Photovoltaic cell, module and system

Abstract

The present disclosure provides a photovoltaic cell, a module, and a system. In a first direction, the spacing between a first finger and a second finger is a first spacing, and the spacing between a third finger and a fourth finger is a second spacing, the second spacing being greater than the first spacing; a fifth finger is located between the third finger and the fourth finger, an extension direction of a first bending portion of the fifth finger intersecting with a second direction.

Description

Photovoltaic cells, modules and systems

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202520175275.2, filed on January 26, 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 photovoltaic technology, and in particular to a back contact battery, battery module and photovoltaic system. Background Technology

[0004] In back-contact batteries, fine grids of two polarities are arranged alternately to collect current. In related technologies, the spacing between two adjacent fine grids of the same polarity in back-contact batteries is too large, resulting in poor current collection and low photoelectric conversion efficiency.

[0005] Therefore, improving the current collection efficiency of the back contact battery has become an urgent problem to be solved.

[0006] Public content

[0007] This disclosure provides a back-contact battery, a battery module, and a photovoltaic system to address the technical problem of how to improve the current collection efficiency of a back-contact battery.

[0008] This disclosure provides a back-contact battery, a battery module, and a photovoltaic system. The back-contact battery includes a plurality of first polarity grids and a plurality of second polarity grids; the first and second polarity grids are alternately arranged along a first direction, and extend along a second direction, which intersects the first direction; the polarities of the first and second polarity grids are opposite. Each first polarity grid includes a first grid and a second grid, which are adjacent to each other, and the spacing between the first and second grids along the first direction is a first spacing. The first polarity grid also includes a third grid and a fourth grid, which are adjacent to each other, and the spacing between the third and fourth grids along the first direction is a second spacing, which is greater than the first spacing. Each second polarity grid includes a fifth grid located between the third and fourth grids, and the fifth grid includes a first bend, the extension direction of which intersects the second direction.

[0009] In some embodiments, the second spacing is 900 micrometers to 1300 micrometers.

[0010] In some embodiments, the fifth fine gate includes a first endpoint and a second endpoint, the first endpoint being the point on the fifth fine gate that is closest to the third fine gate, and the second endpoint being the point on the fifth fine gate that is closest to the fourth fine gate, and the distance between the first endpoint and the second endpoint in a first direction is 20 micrometers to 150 micrometers.

[0011] In some embodiments, the first bend includes a plurality of first bend segments, a plurality of second bend segments, and a plurality of bend points, wherein the bend points are located between adjacent first bend segments and second bend segments.

[0012] In some embodiments, in the second direction, the distance between two adjacent bending points is 40 micrometers to 300 micrometers.

[0013] In some embodiments, there are multiple first bends, each of which is parallel to the others; or, there are multiple second bends, each of which is parallel to the others; or, there are multiple first bends and multiple second bends, each of which is parallel to the others and each of which is parallel to the others.

[0014] In some embodiments, the first bend is a straight segment or a curved segment.

[0015] In some embodiments, the fifth fine grid includes a bent structure, the bent structure including a plurality of first bends.

[0016] In some embodiments, the bending structure is in the shape of a triangular wave.

[0017] In some embodiments, the bending structure is sinusoidal in shape.

[0018] In some embodiments, the fifth fine grid further includes a first non-bent portion, the extension direction of which is parallel to the second direction.

[0019] In some embodiments, the back contact battery further includes a plurality of positioning points located between the third and fourth fine grids.

[0020] In some embodiments, in the second direction, the distance between the fifth fine gate and the positioning point is 200 micrometers to 2000 micrometers.

[0021] In some embodiments, the second polar fine gate includes a sixth fine gate, which is located between the third and fourth fine gates, and the sixth fine gate, the positioning point, and the fifth fine gate are distributed sequentially along a second direction; in the second direction, the distance between the sixth fine gate and the positioning point is 200 micrometers to 2000 micrometers.

[0022] In some embodiments, in the second direction, the spacing between the sixth and fifth fine gates is 400 micrometers to 4000 micrometers.

[0023] In some embodiments, the sixth fine gate is a non-bent gate line, and the extension direction of the sixth fine gate is parallel to the second direction.

[0024] In some embodiments, the sixth fine grid includes a second bend, the extension direction of which intersects with the second direction.

[0025] In some embodiments, the back contact battery further includes a plurality of first polar doped regions and a plurality of second polar doped regions; the first polar doped regions and the second polar doped regions are arranged alternately along a first direction and extend along a second direction; the position of the first polar doped region corresponds to the position of the first polar grid and the position of the second polar doped region corresponds to the position of the second polar grid; the doping polarities of the first polar doped region and the second polar doped region are opposite.

