Back contact cell, cell 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 first edge main grid and a second edge main grid, wherein the first edge main grid and the second edge main grid are different in grid performance; the silicon substrate is provided with a first edge and a second edge which are opposite in a first direction; the first edge main grid comprises a first connecting grid line and a second connecting grid line which are connected with each other, the second connecting grid line extends along a second direction, the extending direction of the first connecting grid line is different from the second direction, and the second direction is crossed with the first direction; the second edge main grid comprises a third connecting grid line and a fourth connecting grid line which are connected with each other, the fourth connecting grid line extends in the second direction, and the extending direction of the third connecting grid line is different from that of the fourth connecting grid line; the first connecting grid lines and the third connecting grid lines are different in shape. According to the back contact battery provided by the invention, the polarity of the first edge main grid and the polarity of the second edge main grid can be distinguished.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a back-contact cell, a cell assembly and a photovoltaic system. Background Art

[0002] At present, solar cells include positive and negative busbars. After the busbars are printed, the polarity of the busbars needs to be distinguished. However, it is difficult to distinguish the positive and negative busbars, which makes it impossible to confirm whether the positive and negative busbars are printed reversely on the silicon substrate. Based on this, how to distinguish the positive and negative busbars of solar cells has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] The present application provides a back-contact cell, a cell assembly and a photovoltaic system, aiming to solve the technical problem in the prior art that it is difficult to distinguish between the positive main grid and the negative main grid of a solar cell.

[0004] The present application provides a back contact battery, comprising: a silicon substrate, a first edge main grid and a second edge main grid, wherein the first edge main grid and the second edge main grid have different properties;

[0005] The silicon substrate has a first edge and a second edge opposite to 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;

[0006] The first edge main gate includes a first connecting gate line and a second connecting gate line connected to each other, the second connecting gate line extends along a second direction, the extending direction of the first connecting gate line is different from the second direction, and the second direction intersects the first direction;

[0007] The second edge main gate includes a third connecting gate line and a fourth connecting gate line connected to each other, the fourth connecting gate line extends along the second direction, and the extending direction of the third connecting gate line is different from the extending direction of the fourth connecting gate line;

[0008] The first connection gate line and the third connection gate line have different shapes.

[0009] In some embodiments, the first connecting gate line includes a first gate line segment, and the first gate line segment is a gate line segment extending along a third direction, and the third direction is different from an extending direction of the first connecting gate line.

[0010] 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, and the fourth direction is the same as an extending direction of the third connecting gate line.

[0011] In some embodiments, in the extension direction of the first connecting gate line, the first connecting gate line has a first end and a second end;

[0012] 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.

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

[0014] 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.

[0015] In some embodiments, the silicon substrate further includes a first chamfer, wherein the first chamfer is connected to an end of the first edge;

[0016] The distance between the first connecting gate line and the first chamfer is smaller than the distance between the second connecting gate line and the first chamfer.

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

[0018] The distance between the third connecting gate line and the second chamfer is smaller than the distance between the fourth connecting gate line and the second chamfer.

[0019] In some embodiments, a distance between the first connecting gate line and the first chamfer is 500 μm to 800 μm.

[0020] In some embodiments, a distance between the second connecting gate line and the first edge is 250 μm to 500 μm.

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

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

[0023] In some embodiments, the silicon substrate has a third edge in the second direction;

[0024] Among the ends of the first edge main grid in the second direction, the distance from one end close to the third edge to the third edge is a first distance;

[0025] Among the ends of the second edge main grid in the second direction, the distance between the end close to the third edge and the third edge is a second distance;

[0026] The first distance is greater than the second distance.

[0027] In some embodiments, 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;

[0028] A distance from one end of the first internal main grid close to the third edge in the second direction to the third edge is a third distance, and a distance from one end of the second internal main grid close to the third edge in the second direction to the third edge is a fourth distance;

[0029] The third distance is greater than the fourth distance.

[0030] The present application also provides a battery assembly, which includes the back-contact battery described in any one of the above items.

[0031] The present application also provides a photovoltaic system, which includes the above-mentioned battery assembly.

