Back contact cell, assembly, and system

Abstract

The present disclosure provides a back contact cell, a cell module, and a photovoltaic system. In a first edge busbar, a second connection grid line extends in a second direction, and the extension direction of a first connection grid line is different from the second direction. In a second edge busbar, a fourth connection grid line extends in the second direction, and the extension direction of a third connection grid line is different from the extension direction of the fourth connection grid line.

Description

Back contact batteries, components and systems

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202510096025.4, filed on January 21, 2025, entitled “Back Contact Battery, Battery Module and Photovoltaic System”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of solar cell technology, and more particularly to a back-contact cell, a cell module, and a photovoltaic system. Background Technology

[0004] Currently, solar cells consist of a positive grid and a negative grid. After the grid lines are printed, it is necessary to distinguish their polarity. However, the positive and negative grids are difficult to differentiate, making it impossible to confirm whether they are printed in reverse on the silicon substrate. Therefore, how to distinguish the positive and negative grids of a solar cell has become a pressing technical problem that needs to be solved. Summary of the Invention

[0005] This disclosure provides a back-contact battery, a battery module, and a photovoltaic system, aiming to solve the technical problem in the prior art that it is difficult to distinguish between the positive and negative main grids of a solar cell.

[0006] This disclosure provides a back contact battery, including: a silicon substrate, a first edge main gate and a second edge main gate, wherein the first edge main gate and the second edge main gate have different characteristics;

[0007] The silicon substrate has a first edge and a second edge opposite each other in a first direction, the first edge main gate is the main gate closest to the first edge, and the second edge main gate is the main gate closest to the second edge;

[0008] The first edge main grid includes a first connecting grid line and a second connecting grid line that are interconnected. The second connecting grid line extends along a second direction. The extension direction of the first connecting grid line is different from the second direction. The second direction intersects the first direction.

[0009] The second edge main grid includes a third connecting grid line and a fourth connecting grid line that are connected to each other. The fourth connecting grid line extends along the second direction, and the extension directions of the third connecting grid line and the fourth connecting grid line are different.

[0010] The first connecting grid line and the third connecting grid line have different shapes.

[0011] In some embodiments, the first connecting gate line includes a first gate line segment, which is a gate line segment extending along a third direction, and the third direction is different from the extension direction of the first connecting gate line.

[0012] In some embodiments, the third connecting gate line includes a second gate line segment; the second gate line segment is a gate line segment extending in a fourth direction, the fourth direction being the same as the extension direction of the third connecting gate line.

[0013] In some embodiments, in the extending direction of the first connecting gate line, the first connecting gate line has a first end and a second end;

[0014] The first end of the first connecting gate line is connected to the end of the second connecting gate line, and the first gate line segment is located at the second end of the first connecting gate line.

[0015] In some embodiments, the third connecting gate line has a first end and a second end in the extending direction of the third connecting gate line;

[0016] The first end of the third connecting gate line is connected to the end of the fourth connecting gate line, and the second gate line segment is located at the second end of the third connecting gate line.

[0017] In some embodiments, the silicon substrate further includes a first chamfer, the first chamfer being connected to the end of the first edge;

[0018] The distance between the first connecting grid line and the first chamfer is less than the distance between the second connecting grid line and the first chamfer.

[0019] In some embodiments, the silicon substrate further includes a second chamfer, which is connected to the end of the second edge;

[0020] The distance between the third connecting grid line and the second chamfer is less than the distance between the fourth connecting grid line and the second chamfer.

[0021] In some embodiments, the distance between the first connecting gate line and the first chamfer is 500μm to 800μm.

[0022] In some embodiments, the distance between the second connecting gate line and the first edge is 250 μm to 500 μm.

[0023] In some embodiments, the distance between the third connecting gate line and the second chamfer is 500 μm to 800 μm.

[0024] In some embodiments, the distance between the fourth connecting gate line and the second edge is 250 μm to 500 μm.

