Back-contact cell, assembly and system

Abstract

Provided are a back-contact solar cell, an assembly, and a system. In the back-contact cell, at least one finger (20) in a first edge region (1012) close to a first edge (1011) of a silicon substrate (101) comprises a bent portion (30), wherein the maximum distance between the bent portion (30) and the first edge (1011) is greater than the distance between a non-bent portion and the first edge (1011); and the bent portion (30) is located in the region of the finger (20) that is electrically connected to a ribbon.

Description

Back contact batteries, components and systems

[0001] Priority information

[0002] This disclosure claims priority and benefits to patent application No. 202411835044.6 filed with the China National Intellectual Property Administration on December 12, 2024, and patent applications Nos. 202510161933.7 and 202510164650.8 filed with the China National Intellectual Property Administration on February 13, 2025, the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] Solar cell power generation is a sustainable and clean energy source that converts sunlight into electrical energy using the photovoltaic effect of semiconductor pn junctions. In related technologies, electrical connectors such as solder ribbons are typically used to connect the back-contact cells to form a cell string. However, these connectors are prone to detaching from the back-contact cells, resulting in poor connection stability.

[0005] Therefore, improving the connection stability between the back contact battery and the electrical connector has become an urgent problem to be solved. Summary of the Invention

[0006] This disclosure provides a back contact battery, a battery module, and a photovoltaic system, aiming to solve the problem of how to improve the connection stability between the back contact battery and electrical connectors.

[0007] In a first aspect, this disclosure provides a back contact battery, comprising: a silicon substrate and a plurality of fine gates disposed on the silicon substrate; each fine gate extends along a first direction, the plurality of fine gates are spaced apart along a second direction, the first direction and the second direction intersect; the silicon substrate has a first edge in the second direction, and the silicon substrate includes a first edge region, the first edge region being an edge region on the silicon substrate close to the first edge; at least one fine gate located in the first edge region includes a bent portion, the maximum distance between the bent portion and the first edge is greater than the distance between the non-bent portion on the fine gate and the first edge, the bent portion being located in a region on the fine gate electrically connected to a solder strip.

[0008] In some embodiments of this disclosure, the bent portion is a recessed bent portion, and the distance from the bottom edge of the recessed bent portion to the first edge is greater than the distance between the non-bent portion on the fine grid and the first edge.

[0009] In some embodiments of this disclosure, the linewidth of the bend is greater than the linewidth of the gate line segments other than the bend on the fine gate.

[0010] In some embodiments of this disclosure, the fine gate closest to the first edge among a plurality of fine gates is the first edge fine gate, the first edge fine gate includes a first bend portion, and a first pad is provided on the first bend portion.

[0011] In some embodiments of this disclosure, the back contact battery includes a second pad located above the first pad, and the second pad is integrally connected to the first pad.

[0012] In some embodiments of this disclosure, the fine grid adjacent to the first bend is a second edge fine grid, the second edge fine grid including a second bend, the midpoint of the second bend and the first bend being on the same straight line.

[0013] In some embodiments of this disclosure, the length of the second bend in the first direction is greater than the length of the first bend in the first direction.

[0014] In some embodiments of this disclosure, in the second direction, the distance between the first bend and the second bend is less than the distance between the non-bend portions of two adjacent fine grids.

[0015] In some embodiments of this disclosure, the polarities of the first edge gate and the second edge gate are different; a third pad is provided on the area of ​​the second edge gate that is electrically connected to the solder strip; the third pad extends toward the first edge, and a break is provided on the first edge gate; the length of the break in the first direction is greater than the length of the third pad in the first direction.

[0016] In some embodiments of this disclosure, the fine gate closest to the first edge among a plurality of fine gates is the first edge fine gate, and the fine gate adjacent to the first edge fine gate is the second edge fine gate; a fourth pad is provided on the first edge fine gate, and the second edge fine gate includes a fourth bend portion, the fourth pad is disposed opposite to the fourth bend portion and extends toward the fourth bend portion.

[0017] In some embodiments of this disclosure, the width of the fourth pad in the second direction is greater than the spacing between two adjacent fine gates in the region on the silicon substrate other than the first edge region.

[0018] Secondly, this disclosure provides another type of back contact battery, comprising: a silicon substrate; a plurality of first polar grids and a plurality of second polar grids disposed on the silicon substrate, the first polar grids and the second polar grids being arranged at intervals along a first direction; the first polar grids include a first grid, the first grids being connected to a first connecting block, the width of the first connecting block being greater than the width of the first grid, and the length of the first connecting block being greater than or equal to 100 μm; the second polar grids include a second grid, the second grids including a connected first grid body portion and a first grid bend portion, the first grid body portion extending along a second direction, the second direction intersecting the first direction, the first grid bend portion being correspondingly disposed with the first connecting block, and the first grid bend portion bending away from the first grid body portion in a direction away from the first connecting block.

[0019] In some embodiments of this disclosure, the difference between the width of the first connecting block and the width of the first fine gate is 5 μm to 290 μm.

[0020] In some embodiments of this disclosure, the maximum distance between the first fine gate bend and the first fine gate body in a first direction is 5 μm to 290 μm.

[0021] In some embodiments of this disclosure, the first fine gate, the first connecting block, and the second fine gate satisfy the following formula: -100μm≤w1-w2-d1≤100μm; where w1 is the width of the first connecting block, w2 is the width of the first fine gate, and d1 is the maximum distance between the bent portion of the first fine gate and the main body portion of the first fine gate in the first direction.

[0022] In some embodiments of this disclosure, the first fine gate is a first polar fine gate closest to the edge of the silicon substrate, and the distance between the first fine gate and the edge is 0.4 mm to 1 mm.

[0023] In some embodiments of this disclosure, the distance from the first connector block to the edge of the silicon substrate is 0.4 mm to 50 mm.

[0024] In some embodiments of this disclosure, the first polar fine gate includes a third fine gate, the third fine gate includes a connected second fine gate body portion and a second fine gate bending portion, the second fine gate body portion extends along a second direction, the second fine gate bending portion is correspondingly disposed with the first connecting block, and the second fine gate bending portion bends from the second fine gate body portion in a direction away from the first connecting block.

[0025] In some embodiments of this disclosure, the bending depth of the first fine grid bend and the second fine grid bend gradually decreases along the direction away from the first connecting block.

[0026] In some embodiments of this disclosure, for adjacent second and third fine gates, the first and second fine gate bends satisfy the following formula: 50μm≤d1-d2≤150μm; where d2 is the maximum distance between the second fine gate bend and the second fine gate body in the first direction, and d1 is the maximum distance between the first fine gate bend and the first fine gate body in the first direction.

[0027] In some embodiments of this disclosure, the back contact battery satisfies at least one of the following: a first fine grid and a first connecting block connected to the first fine grid form a first conductive structure, and each row of the first conductive structure is continuous; each row of the second fine grid is continuous.

[0028] In some embodiments of this disclosure, the first connection block includes at least one of a pad and a gate segment.

[0029] In some embodiments of this disclosure, the first connection includes a hollow area; or, the first connection block is solid.

[0030] In some embodiments of this disclosure, the second polar fine gate includes a fourth fine gate, the fourth fine gate having a second connecting block, the width of the second connecting block being greater than the width of the fourth fine gate.

[0031] In some embodiments of this disclosure, the difference between the width of the second connecting block and the width of the fourth fine gate is 5 μm to 290 μm.

[0032] In some embodiments of this disclosure, the difference between the area of ​​the first connecting block and the area of ​​the second connecting block is -100 μm. 2 Up to 400μm 2 .

[0033] In some embodiments of this disclosure, the first polar fine gate adjacent to the second connecting block is disconnected at a position corresponding to the second connecting block to avoid the second connecting block. In the second direction, the distance between the breakpoints of the second connecting block and the first fine gate is 0.2 mm to 1 mm.

[0034] In some embodiments of this disclosure, the fourth fine gate is the second polar fine gate closest to the edge of the silicon substrate, and the distance between the fourth fine gate and the edge is greater than 0.7 mm to 1.3 mm.

[0035] In some embodiments of this disclosure, the distance from the second connector block to the edge of the silicon substrate is 0.7 mm to 50 mm.

[0036] In some embodiments of this disclosure, the fourth fine gate is the second polar fine gate closest to the edge of the silicon substrate, and the second connecting block is located on the side of the fourth fine gate facing the edge.

[0037] In some embodiments of this disclosure, the second connecting block protrudes from the fourth fine gate to both sides of the fourth fine gate.

[0038] In some embodiments of this disclosure, the fourth fine gate includes a connected third fine gate body portion and a third fine gate bend portion, the third fine gate body portion extending along a second direction, the third fine gate bend portion bending from the third fine gate body portion toward an edge away from the silicon substrate, and a second connecting block disposed on the third fine gate bend portion.

[0039] In some embodiments of this disclosure, the maximum distance between the third fine gate bend and the third fine gate body in the first direction is 5 μm to 290 μm.

[0040] In some embodiments of this disclosure, the fourth fine gate and the second fine gate are the same second polarity fine gate.

[0041] In some embodiments of this disclosure, the fourth fine gate and the second connecting block disposed on the fourth fine gate form a second conductive structure, and each row of the second conductive structure is continuous.

[0042] In some embodiments of this disclosure, the second connection block includes at least one of a pad and a gate segment.

[0043] In some embodiments of this disclosure, the second connecting block includes a hollow area; or, the second connecting block is solid.

[0044] In some embodiments of this disclosure, the silicon substrate includes a plurality of first polar doped regions and a plurality of second polar doped regions arranged along a first direction. The first polar doped regions are provided with first polar fine gates, and the second polar doped regions are provided with second polar fine gates. The first polar doped region includes a first doped region, which includes a first region and a second region. The first region is provided with a first fine gate, and the second region corresponds to a first connecting block. The second polar doped region includes a second doped region, which includes a third region and a fourth region. The third region is provided with a first fine gate body portion of the second fine gate, and the fourth region is provided with a first fine gate bend portion of the second fine gate.

[0045] In some embodiments of this disclosure, the second region protrudes from the first region.

[0046] In some embodiments of this disclosure, in a first direction, the second region protrudes from the first region to a maximum depth of 5 μm to 290 μm.

[0047] In some embodiments of this disclosure, the fourth region protrudes from the third region on the side opposite to the second region.

[0048] In some embodiments of this disclosure, in a first direction, the fourth region protrudes from the third region to a maximum depth of 1 μm to 500 μm.

[0049] In some embodiments of this disclosure, the second region protrudes from the first region on the side facing the fourth region, and in a first direction, the difference between the maximum depth of the second region protruding from the first region and the maximum depth of the fourth region protruding from the third region is 50 μm to 200 μm.

[0050] In some embodiments of this disclosure, the first polar fine gate includes a third fine gate, the third fine gate includes a connected second fine gate body portion and a second fine gate bend portion, the second fine gate body portion extends along a second direction, the second fine gate bend portion is correspondingly disposed with the first connecting block, and the second fine gate bend portion bends from the second fine gate body portion in a direction away from the first connecting block; the first polar doped region includes a third doped region, the third doped region includes a fifth region and a sixth region, the fifth region is provided with the second fine gate body portion of the third fine gate, and the sixth region is provided with the second fine gate bend portion of the third fine gate.

[0051] In some embodiments of this disclosure, the sixth region protrudes from the fifth region on the side opposite to the second region.

[0052] In some embodiments of this disclosure, the fourth region protrudes from the third region on the side opposite to the second region, and the protrusion depth of the fourth and sixth regions gradually decreases along the direction away from the second region.

[0053] In some embodiments of this disclosure, for adjacent second and third doped regions, the fourth and sixth regions satisfy the following formula: 50μm≤H2-H3≤200μm; where H2 is the maximum depth of the fourth region protruding from the third region on the side away from the second region in the first direction, and H3 is the maximum depth of the sixth region protruding from the fifth region on the side away from the second region in the first direction.

[0054] In some embodiments of this disclosure, the back contact battery satisfies at least one of the following: each row of the first doped region is continuous; each row of the second doped region is continuous.

[0055] In some embodiments of this disclosure, the doped region closest to the edge of the silicon substrate is a P-region.

[0056] In some embodiments of this disclosure, the second polar fine gate includes a fourth fine gate, the fourth fine gate is connected to the second connection block, and the width of the second connection block is greater than the width of the fourth fine gate; the second polar doped region includes a fourth doped region, the fourth doped region includes a seventh region and an eighth region, the seventh region is provided with the fourth fine gate, and the eighth region corresponds to the second connection block.

[0057] In some embodiments of this disclosure, the eighth region protrudes from the seventh region.

[0058] In some embodiments of this disclosure, the maximum depth of the eighth region protruding from the seventh region is from 5 μm to 290 μm.

[0059] In some embodiments of this disclosure, the fourth doped region and the second doped region are the same second polar doped region.

[0060] In some embodiments of this disclosure, the fourth doped region in each row is continuous.

[0061] In some embodiments of this disclosure, the fourth fine gate includes a connected third fine gate body portion and a third fine gate bend portion, the third fine gate body portion extends along a second direction, the third fine gate bend portion bends from the third fine gate body portion toward an edge away from the silicon substrate, and a second connecting block is disposed on the third fine gate bend portion; the fourth doped region includes a ninth region, and the ninth region is provided with the third fine gate bend portion.

[0062] In some embodiments of this disclosure, the ninth region protrudes from the seventh region on the side opposite to the eighth region.

[0063] In some embodiments of this disclosure, the first polar fine gate is a positive fine gate, and the first polar fine gate includes a fifth fine gate and a sixth fine gate. The spacing between the sixth fine gate and the adjacent second polar fine gate is greater than the spacing between the fifth fine gate and the adjacent second polar fine gate.

[0064] In some embodiments of this disclosure, the sixth fine gate is connected to the third connecting block, and the width of the third connecting block is greater than the width of the sixth fine gate.

[0065] In some embodiments of this disclosure, the distance between the sixth fine gate and the adjacent second polar fine gate is a first distance, and the distance between the fifth fine gate and the adjacent second polar fine gate is a second distance, with the difference between the first distance and the second distance being 0.05 to 0.1 mm.

[0066] Thirdly, this disclosure also provides a battery assembly including any of the back-contact batteries described above.

[0067] Fourthly, this disclosure also provides a photovoltaic system including the aforementioned battery module.

[0068] The back contact battery provided in the first aspect of this disclosure, by providing a bending portion on at least one fine grid in the first edge region, makes the area on the fine grid that is electrically connected to the solder ribbon closer to the middle region of the silicon substrate, reducing the distance between the fine grid in the first edge region and the end of the solder ribbon. This reduces the precision requirements for solder ribbon placement, ensures that the portion of the solder ribbon can achieve effective electrical connection with the fine grid in the first edge region, improves the current collection effect, and thus improves the battery power generation efficiency and battery reliability. At the same time, the grid line segment corresponding to the bending portion can form a larger space to increase the printing area, thereby increasing the welding area and thus increasing the welding pull between the fine grid and the end of the solder ribbon.

[0069] The back contact battery provided in the second aspect of this disclosure has an increased contact area between the first connecting block and the electrical connector because the width of the first connecting block is greater than the width of the first fine grid and its length is greater than or equal to 100 μm. This increases the tensile strength, reduces the risk of the electrical connector detaching from the back contact battery, and improves the connection stability between the back contact battery and the electrical connector. Simultaneously, because the first bent portion in the second fine grid bends away from the main body of the first fine grid, more space can be provided for the wider first connecting block, facilitating its widening and reducing the risk of short circuits caused by insufficient spacing between the two polarities of electrodes. Attached Figure Description

[0070] Figure 1 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0071] Figure 2 is a second schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0072] Figure 3 is a third schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0073] Figure 4 is a fourth schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0074] Figure 5 is a fifth schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0075] Figure 6 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0076] Figure 7 is a seventh schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0077] Figure 8 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0078] Figure 9 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0079] Figure 10 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0080] Figure 11 is an eleventh schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0081] Figure 12 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0082] Figure 13 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0083] Figure 14 is a fourteenth schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0084] Figure 15 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0085] Figure 16 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0086] Figure 17 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0087] Figure 18 is an eighteenth schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0088] Figure 19 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0089] Figure 20 is a schematic diagram of the structure of a battery assembly provided according to an embodiment of the present disclosure;

[0090] Figure 21 is a schematic diagram of the structure of a photovoltaic system provided according to an embodiment of the present disclosure;

[0091] Figure 22 is a schematic diagram of a partial structure of a back contact battery according to an embodiment of the present disclosure;

[0092] Figure 23 is an enlarged schematic diagram of a portion of the back contact battery structure in Figure 22;

[0093] Figure 24 is a schematic diagram of the structure of a back contact battery provided according to an embodiment of the present disclosure;

[0094] Figure 25 is a second schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0095] Figure 26 is a third schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0096] Figure 27 is a fourth schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0097] Figure 28 is a fifth schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0098] Figure 29 is an enlarged schematic diagram of a portion of the back contact battery structure in Figure 28;

[0099] Figure 30 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0100] Figure 31 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0101] Figure 32 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0102] Figure 33 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0103] Figure 34 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0104] Figure 35 is an eleventh schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0105] Figure 36 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0106] Figure 37 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0107] Figure 38 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0108] Figure 39 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0109] Figure 40 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0110] Figure 41 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0111] Figure 42 is an eighteenth schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0112] Figure 43 is an enlarged schematic diagram of a portion of the back contact battery structure in Figure 42;

[0113] Figure 44 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0114] Figure 45 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0115] Figure 46 is a schematic diagram of a partial structure of a back contact battery provided according to an embodiment of the present disclosure;

[0116] Figure 47 is a schematic diagram of a back contact battery provided according to an embodiment of the present disclosure;

[0117] Figure 48 is a schematic diagram of a portion of the back contact battery structure shown in Figure 47. Detailed Implementation

[0118] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this disclosure, and should not be construed as limiting this disclosure. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this disclosure and are not intended to limit this disclosure.

[0119] In the description of this disclosure, it should be understood that the terms “length”, “width”, “upper”, “lower”, “left”, “right”, “horizontal”, “top”, “bottom”, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and are not intended to 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.

[0120] 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.

[0121] 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.

[0122] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0123] 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.