[0026] In some embodiments, the second polar fine gate includes a seventh fine gate located between the first fine gate and the second fine gate; the second polar doped region corresponding to the location of the fifth fine gate is the first doped region, and the size of the first doped region in the first direction is a first dimension; the second polar doped region corresponding to the location of the seventh fine gate is the second doped region, and the size of the first doped region in the first direction is a second dimension; the first dimension is larger than the second dimension.

[0027] In some embodiments, the first polar doped region includes a third doped region and a fourth doped region, which are adjacent to each other, and the first doped region is located between the third doped region and the fourth doped region; the distance between the third doped region and the fourth doped region along a first direction is a third distance; the first polar doped region further includes a fifth doped region and a sixth doped region, which are adjacent to each other, and a second doped region is located between the fifth doped region and the sixth doped region; the distance between the fifth doped region and the sixth doped region along the first direction is a fourth distance; the fourth distance is smaller than the third distance in the first direction.

[0028] This disclosure also provides a battery assembly, which includes a back contact battery as described in any of the above embodiments.

[0029] This disclosure also provides a photovoltaic system, which includes a battery module as described in any of the above embodiments.

[0030] In the back contact cell of this disclosure, since the fifth fine grid is located between the third and fourth fine grids with a large spacing and the same polarity, and the fifth fine grid includes a first bend that extends in a direction that intersects with the second direction, the current between the third and fourth fine grids can be collected better, thereby improving the photoelectric conversion efficiency of the back contact cell. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 is a schematic diagram of a photovoltaic system provided in an embodiment of this disclosure;

[0033] Figure 2 is a partial structural schematic diagram of a solar cell provided in an embodiment of this disclosure;

[0034] Figure 3 is a schematic diagram of another part of the structure of a solar cell provided in an embodiment of the present disclosure;

[0035] Figure 4 is a schematic diagram of another part of the structure of a solar cell provided in an embodiment of this disclosure;

[0036] Figure 5 is a schematic diagram of another part of the structure of a solar cell provided in an embodiment of this disclosure;

[0037] Figure 6 is a schematic diagram of another part of the structure of a solar cell provided in an embodiment of this disclosure;

[0038] Figure 7 is a schematic diagram of another part of the structure of a solar cell provided in an embodiment of this disclosure;

[0039] Figure 8 is a partial structural schematic diagram of the fifth fine gate provided in an embodiment of the present disclosure;

[0040] Figure 9 is a schematic diagram of another part of the structure of the fifth fine gate provided in an embodiment of the present disclosure;

[0041] Figure 10 is a schematic diagram of another part of the structure of a solar cell provided in one embodiment of the present disclosure.

[0042] Figure 11 is a schematic diagram of another part of the structure of a solar cell provided in one embodiment of the present disclosure. Key component symbols: 1000, Photovoltaic system; 1001, Battery module; 100, Back contact cell; 10, First polar grid; 20, Second polar grid; 30, Positioning point; 40, First polar doped region; 50, Second polar doped region; 11, First grid; 12, Second grid; 13, Third grid; 14, Fourth grid; 21, Fifth grid; 22, Sixth grid; 23, Seventh grid; 41, Third doped region; 42, Fourth doped region; 43, Fifth doped region; 44, Sixth doped region; 51, First doped region; 52, Second doped region; 211, First endpoint; 212, Second endpoint; 710, Bending structure; 711, First bending portion; 712, First non-bending portion; 713, Second bending portion; 7111, First bending segment; 7112, Second bending segment; 7113, Bending point. Detailed Implementation

[0043] 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. 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 it. Furthermore, it should be understood that the specific embodiments described herein are merely illustrative of this disclosure and are not intended to limit it.

[0044] In the description of this disclosure, it should be understood that the terms “length”, “width”, “upper”, “lower”, “top”, “bottom”, “lateral”, “longitudinal”, 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.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0047] 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.

[0048] Referring to Figure 1, the photovoltaic system 1000 in this embodiment may include the battery module 1001. The battery module 1001 may include a plurality of back-contact batteries 100. The plurality of back-contact batteries 100 may be connected in series with solder strips to form a battery string. The battery strings in the battery module 1001 may be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between the battery strings may be achieved by busbars.