[0032] The back-contact cell, cell module and photovoltaic system provided by the embodiments of the present application, by setting the first connecting grid line and the second connecting grid line to different shapes, the polarity of the first edge main grid and the second edge main grid can be distinguished by shape, and whether the problem of reverse printing occurs can be confirmed in time after the grid line printing is completed. The polarity of the first edge main grid and the second edge main grid can also be distinguished when the module is welded, thereby reducing the probability of errors in module welding, thereby improving product yield.

[0033] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of a back contact battery provided in an embodiment of the present application;

[0035] Figure 2 is a schematic diagram of the structure of a battery assembly provided in an embodiment of the present application;

[0036] Figure 3 It is a schematic diagram of the structure of the photovoltaic system provided in the embodiment of the present application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below 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 throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0038] In the description of the present application, it should be understood that the terms "upper", "lower", "back", "front", etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0039] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0041] Figure 1 Schematic diagram of the structure of the back contact battery provided in the embodiment of the present application. Figure 1 As shown, the present application provides a back contact battery, comprising: a silicon substrate 10, a first edge main grid 20 and a second edge main grid 30, wherein the first edge main grid 20 and the second edge main grid 30 have different polarities;

[0042] 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;

[0043] The first edge main gate 20 includes a first connecting gate line 201 and a second connecting gate line 202 connected to each other, the second connecting gate line 202 extends along a second direction, the extending direction of the first connecting gate line 201 is different from the second direction, and the second direction intersects the first direction;

[0044] The second edge main grid 30 includes a third connecting grid line 301 and a fourth connecting grid line 302 connected to each other, the fourth connecting grid line 302 extends along the second direction, and the extending direction of the third connecting grid line 301 is different from the extending direction of the fourth connecting grid line 302;

[0045] The first connection gate line 201 and the third connection gate line 301 have different shapes.

[0046] In the embodiment of the present application, the back contact cell can be a main grid back contact cell. The back contact cell includes a silicon substrate 10. The silicon substrate 10 can be a whole cell, or a half cell, a third cell, or a cell of other proportions divided from a whole cell. It should be noted that the drawings provided in the present application are schematic diagrams and do not limit the specific form of the back contact cell.

[0047] Furthermore, the silicon substrate 10 may include a front side and a back side relative to each other, wherein the front side faces the sun and mainly receives direct sunlight, and the back side faces the installation surface of the photovoltaic module and mainly receives sunlight reflected by the installation surface, such as the ground or a roof.

[0048] Several fine grids and several main grids are arranged on the back side of the silicon substrate 10, and a stacked doping layer and a passivation layer are also arranged on the back side of the silicon substrate 10, and the doping layer can be connected with several fine grids to establish ohmic contact. The fine grid is mainly used to collect the current generated by the back contact battery. When sunlight shines on the back contact battery, photons are absorbed and stimulate electrons, which are captured and transmitted by the fine grids. The main grid is responsible for collecting the current on the fine grids and transmitting it to the output end of the battery.

[0049] A plurality of main grids extend along the second direction and are arranged at intervals along the first direction, and a plurality of fine grids extend along the first direction and are arranged at intervals along the second direction. The first direction may be Figure 1 The horizontal direction in the second direction can be Figure 1 Of course, in other embodiments, the first direction and the second direction may also be other directions, such as a diagonal direction, etc., which are not specifically limited here.

[0050] The silicon substrate 10 has a first edge 101 and a second edge 102 opposite to each other in the first direction. Among the plurality of busbars arranged in intervals along the first direction, the first edge busbar 20 is the busbar closest to the first edge, and the second edge busbar 30 is the busbar closest to the second edge 102 .

[0051] The first edge bus gate 20 includes a first connection gate line 201 and a second connection gate line 202 connected to the first connection gate line 201 .

[0052] 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; any point on the first connecting gate line 201 is connected to the end of the second connecting gate line 202.

[0053] It should be noted that the end of the first connecting gate line 201 refers to any one of the two ends of the first connecting gate line 201 in the extension direction of the first connecting gate line 201; the end on the second connecting gate line 202 refers to any one of the two ends of the second connecting gate line 202 in the extension direction of the second connecting gate line 202.