[0124] Figure 1 is a schematic diagram of the structure of a back contact battery provided in an embodiment of the present disclosure. As shown in Figure 1, the present disclosure provides a back contact battery, including: a silicon substrate 101 and a plurality of fine gates 20 disposed on the silicon substrate 101, each fine gate 20 extending along a first direction, the plurality of fine gates 20 being arranged at intervals in a second direction, the first direction and the second direction intersecting; the silicon substrate 101 has a first edge 1011 in the second direction, and the silicon substrate 101 includes a first edge region 1012, the first edge region 1012 being an edge region on the silicon substrate 101 close to the first edge 1011; at least one fine gate 20 located in the first edge region 1012 includes a bent portion 30, the maximum distance between the bent portion 30 and the first edge 1011 is greater than the distance between the non-bent portion on the fine gate 20 and the first edge 1011, the bent portion 30 being located in the region on the fine gate 20 that is electrically connected to the solder strip.

[0125] In this embodiment, the back contact battery is a gridless back contact battery. The silicon substrate 101 included in the back contact battery can be a single cell, or it can be a half-cell, a third-cell, or other proportioned cell divided from a single cell. It should be noted that the accompanying drawings provided in this disclosure are schematic diagrams and do not represent a limitation on the specific form of the back contact battery.

[0126] The silicon substrate 101 may include a front side and a back side, with the front side facing the sun and primarily receiving direct sunlight, and the back side facing the mounting surface of the battery module and primarily receiving sunlight reflected from the mounting surface, such as the ground or a roof. A plurality of fine gates 20 are disposed on the back side of the silicon substrate 101, and a doped layer and a passivation layer are stacked on the back side of the silicon substrate 101. The doped layer can be connected to the plurality of fine gates 20 to establish an ohmic contact.

[0127] A plurality of fine gates 20 are disposed on the back side of the silicon substrate 101. Each fine gate 20 extends along a first direction, and fine gates 20 with opposite polarities are arranged alternately along a second direction, which intersects the first direction. The spacing between two adjacent fine gates 20 may be equal or unequal, and is not specifically limited here.

[0128] It should be noted that the first direction can be the length direction of the fine grid 20, i.e., the horizontal direction in Figure 1; the second direction can be the width direction of the fine grid 20, i.e., the vertical direction in Figure 1. In other embodiments, the first and second directions can also be other directions, such as the diagonal direction, etc., which are not specifically limited here.

[0129] The silicon substrate 101 has two opposing edges in a second direction, one of which is designated as a first edge 1011. A region on the back surface of the silicon substrate 101 near the first edge 1011 is designated as a first edge region 1012. The length of the first edge region 1012 in the first direction may include the length of the silicon substrate in the first direction. The size of the first edge region 1012 in the second direction may be determined based on the number of gate lines near the first edge 1011 or the size of the central region of the silicon substrate, and is not specifically limited here.

[0130] At least one fine gate 20 located within the first edge region 1012 also has several regions electrically connected to the solder strip for current extraction and transmission.

[0131] In practice, a plurality of solder strips are provided on the back side of the silicon substrate 101. These solder strips extend along a second direction and are arranged alternately along a first direction. Adjacent solder strips collect currents from the fine gate 20 of opposite polarities. For example, the solder strip collecting the current from the positive fine gate can be the first solder strip, and the solder strip collecting the current from the negative fine gate can be the second solder strip. In this case, the positive fine gate is electrically connected to the first solder strip, and the first solder strip is insulated from the negative fine gate; the negative fine gate is electrically connected to the second solder strip, and the second solder strip is insulated from the positive fine gate.

[0132] In this embodiment of the present disclosure, the area on the fine grid 20 within the first edge region 1012 that is electrically connected to the solder strip is the position where the fine grid 20 is electrically connected to the end of the solder strip, and a bending portion 30 is provided at this position. The extension direction of the bending portion 30 is different from the extension direction of the fine grid 20, and it is spaced apart from the fine grid 20 adjacent to the bending portion 30 and the fine grid 20 corresponding to the bending portion 30, so as to avoid short circuit.

[0133] As shown in Figure 2, the bending portion 30 can be a sawtooth-shaped grid line segment. As shown in Figure 3, the bending portion 30 can be a wavy grid line segment. As shown in Figures 4, 5 and 6, the bending portion 30 can also be a grid line segment that is recessed to the side away from the first edge.

[0134] As can be seen from Figures 2 to 6, the maximum distance between the bent portion 30 and the first edge 1011 in the second direction is greater than the distance between the fine gate 20 and the first edge 1011. Specifically, the maximum distance between the bent portion 30 and the first edge 1011 is the maximum distance from a point on the gate line segment corresponding to the bent portion 30 to the first edge 1011, and the distance between the fine gate 20 and the first edge 1011 is the maximum distance from a point on the gate line segment on the fine gate 20 that is not corresponding to the bent portion to the first edge 1011.

[0135] Understandably, for the same fine gate 20, the gate segment corresponding to the bend 30 is closer to the middle region of the silicon substrate 101 than the gate segment corresponding to the non-bend 30. This makes it easier for the solder ribbon end to contact the bend 30, and the bend 30 can form a larger space, thereby increasing the printing area. The printing area can be directly printed with solder paste, or the pads can be printed first and then the solder paste can be printed. The gate segment corresponding to the bend 30 provides a larger printing area for the pads or solder paste compared to the gate segment without the bend 30.

[0136] The back contact battery provided in this embodiment of the present disclosure, by providing a bend in at least one fine grid in the first edge region, makes the area on the fine grid that is electrically connected to the solder strip closer to the middle region of the silicon substrate, reducing the distance between the grid line segment corresponding to the bend and the end of the solder strip. This reduces the precision requirements for solder strip placement, ensuring that this part of the solder strip can achieve effective electrical connection with the fine grid in the first edge region, improving the current collection effect, and thus improving the battery power generation efficiency and battery reliability. At the same time, the grid line segment corresponding to the bend can form a larger space to increase the printing area, thereby increasing the welding area and increasing the welding pull between the fine grid and the end of the solder strip.

[0137] In some embodiments, the line width of the bend 30 is greater than the line width of the gate line segments on the fine gate 20 excluding the bend 30.

[0138] As shown in Figures 1 to 6, the line width of the bent portion 30 is greater than the line width of the gate line segments on the fine gate 20 excluding the bent portion 30. The line width of the bent portion 30 can be the line width of the gate line segment corresponding to the bent portion 30.

[0139] If the fine gate 20 is a positive fine gate, the linewidth of the gate line segment other than the bending portion 30 can be about 38μm. For example, the linewidth of the bending portion 30 on the positive fine gate can be 38μm to 50μm, or it can be 39μm, 40μm, 42μm, 44μm, 46μm, 48μm, 50μm, or a value greater than 38μm.

[0140] If the fine gate 20 is a negative electrode fine gate, the linewidth of the gate line segment other than the bending portion 30 can be about 35μm. For example, the linewidth of the bending portion 30 on the negative electrode fine gate can be 35μm to 50μm, or it can be 36μm, 38μm, 40μm, 42μm, 44μm, 46μm, 48μm, 50μm, or a value greater than 35μm.

[0141] In other embodiments, the line width of the fine grid 20 can be adjusted according to the actual situation, and the line width of the bent portion 30 can also be adjusted to a larger line width accordingly, which is not limited here.

[0142] Understandably, the larger the linewidth of the bend 30, the closer the lower edge of the fine gate corresponding to the bend 30 is to the middle region of the silicon substrate in the second direction, making it easier for the solder ribbon end to connect with the gate line segment corresponding to the bend 30, thus increasing the chance of the solder ribbon end contacting the gate line segment corresponding to the bend 30.

[0143] The back contact battery provided in this embodiment of the present disclosure further reduces the distance between the grid line segment corresponding to the bend and the end of the solder strip by increasing the line width of the bend. This reduces the precision requirements for the placement of the solder strip and ensures that the solder strip and the fine grid in the first edge region can achieve effective electrical connection.

[0144] In some embodiments, the fine gate 20 closest to the first edge 1011 among a plurality of fine gates is the first edge fine gate 201, the first edge fine gate 201 includes a first bending portion 301, and a first pad 41 is provided on the first bending portion 301.

[0145] As shown in Figure 7, the first edge fine grid 201 is the fine grid 20 closest to the first edge 1011 in the first edge region 1012. That is, compared with other fine grids in the first edge region 1012, the point on the first edge fine grid 201 has the smallest distance to the first edge 1011 in the second direction.

[0146] A first bend 301 can be provided in the area on the first edge fine grid 201 that is electrically connected to the welding strip.

[0147] A first bending portion 301 is provided with a first pad 41, and the first pad 41 is connected to the first bending portion 301. The length of the first pad 41 in the first direction is less than or equal to the length of the first bending portion 301 in the first direction.

[0148] It can be understood that solder paste can be printed on the first pad 41. The solder tape is placed on the pad coated with solder paste. After the solder paste melts, solder joints are formed between the solder tape and the first pad 41, so that a good welding connection can be formed between the first bending portion 301 and the first pad 41. Alternatively, solder paste can also be directly printed on the first bending portion 301, because the first bending portion 301 can provide a larger printing area. Setting the first bending portion 301 can enable the first pad 41 or the solder paste to cover a larger area, and the specific size of the area can be selected according to the required welding tensile force, which is not specifically limited herein.

[0149] The back-contact battery provided by the embodiment of the present disclosure increases the welding area by providing a first pad on the first bending portion. When the solder tape is connected to the fine grid, the welding tensile force between the grid segment corresponding to the first bending portion and the solder tape can be increased, and the first pad on the first bending portion is closer to the middle area of the silicon substrate, which improves the probability of forming an effective electrical connection between the end of the solder tape and the fine grid in the first edge region, making it easier for the end of the solder tape to be connected to the first bending portion, thereby improving the current collection effect, and further improving the battery power generation efficiency and battery reliability.

[0150] In some embodiments, the back-contact battery is provided with a second pad 42. The second pad 42 is located above the first pad 41 and is integrally connected to the first pad 41. The length of the first pad 41 in the first direction is greater than or equal to the length of the second pad 42 in the first direction, and the length of the second pad 42 in the first direction does not exceed the length of the first bending portion 301 in the first direction.

[0151] As shown in FIG. 8, a second pad 42 integrally connected to the first pad 41 is provided above the first pad 41, and the second pad 42 extends toward the first edge 1011 or extends in the second direction.

[0152] Wherein, the second pad 42 can be composed of one or more pads.

[0153] [[ID=I9]]The integrally connected second pad 42 and first pad 41 can be in a "mountain" shape, as shown in FIG. 8; or can also be in an "inverted π" shape, as shown in FIG. 9; can also be in an "inverted T" shape, as shown in FIG. 10; or can also be in a comb shape or a zigzag shape, etc., which is not specifically limited herein.

[0154] It is understandable that the second pad 42 can further expand the soldering area of ​​the first pad 41 in the second direction, thereby increasing the solder joint area. The distribution of the second pad 42 in the first direction can be a distributed multiple pads or a single pad, without specific limitation here. Among them, a distributed multiple pads can also increase the probability of the solder ribbon connecting to the pad.

[0155] The back contact battery provided in this embodiment can increase the welding area by providing an integrally connected second pad above the first pad, thereby increasing the probability of forming an effective electrical connection between the end of the solder strip and the fine grid in the first edge region, and thus increasing the welding pull between the grid line segment corresponding to the first bend and the solder strip.

[0156] In some embodiments, the fine grid adjacent to the first bend 301 is a second edge fine grid 202, which includes a second bend 302, and the midpoint of the second bend 302 and the first bend 301 are on the same straight line.

[0157] It is understandable that the second edge fine grid 202 and the first edge fine grid 201 are fine grids with opposite polarities. If the second edge fine grid 202 adjacent to the first bend 301 is not provided with the second bend 302, the distance between the second edge fine grid 202 adjacent to the first bend 301 and the first edge fine grid 201 will be closer, which will increase the risk of short circuit.

[0158] As shown in Figures 11 and 12, the second edge fine grid 202 is provided with a second bending portion 302. The welding strip connected to the second bending portion 302 is insulated. Optionally, insulating adhesive or other insulating materials can be printed on the second bending portion 302. No specific limitation is made here. The length of the insulating material printed on the second bending portion 302 in the first direction is greater than the width of the welding strip in the first direction.

[0159] Optionally, the solder strip electrically connected to the first bend 301 should be insulated from the second bend 302. The line width of the second bend 302 can be the same as the line width of the non-bend portion on the fine grid 20 where the second bend 302 is located, that is, the second bend 302 does not need to be widened.

[0160] The second bend 302 may have the same or different shapes as the first bend 301, and there is a gap between the second bend 302 and the first bend 301. In some embodiments, the second bend 302 and the first bend 301 are set to have the same shape, which is more conducive to maintaining a gap between the second bend 302 and the first bend 301.

[0161] The midpoints of the second bend 302 and the first bend 301 in the first direction can be located on the same straight line. In some embodiments, the midpoints of the second bend 302 and the first bend 301 in the first direction may not be on the same straight line. In this case, the length of the second bend 302 in the first direction needs to be greater than the length of the first bend 301 in the first direction to prevent the second bend 302 and the first bend 301 from being too close in the second direction.

[0162] The back contact battery provided in this embodiment increases the distance between two adjacent fine grids by providing a second bend on the fine grid adjacent to the first bend, thereby preventing the two adjacent fine grids from contacting each other and thus avoiding short circuits.

[0163] In some embodiments, the length of the second bend 302 in the first direction is greater than the length of the first bend 301 in the first direction.

[0164] As shown in Figures 11 and 12, the length of the second bend 302 in the first direction is greater than the length of the first bend 301 in the first direction, and the midpoint of the second bend 302 in the first direction is on the same straight line as the midpoint of the first bend 301 in the first direction.

[0165] As shown in Figure 13, among the two fine grids 20 adjacent to the second edge fine grid 202, the third edge fine grid 203, in addition to the first edge fine grid 201, may also be provided with a third bending portion 303, the length of the third bending portion 303 in the first direction is greater than the length of the second bending portion 302 in the first direction.

[0166] It is understandable that the linewidth of the third bend 303 is greater than the linewidth of the gate segments other than the third bend 303 on the fine gate where the third bend 303 is located. As shown in Figure 15, the fine gate where the third bend 303 is located is a fine gate of the same polarity as the fine gate where the first bend 301 is located. The third bend 303 can also increase the soldering area to set solder paste or pads, which is not specifically limited here.

[0167] It is understandable that, starting from the first bend 301 of the first edge fine grid 201, the length of the bends arranged sequentially along the second direction can gradually increase in the first direction, which is more conducive to maintaining the interval between the bends on adjacent fine grids 20.

[0168] The back contact battery provided in this embodiment can further reduce the risk of short circuit by providing a second bend, wherein the length of the second bend in the first direction is greater than the length of the first bend in the first direction.

[0169] In some embodiments, in the second direction, the distance between the first bend 301 and the second bend 302 is less than the distance between two adjacent fine grids 20. It should be understood that the distance between two adjacent fine grids 20 mentioned above refers to the distance in the second direction between the non-bend portions (i.e., portions other than bends) of the two adjacent fine grids 20.

[0170] As shown in Figure 13, the maximum bending distance of the first bent portion 301 relative to the first edge fine grid 201 in the second direction is greater than the maximum bending distance of the second bent portion 302 relative to the second edge fine grid 202 in the second direction. Therefore, in the second direction, the distance d between the first bent portion 301 and the second bent portion 302 is less than the distance D between two adjacent fine grids 20.

[0171] It should be noted that, as shown in Figures 2 to 6, the maximum bending distance 'a' of the bent portion 30 refers to the distance between the lower edge of the bent portion 30 in the second direction and the non-bent portion of the first edge fine grid 201. As shown in Figure 13, the distance 'D' between two adjacent fine grids 20 refers to the distance in the second direction between the non-bent portions of two adjacent fine grids 20, such as the first edge fine grid 201 and the second edge fine grid 202.

[0172] It is understandable that, starting from the first bend 301 of the first edge fine grid 201, along the second direction, the maximum bending distance of the bends arranged sequentially in the second direction can be gradually reduced until the maximum bending distance is reduced to 0, at which point there will be no bends on the fine grid 20.

[0173] The back contact battery provided in this embodiment of the present disclosure can gradually reduce the bending distance of the bending portion by setting the distance between the first bending portion and the second bending portion to be smaller than the distance between two adjacent fine grids. This allows for an increase in the distance between the fine grid closer to the bending portion and the fine grid where the bending portion is located in the two fine grids adjacent to the fine grid corresponding to the bending portion, thereby reducing the risk of adjacent fine grids contacting each other and avoiding short circuits.

[0174] In some embodiments, the first edge gate 201 and the second edge gate 202 have different polarities. The area on the second edge gate 202 that conducts current is provided with a third pad 43. The third pad 43 extends toward the first edge 1011. The first edge gate 201 is provided with a break portion 50. The length of the break portion 50 in the first direction is greater than the length of the third pad 43 in the first direction.

[0175] As shown in Figure 14, the second edge fine gate 202 is a fine gate with the opposite polarity to the first edge fine gate 201. The area on the second edge fine gate 202 that conducts current is the area where the solder strip is connected. A third solder pad 43 can be set in this area. The third solder pad 43 extends toward the first edge 1011 and along the second direction.

[0176] The shape of the third pad 43 may be the same as or different from the shape of the integrally connected second pad 42 and first pad 41. For example, the shape of the third pad 43 may be an inverted T shape, a mountain shape, an inverted π shape, or a comb shape, without specific limitations.

[0177] The break portion 50 provided on the first edge fine grid 201 facilitates increasing the coverage area of ​​the third solder pad 43, which can increase the welding area and improve the welding pull force.

[0178] Understandably, the provision of the disconnection portion 50 increases the extension distance of the third pad 43 in the second direction, thereby allowing the third pad 43 to further expand the soldering area. The distribution of the third pad 43 in the first direction can be a plurality of dispersed pads or a single pad; no specific limitation is made here. Among these, a plurality of dispersed pads can also increase the probability of the solder ribbon connecting to the pad.

[0179] The back contact battery provided in this embodiment increases the coverage area of ​​the third solder pad by providing a break on the first edge fine grid and a third solder pad in the area where current is conducted on the second edge fine grid, thereby increasing the welding area and thus increasing the welding pull force.