[0025] In some embodiments, the silicon substrate has a third edge in the second direction;

[0026] In the second direction, the distance from the end of the first edge main grid near the third edge to the third edge is the first distance;

[0027] In the second edge main grid, at the end closest to the third edge in the second direction, the distance of the third edge is the second distance;

[0028] The first distance is greater than the second distance.

[0029] In some embodiments, the silicon substrate further includes a first internal main gate and a second internal main gate with different polarities; both the first internal main gate and the second internal main gate are located between the first edge main gate and the second edge main gate;

[0030] The distance from the end of the first internal main gate near the third edge in the second direction to the third edge is the third distance, and the distance from the end of the second internal main gate near the third edge in the second direction to the third edge is the fourth distance;

[0031] The third distance is greater than the fourth distance.

[0032] This disclosure also provides a battery assembly, which includes the back contact battery of any of the above.

[0033] This disclosure also provides a photovoltaic system, which includes the aforementioned battery module.

[0034] The back contact battery, battery module, and photovoltaic system provided in this disclosure, by setting the first connecting grid line and the second connecting grid line to different shapes, can distinguish the polarity of the first edge main grid and the second edge main grid by shape. This allows for timely confirmation of whether there is a printing reverse problem after the grid line printing is completed, and can also distinguish the polarity of the first edge main grid and the second edge main grid during module welding, thereby reducing the probability of errors in module welding and improving product yield.

[0035] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0036] Figure 1 is a schematic diagram of the structure of the back contact battery provided in an embodiment of this disclosure;

[0037] Figure 2 is a schematic diagram of the structure of the battery assembly provided in an embodiment of this disclosure;

[0038] Figure 3 is a schematic diagram of the structure of the photovoltaic system provided in an embodiment of this disclosure.

[0039] The above figures include the following reference numerals: 10, silicon substrate; 20, first edge main grid; 30, second edge main grid; 40, first internal main grid; 50, second internal main grid; 100, back contact cell; 101, first edge; 102, second edge; 103, first chamfer; 104, second chamfer; 105, third edge; 200, cell module; 201, first connecting grid line; 202, second connecting grid line; 300, photovoltaic system; 301, third connecting grid line; 302, fourth connecting grid line; 2001, first grid line segment. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of 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 disclosure, and should not be construed as limiting this disclosure. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this disclosure and are not intended to limit this disclosure.

[0041] In the description of this disclosure, it should be understood that the terms "upper", "lower", "back", "front", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and 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 disclosure.

[0042] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0044] Figure 1 is a schematic diagram of the structure of a back contact battery provided in an embodiment of this disclosure. As shown in Figure 1, this disclosure provides a back contact battery, including: a silicon substrate 10, a first edge main gate 20, and a second edge main gate 30, wherein the first edge main gate 20 and the second edge main gate 30 have different polarities;

[0045] The silicon substrate 10 has a first edge 101 and a second edge 102 opposite to each other in a first direction. The first edge main gate 20 is the main gate closest to the first edge 101, and the second edge main gate 30 is the main gate closest to the second edge 102.

[0046] The first edge main grid 20 includes a first connecting grid line 201 and a second connecting grid line 202 that are connected to each other. The second connecting grid line 202 extends along a second direction. The extension direction of the first connecting grid line 201 is different from the second direction. The second direction intersects the first direction.

[0047] The second edge main gate 30 includes a third connecting gate line 301 and a fourth connecting gate line 302 that are connected to each other. The fourth connecting gate line 302 extends along the second direction. The extension directions of the third connecting gate line 301 and the fourth connecting gate line 302 are different.

[0048] The first connecting gate line 201 and the third connecting gate line 301 have different shapes.

[0049] In this embodiment, the back contact battery can be a back contact battery with a main grid. The back contact battery includes a silicon substrate 10. The silicon substrate 10 can be a single cell, or it can be a half-cell, a third-cell, or other proportioned cell divided from a single cell. It should be noted that the accompanying drawings provided in this disclosure are schematic diagrams and do not represent a limitation on the specific form of the back contact battery.