[0054] The second connection gate line 202 extends along the second direction. Optionally, the second connection gate line 202 is arranged parallel to the first edge 101. The extension direction of the first connection gate line 201 intersects with the second direction.

[0055] The second edge bus gate 30 includes a third connection gate line 301 and a fourth connection gate line 302 connected to the third connection gate line 301 .

[0056] The connection method between 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; any point on the third connecting gate line 301 is connected to the end of the fourth connecting gate line 302.

[0057] It should be noted that the end of the third connecting gate line 301 refers to any one of the two ends of the third connecting gate line 301 in the extension direction of the third connecting gate line 301; the end on the fourth connecting gate line 302 refers to any one of the two ends of the fourth connecting gate line 302 in the extension direction of the fourth connecting gate line 302.

[0058] The fourth connection gate line 302 extends along the second direction. Optionally, the fourth connection gate line 302 is arranged parallel to the second edge 102. The extension direction of the third connection gate line 301 intersects with the second direction.

[0059] In the embodiment of the present application, different polarities are marked by setting different shapes for the first connection gate line 201 and the third connection gate line 301. The different shapes may be different gate line shapes, different thicknesses, different lengths, different extension directions or different extension angles.

[0060] For example, if the third connecting grid line 301 is curved or folded, the second edge bus grid 30 can be determined to be a positive bus grid; if the first connecting grid line 201 is straight, the first edge bus grid 20 can be determined to be a negative bus grid.

[0061] The third connecting grid line 301 is circular, which can determine that the second edge main grid 30 is a positive main grid; the first connecting grid line 201 is triangular, which can determine that the first edge main grid 20 is a negative main grid.

[0062] The third connecting grid line 301 is in a Y shape, which indicates that the second edge main grid 30 is a positive main grid; the first connecting grid line 201 is in a parabola shape, which indicates that the first edge main grid 20 is a negative main grid.

[0063] The line width of the third connection grid line 301 is twice that of the first connection grid line 201 , which can determine that the second edge bus grid 30 is a positive bus grid and the first edge bus grid 20 is a negative bus grid.

[0064] The length of the third connecting grid line 301 is longer than that of the first connecting grid line 201 , which can determine that the second edge bus grid 30 is a positive bus grid and the first edge bus grid 20 is a negative bus grid.

[0065] It should be noted that the above-mentioned shapes and polarities may present a one-to-one correspondence, and when the shapes of the first connecting gate line 20 or any of the third connecting gate lines 301 are difficult to distinguish, the polarity of the corresponding edge bus grid may be determined by the distinguishable shape corresponding to the other gate line. Since the polarities of the first edge bus grid 20 and the second edge bus grid 30 are opposite, as long as the polarity of one edge bus grid is determined, the polarity of the other edge bus grid may also be determined accordingly.

[0066] The back-contact battery provided in the embodiment of the present application sets the first connecting grid line and the second connecting grid line to different shapes, and then can distinguish the polarity of the first edge main grid and the second edge main grid by shape. After the grid line printing is completed, it can be confirmed in time whether the printing is reversed. The polarity of the first edge main grid and the second edge main grid can also be distinguished when the component is welded, thereby reducing the probability of errors in component welding, thereby improving product yield.

[0067] In some embodiments, the first connecting gate line 201 includes a first gate line segment 2001 . The first gate line segment 2001 is a gate line segment extending along a third direction, and the third direction is different from an extending direction of the first connecting gate line 201 .

[0068] In actual implementation, the first connection line 201 includes a first line segment 2001 for marking polarity and extending along a third direction. The first line segment 2001 is located on the first connection line 201, and the third direction is different from the extension direction of the first connection line 201. The third direction can be the same as or different from the second direction.

[0069] The different extending directions refer to different angles or curvatures of the first gate line segments relative to the first connecting gate lines 201 .

[0070] Optionally, the first gate line segment 2001 may be located at an end of the first connecting gate line 201 in the extending direction, or may be located between two ends of the first connecting gate line 201 , which is not specifically limited herein.