[0180] In some embodiments, as shown in FIG16, the fine gate 20 closest to the first edge 1011 among a plurality of fine gates is the first edge fine gate 201, and the fine gate adjacent to the first edge fine gate 201 is the second edge fine gate 202. The first edge fine gate 201 is provided with a fourth pad 44, and the second edge fine gate 202 includes a fourth bend portion 304. The fourth pad 44 is disposed opposite to the fourth bend portion 304 and extends toward the fourth bend portion 304.

[0181] It is understood that, unlike the above embodiments, the second edge gate 202 is provided with a fourth bend 304. The distance from the lower edge of the fourth bend 304 to the first edge gate 201 in the second direction is greater than the distance from the non-bend portion of the second edge gate 202 to the first edge gate 201. This allows for a larger space to be formed between the first edge gate 201 and the fourth bend 304, enabling the application of more silver paste or solder paste at the position on the first edge gate 201 opposite to the fourth bend 304. Consequently, a fourth pad 44 can be provided on the first edge gate 201 at the position opposite to the fourth bend 304. The fourth pad 44 extends toward the area bent by the fourth bend 304, and the fourth pad 44 is spaced apart from the fourth bend 304. Furthermore, in this embodiment, the width of the fourth pad 44 in the second direction is greater than the line width of the first edge gate 201, facilitating soldering and enhancing component reliability.

[0182] As shown in Figure 16, the fourth pad 44 can be rectangular, and the length of the fourth pad 44 in the first direction is less than the length of the fourth bend 304 in the first direction. Thus, when the fourth pad 44 extends to the fourth bend 304, the extended portion of the pad can extend into the space formed by the fourth bend 304 and remain spaced apart from the fourth bend 304.

[0183] As shown in Figure 17, when the fourth pad 44 extends toward the fourth bend 304, the length of the extended portion of the fourth pad 44 in the first direction is less than the length of the fourth bend 304 in the first direction, so that the extended portion of the pad can extend into the space formed by the fourth bend 304 and remain spaced apart from the fourth bend 304.

[0184] As shown in Figure 18, the fourth pad 44 can extend simultaneously towards both the first edge 1011 and the fourth bend 304. The length of the portion of the fourth pad 44 extending towards the fourth bend 304 in the first direction is less than the length of the fourth bend 304 in the first direction. The length of the portion of the fourth pad 44 extending towards the first edge 1011 in the first direction can be greater than or equal to the length of the fourth bend 304 in the first direction, or it can be less than the length of the fourth bend 304 in the first direction.

[0185] It is understandable that the space formed by the fourth bend 304 can be determined based on the shape of the fourth bend 304. In the portion of the pad 44 extending into the fourth bend 304, the shape of the end near the fourth bend 304 can be adjusted according to the space formed by the fourth bend 304, and is not specifically limited here.

[0186] In some embodiments, the width of the fourth pad 44 in the second direction is greater than the spacing between two adjacent fine gates 20 in the region on the silicon substrate 101 excluding the first edge region 1012.

[0187] It is understood that, as shown in Figures 17 and 18, the fourth pad 44 can extend toward the fourth bend 304, or extend simultaneously toward both the first edge 1011 and the fourth bend 304, and can extend into the space formed by the fourth bend 304. Therefore, the width of the fourth pad 44 in the second direction can be greater than the spacing between two adjacent fine gates 20 in the region on the silicon substrate 101 excluding the first edge region 1012.

[0188] As shown in Figure 19, a fourth pad 44 is provided on the first edge fine gate 201, and a third pad 43 is provided on the second edge fine gate 202. The first edge fine gate 201 and the second edge fine gate 202 are fine gates 20 with opposite polarities. Since a break 50 is provided on the first edge fine gate 201 at the position opposite to the third pad 43, and a fourth bend 304 is provided on the second edge fine gate 202 at the position opposite to the fourth pad 44, a larger space can be formed to increase the printing area. This allows for the provision of wider pads in the second direction on both the first edge fine gate 201 and the second edge fine gate 202, thereby providing greater soldering pull force.

[0189] Figure 20 is a schematic diagram of the structure of a battery assembly provided in an embodiment of this disclosure. As shown in Figure 20, this disclosure provides a battery assembly 2000, including: a back contact battery 1000 as described in any of the above embodiments.

[0190] It should be noted that the back contact battery 1000 has been described in detail in the above embodiments and will not be specifically limited here.

[0191] In this embodiment, the back contact batteries 1000 in the battery assembly 2000 can be connected in series to form a battery string, thereby realizing the series current collection and output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0192] It is understood that in such embodiments, the battery assembly may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back of the solar cells, the photovoltaic glass, and adjacent 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.

[0193] Photovoltaic glass can be applied to the encapsulating film on the front of solar cells. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cells while minimizing impact on their efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cells together, providing sealing, insulation, and waterproofing / moisture protection for the solar cells.

[0194] The backsheet can be attached to the encapsulating film on the back of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc., depending on the specific circumstances and not limited here. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0195] This disclosure provides a battery module 2000. By providing a bending portion on at least one fine grid in a first edge region, the area on the fine grid that is electrically connected to the solder ribbon is brought closer to the middle region of the silicon substrate. This reduces the distance between the fine grid in the first edge region and the end of the solder ribbon, thereby reducing the precision requirements for solder ribbon placement and ensuring that this portion of the solder ribbon can achieve effective electrical connection with the fine grid in the first edge region. This improves the current collection effect, thereby improving the battery power generation efficiency and battery reliability, and thus improving the photoelectric conversion efficiency of the module. At the same time, the grid line segment corresponding to the bending portion can form a larger space to increase the printing area, thereby increasing the welding area and thus increasing the welding pull between the fine grid and the end of the solder ribbon.

[0196] Figure 21 is a schematic diagram of the structure of a photovoltaic system provided in an embodiment of this disclosure. As shown in Figure 21, this disclosure provides a photovoltaic system 3000, including: a battery module 2000 as described in the above embodiment.

[0197] It should be noted that the battery assembly 2000 has been described in the above embodiments and will not be specifically limited here.

[0198] In this embodiment, the photovoltaic system 3000 can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 3000 are not limited to these; that is, the photovoltaic system 3000 can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system grid as an example, the photovoltaic system 3000 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0199] The photovoltaic system provided in this disclosure provides a bending portion on at least one fine grid in the first edge region, which brings the area on the fine grid that is electrically connected to the solder ribbon closer to the middle region of the silicon substrate. This reduces the distance between the fine grid in the first edge region and the end of the solder ribbon, thereby reducing the precision requirements for solder ribbon placement and ensuring that the solder ribbon and the fine grid in the first edge region can achieve effective electrical connection. This improves the current collection effect, thereby improving the power generation efficiency and reliability of the battery, and thus improving the photoelectric conversion efficiency of the module and the power generation efficiency of the system. At the same time, the grid line segment corresponding to the bending portion can form a larger space to increase the printing area, thereby increasing the welding area and increasing the welding tension between the fine grid and the end of the solder ribbon.

[0200] Based on the same concept, this disclosure also provides a back contact battery, as shown in Figures 22, 23, and 24. The back contact battery 1000 of this disclosure embodiment includes: a silicon substrate 101, a plurality of first polarity fine gates 11, and a plurality of second polarity fine gates 12. The plurality of first polarity fine gates 11 and the plurality of second polarity fine gates 12 are disposed on the silicon substrate 101, and the first polarity fine gates 11 and second polarity fine gates 12 are arranged at intervals along a first direction. The first polarity fine gate 11 includes a first fine gate 111, and a first connecting block 112 is provided on the first fine gate 111. The width w1 of the first connecting block 112 is greater than the width w2 of the first fine gate 111, and the length S1 of the first connecting block 112 is greater than or equal to 100 μm. The second polar fine grid 12 includes a second fine grid 121. The second fine grid 121 includes a first fine grid main body portion 1211 and a first fine grid bending portion 1212 connected together. The first fine grid main body portion 1211 extends along a second direction, which intersects with the first direction. The first fine grid bending portion 1212 is correspondingly disposed with the first connecting block 112, and the first fine grid bending portion 1212 bends from the first fine grid main body portion 1211 in a direction away from the first connecting block 112.

[0201] In the back contact battery 1000 of this embodiment, since the width w1 of the first connecting block 112 is greater than the width w2 of the first fine grid 111 and the length s1 is greater than or equal to 100 μm, the contact area between the first connecting block 112 and the electrical connector can be increased, the tensile force can be increased, the risk of the electrical connector falling off the back contact battery 1000 can be reduced, and the connection stability between the back contact battery 1000 and the electrical connector can be improved. At the same time, since the first fine grid bending portion 1212 in the second fine grid 121 bends away from the first fine grid body portion 1211, more space can be provided for the wider first connecting block 112, which facilitates the widening of the first connecting block 112 and can reduce the short circuit risk caused by the small electrode spacing of the two polarities.

[0202] Optionally, the back contact battery 1000 can be a sliced ​​battery formed by cutting a whole battery. For example, Figure 24 shows a half-cell battery formed by cutting a whole battery in half. The back contact battery 1000 can also be a whole battery that has not been cut. The whole back contact battery 1000 may include slicing grooves, along which the whole battery can be cut to obtain the sliced ​​battery shown in Figure 24. The whole back contact battery 1000 may be asymmetrical or symmetrical along the slicing grooves.

[0203] This disclosure uses a back contact battery without a main grid as an example for explanation and illustration. It can be understood that in some embodiments, the back contact battery 1000 may also be a back contact battery with a main grid. When the back contact battery 1000 is a back contact battery with a main grid, the main grid may be located in an area outside the first connecting block 112. This prevents the main grid from interfering with the connection between the first connecting block 112 and the first electrical connector.

[0204] Optionally, the silicon substrate 101 may include a silicon substrate, a first polar doped layer, a second polar doped layer, and a dielectric film layer 1003.

[0205] Optionally, the silicon substrate can be a P-type silicon substrate or an N-type silicon substrate; it can be a monocrystalline silicon substrate or a polycrystalline silicon substrate. No specific form of the silicon substrate is limited here.

[0206] Optionally, a first polar doped layer and a second polar doped layer are disposed on a silicon substrate. The first polar doped layer and the second polar doped layer have different doping polarities. The two doped layers can be formed by diffusion into the silicon substrate or by deposition of films on the silicon substrate.

[0207] It can be understood that, in the thickness direction of the back contact cell 1000, a first polar doped layer is stacked on the silicon substrate, and a second polar doped layer is stacked on the silicon substrate. On a plane perpendicular to the thickness direction of the back contact cell 1000, the first polar doped layer and the second polar doped layer are distributed in regions, corresponding to the first polar doped region 13 and the second polar doped region 14, respectively, as shown in Figures 33 to 41.

[0208] In the following text, "the first polar doped region 13 includes the first doped region 131" and "the first polar doped region 13 includes the third doped region 132" refer to the first doped region 131 and the third doped region 132 being doped regions of the first polarity. In the following text, "the second polar doped region 14 includes the second doped region 141" and "the second polar doped region 14 includes the fourth doped region 142" refer to the second doped region 141 and the fourth doped region 142 being doped regions of the second polarity.

[0209] Optionally, the dielectric film 1003 may cover the first polar doped layer and the second polar doped layer. The first polar fine gate 11 passes through the dielectric film 1003 to contact the first polar doped layer, and the second polar fine gate 12 passes through the dielectric film 1003 to contact the second polar doped layer. Thus, the dielectric film 1003 achieves electrical isolation between the first polar doped layer and the second polar doped layer, while also reducing light reflection and recombination. The dielectric film 1003 may also be disposed between at least one pair of adjacent first polar doped regions 13 and second polar doped regions 14 for electrical isolation between the first polar doped regions 13 and the second polar doped regions 14. To better illustrate the first polar doped region 13 and the second polar doped region 14, the portion of the dielectric film 1003 covering the first polar doped region 13 and the second polar doped region 14 is omitted in Figures 33 to 41.

[0210] Optionally, the first polar fine gate 11 and the second polar fine gate 12 may be distributed over the entire area of ​​the silicon substrate 101, or the first polar fine gate 11 and the second polar fine gate 12 may be distributed over a portion of the silicon substrate 101. It is understood that areas of the silicon substrate 101 where the first polar fine gate 11 and the second polar fine gate 12 are not distributed may have other fine gates, may have a main gate, or may not have gate lines.

[0211] Optionally, the first polar fine gate 11 and the second polar fine gate 12 have different polarities. The first polar fine gate 11 corresponds to the first polar doped layer and the first polar doped region 13. The second polar fine gate 12 corresponds to the second polar doped layer and the second polar doped region 14.

[0212] Optionally, the number of first polar fine gates 11 can be 1, 2, 3, 4, or other numbers. The number of second polar fine gates 12 can be 1, 2, 3, 4, or other numbers. No limitation is made here. The number of first polar fine gates 11 and the number of second polar fine gates 12 can be the same or different.

[0213] Optionally, the first polar fine gate 11 and the second polar fine gate 12 are arranged along the first direction. They can be arranged alternately or non-alternatingly along the first direction, and they can be arranged at equal intervals or unequal intervals along the first direction. No limitation is made here.

[0214] Optionally, the first polarity fine gate 11 and the second polarity fine gate 12 are spaced apart, meaning that a gap is formed between adjacent first polarity fine gates 11 and second polarity fine gates 12. The gap can be filled with an insulating element or can be an air gap.

[0215] The following descriptions of "first polarity fine gate 11 includes first fine gate 111", "first polarity fine gate 11 includes third fine gate 113", and "first polarity fine gate 11 includes fifth fine gate 114 and sixth fine gate 115" refer to the fact that first fine gate 111, third fine gate 113, fifth fine gate 114, and sixth fine gate 115 are all fine gates of the first polarity. The following descriptions of "second polarity fine gate 12 includes second fine gate 121" and "second polarity fine gate 12 includes fourth fine gate 122" refer to the fact that second fine gate 121 and fourth fine gate 122 are both fine gates of the second polarity.

[0216] As shown in Figures 22, 23, and 24, in this embodiment, the first fine gate 111 is the first polar fine gate 11 closest to the edge of the silicon substrate 101. This reduces the risk of the electrical connector detaching from the end of the back contact battery 1000.

[0217] It is understood that in other embodiments, the first fine gate 111 may be located away from the edge of the silicon substrate 101. For example, the first fine gate 111 may be the second, third, fourth, or other sequentially numbered first polarity fine gate 11 from the edge. In this way, the risk of the electrical connector detaching from a more central position in the back contact battery 1000 can be reduced. In this case, a bent second fine gate 121 may be provided on one or both sides of the first fine gate 111 to avoid the first connecting block 112 provided on the first fine gate 111.

[0218] As shown in Figures 22, 23 and 24, the first connecting block 112 is disposed on the first fine grid 111. That is, the first connecting block 112 is connected to the first fine grid 111.

[0219] Optionally, the first connector 112 may penetrate the dielectric film layer 1003 to contact the first polar doped layer. The first connector 112 and the first polar doped layer may also be isolated by the dielectric film layer 1003. The first connector 112 may be fabricated together with the first fine gate 111. Alternatively, the first connector 112 and the first fine gate 111 may be fabricated separately.

[0220] In some embodiments, the first connecting block 112 and the first fine gate 111 are made of the same paste, both of which burn through the dielectric film layer 1003 to contact the first polar doped layer. In other embodiments, the paste of the first fine gate 111 burns through the dielectric film layer 1003 to contact the first polar doped layer, while the paste of the first connecting block 112 does not burn through the dielectric film layer 1003.

[0221] In some embodiments, the first connection block 112 includes at least one of a pad and a gate line segment. This allows for diverse forms of the first connection block 112, facilitating the fulfillment of various production scenarios and requirements. For example, the first connection block 112 may include a pad. Alternatively, the first connection block 112 may include a gate line segment. Yet another example is the first connection block 112 comprising both a pad and a gate line segment. It is understood that when the first connection block 112 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the first polar doped layer. When the first connection block 112 includes a pad, the pad may pass through the dielectric film layer 1003 to contact the first polar doped layer, or it may be isolated from the first polar doped layer by the dielectric film layer 1003.

[0222] In two adjacent back contact batteries 1000, an electrical connector is electrically connected to a grid of one polarity in one back contact battery 1000 and electrically connected to a grid of another polarity in the other back contact battery 1000. This document describes the connection method of the electrical connector in a single back contact battery 1000.

[0223] That is, in a single back contact battery 1000, the first electrical connector is electrically connected to the first polarity fine gate 11 and isolated from the second polarity fine gate 12; the second electrical connector is electrically connected to the second polarity fine gate 12 and isolated from the first polarity fine gate 11. In other words, the fine gates connected to by an electrical connector in the same back contact battery 1000 have the same polarity. It should be understood that this does not mean that the electrical connector has a polarity that is the same as the polarity of the fine gate it is connected to.

[0224] Optionally, the first electrical connector and the second electrical connector extend along a first direction and are arranged alternately along a second direction.

[0225] Optionally, the second polarity grid 12 may be disconnected at the coverage of the first electrical connector to avoid the first electrical connector; alternatively, the second polarity grid 12 may be continuous at the coverage of the first electrical connector, electrically isolated from the first electrical connector by an insulating element. Similarly, the first polarity grid 11 may be disconnected at the coverage of the second electrical connector to avoid the second electrical connector; alternatively, the first polarity grid 11 may be continuous at the coverage of the second electrical connector, electrically isolated from the second electrical connector by an insulating element.

[0226] Optionally, the first connecting block 112 is used to connect the first electrical connector.

[0227] Optionally, the first connecting block 112 and the first electrical connector can be electrically connected by at least one of the following methods: adhesive bonding, direct soldering, solder paste soldering, or physical contact, without limitation.

[0228] Optionally, the entire area of ​​the first connecting block 112 is connected to the first electrical connector. This results in a larger connection area, which is beneficial for improving connection stability. It is understood that in other embodiments, a portion of the first connecting block 112 may also be connected to the first electrical connector.

[0229] Optionally, the first electrical connector includes at least one of a solder strip and a conductive wire. This document uses a solder strip as an example to illustrate the concept. It can be understood that when the first electrical connector is a solder strip, the embodiments of this disclosure can reduce the risk of the solder strip detaching from the back contact battery 1000.

[0230] Optionally, the area covered by the first electrical connector in the back contact battery 1000 is the first pre-connection area.