[0050] Furthermore, the silicon substrate 10 may include a front side and a back side, with the front side facing the sun and mainly receiving direct sunlight, and the back side facing the mounting surface of the photovoltaic module and mainly receiving sunlight reflected by the mounting surface, such as the ground or roof.

[0051] Several fine gates and several main gates are disposed on the back side of the silicon substrate 10. Furthermore, a stacked doped layer and a passivation layer are disposed on the back side of the silicon substrate 10. The doped layer can be connected to the fine gates to establish ohmic contacts. The fine gates are mainly used to collect the current generated by the back contact cell. When sunlight shines on the back contact cell, photons are absorbed and electrons are excited; these electrons are captured and transported by the fine gates. The main gates are responsible for collecting the current on the fine gates and transmitting it to the output terminal of the cell.

[0052] A plurality of main gates extend along a second direction and are spaced apart along a first direction, and a plurality of fine gates extend along the first direction and are spaced apart along the second direction. The first direction can be the horizontal direction in Figure 1, and the second direction can be the vertical direction in Figure 1. Of course, in other embodiments, the first and second directions can also be other directions, such as diagonal directions, etc., which are not specifically limited here.

[0053] The silicon substrate 10 has a first edge 101 and a second edge 102 opposite to each other in a first direction. Among a plurality of main gates spaced apart along the first direction, the first edge main gate 20 is the main gate closest to the first edge, and the second edge main gate 30 is the main gate closest to the second edge 102.

[0054] The first edge main gate 20 includes a first connecting gate line 201 and a second connecting gate line 202 connected to the first connecting gate line 201.

[0055] The connection method of the first connecting gate line 201 and the second connecting gate line 202 may include any of the following: the end of the first connecting gate line 201 is connected to the end of the second connecting gate line 202; the end of the first connecting gate line 201 is connected to any point on the second connecting gate line 202; or any point on the first connecting gate line 201 is connected to the end of the second connecting gate line 202.

[0056] It should be noted that the end of the first connecting gate line 201 refers to either of the two ends of the first connecting gate line 201 in the extension direction of the first connecting gate line 201; the end of the second connecting gate line 202 refers to either of the two ends of the second connecting gate line 202 in the extension direction of the second connecting gate line 202.

[0057] The second connecting gate line 202 extends along the second direction, and optionally, the second connecting gate line 202 is arranged parallel to the first edge 101. The extending direction of the first connecting gate line 201 intersects the second direction.

[0058] The second edge main gate 30 includes a third connecting gate line 301 and a fourth connecting gate line 302 connected to the third connecting gate line 301.

[0059] The connection method of the third connecting gate line 301 and the fourth connecting gate line 302 may include any of the following: the end of the third connecting gate line 301 is connected to the end of the fourth connecting gate line 302; the end of the third connecting gate line 301 is connected to any point on the fourth connecting gate line 302; or any point on the third connecting gate line 301 is connected to the end of the fourth connecting gate line 302.

[0060] It should be noted that the end of the third connecting gate line 301 refers to either of the two ends of the third connecting gate line 301 in the extension direction of the third connecting gate line 301; the end of the fourth connecting gate line 302 refers to either of the two ends of the fourth connecting gate line 302 in the extension direction of the fourth connecting gate line 302.

[0061] The fourth connecting gate line 302 extends along the second direction, and optionally, the fourth connecting gate line 302 is arranged parallel to the second edge 102. The extension direction of the third connecting gate line 301 intersects the second direction.

[0062] In this embodiment of the disclosure, different polarities are indicated by giving the first connecting gate line 201 and the third connecting gate line 301 different shapes. The different shapes can be due to differences in the shape, thickness, length, extension direction, or extension angle of the gate lines.

[0063] For example, if the third connecting gate line 301 is curved or broken, the second edge main gate 30 can be identified as the positive main gate; if the first connecting gate line 201 is straight, the first edge main gate 20 can be identified as the negative main gate.