[0049] The accompanying drawings provided in this disclosure are schematic diagrams, and some elements are not shown. Their purpose is to clearly describe the technical solution and highlight the key points of the disclosure. They are not intended to limit the technical solution to exclude these unshown elements. That is to say, the drawings are merely examples and do not represent a limitation on the specific form of the battery module 1001.

[0050] As shown in Figures 2 to 11, in this embodiment of the present disclosure, the back contact battery 100 has a plurality of first polarity fine grids 10 and a plurality of second polarity fine grids 20. The back contact battery 100 can be a back contact battery 100 with a main grid or a back contact battery 100 without a main grid. In the case of a main grid, the fine grids are electrically connected to the main grid.

[0051] The first polar fine gate 10 and the second polar fine gate 20 are arranged alternately along the first direction. The first polar fine gate 10 and the second polar fine gate 20 extend along the second direction, which intersects the first direction. The polarities of the first polar fine gate 10 and the second polar fine gate 20 are opposite.

[0052] The first polar fine grid 10 includes a first fine grid 11 and a second fine grid 12, which are adjacent to each other. Along a first direction, the distance between the first fine grid 11 and the second fine grid 12 is a first distance D1. The first polar fine grid 10 also includes a third fine grid 13 and a fourth fine grid 14, which are adjacent to each other. Along the first direction, the distance between the third fine grid 13 and the fourth fine grid 14 is a second distance D2, which is greater than the first distance D1. The second polar fine grid 20 includes a fifth fine grid 21, which is located between the third fine grid 13 and the fourth fine grid 14. The fifth fine grid 21 includes a first bend 711, the extension direction of which intersects the second direction.

[0053] Thus, in the back contact battery 100 of this embodiment, since the fifth fine grid 21 is located between the third fine grid 13 and the fourth fine grid 14 with a large spacing and the same polarity, and the fifth fine grid 21 includes a first bend 711 whose extension direction intersects the second direction, the fifth fine grid 21 can better collect the current between the third fine grid 13 and the fourth fine grid 14 through the first bend 711, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0054] As shown in Figures 2 and 3, specifically, the first fine gate 11 and the second fine gate 12, as well as the third fine gate 13 and the fourth fine gate 14, are two sets of two adjacent first polarity fine gates 10. Along the first direction, the second spacing D2 is greater than the first spacing D1, and the third fine gate 13 and the fourth fine gate 14 are a set of adjacent first polarity fine gates 10 with a larger spacing.

[0055] If the spacing between the third fine gate 13 and the fourth fine gate 14 is large, conventional gate lines will find it difficult to collect the current between them. Therefore, in this embodiment, a fifth fine gate 21 is provided between the third fine gate 13 and the fourth fine gate 14. The fifth fine gate 21 includes a first bend 711, the extension direction of which intersects a second direction. Thus, by using the first bend 711 intersecting the second direction, the current collecting area of ​​the fifth fine gate 21 can be increased to better collect the current between the third fine gate 13 and the fourth fine gate 14, thereby improving the photoelectric conversion efficiency of the back contact cell 100.

[0056] In one possible implementation, the third fine gate 13, the fifth fine gate 21, and the fourth fine gate 14 are three fine gates arranged sequentially along a first direction. The third fine gate 13 and the fourth fine gate 14 have the same polarity, while the third fine gate 13 and the fifth fine gate 21 have opposite polarities.

[0057] Of course, in other embodiments, in order to better collect the current between the third fine gate 13 and the fourth fine gate 14, the number of fifth fine gates 21 can be set to multiple. That is, multiple fifth fine gates 21 with first bends 711 are provided between the third fine gate 13 and the fourth fine gate 14, thereby better collecting the current between the third fine gate 13 and the fourth fine gate 14, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0058] Furthermore, in other embodiments, in order to better collect the current between the third fine gate 13 and the fourth fine gate 14, the number of fine gates between the third fine gate 13 and the fourth fine gate 14 can be set to multiple. For example, a number of fifth fine gates 21 or a number of fine gates without the first bend 711 can be provided between the third fine gate 13 and the fourth fine gate 14, which is not limited here.

[0059] In one possible implementation, the second spacing D2 is between 900 micrometers and 1300 micrometers. For example, it can be 900 micrometers, 950 micrometers, 1000 micrometers, 1050 micrometers, 1100 micrometers, 1150 micrometers, 1200 micrometers, 1250 micrometers, or 1300 micrometers. Thus, the fifth fine gate 21 is located between the larger spacing of the third fine gate 13 and the fourth fine gate 14, thereby better collecting the current between the third fine gate 13 and the fourth fine gate 14, and thus improving the photoelectric conversion efficiency of the back contact cell 100.