[0231] Optionally, in the battery assembly, there may be multiple first electrical connectors connected to the same back contact battery 1000. In the back contact battery 1000, a first connecting block 112 may be provided in each first pre-connection area, as shown in FIG24. Alternatively, a first connecting block 112 may be provided in some of the first pre-connection areas, while the remaining first pre-connection areas may not have a first connecting block 112.

[0232] Optionally, in the first pre-connection region, a first connecting block 112 may be provided at each of the first polar fine gates 11, or the first connecting block 112 may be provided at some of the first polar fine gates 11, which is not limited here. In the example of FIG24, the first connecting block 112 is provided at the first polar fine gates 11 at both ends of the first pre-connection region.

[0233] As shown in Figures 22 and 23, the width w1 of the first connecting block 112 refers to the dimension of the first connecting block 112 in the first direction. The width w1 of the first connecting block 112 can be the same everywhere, different everywhere, or partially the same. The width w2 of the first fine grid 111 refers to the dimension of the first fine grid 111 in the first direction. The width w2 of the first fine grid 111 can be the same everywhere, different everywhere, or partially the same.

[0234] Optionally, the width w1 of the first connecting block 112 is greater than the width w2 of the first fine gate 111, that is, the width of the first connecting block 112 at least at one location is greater than the width of the first fine gate 111 at least at one location. This could be: the minimum width of the first connecting block 112 is greater than the maximum width of the first fine gate 111; or the maximum width of the first connecting block 112 is greater than the maximum width of the first fine gate 111; or the maximum width of the first connecting block 112 is greater than the width at the connection point between the first fine gate 111 and the first connecting block 112. No limitation is imposed here.

[0235] As shown in Figure 23, the length s1 of the first connecting block 112 is greater than or equal to 100 μm. For example, it can be 100 μm, 101 μm, 110 μm, 150 μm, 200 μm, 500 μm, 800 μm, 1000 μm, 1800 μm, 2000 μm, or 5000 μm.

[0236] Optionally, the length S1 of the first connecting block 112 refers to the dimension of the first connecting block 112 in the second direction. The length S1 of the first connecting block 112 may be the same everywhere, different everywhere, or partially the same.

[0237] The length S1 of the first connecting block 112 is greater than or equal to 100 μm, meaning that the length of the first connecting block 112 at least at one point is greater than or equal to 100 μm. This can mean that the minimum length of the first connecting block 112 is greater than or equal to 100 μm, i.e., the length of the first connecting block 112 at all points is greater than or equal to 100 μm; or it can mean that the maximum length of the first connecting block 112 is greater than or equal to 100 μm. No specific limitation is imposed here.

[0238] As shown in Figures 23 and 25, in some embodiments, the first connecting block 112 includes a first hollow area 1120. This allows for the reduction of material used in the first connecting block 112 while maintaining its coverage area, thus improving connection stability while reducing costs.

[0239] As shown in Figure 26, in some embodiments, the first connecting block 112 is solid. This maximizes the area of ​​the first connecting block 112, thereby increasing the contact area between the first connecting block 112 and the electrical connector, increasing the tensile strength, reducing the risk of the electrical connector detaching from the back contact battery 1000, and improving the connection stability between the back contact battery 1000 and the electrical connector.

[0240] As shown in Figures 22 and 23, in some embodiments, the first connecting block 112 is rectangular. It is understood that in other embodiments, the first connecting block 112 may be circular, annular, elliptical, triangular, racetrack-shaped, or other shapes. The specific shape of the first connecting block 112 is not limited here.

[0241] As shown in Figures 22, 23 and 24, the second fine grid 121 includes a connected first fine grid main body 1211 and a first fine grid bending part 1212. The first fine grid main body 1211 extends along a second direction, which intersects with the first direction. The first fine grid bending part 1212 is correspondingly disposed with the first connecting block 112 and bends from the first fine grid main body 1211 in a direction away from the first connecting block 112.

[0242] Optionally, the connection between the first fine gate body portion 1211 and the first fine gate bending portion 1212 means that the first fine gate body portion 1211 and the first fine gate bending portion 1212 are electrically connected and not disconnected.

[0243] Optionally, "the first fine gate body portion 1211 extends along the second direction" means that the overall extension direction of the first fine gate body portion 1211 is the second direction. This does not represent a limitation on the specific shape of the first fine gate body portion 1211. In this embodiment, the first fine gate body portion 1211 is straight, and the extension direction of the first fine gate body portion 1211, i.e., the second direction, is the length direction of the first fine gate body portion 1211. In other embodiments, the first fine gate body portion 1211 may also be wavy, zigzag, or other shapes.

[0244] Optionally, the second direction intersects the first direction, meaning the second direction and the first direction do not overlap, are not the same, and are not opposite. In this embodiment, the first direction and the second direction are perpendicular to each other. The first direction and the second direction are parallel to two adjacent long sides of the silicon substrate 101, respectively. It is understood that in other embodiments, the first direction and the second direction may also form acute or obtuse angles, and the first direction and the second direction may also form acute or obtuse angles to two adjacent long sides of the silicon substrate 101, respectively. This is not limited here. Please note that "two adjacent long sides" here refers to the sides other than the corners of the silicon substrate 101, not considering the rounded or chamfered arc edges or short sides of the corners of the silicon substrate 101.

[0245] Optionally, the first fine grid bend 1212 is correspondingly disposed with the first connecting block 112. That is, regardless of the thickness of the first fine grid bend 1212 and the first connecting block 112, in the first direction, the projections of the first fine grid bend 1212 and the first connecting block 112 on the same plane at least partially overlap. In other words, the areas occupied by the first fine grid bend 1212 and the first connecting block 112 in the second direction at least partially overlap.

[0246] In this embodiment, the area occupied by the first fine gate bend 1212 in the second direction covers and exceeds the area occupied by the first connecting block 112 in the second direction; that is, the length of the first fine gate bend 1212 in the second direction is greater than the length of the first connecting block 112 in the second direction. Thus, by utilizing the first fine gate bend 1212 to avoid the first connecting block 112 as much as possible, more space can be provided for the wider first connecting block 112, facilitating its widening and minimizing the risk of short circuits caused by excessively small electrode spacing between the two polarities.

[0247] It is understood that in other embodiments, the area occupied by the first connecting block 112 in the second direction may cover and exceed the area occupied by the first fine gate bending portion 1212 in the second direction; or the area occupied by the first connecting block 112 in the second direction may completely overlap with the area occupied by the first fine gate bending portion 1212 in the second direction; or the area occupied by the first connecting block 112 in the second direction may intersect with the area occupied by the first fine gate bending portion 1212 in the second direction.

[0248] Optionally, the first fine grid bending portion 1212 bends from the first fine grid main body portion 1211 in a direction away from the first connecting block 112, which means that in the first direction, the maximum distance between the first fine grid bending portion 1212 and the first fine grid main body portion 1211 is greater than 0.

[0249] Optionally, the first fine grid bending portion 1212 includes a first bending segment, a first connecting segment, and a second bending segment connected in sequence. The first bending segment connects one end of the first fine grid main body portion 1211 and the first connecting segment, and the second bending segment connects the other end of the first fine grid main body portion 1211 and the first connecting segment. In the example of FIG1, the first connecting segment is a straight segment.

[0250] It is understood that in other examples, the first fine grid bend 1212 may be wavy, zigzag, or other shapes. The first connecting segment may be wavy, zigzag, or other shapes. No limitation is made here.

[0251] As shown in Figures 22 and 23, in some embodiments, the difference between the width w1 of the first connecting block 112 and the width w2 of the first fine gate 111 is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0252] In this way, the width difference between the first connecting block 112 and the first fine gate 111 is within a suitable range. This avoids the first connecting block 112 being too narrow and the connection stability of the first electrical connector being poor, which would be caused by the difference being too small. It also avoids the first connecting block 112 having too large a series resistance and large current loss due to the difference being too large.

[0253] As shown in Figures 22 and 23, in some embodiments, the width w1 of the first connecting block 112 is from 10 μm to 300 μm. For example, it is 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, or 300 μm.

[0254] In this way, the width w1 of the first connecting block 112 is within a suitable range, which can avoid the situation where the width is too small, resulting in a small contact width with the first electrical connector and poor connection stability of the first electrical connector. It can also avoid the situation where the width is too large, resulting in too large series resistance of the first connecting block 112 and large current loss.

[0255] As shown in Figures 22 and 23, in some embodiments, the width w2 of the first fine gate 111 is from 5 μm to 250 μm. For example, it is 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, or 250 μm.

[0256] In this way, the width w2 of the first fine gate 111 is within a suitable range, which can avoid the gate line being easy to break and the poor effect of carrying out carriers from the silicon substrate 101 due to the width being too small, and can also avoid the series resistance being too large, the current loss being too large, and the cost being too high due to the width being too large.

[0257] As shown in Figures 22 and 23, in some embodiments, the maximum distance d1 between the first fine gate bending portion 1212 and the first fine gate body portion 1211 in the first direction is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0258] In this way, the maximum distance d1 between the first fine gate bending portion 1212 and the first fine gate main body portion 1211 in the first direction is within a suitable range. This avoids the risk of short circuits caused by the first fine gate bending portion 1212 and the first connecting block 112 being too close due to the small distance between them, and also avoids the risk of the second fine gate 121 being too long, having too much series resistance, and having too much current loss due to the large distance between them.

[0259] As shown in Figures 22 and 23, in some embodiments, the first fine gate 111, the first connecting block 112, and the second fine gate 121 satisfy the following formula:

[0260] -100μm≤w1-w2-d1≤100μm;

[0261] Wherein, w1 is the width of the first connecting block 112, w2 is the width of the first fine grid 111, and d1 is the maximum distance between the first fine grid bending portion 1212 and the first fine grid main body portion 1211 in the first direction.

[0262] In this way, the difference between the width difference between the first connecting block 112 and the first fine gate 111 and the difference between the maximum bending depth of the first fine gate bending portion 1212 are within a suitable range. This avoids the situation where the difference is too small, resulting in the maximum bending depth of the first fine gate bending portion 1212 being too large compared to the width difference between the first connecting block 112 and the first fine gate 111. This would not significantly improve the short circuit risk and would also result in the second fine gate 121 having too large a series resistance. Conversely, it also avoids the situation where the difference is too large, resulting in the maximum bending depth of the first fine gate bending portion 1212 being too small compared to the width difference between the first connecting block 112 and the first fine gate 111, which would lead to a greater short circuit risk.

[0263] Optionally, the values ​​of w1-w2-d1 are, for example, -100μm, -80μm, -50μm, -20μm, 0μm, 10μm, 20μm, 50μm, 80μm, and 100μm.

[0264] Alternatively, the value of w1-w2-d1 can be 0. That is, w1-w2 = d1. In this way, both short-circuit risk and series resistance are taken into account, and the overall effect is better.

[0265] As shown in Figures 22 and 23, in some embodiments, the first fine gate 111 is the first polar fine gate 11 closest to the edge of the silicon substrate 101, and the distance x1 between the first fine gate 111 and the edge is 0.4 mm to 1 mm. For example, it is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0266] In this way, the distance x1 between the first fine gate 111 and the edge is within a suitable range, which can avoid the inconvenience of stacking due to the distance being too small, and can also avoid the poor effect of collecting charge carriers due to the distance being too large.

[0267] Optionally, the distance x1 between the first fine gate 111 and the edge is 0.5mm to 0.8mm. For example, it can be 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, 0.62mm, 0.65mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, or 0.8mm. This further optimizes the distance x1 between the first fine gate 111 and the edge, resulting in a better overall effect.

[0268] As shown in Figures 22 and 23, in some embodiments, the distance x2 from the first connecting block 112 to the edge is 0.4 mm to 50 mm. For example, it is 0.4 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 48 mm, or 50 mm.

[0269] In this way, the distance x2 from the first connecting block 112 to the edge is within a suitable range, which can avoid the inconvenience of stacking due to the distance being too small, and can also avoid the poor connection stability between the end area of ​​the back contact battery 1000 and the first electrical connector due to the distance being too large.

[0270] Optionally, the distance x2 from the first connecting block 112 to the edge is 0.8mm to 5mm. For example, it is 0.8mm, 0.82mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, or 5mm. In this way, the distance x2 from the first connecting block 112 to the edge is further optimized, resulting in better connection stability between the back contact battery 1000 and the first electrical connector.

[0271] As shown in FIG27, in some embodiments, the first polar fine grid 11 includes a third fine grid 113. The third fine grid 113 includes a connected second fine grid main body portion 1131 and a second fine grid bending portion 1132. The second fine grid main body portion 1131 extends along a second direction, and the second fine grid bending portion 1132 is correspondingly disposed with the first connecting block 112 and bends from the second fine grid main body portion 1131 in a direction away from the first connecting block 112.

[0272] In this way, the bent third fine grid 113 can provide more space for the wider first connecting block 112 and the second fine grid 121 which is bent to avoid the first connecting block 112, which facilitates the widening of the first connecting block 112, facilitates the bending of the second fine grid 121, and can reduce the risk of short circuit caused by the small distance between the two polarities of electrodes.

[0273] Optionally, the connection between the second fine grid main body 1131 and the second fine grid bending portion 1132 means that the second fine grid main body 1131 and the second fine grid bending portion 1132 are electrically connected and not disconnected.

[0274] Optionally, "the second fine gate body portion 1131 extends along the second direction" means that the overall extension direction of the second fine gate body portion 1131 is the second direction. This does not represent a limitation on the specific shape of the second fine gate body portion 1131. In this embodiment, the second fine gate body portion 1131 is straight, and the extension direction of the second fine gate body portion 1131, i.e., the second direction, is the length direction of the second fine gate body portion 1131. In other embodiments, the second fine gate body portion 1131 may also be wavy, zigzag, or other shapes.

[0275] Optionally, the second fine grid bend 1132 is correspondingly disposed with the first connecting block 112, meaning that, regardless of the thickness of the second fine grid bend 1132 and the first connecting block 112, in the first direction, the projections of the second fine grid bend 1132 and the first connecting block 112 onto the same plane at least partially overlap. In other words, the areas occupied by the second fine grid bend 1132 and the first connecting block 112 in the second direction at least partially overlap.

[0276] In this embodiment, the area occupied by the second fine gate bend 1132 in the second direction covers and exceeds the area occupied by the first connecting block 112 in the second direction; that is, the length of the second fine gate bend 1132 in the second direction is greater than the length of the first connecting block 112 in the second direction. Thus, by utilizing the second fine gate bend 1132 to avoid the first connecting block 112 as much as possible, more space can be provided for the wider first connecting block 112, facilitating its widening, and minimizing the risk of short circuits caused by excessively small electrode spacing between the two polarities.

[0277] It is understood that in other embodiments, the area occupied by the first connecting block 112 in the second direction may cover and exceed the area occupied by the second fine gate bending portion 1132 in the second direction; or the area occupied by the first connecting block 112 in the second direction may completely overlap with the area occupied by the second fine gate bending portion 1132 in the second direction; or the area occupied by the first connecting block 112 in the second direction may intersect with the area occupied by the second fine gate bending portion 1132 in the second direction.

[0278] Optionally, the second fine grid bending portion 1132 bends from the second fine grid main body portion 1131 in a direction away from the first connecting block 112, meaning that in the first direction, the maximum distance between the second fine grid bending portion 1132 and the second fine grid main body portion 1131 is greater than 0.

[0279] Optionally, the second fine grid bending portion 1132 includes a third bending segment, a second connecting segment, and a fourth bending segment connected in sequence. The third bending segment connects one end of the second fine grid main body portion 1131 and the second connecting segment, and the fourth bending segment connects the other end of the second fine grid main body portion 1131 and the second connecting segment. In the example of FIG27, the second connecting segment is a straight segment.

[0280] It is understood that in other examples, the second fine grid bend 1132 may be wavy, zigzag, or other shapes. The second connecting segment may be wavy, zigzag, or other shapes. No limitation is made here.

[0281] The second fine grid 121 is a bent second polarity fine grid 12, and the third fine grid 113 is a bent first polarity fine grid 11. The second fine grid 121 may be adjacent to the first fine grid 111 or may not be adjacent to the first fine grid 111. The third fine grid 113 may be adjacent to the second fine grid 121 or may not be adjacent to the second fine grid 121.

[0282] In the examples of Figures 22 to 26, there is one second fine grid 121, which is adjacent to the first fine grid 111, and there is no third fine grid 113 in the back contact battery 1000. That is, the first fine grid 111 and the second fine grid 121 are arranged sequentially in the direction away from the edge.

[0283] In the example of Figure 27, there are two second fine grids 121 and one third fine grid 113. One second fine grid 121 is adjacent to the first fine grid 111, and the third fine grid 113 is located between the two second fine grids 121. That is, along the direction away from the edge, the first fine grid 111, the second fine grid 121, the third fine grid 113, and the second fine grid 121 are arranged in sequence.

[0284] It is understandable that in other examples, the first fine grid 111, the second fine grid 121, the third fine grid 113, the second fine grid 121, and the third fine grid 113 could be arranged sequentially along the direction away from the edge.

[0285] As shown in FIG27, in some embodiments, the bending depth of the first fine grid bending portion 1212 and the second fine grid bending portion 1132 gradually decreases along the direction away from the first connecting block 112.

[0286] Thus, along the direction away from the first connecting block 112, the bending depth of the fine grid bend gradually decreases. This not only allows the fine grid bend to avoid the first connecting block 112 or adjacent fine grid bends and reduce the risk of short circuits, but also achieves a transition from bending to smoothness.

[0287] Optionally, the bending depth of the first fine gate bending portion 1212 is the maximum distance between the first fine gate bending portion 1212 and the first fine gate main body portion 1211 in the first direction in the second fine gate 121, which is d1 as shown in FIG. 27. The bending depth of the second fine gate bending portion 1132 is the maximum distance between the second fine gate bending portion 1132 and the second fine gate main body portion 1131 in the first direction in the third fine gate 113, which is d2 as shown in FIG. 27.

[0288] In the example of Figure 27, along the direction away from the edge, the first fine grid 111, the second fine grid 121, the third fine grid 113, and the second fine grid 121 are arranged in sequence, and the bending depth of the corresponding fine grid bending portion gradually decreases.