[0064] The third connecting gate line 301 is circular, which determines that the second edge main gate 30 is the positive main gate; the first connecting gate line 201 is triangular, which determines that the first edge main gate 20 is the negative main gate.

[0065] The third connecting gate line 301 is Y-shaped, which determines that the second edge main gate 30 is the positive main gate; the first connecting gate line 201 is parabolic, which determines that the first edge main gate 20 is the negative main gate.

[0066] The linewidth of the third connecting gate line 301 is twice that of the first connecting gate line 201, which determines that the second edge main gate 30 is the positive main gate and the first edge main gate 20 is the negative main gate.

[0067] The length of the third connecting gate line 301 is longer than the length of the first connecting gate line 201, which determines that the second edge main gate 30 is the positive main gate and the first edge main gate 20 is the negative main gate.

[0068] It should be noted that the above shapes and polarities can have a one-to-one correspondence. In cases where the shapes of either the first connecting gate line 201 or the third connecting gate line 301 are difficult to distinguish, the polarity of the corresponding edge main gate can be determined by the distinguishable shape of the other gate line. Since the polarities of the first edge main gate 20 and the second edge main gate 30 are opposite, determining the polarity of one edge main gate will automatically determine the polarity of the other.

[0069] The back contact battery provided in this embodiment sets the first connecting grid line and the second connecting grid line to different shapes, thereby distinguishing the polarity of the first edge main grid and the second edge main grid by shape. This allows for timely confirmation of whether there is a printing reverse problem after the grid line printing is completed, and also allows for differentiation of the polarity of the first edge main grid and the second edge main grid during component welding, reducing the probability of errors in component welding and thus improving product yield.

[0070] In some embodiments, the first connecting gate line 201 includes a first gate line segment 2001, which is a gate line segment extending along a third direction, and the third direction is different from the extension direction of the first connecting gate line 201.

[0071] In actual implementation, the first connecting gate line 201 includes a first gate line segment 2001 for indicating polarity and extending along a third direction. The first gate line segment 2001 is located on the first connecting gate line 201, and the third direction is different from the extension direction of the first connecting gate line 201. The third direction may be the same as or different from the second direction.

[0072] The different extension directions refer to the different angles or curvatures of the first grid line segment relative to the first connecting grid line 201.

[0073] Optionally, the first gate segment 2001 may be located at one end in the extension direction of the first connecting gate line 201, or it may be located between the two ends of the first connecting gate line 201, without specific limitation.

[0074] The back contact battery provided in this embodiment facilitates the identification of the main gate polarity by setting a first gate segment for polarity differentiation on the first connecting gate line, thereby improving the identifiability of the polarity of the first edge main gate. Furthermore, the extension direction of the first gate segment is different from that of the first connecting gate line, which allows for a more intuitive determination of the main gate polarity and facilitates the rapid acquisition of effective information for polarity differentiation.

[0075] In some embodiments, the third connecting gate line 301 includes a second gate line segment; the second gate line segment is a gate line segment extending in a fourth direction, the fourth direction being the same as the extending direction of the third connecting gate line 301.

[0076] In actual implementation, the third connecting gate line 301 includes a second gate line segment for indicating polarity and extending along a fourth direction. The second gate line segment is located within the third connecting gate line 301, and the fourth direction is the same as the extension direction of the third connecting gate line 301, but different from the second direction.

[0077] The same extension direction means that the angle between the second grid line segment and the third connecting grid line 301 is 0 degrees or the curvature is the same.

[0078] Optionally, the second gate segment may be located at one end in the extension direction of the third connecting gate line 301, or it may be located between the two ends of the third connecting gate line 301, without specific limitation.

[0079] The back contact battery provided in this embodiment facilitates the identification of the polarity of the main gate by providing a second gate segment for polarity differentiation on the third connecting gate line, thereby improving the identifiability of the polarity of the second edge main gate and reducing the risk of the main gate polarity being indistinguishable when the shape of the first gate segment is not identifiable.