[0071] The back-contact battery provided in the embodiment of the present application is convenient for distinguishing the main grid property by setting a first grid line segment for distinguishing polarity on the first connecting grid line, thereby improving the identifiability of the polarity of the first edge main grid, and the extension direction of the first grid line segment is different from that of the first connecting grid line, so the main grid property can be determined more intuitively, thereby facilitating the rapid acquisition of effective information for distinguishing polarity.

[0072] 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, and the fourth direction is the same as the extending direction of the third connecting gate line 301 .

[0073] In actual implementation, the third connection gate line 301 includes a second gate line segment for marking polarity and extending along a fourth direction. The second gate line segment is located on the third connection gate line 301, and the fourth direction is the same as the extension direction of the third connection gate line 301, and the fourth direction is different from the second direction.

[0074] The same extension direction means that the included angle of the second gate line segment with respect to the third connecting gate line 301 is 0 degree or the curvature is the same.

[0075] Optionally, the second gate line segment may be located at an end portion of the third connecting gate line 301 in the extending direction, or may be located between two ends of the third connecting gate line 301 , which is not specifically limited herein.

[0076] The back-contact battery provided in the embodiment of the present application facilitates the identification of the main grid by setting a second grid line segment for polarity distinction on the third connecting grid line, improves the identifiability of the polarity of the second edge main grid, and can also reduce the risk of being unable to distinguish the main grid when the shape of the first grid line segment cannot be identified.

[0077] In some embodiments, in the extension direction of the first connection gate line 201, the first connection gate line 201 has a first end and a second end;

[0078] 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 .

[0079] In actual implementation, in the extension direction of the first connection gate line 201, the first end of the first connection gate line 201 is connected to the end of the second connection gate line 202 in the second direction. The second end of the first connection gate line 201 is provided with a first gate line segment 2001 extending along the third direction, and it can be seen that the first connection gate line 201 is bent or folded at the end.

[0080] The back contact battery provided in the embodiment of the present application, by setting the first gate line segment at the end of the first connecting gate line, the first gate line segment can be more clearly observed visually, which is more conducive to the identification of the main gate.

[0081] In some embodiments, in the extension direction of the third connection gate line 301, the third connection gate line 301 has a first end and a second end;

[0082] A first end of the third connecting gate line 301 is connected to an end of the fourth connecting gate line 302 , and the second gate line segment is located at a second end of the third connecting gate line 301 .

[0083] In actual implementation, in the extension direction of the third connection gate line 301, the first end of the third connection gate line 301 is connected to the end of the fourth connection gate line 302 in the second direction. The second end of the third connection gate line 301 is provided with a second gate line segment extending along the fourth direction, and it can be seen that the third connection gate line 301 has no bend or bend at the end, but is in a straight line shape.

[0084] The back contact battery provided in the embodiment of the present application, by setting the second gate line segment at the end of the third connecting gate line, the second gate line segment can be more clearly observed visually, which is more conducive to the identification of the main gate.

[0085] In some embodiments, the silicon substrate 10 further includes a first chamfer 103 , and the first chamfer 103 is connected to an end of the first edge 101 ;

[0086] The distance between the first connecting gate line 201 and the first chamfer 103 is greater than the distance between the second connecting gate line 202 and the first chamfer 103 .

[0087] In actual implementation, a first chamfer 103 is provided at the connection between the first edge 101 and the adjacent edge of the silicon substrate 10. The first connection gate line 201 is connected to the end of the second connection gate line 202, and the second connection gate line 202 extends along the second direction. The first connection gate line 201 and the second connection gate line 202 extend in different directions.

[0088] The distance between the first connecting gate line 201 and the first chamfer 103 refers to the distance from any point on the first connecting gate line 201 to any point on the first chamfer 103 , and the distance between the second connecting gate line 202 and the first chamfer 103 refers to the distance from any point on the second connecting gate line 202 to any point on the first chamfer 103 .

[0089] 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 smaller than the distance between the second connecting gate line 202 and the first chamfer 103. Then, 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.

[0090] It can be understood that there is a larger space at the first chamfer, so the first gate line segment of the first connecting gate line 201 can maintain a sufficient distance from the first chamfer.