[0289] Referring to Figure 27, in some embodiments, for adjacent second fine gates 121 and third fine gates 113, the first fine gate bend 1212 and the second fine gate bend 1132 satisfy the following formula:

[0290] 50μm≤d1-d2≤150μm;

[0291] Wherein, d2 is the maximum distance between the second fine grid bending portion 1132 and the second fine grid main body portion 1131 in the first direction, and d1 is the maximum distance between the first fine grid bending portion 1212 and the first fine grid main body portion 1211 in the first direction.

[0292] In this way, the difference in bending depth between adjacent second fine grids 121 and third fine grids 113 is within a suitable range. This avoids the situation where the difference is too small, which would require more fine grids to achieve the transition from bending to smoothness, increasing process complexity and reducing production efficiency. It also avoids the situation where the difference is too large, which would result in insufficient bending depth of one fine grid, close distance between the bending parts of the fine grids with opposite polarity, and a high risk of short circuit.

[0293] Optionally, the values ​​of d1-d2 are, for example, 50μm, 52μm, 80μm, 90μm, 100μm, 120μm, 140μm, and 150μm.

[0294] As shown in Figures 22, 23 and 24, in some embodiments, the first fine gate 111 and the first connecting block 112 disposed on the first fine gate 111 form a first conductive structure 1001, and each row of the first conductive structure 1001 is continuous.

[0295] In this way, the first conductive structure 1001 in each row is not broken or interrupted, which makes the power of the back contact battery 1000 better.

[0296] As shown in Figures 22, 23 and 24, in some embodiments, each row of the second fine grid 121 is continuous.

[0297] In this way, the second fine grid 121 in each row is not interrupted and has no breaks, which makes the power of the back contact battery 1000 better.

[0298] As shown in Figures 28 and 29, in some embodiments, the second polar fine gate 12 includes a fourth fine gate 122, the fourth fine gate 122 is provided with a second connecting block 123, the fourth fine gate 122 is connected to the second connecting block 123, and the width w3 of the second connecting block 123 is greater than the width w4 of the fourth fine gate 122.

[0299] This increases the contact area between the second connecting block 123 and the second electrical connector, increases the tensile force, reduces the risk of the second electrical connector falling off the back contact battery 1000, and improves the connection stability between the back contact battery 1000 and the second electrical connector.

[0300] As shown in Figures 28 and 29, in some embodiments, the fourth fine gate 122 and the second fine gate 121 are the same second polarity fine gate 12. Thus, integrating the first fine gate bend 1212 and the second connecting block 123 onto the same second polarity fine gate 12 enhances the stability of the connection with the second electrical connector. Furthermore, centralized design and fabrication are possible, improving manufacturing efficiency.

[0301] When the fourth fine gate 122 and the second fine gate 121 are the same second polarity fine gate 12, the fourth fine gate 122 and the second fine gate 121 can be regarded as part of the structure of the second polarity fine gate 12.

[0302] It is understood that in other examples, the fourth fine gate 122 and the second fine gate 121 may also be different second polarity fine gates 12. This is not a limitation here.

[0303] Optionally, the second connecting block 123 is used to connect the second electrical connector.

[0304] Optionally, the second connecting block 123 and the second electrical connector can be electrically connected by at least one of the following methods: adhesive bonding, direct soldering, solder paste soldering, or physical contact. No limitation is imposed here.

[0305] Optionally, the entire area of ​​the second connecting block 123 is connected to the second electrical connector. This results in a larger connection area, which is beneficial for improving connection stability. It is understood that in other embodiments, a portion of the second connecting block 123 may also be connected to the second electrical connector.

[0306] Optionally, the second electrical connector includes at least one of a solder strip and a conductive wire. This document uses a solder strip as an example to illustrate the use of a solder strip as the second electrical connector. It can be understood that, in the case of a solder strip as the second electrical connector, the embodiments of this disclosure can reduce the risk of the solder strip detaching from the back contact battery 1000.

[0307] Optionally, the area covered by the second electrical connector in the back contact battery 1000 is the second pre-connection area.

[0308] Optionally, in the battery assembly, there are multiple second electrical connectors connected to the same back contact battery 1000. In the back contact battery 1000, a second connection block 123 may be provided in each second pre-connection area. Alternatively, a second connection block 123 may be provided in a portion of the second pre-connection areas, while the remaining second pre-connection areas may not have a second connection block 123. Optionally, in the second pre-connection area, a second connection block 123 may be provided at each second polarity grid 12, or a second connection block 123 may be provided at a portion of the second polarity grid 12; this is not limited here. In this embodiment, second connection blocks 123 are provided at the second polarity grids 12 at both ends of the second pre-connection area.

[0309] In some embodiments, the second connection block 123 includes at least one of a pad and a gate line segment. This allows for diverse forms of the second connection block 123, facilitating the fulfillment of various production scenarios and requirements. For example, the second connection block 123 may include a pad. Alternatively, the second connection block 123 may include a gate line segment. Yet another example is that the second connection block 123 may include both a pad and a gate line segment. It is understood that when the second connection block 123 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the second polar doped layer. When the second connection block 123 includes a pad, the pad may pass through the dielectric film layer 1003 to contact the second polar doped layer, or it may be isolated from the second polar doped layer by the dielectric film layer 1003.

[0310] As shown in Figures 28 and 29, the width w3 of the second connecting block 123 refers to the dimension of the second connecting block 123 in the first direction. The width w3 of the second connecting block 123 can be the same everywhere, different everywhere, or partially the same. The width w4 of the fourth fine grid 122 refers to the dimension of the fourth fine grid 122 in the first direction. The width w4 of the fourth fine grid 122 can be the same everywhere, different everywhere, or partially the same.

[0311] Optionally, the width w3 of the second connecting block 123 is greater than the width w4 of the fourth fine gate 122, meaning that the width of the second connecting block 123 at least at one location is greater than the width of the fourth fine gate 122 at least at one location. This could be: the minimum width of the second connecting block 123 is greater than the maximum width of the fourth fine gate 122; or the maximum width of the second connecting block 123 is greater than the maximum width of the fourth fine gate 122; or the maximum width of the second connecting block 123 is greater than the width at the connection point between the fourth fine gate 122 and the second connecting block 123. No limitation is imposed here.

[0312] As shown in Figure 30, in some embodiments, the second connecting block 123 includes a second hollow area 1230. This allows for the reduction of material used in the second connecting block 123 while maintaining its coverage area, thus improving connection stability while lowering costs.

[0313] As shown in Figure 31, in some embodiments, the second connecting block 123 is solid. This maximizes the area of ​​the second connecting block 123, thereby increasing the contact area between the second connecting block 123 and the electrical connector, increasing the tensile strength, reducing the risk of the electrical connector detaching from the back contact battery 1000, and improving the connection stability between the back contact battery 1000 and the electrical connector.

[0314] As shown in Figures 28 and 29, in some embodiments, the second connecting block 123 is rectangular. It is understood that in other embodiments, the second connecting block 123 may be circular, annular, elliptical, triangular, racetrack-shaped, or other shapes. The specific shape of the second connecting block 123 is not limited here.

[0315] As shown in Figures 28 and 29, in some embodiments, the difference between the width w3 of the second connecting block 123 and the width w4 of the fourth fine gate 122 is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0316] In this way, the width difference between the second connecting block 123 and the fourth fine gate 122 is within a suitable range. This avoids the second connecting block 123 being too narrow and the connection stability of the second electrical connector being poor, which would be caused by the difference being too small. It also avoids the second connecting block 123 having too large a series resistance and too large a current loss, which would be caused by the difference being too large.

[0317] As shown in Figures 28 and 29, in some embodiments, the width w3 of the second connecting block 123 is from 10 μm to 300 μm. For example, it is 10 μm, 12 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 280 μm, or 300 μm.

[0318] In this way, the width w3 of the second connecting block 123 is within a suitable range, which can avoid the situation where the width is too small, resulting in a small contact width with the second electrical connector and poor connection stability of the second electrical connector. It can also avoid the situation where the width is too large, resulting in too large series resistance of the second connecting block 123 and large current loss.

[0319] As shown in Figures 28 and 29, in some embodiments, the width w4 of the fourth fine gate 122 is from 5 μm to 250 μm. For example, it is 5 μm, 7 μm, 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 240 μm, or 250 μm.

[0320] This ensures that the width w4 of the fourth fine gate 122 is within a suitable range, avoiding the problem of the fine gate being easily broken due to an excessively small width, resulting in poor performance in extracting charge carriers from the silicon substrate 101, and also avoiding the problem of excessively large width leading to excessive series resistance, large current loss, and high cost.

[0321] As shown in Figures 28 and 29, in some embodiments, the difference between the area of ​​the first connecting block 112 and the area of ​​the second connecting block 123 is -400 μm. 2 Up to 400μm 2 For example, -400μm 2 -400μm2 -400μm 2 -400μm 2 -400μm 2 400μm 2 .

[0322] This ensures that the difference between the area of ​​the first connecting block 112 and the area of ​​the second connecting block 123 is within a suitable range, avoiding a large difference in area between the first connecting block 112 and the second connecting block 123 due to an excessively small or large difference. This makes the contact area between the first connecting block 112 and the first electrical connector, and the contact area between the second connecting block 123 and the second electrical connector, approximately the same. Consequently, the pulling force of the first electrical connector and the second electrical connector on the connecting block is approximately the same, which is beneficial to improving the connection stability between the electrical connector and the back contact battery 1000.

[0323] As shown in Figures 28 and 29, in some embodiments, the first polar fine grid adjacent to the second connecting block 123 is disconnected at a position corresponding to the second connecting block 123 to avoid the second connecting block 123. In the second direction, the distance d3 between the breakpoint of the second connecting block 123 and the first fine grid 111 is 0.2 mm to 1 mm. For example, it is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0324] Thus, by utilizing the space of the first polar fine grid adjacent to the second connecting block 123, the area of ​​the second connecting block 123 is made larger, which is beneficial to increasing the contact area between the second connecting block 123 and the second electrical connector and improving the connection stability. At the same time, it ensures that the distance d3 between the breakpoint of the second connecting block 123 and the first fine grid 111 is within a suitable range. This avoids the risk of short circuits caused by the opposite electrodes being too close due to too small a distance, and also avoids the poor carrier collection effect and poor battery efficiency caused by too large a distance.

[0325] Optionally, the first polarity fine gate adjacent to the second connecting block 123 is disconnected at the position corresponding to the second connecting block 123. This means that the line connecting the two break points of the first polarity fine gate passes through the second connecting block 123. In order to avoid the second connecting block 123 with opposite polarity, the first polarity fine gate is disconnected, forming two break points.

[0326] Optionally, the distance d3 between the breakpoint of the second connecting block 123 and the first fine gate 111 is 0.3 mm to 0.6 mm. For example, it can be 0.3 mm, 0.32 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.58 mm, or 0.6 mm. In this way, the distance d3 between the breakpoint of the second connecting block 123 and the first fine gate 111 is further optimized, taking into account both the area of ​​the second connecting block 123 and carrier collection, resulting in better overall performance.

[0327] As shown in Figures 28 and 29, in some embodiments, the fourth fine gate 122 is the second polar fine gate 12 closest to the edge of the silicon substrate 101, and the distance x3 between the fourth fine gate 122 and the edge is greater than 0.7 mm to 1.3 mm.

[0328] In this way, the distance x3 between the fourth fine gate 122 and the edge is within a suitable range, which can avoid the inconvenience of stacking due to the distance being too small, and can also avoid the poor effect of collecting charge carriers due to the distance being too large.

[0329] Optionally, the distance x3 between the fourth fine gate 122 and the edge is from 0.8 mm to 1.1 mm. For example, it can be 0.8 mm, 0.82 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.95 mm, 1 mm, 1.02 mm, 1.05 mm, 1.08 mm, or 1.1 mm. This further optimizes the distance x3 between the fourth fine gate 122 and the edge, resulting in a better overall effect.

[0330] It is understood that in other embodiments, the fourth fine gate 122 may be located on the silicon substrate 101 away from the edge. For example, the fourth fine gate 122 may be the second, third, fourth, or other sequentially numbered second polar fine gate 12 from the edge. This can reduce the risk of the electrical connector detaching from a more central position in the back contact battery 1000. In this case, a bent first polar fine gate 11 may be provided on one or both sides of the fourth fine gate 122 to avoid the second connecting block 123 connected to the fourth fine gate 122.

[0331] As shown in Figures 28 and 29, in some embodiments, the distance x4 from the second connecting block 123 to the edge of the silicon substrate 101 is 0.7 mm to 50 mm. For example, it is 0.7 mm, 0.8 mm, 1 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 48 mm, or 50 mm.

[0332] In this way, the distance x4 from the second connecting block 123 to the edge is within a suitable range, which can avoid the inconvenience of stacking due to the distance being too small, and can also avoid the poor connection stability between the end area of ​​the back contact battery 1000 and the second electrical connector due to the distance being too large.

[0333] Optionally, the distance x4 from the second connecting block 123 to the edge is 1mm to 5mm. For example, it is 1mm, 1.02mm, 1.5mm, 2mm, 3mm, 4mm, 4.5mm, or 5mm. In this way, the distance x4 from the second connecting block 123 to the edge is further optimized, resulting in better connection stability between the back contact battery 1000 and the second electrical connector.

[0334] As shown in Figures 28 and 29, in some embodiments, the fourth fine gate 122 is the second polar fine gate 12 closest to the edge of the silicon substrate 101, and the second connecting block 123 is located on the side of the fourth fine gate 122 facing the edge.

[0335] In this way, the space at the edge can be fully utilized, making the range of the second connecting block 123 larger and the range of the connecting solder strip larger, which is beneficial to improving the connection stability between the back contact battery 1000 and the second electrical connector.

[0336] In some embodiments, the second connecting block 123 protrudes from the fourth fine gate 122 to both sides of the fourth fine gate 122.

[0337] In this way, the space between the two sides of the second connecting block 123 and the irregular fine grid can be fully utilized, making the range of the second connecting block 123 larger and the range of the connecting solder strip larger, which is conducive to improving the connection stability between the back contact battery 1000 and the second electrical connector.

[0338] As shown in FIG32, in some embodiments, the fourth fine gate 122 includes a connected third fine gate body portion 1221 and a third fine gate bending portion 1222. The third fine gate body portion 1221 extends along a second direction, and the third fine gate bending portion 1222 bends from the third fine gate body portion 1221 toward the edge away from the silicon substrate 101. A second connecting block 123 is disposed on the third fine gate bending portion 1222 and the second connecting block 123 connects to the third fine gate bending portion 1222.

[0339] Thus, the second connecting block 123 is located at the part of the fourth fine gate 122 that bends away from the edge of the silicon substrate 101. This allows the second connecting block 123 to be positioned further away from the edge of the silicon substrate 101, further away from the end of the second electrical connector, and closer to the middle of the second electrical connector. This avoids the second electrical connector's end being difficult to extend to the second connecting block 123 near the edge of the silicon substrate 101 due to offset or cutting errors, making it easier for the second connecting block 123 to connect with the second electrical connector and resulting in higher connection stability.

[0340] Optionally, the third fine grid bending portion 1222 includes a fifth bending segment, a third connecting segment, and a sixth bending segment connected in sequence. The fifth bending segment connects one end of the third fine grid main body 1221 and the third connecting segment, and the sixth bending segment connects the other end of the third fine grid main body 1221 and the fourth connecting segment. In the example of FIG32, the third connecting segment is a straight segment.

[0341] It is understood that in other examples, the third fine grid bend 1222 may be wavy, zigzag, or other shapes. The second connecting segment may be wavy, zigzag, or other shapes. No limitation is made here.

[0342] As shown in Figure 32, in some embodiments, the maximum distance d4 between the third fine gate bending portion 1222 and the third fine gate main body portion 1221 in the first direction is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0343] Thus, the maximum distance d4 between the third fine gate bending portion 1222 and the third fine gate main body portion 1221 in the first direction is within a suitable range. This avoids the situation where the distance between the third fine gate bending portion 1222 and the adjacent dissimilar fine gate is too close due to the small distance, resulting in a high risk of short circuit. It also avoids the situation where the total length of the fourth fine gate 122 is too large, resulting in too much series resistance and too much current loss due to the large distance.

[0344] As shown in FIG28, in some embodiments, the fourth fine gate 122 and the second connecting block 123 disposed on the fourth fine gate 122 form a second conductive structure 1002, and each row of the second conductive structure 1002 is continuous.

[0345] In this way, the second conductive structure 1002 in each row is not interrupted and has no breaks, which makes the power of the back contact battery 1000 better.

[0346] As shown in Figures 33 and 23, in some embodiments, the silicon substrate 101 includes a plurality of first polar doped regions 13 and a plurality of second polar doped regions 14 arranged along a first direction. The first polar doped regions 13 are provided with first polar fine gates 11, and the second polar doped regions 14 are provided with second polar fine gates 12. The first polar doped region 13 includes a first doped region 131, which includes a first region 1311 and a second region 1312. The first region 1311 is provided with a first fine gate 111, and the second region 1312 corresponds to a first connecting block 112. The second polar doped region 14 includes a second doped region 141, which includes a third region 1411 and a fourth region 1412. The third region 1411 is provided with a first fine gate body portion 1211 of the second fine gate 121, and the fourth region 1412 is provided with a first fine gate bend portion 1212 of the second fine gate 121.

[0347] This allows the two polarity doped regions to correspond to the two polarity fine gates, making it easier to fabricate fine gates of the corresponding polarity on the doped regions and to achieve electrical connection between the doped regions and the fine gates of the corresponding polarity. This helps to reduce process difficulty, improve fabrication efficiency, and reduce costs.

[0348] Optionally, "the first region 1311 is provided with a first fine grid 111" means that the first fine grid 111 is in electrical contact with the first region 1311.

[0349] Optionally, "the second region 1312 corresponds to the first connecting block 112" means that, in the thickness direction of the back contact battery 1000, the projections of the first connecting block 112 and the second region 1312 on the same plane at least partially overlap. The first connecting block 112 may be in electrical contact with the second region 1312 or may be electrically isolated from the second region 1312.

[0350] Optionally, "the third region 1411 is provided with the first fine gate body portion 1211 of the second fine gate 121" means that the first fine gate body portion 1211 of the second fine gate 121 is in electrical contact with the third region 1411.

[0351] Optionally, "the fourth region 1412 is provided with the first fine grid bend 1212 of the second fine grid 121" means that the first fine grid bend 1212 of the second fine grid 121 is in electrical contact with the fourth region 1412.