[0060] In some embodiments, the first bend 711 intersects the extending direction of the fine grid. The angle between the first bend 711 and the second direction can be selected according to actual conditions and is not limited here. In the fifth fine grid 21, the number of first bends 711 can be set to one or more. In one possible embodiment, the entire fifth fine grid 21 can be set to first bends 711 to better collect the current between the third fine grid 13 and the fourth fine grid 14, thereby improving the photoelectric conversion efficiency of the back contact cell 100.

[0061] As shown in Figures 2 and 3, in one possible embodiment, the fifth fine gate 21 includes a first endpoint 211 and a second endpoint 212. The first endpoint 211 is the point on the fifth fine gate 21 that is closest to the third fine gate 13, and the second endpoint 212 is the point on the fifth fine gate 21 that is closest to the fourth fine gate 14. The distance D3 between the first endpoint 211 and the second endpoint 212 in a first direction is 20 micrometers to 150 micrometers. For example, it is 20 micrometers, 40 micrometers, 50 micrometers, 60 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 140 micrometers, or 150 micrometers.

[0062] Specifically, if the distance D3 between the first endpoint 211 and the second endpoint 212 in the first direction is too close, the fifth fine gate 21 may be unable to effectively collect the current between the third fine gate 13 and the fourth fine gate 14, affecting the photoelectric conversion efficiency of the back contact cell 100. If the distance D3 between the first endpoint 211 and the second endpoint 212 in the first direction is too far, the fifth fine gate 21 may be too close to at least one of the fourth fine gate 14 and the third fine gate 13, causing electrical contact between the fifth fine gate 21 and at least one of the fourth fine gate 14 and the third fine gate 13, thereby leading to a short circuit.

[0063] Therefore, the distance D3 between the first endpoint 211 and the second endpoint 212 in the first direction is 20 micrometers to 150 micrometers. This allows for sufficient collection of the current between the third fine gate 13 and the fourth fine gate 14 while preventing the fifth fine gate 21 from being too close to the third fine gate 13 or the fourth fine gate 14, which could lead to a short circuit.

[0064] Furthermore, depending on the specific structure of the different fifth fine gate 21, there may be one or more first endpoints 211 and second endpoints 212.

[0065] As shown in Figures 2 and 4, in one possible implementation, the first bending portion 711 includes a plurality of first bending segments 7111, a plurality of second bending segments 7112, and a plurality of bending points 7113, wherein the bending points 7113 are located between adjacent first bending segments 7111 and second bending segments 7112.

[0066] Specifically, the first bending portion 711 includes a first bending segment 7111 and a second bending segment 7112, the extending directions of the first bending segment 7111 and the second bending segment 7112 intersect. The first bending segment 7111 and the second bending segment 7112 are connected at the bending point 7113.

[0067] Within a first bend 711, the number of first bend segments 7111, second bend segments 7112, and bend points 7113 can be one or more, and this is not limited here. Furthermore, the number of first bend segments 7111, second bend segments 7112, and bend points 7113 can be set to be the same.

[0068] Specifically, in the second direction, the distance D4 between two adjacent bending points 7113 is 40 micrometers to 300 micrometers. For example, it is 40 micrometers, 60 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 150 micrometers, 180 micrometers, 200 micrometers, 220 micrometers, 250 micrometers, 270 micrometers, or 300 micrometers.

[0069] Understandably, the bending point 7113 is located between the adjacent first bending segment 7111 and second bending segment 7112. By setting the spacing D4 between two adjacent bending points 7113 to 40 micrometers to 300 micrometers, the specific position and angle of the first bending portion 711 can be controlled. In the second direction, if the spacing D4 between two adjacent bending points 7113 is too large, the fifth fine gate 21 cannot fully collect the current between the third fine gate 13 and the fourth fine gate 14; if the spacing D4 between two adjacent bending points 7113 is too small, it will increase the manufacturing difficulty of the fifth fine gate 21 and increase the manufacturing cost.

[0070] Therefore, in the second direction, the spacing D4 between two adjacent bending points 7113 is 40 micrometers to 300 micrometers. This allows for sufficient current collection between the third fine gate 13 and the fourth fine gate 14 while reducing the manufacturing cost of the fifth fine gate 21.

[0071] In one possible implementation, there are multiple first bending segments 7111, each of which is parallel to the others; or, there are multiple second bending segments 7112, each of which is parallel to the others; or, there are multiple first bending segments 7111 and multiple second bending segments 7112, each of which is parallel to the others. Thus, by providing parallel first or second bending portions, the manufacturing difficulty of the fifth fine grid 21 can be reduced, and the manufacturing process of the fifth fine grid 21 can be simplified.

