm-1.8mm.

[0083] Thus, the spacing between the first pad 15 and the second pad 16 in the second direction is relatively large, which can reduce the risk of short circuits caused by pads of different polarities being too close together.

[0084] Furthermore, the second spacing d2 can be 1.2mm-1.8mm.

[0085] Thus, the spacing between the first pad 15 and the second pad 16 in the second direction is within an optimal range, which can further reduce the risk of short circuits caused by pads of different polarities being too close together.

[0086] Specifically, the second spacing d2 can be 1.8mm. In this case, the first spacing d1 is 0.6mm, and the third spacing d3 is 0.6mm. This minimizes the risk of short circuits caused by pads of different polarities being too close together, and ensures uniform gate line distribution and optimal current conduction.

[0087] Please see Figure 1 , Figure 2 In some embodiments, the spacing between the first pad 15 and the second pad 16 in the first direction is 1.5mm-6mm.

[0088] This ensures that the spacing between different solder strips connected to the pads is within an appropriate range, avoiding the risk of short circuits or breakdowns caused by excessively narrow spacing. Simultaneously, it avoids the waste of materials in the production of composite solder strips 200 and the risk of short circuits caused by excessively wide spacing when the back contact battery 100 is connected using composite solder strips 200, as well as the risk of short circuits due to excessively close distance between the composite solder strips and the battery's grid lines.

[0089] Specifically, the spacing between the first pad 15 and the second pad 16 in the first direction can be 3mm-4.5mm. This reduces the risk of short circuits or breakdowns caused by solder strips of different polarities.

[0090] Specifically, in this embodiment, the distance between the first pad 15 and the second pad 16 in the first direction is 3mm. This reduces the risk of short circuits or breakdowns between solder strips of different polarities, while also taking into account the performance of the corresponding composite solder strip 200 and the amount of material used.

[0091] Please see Figure 3 The battery assembly 1000 in this application embodiment includes the back contact battery 100 described above.

[0092] In this embodiment, multiple back-contact batteries 100 in the battery assembly can be connected in series to form a battery string, thereby realizing the series current charging output. For example, the back-contact batteries can be connected in series by setting solder strips (busbars, interconnecting strips), conductive back plates, etc.

[0093] 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 of the solar cells, the photovoltaic glass, adjacent back contact 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.

[0094] Photovoltaic glass can be applied to the encapsulating film on the front of solar cells. This photovoltaic glass can be ultra-clear glass, characterized by 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 solar cells while minimizing impact on their efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cells together, providing sealing, insulation, and waterproofing / moisture protection for the solar cells.

[0095] The backsheet can be attached to the encapsulating film on the back of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc., depending on the specific circumstances and not limited here. The backsheet, solar cell, encapsulating 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.

[0096] Please see Figure 3 The battery assembly 1000 of this application embodiment includes a composite solder ribbon 200, which includes a first solder ribbon 21, an insulating ribbon 22, and a second solder ribbon 23. The first solder ribbon 21, the insulating ribbon 22, and the second solder ribbon 23 are sequentially connected in contact along a first direction and extend along a second direction. The first solder ribbon 21 of the composite solder ribbon 200 is connected to a first solder pad 15, and the second solder ribbon 23 of the composite solder ribbon 200 is connected to a second solder pad 16.

[0097] Thus, by integrating the first solder strip 21 and the second solder strip 23 together through the insulating strip 22, the frequency of solder strip arrangement can be reduced, thereby simplifying the connection steps between the composite solder strip 200 and the back contact battery 100.

[0098] Specifically, the spacing between the first solder ribbon 21 and the second solder ribbon 23 corresponds to the spacing between the first solder pad 15 and the second solder pad 16 in the first direction. Simultaneously, the contact areas of the first solder ribbon 21 and the second solder ribbon 23 with the back contact battery 100 correspond to the first solder pad 15 and the second solder pad 16. Thus, the composite solder ribbon 200 is adapted to the back contact battery 100, and the composite solder ribbon 200 is securely connected to the back contact battery 100.

[0099] Furthermore, the dimensions of the first pad 15 and the second pad 16 in the first direction are smaller than their dimensions in the second direction. That is, the first pad 15 and the second pad 16 are rectangular, and their length direction is arranged along the second direction. In this way, the contact area between the first pad 15 and the second pad 16 and the first solder strip 21 and the second solder strip 23 is larger, and the connection between the composite solder strip 200 and the back contact battery 100 is more stable.

[0100] Other beneficial effects of the battery assembly 1000 in this embodiment are equivalent to the beneficial effects of the back contact battery 100 described above, and will not be repeated here.

[0101] The beneficial effects of the battery assembly in this embodiment are equivalent to those of the battery assembly 1000 described above, and will not be repeated here.

[0102] The photovoltaic system of this application embodiment includes the battery module described above.

[0103] 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.

[0104] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0105] In the description of this specification, the 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 this application. 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.

[0106] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A back-contact battery, characterized in that, include: Silicon substrate; A plurality of first polarity fine gates and a plurality of second polarity fine gates are disposed on the silicon substrate, extending along a first direction and arranged along a second direction; A plurality of first polarity collecting gates are located between the first polarity fine gate and the second polarity fine gate, and are connected to the first polarity fine gate; The first pad is located at the connection between the first polar collection gate and the first polar fine gate; The second pad is located on the second polarity fine gate; Wherein, the distance between the first polar collection gate and the second polar fine gate in the second direction is the first distance, the distance between the first pad and the second pad in the second direction is the second distance, and the ratio of the second distance to the first distance is 1.125-18.

2. The back contact battery according to claim 1, characterized in that, The first polarity collection gate includes a first collection portion and a second collection portion. The first collection portion extends along a first direction, and the second collection portion bends from the first collection portion and connects to the first polarity fine gate. The first pad is disposed at the connection between the second collection portion and the first polarity fine gate. The first spacing is the spacing between the first collection portion and the second polarity fine gate in the second direction.

3. The back contact battery according to claim 1, characterized in that, The back contact battery includes a second polarity collection grid, which is located between the first polarity fine grid and the second polarity fine grid, and is connected to the second polarity fine grid; the second pad is disposed at the connection between the second polarity collection grid and the second polarity fine grid. The distance between the second polar collection gate and the first polar fine gate in the second direction is the third distance, and the ratio of the second distance to the third distance is 1.125-18.

4. The back contact battery according to claim 3, characterized in that, The second polarity collection gate includes a third collection portion and a fourth collection portion. The third collection portion extends along a first direction, and the fourth collection portion bends from the third collection portion and connects to the second polarity fine gate. The second pad is disposed at the connection between the fourth collection portion and the second polarity fine gate. The third spacing is the spacing between the third collection portion and the first polarity fine gate in the second direction.

5. The back contact battery according to claim 1, characterized in that, The first spacing is 0.1mm-1.6mm.

6. The back contact battery according to claim 1, characterized in that, The second spacing is 0.3mm-1.8mm.

7. The back contact battery according to claim 1, characterized in that, The distance between the first pad and the second pad in the first direction is 1.5mm-6mm.

8. A battery assembly, characterized in that, Includes the back contact battery as described in any one of claims 1-7.

9. The battery assembly according to claim 8, characterized in that, The battery assembly includes a composite solder strip, which includes a first solder strip, an insulating strip, and a second solder strip. The first solder strip, the insulating strip, and the second solder strip are sequentially connected in contact along a first direction and extend along a second direction. The first solder strip of the composite solder strip is connected to the first pad of the back contact battery, and the second solder strip of the composite solder strip is connected to the second pad of the back contact battery.

10. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 9.

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