[0080] In some embodiments, in the extending direction of the first connecting gate line 201, the first connecting gate line 201 has a first end and a second end;

[0081] The first end of the first connecting gate line 201 is connected to the end of the second connecting gate line 202, and the first gate line segment 2001 is located at the second end of the first connecting gate line 201.

[0082] In actual implementation, in the extension direction of the first connecting grid line 201, the first end of the first connecting grid line 201 is connected to the end of the second connecting grid line 202 in the second direction. The second end of the first connecting grid line 201 is provided with a first grid line segment 2001 extending in the third direction, so it can be seen that the first connecting grid line 201 has a bend or twist at the end.

[0083] The back contact battery provided in this embodiment allows for more visual observation of the first grid line segment by setting it at the end of the first connecting grid line, which is more conducive to the identification of the main grid.

[0084] In some embodiments, the third connecting gate line 301 has a first end and a second end in the extending direction of the third connecting gate line 301;

[0085] The first end of the third connecting gate line 301 is connected to the end of the fourth connecting gate line 302, and the second gate line segment is located at the second end of the third connecting gate line 301.

[0086] In actual implementation, in the extension direction of the third connecting grid line 301, the first end of the third connecting grid line 301 is connected to the end of the fourth connecting grid line 302 in the second direction. The second end of the third connecting grid line 301 is provided with a second grid line segment extending in the fourth direction, so it can be seen that the third connecting grid line 301 does not have any bends or turns at the end, but is straight.

[0087] The back contact battery provided in this embodiment allows the second grid line segment to be more clearly observed visually by placing it at the end of the third connecting grid line, which is more conducive to the identification of the main grid.

[0088] In some embodiments, the silicon substrate 10 further includes a first chamfer 103, which is connected to the end of the first edge 101;

[0089] The distance between the first connecting grid line 201 and the first chamfer 103 is greater than the distance between the second connecting grid line 202 and the first chamfer 103.

[0090] In actual implementation, a first chamfer 103 is provided at the connection between the first edge 101 and its adjacent edge in the silicon substrate 10. The ends of the first connecting gate line 201 and the second connecting gate line 202 are connected, and the second connecting gate line 202 extends along a second direction. The extension directions of the first connecting gate line 201 and the second connecting gate line 202 are different.

[0091] The distance between the first connecting grid line 201 and the first chamfer 103 refers to the distance from any point on the first connecting grid line 201 to any point on the first chamfer 103, and the distance between the second connecting grid line 202 and the first chamfer 103 refers to the distance from any point on the second connecting grid line 202 to any point on the first chamfer 103.

[0092] The second connecting gate line 202 extends close to the first edge 101, and the first connecting gate line 201 extends close to the first chamfer 103. Therefore, the distance between the first connecting gate line 201 and the first chamfer 103 is less than the distance between the second connecting gate line 202 and the first chamfer 103. Thus, the distance between the first connecting gate line 201 and the first edge 101 is greater than the distance between the second connecting gate line 202 and the first edge 101.

[0093] Understandably, there is more space at the first chamfer, so the first grid line segment of the first connecting grid line 201 can maintain a sufficient distance from the first chamfer.

[0094] The back contact battery provided in this embodiment provides sufficient spacing for the placement of the first grid line segment by setting the first grid line closer to the first chamfer relative to the distance between the second grid line and the first chamfer, thereby ensuring battery reliability.

[0095] In some embodiments, the silicon substrate 10 further includes a second chamfer 104, which is connected to the end of the second edge 102;

[0096] The distance between the third connecting grid line 301 and the second chamfer 104 is greater than the distance between the fourth connecting grid line 302 and the second chamfer 104.