[0091] The back-contact battery provided in the embodiment of the present application can provide sufficient spacing for the setting position of the first gate line segment by setting the first connecting gate line at a position closer to the first chamfer relative to the distance between the second connecting gate line and the first chamfer, thereby ensuring battery reliability.

[0092] In some embodiments, the silicon substrate 10 further includes a second chamfer 104 , and the second chamfer 104 is connected to an end of the second edge 102 ;

[0093] The distance between the third connecting gate line 301 and the second chamfer 104 is greater than the distance between the fourth connecting gate line 302 and the second chamfer 104 .

[0094] In actual implementation, a second chamfer 104 is provided at the connection between the second edge 102 and the adjacent edge of the silicon substrate 10. The third connection gate line 301 is connected to the end of the fourth connection gate line 302, and the fourth connection gate line 302 extends along the second direction. The third connection gate line 301 and the fourth connection gate line 302 extend in the same direction.

[0095] The distance between the third connecting gate line 301 and the second chamfer 104 refers to the distance from any point on the third connecting gate line 301 to any point on the second chamfer 104 , and the distance between the fourth connecting gate line 302 and the second chamfer 104 refers to the distance from any point on the fourth connecting gate line 302 to any point on the second chamfer 104 .

[0096] The fourth connecting gate line 302 extends close to the second edge 102, and the third connecting gate line 301 extends close to the second chamfer 104. Therefore, the distance between the third connecting gate line 301 and the second chamfer 104 is smaller than the distance between the second connecting gate line 202 and the second chamfer 104. Then, the distance between the third connecting gate line 301 and the second edge 102 is greater than the distance between the second connecting gate line 202 and the second edge 102.

[0097] The back-contact battery provided in the embodiment of the present application can provide sufficient spacing for the setting position of the second gate line segment by setting the third connecting gate line at a position closer to the second chamfer relative to the distance between the fourth connecting gate line and the second chamfer, thereby ensuring that the battery reliability is not affected.

[0098] Optionally, the distance between the first connecting gate line 201 and the first chamfer 103 is 500 μm to 800 μm.

[0099] In actual implementation, the distance between the first connection gate line 201 and the first chamfer 103 may be, for example, 500 μm, 600 μm, 700 μm or 800 μm, or may be in the range of 500 μm to 800 μm, which is not specifically limited herein.

[0100] The back-contact battery provided in the embodiment of the present application can provide space for the arrangement of the first gate line segment by setting the distance between the first connecting gate line and the first chamfer between 500 μm and 800 μm, while ensuring that the battery reliability is not affected.

[0101] Optionally, the distance between the second connecting gate line 202 and the first edge 101 is 250 μm to 500 μm.

[0102] In actual implementation, the distance between the second connection gate line 202 and the first edge 101 may be, for example, 250 μm, 275 μm, 300 μm, 400 μm, 465 μm or 500 μm, or may be in the range of 250 μm to 500 μm, which is not specifically limited herein.

[0103] The back-contact battery provided in the embodiment of the present application can ensure that the second connecting grid line maintains a safe distance from the first edge by setting the distance between the second connecting grid line and the first edge between 250 μm and 500 μm, thereby improving the battery reliability.

[0104] Optionally, the distance between the third connecting gate line 301 and the second chamfer 104 is 500 μm to 800 μm.

[0105] In actual implementation, the distance between the third connection gate line 301 and the second chamfer 104 may be, for example, 500 μm, 600 μm, 700 μm or 800 μm, or may be in the range of 500 μm to 800 μm, which is not specifically limited herein.

[0106] The back-contact battery provided in the embodiment of the present application can provide space for the arrangement of the second gate line segment by setting the distance between the third connecting gate line and the second chamfer between 500 μm and 800 μm, while ensuring that the battery reliability is not affected.

[0107] Optionally, the distance between the fourth connecting gate line 302 and the second edge 102 is 250 μm to 500 μm.

[0108] In actual implementation, the distance between the fourth connection gate line 302 and the second edge 102 may be, for example, 250 μm, 275 μm, 300 μm, 400 μm, 465 μm or 500 μm, or may be in the range of 250 μm to 500 μm, which is not specifically limited herein.