[0352] Optionally, the first polar doped region 13 and the second polar doped region 14 may be formed in the entire region of the silicon substrate 101, such that the first polar fine gate 11 and the second polar fine gate 12 are distributed in the entire region of the silicon substrate 101; or the first polar doped region 13 and the second polar doped region 14 may be formed in a portion of the silicon substrate 101, such that the first polar fine gate 11 and the second polar fine gate 12 are distributed in a portion of the silicon substrate 101.

[0353] Optionally, the first polar doped region 13 and the second polar doped region 14 have different polarities. The first polar doped region 13 corresponds to the first polar doped layer. The second polar doped region 14 corresponds to the second polar doped layer.

[0354] Optionally, the number of first polar doped regions 13 can be 1, 2, 3, 4, or other numbers. The number of second polar doped regions 14 can be 1, 2, 3, 4, or other numbers. No limitation is made here. The number of first polar doped regions 13 and the number of second polar doped regions 14 can be the same or different.

[0355] Optionally, the first polar doped region 13 and the second polar doped region 14 are arranged along the first direction, and may be arranged alternately or non-alternatingly along the first direction; they may be arranged at equal intervals or unequal intervals along the first direction. No limitation is made here.

[0356] It is understandable that gaps can be formed between adjacent first polar doped regions 13 and second polar doped regions 14, they can contact each other, or other film structures can be set.

[0357] In some embodiments, a dielectric film 1003 is provided between at least one pair of adjacent first polar doped regions 13 and second polar doped regions 14, and the dielectric film 1003 electrically isolates the first polar doped regions 13 and the second polar doped regions 14.

[0358] Thus, the dielectric film 1003 is used to achieve electrical isolation between the first doped layer and the second doped layer. At the same time, the refractive index difference and surface passivation effect of the dielectric film 1003 can be used to reduce optical loss and carrier recombination.

[0359] Optionally, the dielectric film 1003 may be disposed between a pair of adjacent first polar doped regions 13 and second polar doped regions 14; or it may be disposed between multiple pairs of adjacent first polar doped regions 13 and second polar doped regions 14. In this embodiment, the dielectric film 1003 is disposed between all adjacent first polar doped regions 13 and second polar doped regions 14.

[0360] Optionally, the dielectric film 1003 covers the first doped layer and the second doped layer. The first polar fine gate 11 passes through the dielectric film 1003 and contacts the first doped layer, and the second polar fine gate 12 passes through the dielectric film 1003 and contacts the second doped layer. To better show the first polar doped region 13 and the second polar doped region 14, the portion of the dielectric film 1003 covering the first polar doped region 13 and the second polar doped region 14 is omitted in the figure.

[0361] Optionally, the dielectric film layer 1003 includes at least one of an aluminum oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbide layer, an amorphous silicon layer, and a silicon oxide layer.

[0362] In some embodiments, a trench is formed between the first polar doped region 13 and the second polar doped region 14, and the dielectric film layer 1003 is at least partially disposed in the trench.

[0363] In this way, trenches can be used to electrically isolate the first polar doped region 13 and the second polar doped region 14 inside the silicon substrate 101, reducing the risk of conduction between the first polar doped region 13 and the second polar doped region 14.

[0364] Optionally, "the dielectric film layer 1003 is at least partially disposed in the trench" means that a portion of the dielectric film layer 1003 is disposed in the trench and the remainder is disposed outside the trench, or that the entire dielectric film layer 1003 is disposed in the trench.

[0365] Optionally, the trench is continuously disposed between the first polar doped region 13 and the second polar doped region 14. Alternatively, the first polar doped region 13 and the second polar doped region 14 are separated by the trench. This ensures that the first polar doped region 13 and the second polar doped region 14 cannot be connected across the trench.

[0366] In some embodiments, a tunneling layer is provided between at least one pair of adjacent first polar doped regions 13 and second polar doped regions 14, and both the first polar doped region 13 and the second polar doped region 14 are in contact with the tunneling layer.

[0367] This reduces the reverse bias voltage, decreasing the heat generation of the back contact cell 1000 when it becomes a load after being shielded in the module. Furthermore, the tunneling layer acts as a passivation layer, reducing recombination at the interface between the first polar doped region 13 and the second polar doped region 14.

[0368] Optionally, the tunneling layer includes at least one of a silicon oxide layer, an aluminum oxide layer, and a silicon carbide layer.

[0369] In some embodiments, at least one pair of adjacent first polar doped regions 13 and second polar doped regions 14 are in contact with each other.

[0370] In this way, the reverse bias can be reduced, thereby reducing the heat generation power of the back contact battery 1000 when it becomes a load after being blocked in the module.

[0371] Optionally, adjacent first polar doped regions 13 and second polar doped regions 14 may be in contact with each other in their entire adjacent region or in only a portion of their adjacent region.

[0372] As shown in Figures 34 and 35, in some embodiments, the second region 1312 protrudes from the first region 1311.

[0373] Thus, the first region 1311, which has a first fine gate 111, protrudes from the second region 1312 corresponding to the first connecting block 112, providing sufficient space for the wider first connecting block 112. Moreover, when the first connecting block 112 is located in the second region 1312 and is in electrical contact with the second region 1312, the risk of short circuit caused by the small edge distance between the wider first connecting block 112 and the first region 1311, and its proximity to the adjacent second polar doped region 14, can be reduced.

[0374] As shown in Figure 34, optionally, the width W2 of the second region 1312 is greater than the width W1 of the first region 1311. This allows the wider second region 1312 to better correspond to the wider first connecting block 112.

[0375] Optionally, the width W2 of the second region 1312 is from 12 μm to 2000 μm. For example, it can be 12 μm, 15 μm, 20 μm, 50 μm, 100 μm, 500 μm, 800 μm, 1000 μm, 1500 μm, 1800 μm, or 2000 μm. This ensures that the width W2 of the second region 1312 is within a suitable range, avoiding insufficient space for the first connecting block 112 and a high risk of short circuits due to a smaller width, and also avoiding poor collection of carriers of the other polarity due to an excessively large width.

[0376] Optionally, the width W2 of the second region 1312 is between 500 μm and 1500 μm. For example, it can be 500 μm, 510 μm, 600 μm, 800 μm, 1000 μm, 1200 μm, 1400 μm, or 1500 μm. This further optimizes the width W2 of the second region 1312, balancing short-circuit risk and carrier collection performance, resulting in better overall performance.

[0377] Optionally, the width W1 of the first region 1311 is between 6 μm and 800 μm. This ensures that the width W1 of the first region 1311 is within a suitable range, avoiding insufficient area for the first fine gate 111, high risk of short circuit, and poor carrier collection effect corresponding to the first fine gate 111 due to a small width, and also avoiding poor collection effect of carriers of the other polarity due to an excessively large width.

[0378] Optionally, the width W1 of the first region 1311 can be from 10 μm to 600 μm. For example, it can be 10 μm, 12 μm, 20 μm, 80 μm, 100 μm, 200 μm, 500 μm, or 600 μm. This further optimizes the width W1 of the first region 1311, balancing short-circuit risk and carrier collection effectiveness for both polarities, resulting in better overall performance.

[0379] It is understood that in other embodiments, the widths of the first region 1311 and the second region 1312 may be the same. For example, based on the example of FIG. 34, the upper side of the second region 1312 is recessed, with the recess depth equal to the protrusion depth of the lower side. In other embodiments, the width W2 of the second region 1312 may be smaller than the width W1 of the first region 1311. For example, based on the example of FIG. 34, the upper side of the second region 1312 is recessed, with the recess depth greater than the protrusion depth of the lower side. No limitation is imposed here.

[0380] Referring to Figure 34, in some embodiments, in the first direction, the maximum depth H1 of the second region 1312 protruding from the first region 1311 is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0381] In this way, the maximum depth H1 of the second region 1312 protruding from the first region 1311 is within a suitable range. This avoids the situation where the setting area of ​​the first connecting block 112 is insufficient and the risk of short circuit is too high due to the depth being too small, and also avoids the situation where the depth is too large and it is not conducive to collecting carriers of the other polarity.

[0382] Referring to Figure 35, in some embodiments, the fourth region 1412 is recessed from the third region 1411 on the side facing the second region 1312. This allows the recessed fourth region 1412 to work in conjunction with the protruding second region 1312, making full use of space, resulting in a more rational arrangement of the doped regions, which is beneficial for better carrier collection and improves the photoelectric conversion efficiency of the battery.

[0383] As shown in Figures 36 and 37, in some embodiments, the fourth region 1412 protrudes from the third region 1411 on the side opposite to the second region 1312.

[0384] Thus, the fourth region 1412 corresponding to the first fine gate bending portion 1212 protrudes from the third region 1411 of the first fine gate main body portion 1211, which can provide sufficient space for the bent first fine gate bending portion 1212, reducing the risk of short circuit caused by the small edge distance between the bent first fine gate bending portion 1212 and the fourth region 1412 and the close proximity to the adjacent heterogeneous doped region.

[0385] As shown in Figure 37, in some embodiments, the side of the fourth region 1412 facing the second region 1312 is recessed from the third region 1411, and the side of the fourth region 1412 away from the second region 1312 protrudes from the third region 1411.

[0386] In this way, the space can be fully utilized in conjunction with the protruding second region 1312, making the arrangement of the doped regions more reasonable and facilitating better collection of charge carriers. At the same time, sufficient space can be provided for the bent first fine gate bending portion 1212, reducing the risk of short circuit caused by the small edge spacing between the bent first fine gate bending portion 1212 and the fourth region 1412 and its close proximity to the adjacent heterogeneous doped region.

[0387] Optionally, the depth of the depression and the depth of the protrusion in the fourth region 1412 are the same. This makes the size of the fourth region 1412 the same as that of the third region 1411 in the second direction, which is beneficial for better collection of charge carriers.

[0388] It is understood that in other embodiments, the recess depth of the fourth region 1412 may be greater than or less than the protrusion depth. No limitation is imposed here.

[0389] As shown in Figures 36 and 37, in some embodiments, in the first direction, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 on the side opposite to the second region 1312 is 1 μm to 500 μm. For example, it is 1 μm, 2 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, or 500 μm.

[0390] In this way, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is within a suitable range. This avoids the risk of short circuits caused by the small edge spacing between the first fine gate bend 1212 and the fourth region 1412 and the proximity to the adjacent heterogeneous doped region due to the small protrusion depth. It also avoids the poor carrier collection effect caused by the excessive protrusion depth.

[0391] Optionally, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 on the side opposite to the second region 1312 is between 5 μm and 190 μm. For example, it can be 5 μm, 6 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 180 μm, or 190 μm. This further optimizes the maximum depth of the fourth region 1412 protruding from the third region 1411, balancing short-circuit risk and carrier collection, resulting in better overall performance.

[0392] Optionally, the third region 1411 and the fourth region 1412 have the same width. This facilitates better collection of charge carriers.

[0393] It is understood that in other embodiments, the width W4 of the fourth region 1412 may be smaller than the width W3 of the third region 1411, as shown in Figure 35; or the width W4 of the fourth region 1412 may be larger than the width W3 of the third region 1411, as shown in Figure 36. No limitation is imposed here.

[0394] As shown in Figures 36 and 37, in some embodiments, the second region 1312 protrudes from the first region 1311 on the side facing the fourth region 1412. In a first direction, the difference between the maximum depth H1 of the second region 1312 protruding from the first region 1311 and the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is 50 μm to 200 μm. For example, it is 50 μm, 52 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, or 200 μm.

[0395] This ensures that the difference between the maximum depth of the protrusion of the second region 1312 and the maximum depth of the protrusion of the fourth region 1412 is within a suitable range. This avoids the situation where the maximum depth of the protrusion of the fourth region 1412 is similar to that of the second region 1312 due to an excessively small difference, requiring adjacent heterogeneous doped regions to be recessed to avoid this, resulting in greater process complexity. Conversely, it avoids the situation where the width of the fourth region 1412 is too small due to an excessively large difference, resulting in poor carrier collection and a greater risk of short circuits.

[0396] Optionally, the maximum depth H2 of the fourth region 1412 protruding from the third region 1411 is the same as the maximum depth of the fourth region 1412 recessed from the third region 1411. This ensures that the difference between the maximum depth of the second region 1312 protruding and the maximum depth of the fourth region 1412 recessed is within a suitable range. This avoids a situation where the difference is too small, resulting in the maximum depth of the fourth region 1412 recessed being similar to the maximum depth of the second region 1312 protruding, leading to a smaller width of the fourth region 1412 and poorer carrier collection efficiency. Conversely, it avoids a situation where the difference is too large, resulting in poor coordination between the recess of the fourth region 1412 and the protrusion of the second region 1312, poor space utilization, and poor carrier collection efficiency.

[0397] As shown in Figures 38, 39, and 27, in some embodiments, the first polar fine gate 11 includes a third fine gate 113. The third fine gate 113 includes a connected second fine gate body portion 1131 and a second fine gate bending portion 1132. The second fine gate body portion 1131 extends along a second direction, and the second fine gate bending portion 1132 is correspondingly disposed with the first connecting block 112. The second fine gate bending portion 1132 bends from the second fine gate body portion 1131 in a direction away from the first connecting block 112. The first polar doped region 13 includes a third doped region 132. The third doped region 132 includes a fifth region 1321 and a sixth region 1322. The fifth region 1321 is provided with the second fine gate body portion 1131 of the third fine gate 113, and the sixth region 1322 is provided with the second fine gate bending portion 1132 of the third fine gate 113.

[0398] This makes the third doped region 132 correspond to the third fine gate 113, which facilitates the fabrication of the third fine gate 113 on the third doped region 132 and the electrical connection between the third doped region 132 and the third fine gate 113. This helps to reduce the difficulty of the process, improve the fabrication efficiency and reduce the cost.

[0399] Optionally, "the fifth region 1321 is provided with the second fine gate body portion 1131 of the third fine gate 113" means that the second fine gate body portion 1131 of the third fine gate 113 is in electrical contact with the fifth region 1321.

[0400] Optionally, "the sixth region 1322 is provided with the second fine grid bend 1132 of the third fine grid 113" means that the second fine grid bend 1132 of the third fine grid 113 is in electrical contact with the sixth region 1322.

[0401] As shown in Figures 38 and 39, in some embodiments, the sixth region 1322 is recessed from the fifth region 1321 on the side facing the second region 1312. This allows the recessed sixth region 1322 to work in conjunction with the protruding fourth region 1412, making full use of space and resulting in a more rational arrangement of the doped regions. This facilitates better carrier collection and improves the photoelectric conversion efficiency of the battery.

[0402] As shown in Figures 38 and 39, in some embodiments, the sixth region 1322 protrudes from the fifth region 1321 on the side opposite to the second region 1312.

[0403] Thus, the sixth region 1322 corresponding to the second fine gate bending portion 1132 protrudes from the fifth region 1321 of the second fine gate main body portion 1131, which can provide sufficient space for the bent second fine gate bending portion 1132, reducing the risk of short circuit caused by the small edge distance between the bent second fine gate bending portion 1132 and the sixth region 1322 and the close proximity to the adjacent heterogeneous doped region.

[0404] As shown in Figure 39, in some embodiments, the sixth region 1322 is recessed from the fifth region 1321 on the side facing the second region 1312, and the sixth region 1322 protrudes from the fifth region 1321 on the side away from the second region 1312.

[0405] In this way, the space can be fully utilized in conjunction with the protruding fourth region 1412, making the arrangement of doped regions more reasonable and facilitating better collection of charge carriers. At the same time, sufficient space can be provided for the bent second fine gate bending portion 1132, reducing the risk of short circuit caused by the small edge spacing between the bent second fine gate bending portion 1132 and the sixth region 1322 and its proximity to the adjacent heterogeneous doped region.

[0406] Optionally, the depth of the depression and the depth of the protrusion in the sixth region 1322 are the same. This makes the size of the sixth region 1322 the same as that of the fifth region 1321 in the second direction, which is beneficial for better collection of charge carriers.

[0407] It is understood that in other embodiments, the recess depth of the sixth region 1322 may be greater than or less than the protrusion depth. No limitation is imposed here.

[0408] As shown in Figure 39, in some embodiments, the fourth region 1412 protrudes from the third region 1411 on the side opposite to the second region 1312, and the protrusion depth of the fourth region 1412 and the sixth region 1322 gradually decreases along the direction away from the second region 1312.

[0409] Thus, along the direction away from the second region 1312, the depth of the protrusion gradually decreases, achieving a transition from protrusion to smoothness.

[0410] Optionally, the protrusion depth of the fourth region 1412 is the maximum depth of the fourth region 1412 protruding from the third region 1411 in the first direction, away from the second region 1312, which is H2 as shown in Figure 39. The protrusion depth of the sixth region 1322 is the maximum depth of the sixth region 1322 protruding from the fifth region 1321 in the first direction, away from the second region 1312, which is H3 as shown in Figure 39.

[0411] In the example of Figure 39, the first doped region 131, the second doped region 141, the third doped region 132, and the second doped region 141 are arranged in sequence along the direction away from the edge, and the corresponding protrusion depth gradually decreases.

[0412] As shown in Figure 39, in some embodiments, for adjacent second doped regions 141 and third doped regions 132, the fourth region 1412 and the sixth region 1322 satisfy the following formula:

[0413] 50μm≤H2-H3≤200μm;

[0414] Wherein, H2 is the maximum depth of the fourth region 1412 protruding from the third region 1411 on the side away from the second region 1312 in the first direction, and H3 is the maximum depth of the sixth region 1322 protruding from the fifth region 1321 on the side away from the second region 1312 in the first direction.

[0415] In this way, the difference in protrusion depth between the adjacent second doped region 141 and the third doped region 132 is within a suitable range. This avoids the situation where the difference is too small, which would require more doped regions to protrude to achieve the transition from bending to smoothness, increasing process complexity and reducing production efficiency. It also avoids the situation where the difference is too large, which would result in insufficient protrusion depth of one doped region, a close distance between the corresponding fine gate bend and the edge of the doped region, and a high risk of short circuit.

[0416] Optionally, the values ​​of H2-H3 are, for example, 50μm, 52μm, 80μm, 90μm, 100μm, 120μm, 140μm, 150μm, 180μm, and 200μm.

[0417] In some embodiments, each row of the first doped region 131 is continuous. Thus, the continuous arrangement of each row of the first doped region 131 results in better power delivery to the back contact battery 1000.