[0097] In actual implementation, a second chamfer 104 is provided at the connection between the second edge 102 and its adjacent edge in the silicon substrate 10. The ends of the third connecting gate line 301 and the fourth connecting gate line 302 are connected, the fourth connecting gate line 302 extends along the second direction, and the third connecting gate line 301 and the fourth connecting gate line 302 extend in the same direction.

[0098] The distance between the third connecting grid line 301 and the second chamfer 104 refers to the distance from any point on the third connecting grid line 301 to any point on the second chamfer 104, and the distance between the fourth connecting grid line 302 and the second chamfer 104 refers to the distance from any point on the fourth connecting grid line 302 to any point on the second chamfer 104.

[0099] The fourth connecting grid line 302 extends close to the second edge 102, and the third connecting grid line 301 extends close to the second chamfer 104. Therefore, the distance between the third connecting grid line 301 and the second chamfer 104 is less than the distance between the second connecting grid line 202 and the second chamfer 104. Thus, the distance between the third connecting grid line 301 and the second edge 102 is greater than the distance between the second connecting grid line 202 and the second edge 102.

[0100] The back contact battery provided in this embodiment, by placing the third connecting grid line closer to the second chamfer relative to the distance between the fourth connecting grid line and the second chamfer, can provide sufficient spacing for the placement of the second grid line segment, thereby ensuring that the battery reliability is not affected.

[0101] Optionally, the distance between the first connecting gate line 201 and the first chamfer 103 is 500μm to 800μm.

[0102] In actual implementation, the distance between the first connecting grid line 201 and the first chamfer 103 can be, for example, 500μm, 600μm, 700μm or 800μm, or it can be in the range of 500μm to 800μm, and no specific limitation is made here.

[0103] The back contact battery provided in this embodiment provides space for setting the first grid line segment by setting the distance between the first connecting grid line and the first chamfer between 500μm and 800μm, while ensuring that the battery reliability is not affected.

[0104] Optionally, the distance between the second connecting gate line 202 and the first edge 101 is 250μm to 500μm.

[0105] In actual implementation, the distance between the second connecting gate line 202 and the first edge 101 can be, for example, 250μm, 275μm, 300μm, 400μm, 465μm or 500μm, or it can be in the range of 250μm to 500μm, and no specific limitation is made here.

[0106] The back contact battery provided in this embodiment of the present disclosure can ensure that the second connecting grid line and the first edge maintain a safe distance by setting the distance between the second connecting grid line and the first edge between 250μm and 500μm, thereby improving battery reliability.

[0107] Optionally, the distance between the third connecting gate line 301 and the second chamfer 104 is 500μm to 800μm.

[0108] In actual implementation, the distance between the third connecting grid line 301 and the second chamfer 104 can be, for example, 500μm, 600μm, 700μm or 800μm, or it can be in the range of 500μm to 800μm, and no specific limitation is made here.

[0109] The back contact battery provided in this embodiment provides space for the second grid line segment by setting the distance between the third connecting grid line and the second chamfer between 500μm and 800μm, while ensuring that the battery reliability is not affected.

[0110] Optionally, the distance between the fourth connecting gate line 302 and the second edge 102 is 250μm to 500μm.

[0111] In actual implementation, the distance between the fourth connecting gate line 302 and the second edge 102 can be, for example, 250μm, 275μm, 300μm, 400μm, 465μm or 500μm, or it can be in the range of 250μm to 500μm, and no specific limitation is made here.

[0112] The back contact battery provided in this embodiment of the present disclosure can ensure that the fourth connecting grid line and the first edge maintain a safe distance by setting the distance between the fourth connecting grid line and the second edge between 250μm and 500μm, thereby improving battery reliability.

[0113] In some embodiments, the silicon substrate 10 has a third edge 105 in a second direction;

[0114] In the second direction, the distance from the end of the first edge main gate 20 near the third edge 105 to the third edge 105 is the first distance;

[0115] In the second edge main gate 30, at one end in the second direction, the distance from the third edge 105 to the end of the third edge 105 is the second distance;

[0116] The first distance is greater than the second distance.