[0072] Preferably, the adjacent first bend segment 7111 and second bend segment 7112 are symmetrical along the first direction. This ensures more uniform current collection at the bends, preventing insufficient current collection or overload on one side. The symmetrical first bend segment 7111 and second bend segment 7112 also allow for more balanced current collection in the fifth fine grid 21.

[0073] As shown in Figures 2, 4, 8, and 9, in one possible embodiment, the first bend 711 is a straight segment or a curved segment. When the first bend 711 is a straight segment, it is easier to manufacture, reducing the manufacturing cost of the fifth fine grid 21. When the first bend 711 is a curved segment, the current collecting area of ​​the fifth fine grid 21 can be further increased to better collect the current between the third fine grid 13 and the fourth fine grid 14, thereby improving the photoelectric conversion efficiency of the back contact cell 100.

[0074] In one possible implementation, the fifth fine grid 21 includes a bent structure 710, which comprises a plurality of first bends 711. The bent structure 710 is triangular or sinusoidal. Specifically, the fifth fine grid 21 may include a triangular-wave bent structure 710 or a sinusoidal-wave bent structure 710. Thus, the structure of the fifth fine grid 21 can be adjusted by adjusting the period or amplitude of the bent structure 710 to accommodate different second spacing D2.

[0075] As shown in Figures 2 and 5, in one possible embodiment, the fifth fine grid 21 may further include a first non-bent portion 712, the extension direction of which is parallel to the second direction. Thus, by combining the first non-bent portion 712 and the first bent portion 711, the flexibility of the fifth fine grid 21 can be improved, and the manufacturing difficulty of the fifth fine grid 21 can be reduced.

[0076] Specifically, the first non-bending portion 712 may be connected to the first bending portion 711. The fifth fine grid 21 may specifically include one or more first non-bending portions 712 and first bending portions 711, which is not limited here.

[0077] As shown in Figures 2, 6, and 7, in one possible embodiment, the back contact cell 100 further includes a plurality of positioning points 30 located between the third fine grid 13 and the fourth fine grid 14. Specifically, the back contact cell 100 includes a plurality of positioning points 30, which can be used to position the grid lines of the solar cell. By setting the positioning points 30, the grid lines can be better positioned and aligned during grid line arrangement.

[0078] Meanwhile, in the second direction, because the spacing between the third fine grid 13 and the fourth fine grid 14 is relatively large, there is sufficient space between the third fine grid 13 and the fourth fine grid 14 to place the positioning point 30, so the positioning point 30 can be set larger, improving the recognizability of the positioning point 30.

[0079] Specifically, the positioning point 30 is located between the third fine grid 13 and the fourth fine grid 14. That is, both the fifth fine grid 21 and the positioning point 30 are located between the third fine grid 13 and the fourth fine grid 14, thus, the current in the area corresponding to the current arrangement positioning point 30 can be collected better.

[0080] Specifically, in the second direction, the distance D5 between the fifth fine grid 21 and the positioning point 30 is 200 micrometers to 2000 micrometers. For example, it is 200 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers, 1200 micrometers, 1500 micrometers, 1700 micrometers, 1800 micrometers, or 2000 micrometers.

[0081] As shown in Figures 2, 6, and 7, in one possible embodiment, the second polarity gate 20 includes a sixth gate 22 located between the third gate 13 and the fourth gate 14. The sixth gate 22, the positioning point 30, and the fifth gate 21 are sequentially distributed along a second direction. In this second direction, the distance D6 between the sixth gate 22 and the positioning point 30 is between 200 micrometers and 2000 micrometers. Examples include 200 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers, 1200 micrometers, 1500 micrometers, 1700 micrometers, 1800 micrometers, and 2000 micrometers.

[0082] It is understandable that "the sixth fine grid 22, the positioning point 30, and the fifth fine grid 21 are distributed sequentially along the second direction." This means that, in the second direction, the sixth fine grid 22, the positioning point 30, and the fifth fine grid 21 are arranged and distributed along the second direction. For example, the sixth fine grid 22, the positioning point 30, and the fifth fine grid 21 can be arranged sequentially in a leftward direction; or, the sixth fine grid 22, the positioning point 30, and the fifth fine grid 21 can be arranged sequentially in a rightward direction.