[0418] In some embodiments, each row of the second doped region 141 is continuous. Thus, the continuous arrangement of each row of the second doped region 141 results in better power delivery to the back contact battery 1000.

[0419] In some embodiments, the doped region closest to the edge of the silicon substrate 101 is a P-region. In this way, the area of ​​the P-region can be increased by utilizing the space at the edge, making the area of ​​the P-region larger and facilitating the collection of charge carriers.

[0420] It is understood that in other embodiments, the doped region closest to the edge of the silicon substrate 101 may also be an N-region.

[0421] As shown in Figures 40 and 29, in some embodiments, the second polar fine gate 12 includes a fourth fine gate 122, the fourth fine gate 122 is provided with a second connecting block 123, and the width of the second connecting block 123 is greater than the width of the fourth fine gate 122.

[0422] The second polar doped region 14 includes a fourth doped region 142, which includes a seventh region 1421 and an eighth region 1422. The seventh region 1421 is provided with a fourth fine gate 122, and the eighth region 1422 corresponds to the second connection block 123.

[0423] This makes the fourth doped region 142 correspond to the fourth fine gate 122, which makes it easier to fabricate the fourth fine gate 122 on the fourth doped region 142, which helps to reduce the difficulty of the process, improve the fabrication efficiency and reduce the cost.

[0424] Optionally, "the seventh region 1421 is provided with a fourth fine gate 122" means that the fourth fine gate 122 is in electrical contact with the seventh region 1421.

[0425] Optionally, "eighth region 1422 corresponds to second connecting block 123" means that, in the thickness direction of the back contact battery 1000, the projections of the second connecting block 123 and the eighth region 1422 on the same plane at least partially overlap. The second connecting block 123 may be in electrical contact with the eighth region 1422, or it may be electrically isolated from the eighth region 1422.

[0426] As shown in Figures 40 and 29, in some embodiments, the fourth doped region 142 and the second doped region 141 are the same second polar doped region 14. Thus, integrating the fourth region 1412 and the eighth region 1422 into the same second polar doped region 14 can improve the connection stability with the second electrical connector. Furthermore, centralized design and fabrication can be performed, which improves manufacturing efficiency.

[0427] When the fourth doped region 142 and the second doped region 141 are the same second polar doped region 14, the fourth doped region 142 and the second doped region 141 can be regarded as part of the structure of the second polar doped region 14.

[0428] It is understood that in other examples, the fourth doped region 142 and the second doped region 141 may also be different second polarity doped regions 14. This is not a limitation here.

[0429] As shown in Figure 40, in some embodiments, the eighth region 1422 is electrically connected to the second connecting block 123, and the eighth region 1422 protrudes from the seventh region 1421.

[0430] Thus, the seventh region 1421, which has a fourth fine gate 122, protrudes from the eighth region 1422 corresponding to the second connecting block 123, providing ample space for the wider second connecting block 123. Moreover, when the second connecting block 123 is located in the eighth region 1422 and in electrical contact with the eighth region 1422, the risk of short circuits caused by the small edge spacing between the wider second connecting block 123 and the eighth region 1422, or by its proximity to adjacent hetero-doped regions, can be reduced.

[0431] Optionally, the side of the eighth region 1422 facing the edge of the back contact battery 1000 may protrude from the seventh region 1421, or the side of the eighth region 1422 away from the edge of the back contact battery 1000 may protrude from the seventh region 1421, or both sides of the eighth region 1422 may protrude from the seventh region 1421. No limitation is imposed here.

[0432] It is understood that in other embodiments, the eighth region 1422 may also be aligned with the seventh region 1421. The eighth region 1422 may also be recessed from the seventh region 1421. This is not a limitation.

[0433] As shown in Figure 40, in some embodiments, the maximum depth H4 of the eighth region 1422 protruding from the seventh region 1421 is 5 μm to 290 μm. For example, it is 5 μm, 8 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 280 μm, or 290 μm.

[0434] In this way, the maximum depth H4 of the eighth region 1422 protruding from the seventh region 1421 is within a suitable range. This avoids the situation where the setting area of ​​the second connecting block 123 is insufficient and the risk of short circuit is too high due to the depth being too small, and also avoids the situation where the depth is too large and it is not conducive to collecting carriers of the other polarity.

[0435] In some embodiments, each row of the fourth doped region 142 is continuous. Thus, the continuous arrangement of each row of the fourth doped region 142 results in better power delivery to the back contact battery 1000.

[0436] As shown in FIG41, in some embodiments, the fourth fine gate 122 includes a connected third fine gate body portion 1221 and a third fine gate bend portion 1222. The third fine gate body portion 1221 extends along a second direction, and the third fine gate bend portion 1222 bends from the third fine gate body portion 1221 toward the edge away from the silicon substrate 101. The second connecting block 123 connects to the third fine gate bend portion 1222. The fourth doped region 142 includes a ninth region 1423, and the ninth region 1423 is provided with the third fine gate bend portion 1222.

[0437] In this way, the ninth region 1423 of the fourth doped region 142 corresponds to the third fine gate bend 1222 of the fourth fine gate 122, which facilitates the fabrication of the fourth fine gate 122 on the fourth doped region 142, thereby reducing the difficulty of the process, improving the fabrication efficiency and reducing the cost.

[0438] As shown in Figure 41, in some embodiments, the ninth region 1423 protrudes from the seventh region 1421 on the side opposite to the eighth region 1422.

[0439] Thus, the ninth region 1423 corresponding to the third fine gate bending portion 1222 protrudes from the seventh region 1421 of the third fine gate main body portion 1221, which can provide sufficient space for the bent third fine gate bending portion 1222, reducing the risk of short circuit caused by the small edge distance between the bent third fine gate bending portion 1222 and the ninth region 1423 and the close proximity to the adjacent heterogeneous doped region.

[0440] As shown in Figures 42 and 43, in some embodiments, the first polar fine gate 11 is a positive fine gate. The first polar fine gate 11 includes a fifth fine gate 114 and a sixth fine gate 115. The distance L2 between the sixth fine gate 115 and the adjacent second polar fine gate 12 is greater than the distance L1 between the fifth fine gate 114 and the adjacent second polar fine gate 12.

[0441] Thus, since the distance between the sixth fine gate 115 and the adjacent heterogeneous fine gate in the first direction is greater than the distance between the fifth fine gate 114 and the adjacent heterogeneous fine gate, sufficient space can be left in the silicon substrate 101 for setting up the anti-hot spot structure, reducing the risk of short circuit caused by the contact between fine gates and doped regions with different polarities.

[0442] Optionally, the distance L2 between the sixth fine grid 115 and the adjacent second polarity fine grid 12 is greater than the distance L1 between the fifth fine grid 114 and the adjacent second polarity fine grid 12, meaning that the distance between at least one of the sixth fine grid 115 and the adjacent second polarity fine grid 12 is greater than the distance between at least one of the fifth fine grid 114 and the adjacent second polarity fine grid 12. Alternatively, the minimum distance L2 between the sixth fine grid 115 and the adjacent second polarity fine grid 12 may be greater than the maximum distance L1 between the fifth fine grid 114 and the adjacent second polarity fine grid 12; or the maximum distance L2 between the sixth fine grid 115 and the adjacent second polarity fine grid 12 may be greater than the maximum distance L1 between the fifth fine grid 114 and the adjacent second polarity fine grid 12, and this is not limited here.

[0443] As shown in Figures 43 and 44, the first polar doped region 13 includes a fifth doped region 133, and the second polar doped region 14 includes a sixth doped region 143. The fifth doped region 133 includes an overlapping portion 1331 and a non-overlapping portion 1332. The sixth doped region 143 includes a body 1431 and a protrusion 1432. The body 1431 is spaced apart from the fifth doped region 133, and the protrusion 1432 protrudes from the body 1431 and overlaps with the overlapping portion 1331. The sixth fine gate 115 is disposed in the non-overlapping portion 1332.

[0444] Thus, the protrusion 1432 of the sixth doped region 143 overlaps with the overlapping portion 1331 of the fifth doped region 133, thereby forming an anti-hot spot structure. This reduces the reverse bias voltage and the heat generation power of the back contact cell 1000 when it becomes a load after being shielded in the module, thereby reducing the risk of hot spots. At the same time, the fifth fine gate 114 is located in the non-overlapping portion 1332, reducing the risk of short circuits caused by the contact between fine gates and doped regions with different polarities.

[0445] Optionally, the fifth fine grid 114 is located outside the non-overlapping portion 1332.

[0446] Optionally, the body 1431 and the fifth doped region 133 may be separated by trenches. The body 1431 and the non-overlapping portion 1332 may be separated by a dielectric film layer 1003. No limitations are specified here.

[0447] Optionally, the protrusion 1432 can be rectangular, circular, square, triangular, or other shapes. No limitation is imposed here.

[0448] Optionally, the sixth fine gate 115 is disposed in the non-overlapping portion 1332, meaning that the sixth fine gate 115 is in electrical contact with the non-overlapping portion 1332.

[0449] As shown in Figures 45 and 46, in some embodiments, the sixth fine gate 115 is provided with a third connecting block 116, and the width L3 of the third connecting block 116 is greater than the width L4 of the sixth fine gate 115.

[0450] This increases the contact area between the third connecting block 116 and the first electrical connector, increases the pulling force, reduces the risk of the first electrical connector falling off the back contact battery 1000, and improves the connection stability between the back contact battery 1000 and the first electrical connector.

[0451] Optionally, the sixth fine grid 115 is provided with a third connecting block 116. That is, the third connecting block 116 is connected to the sixth fine grid 115.

[0452] Optionally, the third connector 116 may penetrate the dielectric film layer 1003 to contact the first polar doped layer. The third connector 116 and the first polar doped layer may also be isolated by the dielectric film layer 1003. The third connector 116 may be fabricated together with the sixth fine gate 115. Alternatively, the third connector 116 and the sixth fine gate 115 may be fabricated separately.

[0453] In some embodiments, the third connecting block 116 and the sixth fine gate 115 are made of the same paste, both burning through the dielectric film layer 1003 to contact the first polar doped layer. In other embodiments, the paste of the sixth fine gate 115 burns through the dielectric film layer 1003 to contact the first polar doped layer, while the paste of the third connecting block 116 does not burn through the dielectric film layer 1003.

[0454] In some embodiments, the third connection block 116 includes at least one of a pad and a gate line segment. This allows the third connection block 116 to take various forms, which is beneficial for meeting more production scenarios and needs. For example, the third connection block 116 includes a pad. Alternatively, the third connection block 116 includes a gate line segment. Yet another example is that the third connection block 116 includes both a pad and a gate line segment. It is understood that when the third connection block 116 includes a gate line segment, the gate line segment passes through the dielectric film layer 1003 to contact the first polar doped layer. When the third connection block 116 includes a pad, the pad can pass through the dielectric film layer 1003 to contact the first polar doped layer, or it can be isolated from the first polar doped layer by the dielectric film layer 1003.

[0455] Optionally, the third connecting block 116 is used to connect the first electrical connector.

[0456] Optionally, the third connecting block 116 and the first electrical connector can be electrically connected by at least one of the following methods: adhesive bonding, direct soldering, solder paste soldering, or physical contact. No limitation is imposed here.

[0457] Optionally, the entire area of ​​the third connecting block 116 may be connected to the first electrical connector. Alternatively, a portion of the third connecting block 116 may be connected to the first electrical connector.

[0458] Optionally, the width L3 of the third connecting block 116 refers to the dimension of the third connecting block 116 in the first direction. The width L3 of the third connecting block 116 may be the same everywhere, different everywhere, or partially the same. The width L4 of the sixth fine gate 115 refers to the dimension of the sixth fine gate 115 in the first direction. The width L4 of the sixth fine gate 115 may be the same everywhere, different everywhere, or partially the same.

[0459] Optionally, the width L3 of the third connecting block 116 is greater than the width L4 of the sixth fine gate 115, meaning that the width of the third connecting block 116 at least at one location is greater than the width of the sixth fine gate 115 at least at one location. This could be: the minimum width of the third connecting block 116 is greater than the maximum width of the sixth fine gate 115; or the maximum width of the third connecting block 116 is greater than the maximum width of the sixth fine gate 115; or the maximum width of the third connecting block 116 is greater than the width at the connection point between the sixth fine gate 115 and the third connecting block 116. No limitation is imposed here.

[0460] In some embodiments, the third connecting block includes a third hollow area. This allows for the reduction of material used in the third connecting block while maintaining its coverage area, thus improving connection stability while lowering costs.

[0461] In some embodiments, the third connecting block is solid. This maximizes the area of ​​the third connecting block, thereby increasing the contact area between the third connecting block and the electrical connector, increasing the tensile strength, reducing the risk of the electrical connector detaching from the back contact battery 1000, and improving the connection stability between the back contact battery 1000 and the electrical connector.

[0462] In some embodiments, the third connecting block is rectangular. It is understood that in other embodiments, the third connecting block may be circular, annular, elliptical, triangular, racetrack-shaped, or other shapes. The specific shape of the third connecting block is not limited herein.

[0463] As shown in Figures 42, 43, and 44, in some embodiments, the distance L2 between the sixth fine gate 115 and the adjacent second polar fine gate 12 is a first distance, and the distance L1 between the fifth fine gate 114 and the adjacent second polar fine gate 12 is a second distance. The difference between the first distance and the second distance is 0.05 mm to 0.1 mm. For example, it is 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm.

[0464] This ensures that the difference between the first and second spacings is within a suitable range, avoiding insufficient space for setting up the anti-hot spot structure due to an excessively small difference, and also avoiding poor carrier collection performance due to a large difference.

[0465] Optionally, the spacing L2 between the sixth fine grid 115 and the adjacent second polar fine grid 12 can be equal everywhere, unequal everywhere, or partially equal and partially unequal.

[0466] Optionally, the spacing L1 between the fifth fine grid 114 and the adjacent second polar fine grid 12 can be equal everywhere, unequal everywhere, or partially equal and partially unequal.

[0467] Optionally, the difference between the first spacing and the second spacing can be a fixed value within 0.05 mm to 0.1 mm, or it can fluctuate within 0.05 mm to 0.1 mm.

[0468] As shown in Figures 42, 43, and 45, in some embodiments, the spacing L2 between the sixth fine gate 115 and the adjacent second polar fine gate 12 is 0.2 mm to 0.8 mm. For example, it is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm.

[0469] In this way, the distance L2 between the sixth fine gate 115 and the adjacent second polar fine gate 12 is within a suitable range, which can avoid insufficient space for setting up the anti-hot spot structure due to the distance being too small, and can also avoid poor carrier collection effect due to the distance being too large.

[0470] Optionally, the spacing L2 between the sixth fine gate 115 and the adjacent second polar fine gate 12 can be a fixed value within 0.2 mm to 0.8 mm, or it can fluctuate within 0.2 mm to 0.8 mm.

[0471] As shown in Figures 42, 43 and 45, in some embodiments, the spacing L1 between the fifth fine gate 114 and the adjacent second polar fine gate 12 is a second spacing of 0.1 mm to 0.7 mm.

[0472] In this way, the distance L1 between the fifth fine gate 114 and the adjacent second polar fine gate 12 is within a suitable range, which can avoid the fine gates being too dense and costly due to the small distance, and can also avoid the carrier collection effect being poor due to the large distance.

[0473] Optionally, the spacing L1 between the fifth fine gate 114 and the adjacent second polar fine gate 12 can be a fixed value within 0.1 mm to 0.7 mm, or it can fluctuate within 0.1 mm to 0.7 mm.

[0474] As shown in Figure 42, in some embodiments, there are multiple sixth fine gates 115, and the number of fine gates between two adjacent sixth fine gates 115 is 8 to 35. For example, 8, 10, 12, 15, 19, 20, 22, 25, 28, 30, 32, 35.

[0475] This ensures that the number of fine grids between two adjacent sixth fine grids 115 is within a suitable range. It avoids the situation where the number of fine grids between two adjacent sixth fine grids 115 is too small, resulting in a large number of sixth fine grids 115 and low manufacturing efficiency. It also avoids the situation where the number of fine grids between two adjacent sixth fine grids 115 is too large, resulting in a poor effect in reducing the risk of hot spots.

[0476] Optionally, in the back contact battery 1000, there can be multiple sixth fine grids 115, forming multiple pairs of adjacent sixth fine grids 115. The number of fine grids between multiple pairs of adjacent sixth fine grids 115 can be the same, different, or partially the same and otherwise different.

[0477] As shown in Figure 42, in some embodiments, the spacing L5 between two adjacent sixth fine gates 115 is 6 mm to 16.8 mm. For example, it is 6 mm, 7 mm, 8 mm, 10 mm, 12 mm, 14 mm, 15 mm, 16 mm, or 16.8 mm.

[0478] In this way, the spacing L5 between two adjacent sixth fine grids 115 is within a suitable range. This avoids the situation where the spacing is too small, resulting in a large number of sixth fine grids 115 and low manufacturing efficiency, and also avoids the situation where the spacing is too large, resulting in a poor overall effect of reducing hot spot risk.

[0479] Optionally, in the back contact battery 1000, there may be multiple sixth fine grids 115, forming multiple pairs of adjacent sixth fine grids 115. The spacing L5 between the multiple pairs of adjacent sixth fine grids 115 may be the same, different, or partially the same and otherwise different, and is not limited here.

[0480] As shown in Figures 44 and 46, in some embodiments, the depth L6 of the protrusion 1432 protruding from the body 1431 in the first direction is 40 μm to 500 μm. For example, it is 40 μm, 42 μm, 44 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 480 μm, or 500 μm.

[0481] In this way, the depth L6 of the protrusion 1432 protruding from the body 1431 is within a suitable range. This avoids the situation where the protrusion depth is too small, resulting in insufficient contact area with the fifth doped region 133 or even difficulty in contacting the fifth doped region 133, thus reducing the risk of hot spots. It also avoids the situation where the protrusion depth is too large, resulting in a close distance with the sixth fine gate 115 and a greater risk of short circuit.

[0482] Optionally, the depth L6 of the protrusion 1432 protruding from the body 1431 can be a fixed value within 40μm to 500μm, or it can fluctuate within 40μm to 500μm, and is not limited here.

[0483] As shown in Figures 44 and 46, the width L7 of the overlapping portion 1331 is from 45 μm to 500 μm. For example, it is 45 μm, 48 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 480 μm, or 500 μm.