[0117] It is understandable that the polarity of the first edge main gate 20 and the second edge main gate 30 can also be distinguished by their distance from the edge. For example, if the first distance from the end of the first edge main gate 20 near the third edge 105 to the third edge 105 is greater than the second distance from the end of the second edge main gate 30 near the third edge 105 to the third edge 105, then the first edge main gate 20 is the negative electrode main gate, and the second edge main gate 30 is the positive electrode main gate.

[0118] The back contact battery provided in this embodiment can also identify the polarity of the edge main gate by comparing the distance from one end of the first edge main gate and one end of the second edge main gate to the third edge, further improving the prominence and easy identification of the edge main gate polarity.

[0119] In some embodiments, the silicon substrate 10 further includes a first internal main gate 40 and a second internal main gate 50 with different polarities; the first internal main gate 40 and the second internal main gate 50 are both located between the first edge main gate 20 and the second edge main gate 30.

[0120] The distance from the end of the first internal main gate 40 near the third edge 105 in the second direction to the third edge 105 is the third distance, and the distance from the end of the second internal main gate 50 near the third edge 105 in the second direction to the third edge 105 is the fourth distance.

[0121] The third distance is greater than the fourth distance.

[0122] It is understood that the first internal main gate 40 and the second internal main gate 50 are arranged alternately along the first direction, and the polarity of the first internal main gate 40 and the second internal main gate 50 can also be distinguished by their distance from the edge.

[0123] For example, if the third distance from the end of the first internal main gate 40 near the third edge 105 to the third edge 105 is greater than the fourth distance from the end of the second internal main gate 50 near the third edge 105 to the third edge 105, then the first internal main gate 40 is the negative main gate and the second internal main gate 50 is the positive main gate.

[0124] Therefore, in this embodiment of the disclosure, the first internal main gate 40 and the first edge main gate 20 have the same polarity, and the second internal main gate 50 and the second edge main gate 30 have the same polarity.

[0125] The back contact battery provided in this embodiment can also identify the polarity of the internal main gate by comparing the distance from one end of the first internal main gate and one end of the second internal main gate to the third edge, further improving the prominence and easy identification of the internal main gate polarity.

[0126] Figure 2 is a schematic diagram of the structure of a battery assembly provided in an embodiment of this disclosure. As shown in Figure 2, the battery assembly 200 of this embodiment includes the back contact battery 100 in any of the above embodiments.

[0127] The battery assembly of this disclosure, by setting the first connecting grid line and the second connecting grid line to different shapes, can distinguish the polarity of the first edge main grid and the second edge main grid by shape. It can promptly confirm whether there is a printing reverse problem after the grid line printing is completed, and can also distinguish the polarity of the first edge main grid and the second edge main grid during component welding, thereby reducing the probability of component welding errors and improving product yield.

[0128] In this embodiment, multiple solar cells in the battery assembly 200 can be connected in series to form a battery string, thereby realizing the series current collection and output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0129] It is understood that in such embodiments, the battery module 200 may further 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 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.

[0130] Photovoltaic glass can be applied to the encapsulating film on the front of solar cells. 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 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.

[0131] The backsheet can be attached to the encapsulant 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 encapsulant film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, solar cell, encapsulant 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 200, providing stable support and installation. For example, the battery module 200 can be installed at the desired location using the metal frame.

[0132] Figure 3 is a schematic diagram of the structure of a photovoltaic system provided in an embodiment of this disclosure. As shown in Figure 3, the photovoltaic system 300 of this embodiment includes the battery module 200 in the above embodiment.

[0133] The photovoltaic system of this disclosure, by setting the first connecting grid line and the second connecting grid line to different shapes, can distinguish the polarity of the first edge grid line and the second edge grid line by shape. This allows for timely confirmation of whether the grid line printing is reversed after printing, and also distinguishes the polarity of the first edge grid line and the second edge grid line during module welding, reducing the probability of errors in module welding and thus improving product yield.