[0109] The back-contact battery provided in the embodiment of the present application can ensure that the fourth connecting grid line maintains a safe distance from the first edge by setting the distance between the fourth connecting grid line and the second edge between 250 μm and 500 μm, thereby improving the battery reliability.

[0110] In some embodiments, the silicon substrate 10 has a third edge 105 in the second direction;

[0111] The distance between the end of the first edge main grid 20 in the second direction, which is close to the third edge 105, and the third edge 105 is the first distance;

[0112] Among the ends of the second edge main grid 30 in the second direction, the distance between the end close to the third edge 105 and the third edge 105 is the second distance;

[0113] The first distance is greater than the second distance.

[0114] It is understandable that the polarity of the first edge bus grid 20 and the second edge bus grid 30 can also be distinguished by the distance from the edge. For example, if the first distance from the end of the first edge bus grid 20 close to the third edge 105 to the third edge 105 is greater than the second distance from the end of the second edge bus grid 30 close to the third edge 105 to the third edge 105, then the first edge bus grid 20 is a negative electrode bus grid, and the second edge bus grid 30 is a positive electrode bus grid.

[0115] The back-contact battery provided in the embodiment of the present application can also identify the polarity of the edge main grid by comparing the distance from one end of the first edge main grid and one end of the second edge main grid to the third edge, thereby further improving the prominence and identifiability of the edge main grid.

[0116] In some embodiments, the silicon substrate 10 further includes a first internal main gate 40 and a second internal main gate 50 having 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;

[0117] A distance from one end of the first internal main grid 40 close to the third edge 105 in the second direction to the third edge 105 is a third distance, and a distance from one end of the second internal main grid 50 close to the third edge 105 in the second direction to the third edge 105 is a fourth distance;

[0118] The third distance is greater than the fourth distance.

[0119] It can be understood that the first internal main gate 40 and the second internal main gate 50 are alternately arranged along the first direction, and the polarities of the first internal main gate 40 and the second internal main gate 50 can also be distinguished by the distance from the edge.

[0120] For example: if the third distance from one end of the first internal main grid 40 close to the third edge 105 to the third edge 105 is greater than the fourth distance from one end of the second internal main grid 50 close to the third edge 105 to the third edge 105, then the first internal main grid 40 is a negative main grid and the second internal main grid 50 is a positive main grid.

[0121] Therefore, in the embodiment of the present application, the polarity of the first internal bus gate 40 is the same as that of the first edge bus gate 20 , and the polarity of the second internal bus gate 50 is the same as that of the second edge bus gate 30 .

[0122] The back-contact battery provided in the embodiment of the present application can also identify the polarity of the internal main grid by comparing the distance from one end of the first internal main grid and one end of the second internal main grid to the third edge, thereby further improving the significance and recognizability of the internal main grid.

[0123] Figure 2 Schematic diagram of the structure of the battery assembly provided in the embodiment of the present application. Figure 2 As shown, the battery assembly 200 of the embodiment of the present application includes the back contact battery 100 in any of the above embodiments.

[0124] The battery assembly of the embodiment of the present application sets the first connecting grid line and the second connecting grid line to different shapes, and then can distinguish the polarity of the first edge main grid and the second edge main grid by shape. After the grid line printing is completed, it can be confirmed in time whether the problem of reverse printing occurs. The polarity of the first edge main grid and the second edge main grid can also be distinguished when the assembly is welded, thereby reducing the probability of errors in assembly welding, thereby improving product yield.

[0125] In this embodiment, multiple solar cells in the battery assembly 200 can be connected in series in sequence to form a battery string, thereby realizing the series bus output of current. For example, the series connection of battery cells can be realized by setting welding strips (bus bars, interconnecting strips), conductive backplanes, etc.

[0126] It is understandable that in such an embodiment, the battery assembly 200 may also include a metal frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the solar cell and 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 adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0127] Photovoltaic glass can cover the adhesive film on the front of the solar cell. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the solar cell without affecting the efficiency of the solar cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the solar cell together. The presence of the adhesive film can seal and insulate the solar cell and make it waterproof and moisture-proof.