[0484] In this way, the width L7 of the overlapping portion 1331 is within a suitable range, which can avoid the poor effect of reducing hot spot risk caused by the width being too small, and can also avoid the large distance between the sixth fine gate 115 and the heterogeneous doped region, resulting in a greater risk of short circuit.

[0485] Optionally, the width L7 of the overlapping portion 1331 refers to the dimension of the overlapping portion 1331 in the first direction.

[0486] Optionally, the width L7 of the overlapping portion 1331 can be a fixed value within the range of 45 μm to 500 μm, or it can fluctuate within the range of 45 μm to 500 μm. No limitation is made here.

[0487] As shown in Figures 44 and 46, the length L8 of the overlapping portion 1331 ranges from 10 μm to 2000 μm. For example, it can be 10 μm, 12 μm, 50 μm, 100 μm, 300 μm, 500 μm, 800 μm, 1000 μm, 1200 μm, 1500 μm, 1800 μm, or 2000 μm.

[0488] This ensures that the length L8 of the overlapping portion 1331 is within a suitable range, avoiding a poor effect in reducing the risk of hot spots due to excessive or insufficient length.

[0489] Optionally, the length L8 of the overlapping portion 1331 can be a fixed value within the range of 10 μm to 2000 μm, or it can fluctuate within the range of 10 μm to 2000 μm. No limitation is made here.

[0490] Referring to Figures 23 and 25, the width ratio of the overlapping region 1331 to the fifth doped region 133 is less than or equal to 85%. For example, it is 85%, 83%, 80%, 75%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 8%, 5%, 1%, or 0.1%.

[0491] In this way, the width ratio of the overlapping portion 1331 to the fifth doped region 133 is within a suitable range. This avoids the poor effect of reducing hot spot risk caused by an excessively small ratio, and also avoids the risk of short circuits caused by an excessively large ratio leading to a close distance between the sixth fine gate 115 and the heterogeneous doped region.

[0492] Optionally, the width of the fifth doped region 133 refers to the dimension of the fifth doped region 133 in the first direction.

[0493] As shown in Figures 44 and 46, the distance L9 between the protrusion 1432 and the third connecting block 116 is greater than or equal to 50 μm. For example, it is 50 μm, 52 μm, 60 μm, 100 μm, 200 μm, 300 μm, 400 μm, 480 μm, or 500 μm.

[0494] This ensures that the distance L9 between the protrusion 1432 and the third connecting block 116 is within a suitable range, which can avoid the risk of short circuit due to too small a distance, and also avoid the effect of reducing hot spot risk due to too large a distance.

[0495] Optionally, the distance L9 between the protrusion 1432 and the third connecting block 116 can be a fixed value within a range of 50 μm or greater, or it can fluctuate within a range of 50 μm or greater. No limitation is imposed here.

[0496] Please note that the specific features, structures, materials, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples. For example, Figures 47 and 48 combine features from several of the foregoing embodiments or examples.

[0497] Referring to FIG20, the battery assembly 2000 of this disclosure embodiment includes the back contact battery 1000 of any of the above.

[0498] In the battery assembly of this embodiment, since the width of the first connecting block 112 in the back contact battery 1000 is greater than the width of the first fine grid 111 and its length is greater than or equal to 100 μm, the contact area between the first connecting block 112 and the electrical connector can be increased, increasing the tensile force, reducing the risk of the electrical connector detaching from the back contact battery 1000, and improving the connection stability between the back contact battery 1000 and the electrical connector. Simultaneously, since the first fine grid bending portion 1212 in the second fine grid 121 bends away from the first fine grid body portion 1211, more space can be provided for the wider first connecting block 112, facilitating the widening of the first connecting block 112 and reducing the risk of short circuits caused by excessively small electrode spacing between the two polarities.

[0499] In this embodiment, multiple back-contact batteries 1000 in the battery assembly 2000 can be connected in series to form a battery string, thereby realizing the series current collection and output. For example, the battery cells can be connected in series by setting solder strips (busbars, interconnecting strips), conductive backplates, etc.

[0500] It is understood that in such embodiments, the battery module 2000 may further include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back sides of the back contact battery 1000, the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0501] Photovoltaic glass can be applied to the encapsulating film on the front side of the back contact cell 1000. 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%. It can protect the back contact cell 1000 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the back contact cell 1000 together, providing sealing, insulation, and waterproofing / moisture protection for the back contact cell 1000.

[0502] The backsheet can be attached to the adhesive film on the back of the back contact cell 1000. The backsheet provides protection and support for the back contact cell 1000, offering reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite adhesive film, etc. The specific choice depends on the specific circumstances and is not limited here. The backsheet, back contact cell 1000, adhesive film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0503] Referring to FIG21, the photovoltaic system 3000 of this disclosure embodiment includes the above-described battery module 2000.

[0504] In the photovoltaic system of this embodiment, since the width of the first connecting block 112 in the back contact cell 1000 is greater than the width of the first fine grid 111 and its length is greater than or equal to 100 μm, the contact area between the first connecting block 112 and the electrical connector can be increased, the tensile force can be increased, the risk of the electrical connector falling off the back contact cell 1000 can be reduced, and the connection stability between the back contact cell 1000 and the electrical connector can be improved. Simultaneously, since the first fine grid bending portion 1212 in the second fine grid 121 bends away from the first fine grid body portion 1211, more space can be provided for the wider first connecting block 112, facilitating the widening of the first connecting block 112 and reducing the short-circuit risk caused by the small electrode spacing of the two polarities.

[0505] In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0506] 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.

[0507] Furthermore, the above are merely preferred embodiments of this disclosure and are 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

A back-contact battery, wherein, include: A silicon substrate and a plurality of fine gates disposed on the silicon substrate; Each of the fine grids extends along a first direction, and the plurality of fine grids are arranged at intervals along a second direction, wherein the first direction and the second direction intersect. The silicon substrate has a first edge in the second direction, and the silicon substrate includes a first edge region, the first edge region being an edge region on the silicon substrate close to the first edge; At least one fine gate located within the first edge region includes a bend, the maximum distance between the bend and the first edge being greater than the distance between a non-bend on the fine gate and the first edge, the bend being located in the region of the fine gate that is electrically connected to the solder strip. According to claim 1, the back contact battery, wherein, The bent portion is a recessed bent portion, and the distance from the bottom edge of the recessed bent portion to the first edge is greater than the distance between the non-bent portion on the fine grid and the first edge. According to claim 1, the back contact battery, wherein, The line width of the bent portion is greater than the line width of the grid line segments other than the bent portion on the fine grid. According to claim 1, the back contact battery, wherein, The fine gate closest to the first edge among the plurality of fine gates is the first edge fine gate, and the first edge fine gate includes a first bend portion, on which a first pad is provided. According to claim 4, the back contact battery, wherein, The back contact battery includes a second pad, which is located above the first pad and is integrally connected to the first pad. According to claim 4, the back contact battery, wherein, The fine grid adjacent to the first bend is a second edge fine grid, which includes a second bend, and the midpoint of the second bend and the first bend are on the same straight line. According to claim 6, the back contact battery, wherein, The length of the second bend in the first direction is greater than the length of the first bend in the first direction. According to claim 6, the back contact battery, wherein, In the second direction, the distance between the first bent portion and the second bent portion is less than the distance between the non-bent portions of two adjacent fine grids. According to claim 4, the back contact battery, wherein, The first edge gate and the second edge gate have different polarities; A third pad is provided on the area of ​​the second edge fine gate that is electrically connected to the solder strip; The third pad extends toward the first edge, and the fine gate on the first edge has a break portion; The length of the disconnected portion in the first direction is greater than the length of the third pad in the first direction. According to claim 1, the back contact battery, wherein, Among the plurality of fine grids, the fine grid closest to the first edge is the first edge fine grid, and the fine grid adjacent to the first edge fine grid is the second edge fine grid; The first edge gate is provided with a fourth pad, and the second edge gate includes a fourth bend. The fourth pad is disposed opposite to the fourth bend and extends toward the fourth bend. According to claim 10, the back contact battery, wherein, The width of the fourth pad in the second direction is greater than the spacing between two adjacent fine gates in the region on the silicon substrate other than the first edge region. A back-contact battery, wherein, include: Silicon substrate; A plurality of first polar fine gates and a plurality of second polar fine gates are disposed on the silicon substrate, the first polar fine gates and the second polar fine gates being arranged at intervals along a first direction; The first polar fine gate includes a first fine gate, the first fine gate is connected to a first connecting block, the width of the first connecting block is greater than the width of the first fine gate, and the length of the first connecting block is greater than or equal to 100 μm; The second polar fine grid includes a second fine grid, which includes a connected first fine grid body portion and a first fine grid bending portion. The first fine grid body portion extends along a second direction, which intersects with the first direction. The first fine grid bending portion is correspondingly disposed with the first connecting block, and the first fine grid bending portion bends from the first fine grid body portion in a direction away from the first connecting block. According to claim 12, the back contact battery, wherein, The difference between the width of the first connecting block and the width of the first fine gate is 5 μm to 290 μm. According to claim 12, the back contact battery, wherein, The maximum distance between the first fine grid bend and the first fine grid body in the first direction is 5 μm to 290 μm. According to claim 12, the back contact battery, wherein, The first fine gate, the first connecting block, and the second fine gate satisfy the following formula: -100μm≤w1-w2-d1≤100μm; Wherein, w1 is the width of the first connecting block, w2 is the width of the first fine grid, and d1 is the maximum distance between the bent portion of the first fine grid and the main body portion of the first fine grid in the first direction. According to claim 12, the back contact battery, wherein, The first fine gate is the first polar fine gate closest to the edge of the silicon substrate, and the distance between the first fine gate and the edge is 0.4 mm to 1 mm. According to claim 12, the back contact battery, wherein, The distance from the first connecting block to the edge of the silicon substrate is 0.4 mm to 50 mm. According to claim 12, the back contact battery, wherein, The first polar fine grid includes a third fine grid, the third fine grid includes a connected second fine grid body portion and a second fine grid bending portion, the second fine grid body portion extends along the second direction, the second fine grid bending portion is correspondingly disposed with the first connecting block, and the second fine grid bending portion bends from the second fine grid body portion in a direction away from the first connecting block. The back contact battery according to claim 18, wherein, Along the direction away from the first connecting block, the bending depth of the first fine grid bend and the second fine grid bend gradually decreases. The back contact battery according to claim 18, wherein, For adjacent second and third fine grids, the bending portions of the first and second fine grids satisfy the following formula: 50μm≤d1-d2≤150μm; Wherein, d2 is the maximum distance between the second fine grid bending portion and the second fine grid main body portion in the first direction, and d1 is the maximum distance between the first fine grid bending portion and the first fine grid main body portion in the first direction. According to claim 12, the back contact battery, wherein, The back contact battery satisfies at least one of the following: The first fine gate and the first connecting block connected to the first fine gate form a first conductive structure, and each row of the first conductive structure is continuous; The second fine grid in each row is continuous. According to claim 21, the back contact battery, wherein, The first connection block includes at least one of pads and gate segments. According to claim 21, the back contact battery, wherein, The first connecting block includes a hollow area; Alternatively, the first connecting block may be solid. According to claim 12, the back contact battery, wherein, The second polar fine gate includes a fourth fine gate, the fourth fine gate having a second connecting block, the width of the second connecting block being greater than the width of the fourth fine gate. The back contact battery according to claim 24, wherein, The difference between the width of the second connecting block and the width of the fourth fine gate is 5 μm to 290 μm. The back contact battery according to claim 24, wherein, The difference between the area of ​​the first connecting block and the area of ​​the second connecting block is -400 μm² to 400 μm². The back contact battery according to claim 24, wherein, The first polar fine grid adjacent to the second connecting block is disconnected at the position corresponding to the second connecting block to avoid the second connecting block. In the second direction, the distance between the break point of the second connecting block and the first fine grid is 0.2 mm to 1 mm. The back contact battery according to claim 24, wherein, The fourth fine gate is the second polar fine gate closest to the edge of the silicon substrate, and the distance between the fourth fine gate and the edge is greater than 0.7 mm to 1.3 mm. The back contact battery according to claim 24, wherein, The distance from the second connecting block to the edge of the silicon substrate is 0.7 mm to 50 mm. The back contact battery according to claim 24, wherein, The fourth fine gate is the second polar fine gate closest to the edge of the silicon substrate, and the second connecting block is located on the side of the fourth fine gate facing the edge. The back contact battery according to claim 24, wherein, The second connecting block protrudes from the fourth fine grid to both sides of the fourth fine grid. The back contact battery according to claim 24, wherein, The fourth fine gate includes a connected third fine gate body portion and a third fine gate bend portion. The third fine gate body portion extends along the second direction, and the third fine gate bend portion bends from the third fine gate body portion toward an edge away from the silicon substrate. The second connecting block is disposed on the third fine gate bend portion. The back contact battery according to claim 32, wherein, The maximum distance between the third fine grid bend and the third fine grid body in the first direction is 5 μm to 290 μm. The back contact battery according to claim 24, wherein, The fourth fine gate and the second fine gate are the same second polarity fine gate. The back contact battery according to claim 24, wherein, The fourth fine grid and the second connecting block disposed on the fourth fine grid form a second conductive structure, and each row of the second conductive structure is continuous. The back contact battery according to claim 24, wherein, The second connection block includes at least one of pads and gate segments. The back contact battery according to claim 24, wherein, The second connecting block includes a hollow area; Alternatively, the second connecting block may be solid. According to claim 12, the back contact battery, wherein, The silicon substrate includes a plurality of first polar doped regions and a plurality of second polar doped regions arranged along the first direction. The first polar doped regions are provided with first polar fine gates, and the second polar doped regions are provided with second polar fine gates. The first polar doped region includes a first doped region, which includes a first region and a second region. The first region is provided with the first fine gate, and the second region corresponds to the first connecting block. The second polar doped region includes a second doped region, which includes a third region and a fourth region. The third region has the first fine gate body portion of the second fine gate, and the fourth region has the first fine gate bend portion of the second fine gate. The back contact battery according to claim 38, wherein, The second region protrudes from the first region. According to claim 39, the back contact battery, wherein, In the first direction, the second region protrudes from the first region to a maximum depth of 5 μm to 290 μm. The back contact battery according to claim 38, wherein, The fourth region protrudes from the third region on the side opposite to the second region. According to claim 41, the back contact battery, wherein, In the first direction, the maximum depth of the fourth region protruding from the third region is 1 μm to 500 μm. According to claim 41, the back contact battery, wherein, The second region protrudes from the first region on the side facing the fourth region, and in the first direction, the difference between the maximum depth of the second region protruding from the first region and the maximum depth of the fourth region protruding from the third region is 50 μm to 200 μm. The back contact battery according to claim 38, wherein, The first polar fine grid includes a third fine grid, the third fine grid includes a connected second fine grid body portion and a second fine grid bending portion, the second fine grid body portion extends along the second direction, the second fine grid bending portion is correspondingly disposed with the first connecting block, and the second fine grid bending portion bends from the second fine grid body portion in a direction away from the first connecting block; The first polar doped region includes a third doped region, the third doped region includes a fifth region and a sixth region, the fifth region has a second fine gate body portion with a third fine gate, and the sixth region has a second fine gate bend portion with the third fine gate. The back contact battery according to claim 44, wherein, The sixth region protrudes from the fifth region on the side opposite to the second region. The back contact battery according to claim 45, wherein, The fourth region protrudes from the third region on the side opposite to the second region, and the protrusion depth of the fourth region and the sixth region gradually decreases along the direction away from the second region. The back contact battery according to claim 46, wherein, For adjacent second and third doped regions, the fourth and sixth regions satisfy the following formula: 50μm≤H2-H3≤200μm; Wherein, H2 is the maximum depth of the fourth region protruding from the third region on the side away from the second region in the first direction, and H3 is the maximum depth of the sixth region protruding from the fifth region on the side away from the second region in the first direction. The back contact battery according to claim 38, wherein, The back contact battery satisfies at least one of the following: The first doped region in each row is continuous; The second doped region is continuous in each row. The back contact battery according to claim 38, wherein, The doped region closest to the edge of the silicon substrate is the P-region. The back contact battery according to claim 38, wherein, The second polar fine gate includes a fourth fine gate, the fourth fine gate being connected to a second connecting block, the width of the second connecting block being greater than the width of the fourth fine gate; The second polar doped region includes a fourth doped region, which includes a seventh region and an eighth region. The seventh region is provided with the fourth fine gate, and the eighth region corresponds to the second connection block. According to claim 50, the back contact battery, wherein, The eighth region protrudes from the seventh region. According to claim 51, the back contact battery, wherein, The maximum depth of the eighth region protruding from the seventh region is 5 μm to 290 μm. According to claim 50, the back contact battery, wherein, The fourth doped region and the second doped region are the same second polar doped region. According to claim 50, the back contact battery, wherein, The fourth doped region in each row is continuous. According to claim 50, the back contact battery, wherein, The fourth fine gate includes a connected third fine gate body portion and a third fine gate bending portion. The third fine gate body portion extends along the second direction, and the third fine gate bending portion bends from the third fine gate body portion toward an edge away from the silicon substrate. The second connecting block is disposed on the third fine gate bending portion. The fourth doped region includes a ninth region, and the ninth region is provided with the third fine gate bend. The back contact battery according to claim 55, wherein, The ninth region protrudes from the seventh region on the side opposite to the eighth region. According to claim 12, the back contact battery, wherein, The first polar fine gate is a positive fine gate, and the first polar fine gate includes a fifth fine gate and a sixth fine gate. The distance between the sixth fine gate and the adjacent second polar fine gate is greater than the distance between the fifth fine gate and the adjacent second polar fine gate. The back contact battery according to claim 57, wherein, The sixth fine grid is connected to the third connecting block, and the width of the third connecting block is greater than the width of the sixth fine grid. The back contact battery according to claim 57, wherein, The distance between the sixth fine gate and the adjacent second polar fine gate is the first distance, and the distance between the fifth fine gate and the adjacent second polar fine gate is the second distance. The difference between the first distance and the second distance is 0.05 to 0.1 mm. A battery assembly, wherein, Includes the back contact battery as described in any one of claims 1 to 59. A photovoltaic system, wherein, Includes the battery assembly as described in claim 60.

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