[0083] Specifically, in the second direction, the spacing D7 between the sixth fine gate 22 and the fifth fine gate 21 is 400 micrometers to 4000 micrometers. For example, it is 400 micrometers, 500 micrometers, 800 micrometers, 1000 micrometers, 1500 micrometers, 2000 micrometers, 3000 micrometers, or 4000 micrometers.

[0084] In one possible implementation, as shown in FIG6, the sixth fine grid 22 is a non-bent grid line, and the extension direction of the sixth fine grid 22 is parallel to the second direction. This reduces the manufacturing difficulty of the sixth fine grid 22, thereby reducing the manufacturing cost of the back contact battery 100.

[0085] In one possible implementation, as shown in FIG7, the sixth fine gate 22 includes a second bend 713, the extension direction of which intersects the second direction. Thus, the sixth fine gate 22 can better collect the current between the third fine gate 13 and the fourth fine gate 14, improving the photoelectric conversion efficiency of the back contact cell 100.

[0086] As shown in Figures 2, 10, and 11, in one possible embodiment, the back contact battery 100 further includes a plurality of first polar doped regions 40 and a plurality of second polar doped regions 50; the first polar doped regions 40 and the second polar doped regions 50 are arranged alternately along a first direction and extend along a second direction; the positions of the first polar doped regions 40 correspond to the positions of the first polar grid 10, and the positions of the second polar doped regions 50 correspond to the positions of the second polar grid 20; the doping polarities of the first polar doped regions 40 and the second polar doped regions 50 are opposite.

[0087] Specifically, "the position of the first polar doped region 40 corresponds to the position of the first polar fine gate 10" means that one first polar doped region 40 is correspondingly set with one first polar fine gate 10. In other words, along the thickness direction of the back contact cell 100, the projection of the first polar fine gate 10 on the back contact cell 100 is located in the first polar doped region 40.

[0088] Specifically, "the position of the second polar doped region 50 corresponds to the position of the second polar fine gate 20" means that one second polar doped region 50 is correspondingly set with one second polar fine gate 20. In other words, along the thickness direction of the back contact cell 100, the projection of the second polar fine gate 20 on the back contact cell 100 is located in the second polar doped region 50.

[0089] Simultaneously, the first polar fine gate 10 is electrically connected to the first polar doped region 40, enabling the first polar fine gate 10 to collect the current in the first polar doped region 40. Furthermore, the second polar fine gate 20 is electrically connected to the second polar doped region 50, enabling the second polar fine gate 20 to collect the current in the second polar doped region 50.

[0090] In some embodiments, the second polar fine gate 20 includes a seventh fine gate 23, which is located between the first fine gate 11 and the second fine gate 12; the second polar doped region 50 corresponding to the location of the fifth fine gate 21 is a first doped region 51, and the size of the first doped region 51 in the first direction is a first dimension D8; the second polar doped region 50 corresponding to the location of the seventh fine gate 23 is a second doped region 52, and the size of the first doped region 51 in the first direction is a second dimension D9; the first dimension D8 is greater than the second dimension D9.

[0091] Thus, by positioning the fifth fine gate 21 to correspond to the position of the larger first doped region 51, the fifth fine gate 21 can better collect the current from the larger first doped region 51 through the first bend 711, thereby improving the photoelectric conversion efficiency of the back contact cell 100.

[0092] It is worth noting that "first size D8" refers to the distance between the two boundaries of the first doped region 51 in the first direction. "Second size D9" refers to the distance between the two boundaries of the second doped region 52 in the first direction.

[0093] Specifically, in the first direction, the first dimension D8 is 900 micrometers to 1300 micrometers. For example, it is 900 micrometers, 950 micrometers, 1000 micrometers, 1050 micrometers, 1100 micrometers, 1150 micrometers, or 1200 micrometers.

[0094] As shown in Figures 2, 10, and 11, in some embodiments, the first polar doped region 40 includes a third doped region 41 and a fourth doped region 42, which are adjacent to each other, and the first doped region 51 is located between the third doped region 41 and the fourth doped region 42; along the first direction, the distance between the third doped region 41 and the fourth doped region 42 is a third distance D10; the first polar doped region 40 also includes a fifth doped region 43 and a sixth doped region 44, which are adjacent to each other, and the first doped region 51 is located between the fifth doped region 43 and the sixth doped region 44; along the first direction, the distance between the fifth doped region 43 and the sixth doped region 44 is a fourth distance D11; in the first direction, the fourth distance D11 is smaller than the third distance D10.