[0134] In this embodiment, the photovoltaic system 300 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 300 are not limited to these; that is, the photovoltaic system 300 can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system grid as an example, the photovoltaic system 300 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.

[0135] 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 this disclosure. 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.

[0136] Furthermore, the above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A back-contact battery, comprising: A silicon substrate, a first edge main gate, and a second edge main gate, wherein the first edge main gate and the second edge main gate have different characteristics; The silicon substrate has a first edge and a second edge opposite each other in a first direction, the first edge main gate is the main gate closest to the first edge, and the second edge main gate is the main gate closest to the second edge; The first edge main grid includes a first connecting grid line and a second connecting grid line that are connected to each other. The second connecting grid line extends along a second direction. The extension direction of the first connecting grid line is different from the second direction. The second direction intersects the first direction. The second edge main gate includes a third connecting gate line and a fourth connecting gate line that are connected to each other. The fourth connecting gate line extends along a second direction, and the extension directions of the third connecting gate line and the fourth connecting gate line are different. The first connecting gate line and the third connecting gate line have different shapes.

2. The back contact battery according to claim 1, wherein, The first connecting gate line includes a first gate line segment, which is a gate line segment extending along a third direction, and the third direction is different from the extension direction of the first connecting gate line.

3. The back contact battery according to claim 1, wherein, The third connecting gate line includes a second gate line segment; the second gate line segment is a gate line segment extending in a fourth direction, the fourth direction being the same as the extension direction of the third connecting gate line.

4. The back contact battery according to claim 2, wherein, In the extending direction of the first connecting gate line, the first connecting gate line has a first end and a second end; The first end of the first connecting gate line is connected to the end of the second connecting gate line, and the first gate line segment is located at the second end of the first connecting gate line.

5. The back contact battery according to claim 3, wherein, In the extending direction of the third connecting gate line, the third connecting gate line has a first end and a second end; The first end of the third connecting gate line is connected to the end of the fourth connecting gate line, and the second gate line segment is located at the second end of the third connecting gate line.

6. The back contact battery according to claim 1, wherein, The silicon substrate further includes a first chamfer, which is connected to the end of the first edge; The distance between the first connecting gate line and the first chamfer is less than the distance between the second connecting gate line and the first chamfer.

7. The back contact battery according to claim 1, wherein, The silicon substrate further includes a second chamfer, which is connected to the end of the second edge; The distance between the third connecting grid line and the second chamfer is less than the distance between the fourth connecting grid line and the second chamfer.

8. The back contact battery according to claim 6, wherein, The distance between the first connecting gate line and the first chamfer is 500μm to 800μm.

9. The back contact battery according to claim 8, wherein, The distance between the second connecting gate line and the first edge is 250μm to 500μm.

10. The back contact battery according to claim 7, wherein, The distance between the third connecting grid line and the second chamfer is 500μm to 800μm.

11. The back contact battery according to claim 9, wherein, The distance between the fourth connecting gate line and the second edge is 250μm to 500μm.

12. The back contact battery according to claim 1, wherein, The silicon substrate has a third edge in the second direction; In the first edge main gate, the distance from the end closest to the third edge to the third edge in the second direction is the first distance; In the second edge main gate, at one end in the second direction, the distance from the third edge to the end closest to the third edge is the second distance; The first distance is greater than the second distance.

13. The back contact battery according to claim 1, wherein, The silicon substrate further includes a first internal main gate and a second internal main gate with different polarities; the first internal main gate and the second internal main gate are both located between the first edge main gate and the second edge main gate; The distance from the end of the first internal main gate near the third edge in the second direction to the third edge is the third distance, and the distance from the end of the second internal main gate near the third edge in the second direction to the third edge is the fourth distance; The third distance is greater than the fourth distance.

14. A battery assembly, comprising: The back contact battery according to any one of claims 1-13.

15. A photovoltaic system, comprising: The battery assembly as described in claim 14.

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