[0128] The backplane can be attached to the adhesive film on the back of the solar cell. The backplane can protect and support the solar cell and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the backplane, solar cell, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire battery assembly 200 and can stably support and install the battery assembly 200. For example, the battery assembly 200 can be installed at the required installation position through the metal frame.

[0129] Figure 3 Schematic diagram of the structure of the photovoltaic system provided in the embodiment of the present application. Figure 3 As shown, the photovoltaic system 300 of the embodiment of the present application includes the battery assembly 200 in the above embodiment.

[0130] The photovoltaic system of the embodiment of the present application sets the first connecting grid line and the second connecting grid line to different shapes, and then can identify the polarity of the first edge main grid and the second edge main grid by shape. After the grid line printing is completed, it can be confirmed in time whether the problem of reverse printing occurs. The polarity of the first edge main grid and the second edge main grid can also be distinguished when the component is welded, thereby reducing the probability of errors in component welding, thereby improving product yield.

[0131] In this embodiment, the photovoltaic system 300 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system 300 are not limited to this, that is, the photovoltaic system 300 can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 300 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple battery components. For example, multiple battery components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0132] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0133] In addition, the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A back contact battery, characterized in that: include: 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 properties; The silicon substrate has a first edge and a second edge opposite to 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 gate includes a first connecting gate line and a second connecting gate line connected to each other, the second connecting gate line extends along a second direction, the extending direction of the first connecting gate line is different from the second direction, and the second direction intersects the first direction; The second edge main gate includes a third connecting gate line and a fourth connecting gate line connected to each other, the fourth connecting gate line extends along the second direction, and the extending direction of the third connecting gate line is different from the extending direction of the fourth connecting gate line; The first connection gate line and the third connection gate line have different shapes.

2. The back contact cell according to claim 1, characterized in that: The first connecting gate line includes a first gate line segment, and the first gate line segment is a gate line segment extending along a third direction, and the third direction is different from an extending direction of the first connecting gate line.

3. The back contact cell according to claim 1, characterized in that: 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, and the fourth direction is the same as the extending direction of the third connecting gate line.

4. The back contact cell according to claim 2, characterized in that: In the extension 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, characterized in that: In the extension 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 cell according to claim 1, characterized in that: The silicon substrate further includes a first chamfer, wherein the first chamfer is connected to an end of the first edge; The distance between the first connecting gate line and the first chamfer is smaller than the distance between the second connecting gate line and the first chamfer.

7. The back contact cell according to claim 1, characterized in that: The silicon substrate further includes a second chamfer, wherein the second chamfer is connected to an end of the second edge; The distance between the third connecting gate line and the second chamfer is smaller than the distance between the fourth connecting gate line and the second chamfer.

8. The back contact cell according to claim 6, characterized in that: The distance between the first connecting gate line and the first chamfer is 500 μm to 800 μm.

9. The back contact cell according to claim 8, characterized in that: The distance between the second connecting gate line and the first edge is 250 μm to 500 μm.

10. The back contact cell according to claim 7, characterized in that: The distance between the third connecting gate line and the second chamfer is 500 μm to 800 μm.

11. The back contact cell according to claim 9, characterized in that: The distance between the fourth connecting gate line and the second edge is 250 μm to 500 μm.

12. The back contact cell according to claim 1, characterized in that: The silicon substrate has a third edge in the second direction; Among the ends of the first edge main grid in the second direction, the distance from one end close to the third edge to the third edge is a first distance; Among the ends of the second edge main grid in the second direction, the distance between the end close to the third edge and the third edge is a second distance; The first distance is greater than the second distance.

13. The back contact cell according to claim 1, characterized in that: The silicon substrate further comprises a first internal main gate and a second internal main gate having 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; A distance from one end of the first internal main grid close to the third edge in the second direction to the third edge is a third distance, and a distance from one end of the second internal main grid close to the third edge in the second direction to the third edge is a fourth distance; The third distance is greater than the fourth distance.

14. A battery assembly, characterized in that: include: A back contact battery according to any one of claims 1 to 13.

15. A photovoltaic system, characterized in that: include: A battery pack as claimed in claim 14.

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