[0095] Thus, by setting the fourth spacing D11 to be smaller than the third spacing D10, the fifth fine grid 21 can better collect the current between the larger-spacing third doped region 41 and fourth doped region 42 through the first bend 711, thereby improving the photoelectric conversion efficiency of the back contact cell 100.

[0096] It is worth noting that "third spacing D10" refers to the distance between the boundary of the third doped region 41 closest to the first doped region 51 in the first direction and the boundary of the fourth doped region 42 closest to the first doped region 51 in the first direction. "Fourth spacing D11" refers to the distance between the boundary of the fifth doped region 43 closest to the second doped region 52 in the first direction and the boundary of the sixth doped region 44 closest to the second doped region 52 in the first direction.

[0097] Specifically, the third doped region 41 and the fourth doped region 42, as well as the fifth doped region 43 and the sixth doped region 44, are two sets of two adjacent first polar doped regions 40. Along the first direction, the fourth spacing D11 is smaller than the third spacing D10, that is, the third doped region 41 and the fourth doped region 42 are a set of adjacent first polar doped regions 40 with a larger spacing.

[0098] Furthermore, in the first direction, the third spacing D10 is greater than or equal to the first dimension D8. When the third spacing D10 is greater than the first dimension D8, an isolation region is provided between the third doped region 41 and the first doped region 51, or between the first doped region 51 and the fourth doped region 42, or isolation regions are provided between the third doped region 41 and the first doped region 51 and between the first doped region 51 and the fourth doped region 42.

[0099] It is understood that an isolation region refers to a space between two doped regions. Specifically, there is a space between the third doped region 41 and the first doped region 51, or a space between the first doped region 51 and the fourth doped region 42, or isolation regions are provided between the third doped region 41 and the first doped region 51, as well as between the first doped region 51 and the fourth doped region 42.

[0100] When the third spacing D10 is equal to the first size D8, no isolation region is provided between the third doped region 41 and the first doped region 51, and between the first doped region 51 and the fourth doped region 42.

[0101] Similarly, in the first direction, the fourth spacing D11 is greater than or equal to the second dimension D9. When the fourth spacing D11 is greater than the second dimension D9, an isolation region is provided between the fifth doped region 43 and the second doped region 52, or an isolation region is provided between the sixth doped region 44 and the second doped region 52, or isolation regions are provided between the fifth doped region 43 and the second doped region 52 and between the sixth doped region 44 and the second doped region 52.

[0102] It is understood that there is a gap between the fifth doped region 43 and the second doped region 52, or between the sixth doped region 44 and the second doped region 52, or both between the fifth doped region 43 and the second doped region 52 and between the sixth doped region 44 and the second doped region 52.

[0103] When the fourth spacing D11 is equal to the second dimension D9, no isolation region is provided between the fifth doped region 43 and the second doped region 52, and between the sixth doped region 44 and the second doped region 52.

[0104] It is understood that in such an embodiment, the battery module 1001 may also include a frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back of the battery cells, as well as between the photovoltaic glass and adjacent battery cells. 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.

[0105] Photovoltaic glass can be applied to the encapsulating film on the front of the solar cell. 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 cell while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell together, providing sealing, insulation, and waterproofing / moisture protection for the cell.

[0106] The backsheet can be attached to the adhesive film on the back of the solar cells. The backsheet protects and supports the cells, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy composite adhesive film, etc., and the specific choice is determined based on the specific circumstances and is not limited here. The backsheet, solar cells, adhesive film, and photovoltaic glass together form a frame. The frame serves as the main external support structure for the entire solar module 1001, providing stable support and installation for the module. For example, the frame can be used to install the solar module 1001 at the desired location.

[0107] 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.

[0108] 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 plurality of first polarity grids and a plurality of second polarity grids; The first polar fine gate and the second polar fine gate are arranged alternately along a first direction, and the first polar fine gate and the second polar fine gate extend along a second direction, which intersects the first direction. The polarities of the first polar fine gate and the second polar fine gate are opposite. The first polar fine gate includes a first fine gate and a second fine gate, the first fine gate and the second fine gate are adjacent to each other, and the distance between the first fine gate and the second fine gate along the first direction is a first distance; The first polar fine gate further includes a third fine gate and a fourth fine gate, the third fine gate and the fourth fine gate are adjacent to each other, and the distance between the third fine gate and the fourth fine gate along the first direction is a second distance, the second distance being greater than the first distance; The second polar fine gate includes a fifth fine gate, which is located between the third fine gate and the fourth fine gate. The fifth fine gate includes a first bend, the extension direction of which intersects the second direction.

2. The back contact battery according to claim 1, wherein, The second spacing is 900 micrometers to 1300 micrometers.

3. The back contact battery according to claim 1, wherein, The fifth fine gate includes a first endpoint and a second endpoint. The first endpoint is the point on the fifth fine gate that is closest to the third fine gate, and the second endpoint is the point on the fifth fine gate that is closest to the fourth fine gate. The distance between the first endpoint and the second endpoint in the first direction is 20 micrometers to 150 micrometers.

4. The back contact battery according to claim 1, wherein, The first bending portion includes a plurality of first bending segments, a plurality of second bending segments, and a plurality of bending points, wherein the bending points are located between adjacent first bending segments and second bending segments.

5. The back contact battery according to claim 4, wherein, In the second direction, the distance between two adjacent bending points is 40 micrometers to 300 micrometers.

6. The back contact battery according to claim 4, wherein, The number of first bending segments is multiple, and each first bending segment is parallel to the others; or, the number of second bending segments is multiple, and each second bending segment is parallel to the others; or, the number of both first bending segments and second bending segments is multiple, and each first bending segment is parallel to the others, and each second bending segment is parallel to the others.

7. The back contact battery according to claim 1, wherein, The first bend is a straight segment or a curved segment.

8. The back contact battery according to claim 1, wherein, The fifth fine grid includes a bent structure, and the bent structure includes a plurality of the first bent portions.

9. The back contact battery according to claim 8, wherein, The bending structure has a triangular wave shape.

10. The back contact battery according to claim 8, wherein, The bending structure is sinusoidal in shape.

11. The back contact battery according to claim 1, wherein, The fifth fine grid also includes a first non-bent portion, the extension direction of which is parallel to the second direction.

12. The back contact battery according to claim 1, wherein, The back contact battery also includes several positioning points, which are located between the third fine grid and the fourth fine grid.

13. The back contact battery according to claim 12, wherein, In the second direction, the distance between the fifth fine grid and the positioning point is 200 micrometers to 2000 micrometers.

14. The back contact battery according to claim 12, wherein, The second polar fine grid includes a sixth fine grid, which is located between the third fine grid and the fourth fine grid, and the sixth fine grid, the positioning point, and the fifth fine grid are distributed sequentially along the second direction; In the second direction, the distance between the sixth fine grid and the positioning point is 200 micrometers to 2000 micrometers.

15. The back contact battery according to claim 14, wherein, In the second direction, the spacing between the sixth fine gate and the fifth fine gate is 400 micrometers to 4000 micrometers.

16. The back contact battery according to claim 14, wherein, The sixth fine grid is a non-bent grid line, and the extension direction of the sixth fine grid is parallel to the second direction.

17. The back contact battery according to claim 14, wherein, The sixth fine grid includes a second bend, the extension direction of which intersects the second direction.

18. The back contact battery according to claim 1, wherein, The back contact battery also includes multiple first polarity doped regions and multiple second polarity doped regions; The first polar doped region and the second polar doped region are arranged alternately along the first direction and extend along the second direction. The position of the first polar doped region corresponds to the position of the first polar fine gate, and the position of the second polar doped region corresponds to the position of the second polar fine gate. The doping polarities of the first polar doped region and the second polar doped region are opposite.

19. The back contact battery according to claim 18, wherein, The second polar fine gate includes a seventh fine gate, which is located between the first fine gate and the second fine gate; The second polar doped region corresponding to the location of the fifth fine gate is the first doped region, and the size of the first doped region in the first direction is the first size; The second polar doped region corresponding to the location of the seventh fine gate is the second doped region, and the size of the first doped region in the first direction is the second size; The first dimension is larger than the second dimension.

20. The back contact battery according to claim 19, wherein, The first polar doped region includes a third doped region and a fourth doped region, the third doped region and the fourth doped region are adjacent to each other, and the first doped region is located between the third doped region and the fourth doped region; Along the first direction, the distance between the third doped region and the fourth doped region is the third distance; The first polar doped region further includes a fifth doped region and a sixth doped region, the fifth doped region and the sixth doped region being adjacent to each other, and the second doped region being located between the fifth doped region and the sixth doped region; Along the first direction, the spacing between the fifth doped region and the sixth doped region is the fourth spacing; In the first direction, the fourth spacing is smaller than the third spacing.

21. A battery assembly comprising a back-contact battery as described in any one of claims 1 to 20.

22. A photovoltaic system comprising the battery module as described in claim 21.

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