Battery piece and photovoltaic module

Abstract

The invention discloses a battery piece and a photovoltaic module. The battery piece comprises a substrate, and the surface of the substrate is provided with an N-type doped layer, a P-type doped layer and an isolation region arranged between the N-type doped layer and the P-type doped layer; the N-type doping layer and the P-type doping layer are arranged in an interdigital manner, each of the N-type doping layer and the P-type doping layer comprises a main body part and a finger-shaped part, the main body parts extend along a first direction, and the finger-shaped parts are arranged on at least one side of the main body parts along a second direction; the finger-shaped part is provided with a current collection electrode extending along a second direction; the first insulating layer is arranged at the position, close to the main body part of the opposite conductive type, of the finger-shaped part; the first insulating layer covers the end portion of the collector electrode, and the first insulating layer and the adjacent isolation region are arranged at an interval in the second direction. The first insulating layer is utilized to play an insulating and isolating role, meanwhile, the shielding area of the first insulating layer on the surface of the substrate is reduced, and the problem of poor local connection of the interconnector caused by the fact that the interconnector is heightened due to the fact that the first insulating layer partially extends below the interconnector can also be avoided.

Description

A type of solar cell and photovoltaic module Technical Field

[0001] This application belongs to the field of photovoltaic technology, specifically relating to a solar cell and a photovoltaic module. Background Technology

[0002] Back-contact solar cells, by placing all electrodes on the back side, avoid the grid lines blocking the front of the cell, thus improving the conversion efficiency of solar cells and gaining widespread application and attention. Since both the positive and negative electrodes of a back-contact cell are located on the back side, to prevent short circuits with dissimilar electrodes when connecting cells in series using solder ribbons, an insulating layer is typically applied to a portion of the back side of the cell to insulate the solder ribbons from adjacent dissimilar sub-grids. However, in existing solar cell technologies, while the insulating layer provides insulation, it also affects the cell's light absorption and can easily lead to poor solder joints. Summary of the Invention

[0003] This application aims to provide a solar cell and a photovoltaic module that can solve the problem that setting an insulating adhesive layer in the solar cell in the prior art will affect the light absorption rate of the solar cell and easily lead to poor soldering of the solder strip.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, embodiments of this application propose a battery cell, comprising: a substrate, the surface of which is provided with an N-type doped layer and a P-type doped layer, and an isolation region is provided between the N-type doped layer and the P-type doped layer; the N-type doped layer and the P-type doped layer are arranged in an interdigitated manner, each of the N-type doped layer and the P-type doped layer includes a main body portion and a finger portion, the main body portion extending along a first direction, and the finger portion disposed on at least one side of the main body portion along a second direction, the second direction intersecting the first direction; a current collector electrode extending along the second direction is provided on the finger portion; a first insulating layer is disposed on the finger portion near the main body portion of the opposite conductivity type; the first insulating layer covers the end of the current collector electrode, and is spaced apart from the adjacent isolation region in the second direction.

[0005] Secondly, embodiments of this application propose a photovoltaic module including multiple battery strings, each battery string including multiple solar cells and interconnects, wherein the multiple solar cells are connected together in series through the interconnects, and the solar cells are the type described in the first aspect.

[0006] In the embodiments of this application, a first insulating layer is provided on the finger-shaped portion of the doped layer. The first insulating layer is located on the finger-shaped portion near the main body portion of the opposite conductivity type, and the first insulating layer covers the end of the current collector electrode on the finger-shaped portion. This allows the first insulating layer to insulate the current collector electrode from the interconnect on the main body portion of the opposite conductivity type when connecting the cells in series using interconnects, thereby avoiding short circuits. Furthermore, the first insulating layer is spaced apart from the adjacent isolation region in the second direction. This ensures that the first insulating layer provides insulation while reducing the area of ​​the first insulating layer blocking the substrate surface, thereby increasing the light absorption of the cell surface and improving the conversion efficiency of the cell. At the same time, when connecting the cells in series using interconnects, it also prevents the first insulating layer from extending under the interconnect, which would cause the interconnect to be raised and lead to poor local connections.

[0007] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below, wherein: Figure 1 is a schematic diagram of a battery cell according to an embodiment of this application; Figure 2 is a schematic diagram of a battery cell according to another embodiment of this application; Figure 3 is an enlarged view of part A circled in Figure 2; Figure 4 is an enlarged view of part B circled in Figure 2; Figure 5 is an enlarged view of part C circled in Figure 2; Figure 6 is an enlarged view of part D circled in Figure 2; Figure 7 is an enlarged view of an embodiment of the structure of part D circled in Figure 2; Figure 8 is an enlarged view of part D circled in Figure 2; Figure 9 is an enlarged view of another embodiment of the structure of part E circled in Figure 2; Figure 10 is a structural schematic diagram of a structure with interconnecting members provided at part A circled in Figure 2; Figure 11 is a structural schematic diagram of a structure with interconnecting members and a fixing film provided at part A circled in Figure 2; Figure 12 is a structural schematic diagram of a structure with interconnecting members and an adhesive member provided at part A circled in Figure 2; Figure 13 is a cross-sectional view along line MM in Figure 3; Figure 14 is a cross-sectional view along line NN in Figure 10; Figure 15 is a schematic diagram of a photovoltaic module according to an embodiment of this application.

[0009] Reference numerals: 1: Solar cell; 11: Substrate; 11a: Middle region; 11b: Edge region; 101: First welding region; 102: Second welding region; 103: Third welding region; 104: Fourth welding region; 12: Doped layer; 121: P-type doped layer; 121a: P-type main body; 121b: P-type finger; 122: N-type doped layer; 122a: N-type main body; 122b: N-type finger; 123: Isolation region; 13: Current collector electrode; 131: P-region current collector electrode ; 132: N-region current collector electrode; 133: junction; 14: bus electrode; 141: P-region bus electrode; 142: N-region bus electrode; 14a: edge bus electrode; 14b: sub-edge bus electrode; 15: bridging electrode; 16: first insulating layer; 17: second insulating layer; 18: passivation layer; 2: interconnect; 21: body; 22: junction layer; 3: adhesive; 4: fixing film; 5: front plate; 6: back plate; 7: encapsulation film layer; X: first direction; Y: second direction. Detailed Implementation

[0010] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0011] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0012] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0013] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0014] The battery cells and photovoltaic modules provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0015] As shown in Figure 1, a battery cell 1 according to some embodiments of this application includes: a substrate 11, on the surface of which are provided an N-type doped layer 122 and a P-type doped layer 121, and an isolation region 123 is provided between the N-type doped layer 122 and the P-type doped layer 121; the N-type doped layer 122 and the P-type doped layer 121 are arranged in an interdigitated manner, and each of the N-type doped layer 122 and the P-type doped layer 121 includes a main body portion and a finger portion, the main body portion extends along a first direction X, and the finger portion is disposed on at least one side of the main body portion along a second direction Y, the second direction Y intersecting the first direction X; a current collector electrode 13 extending along the second direction Y is provided on the finger portion; a first insulating layer 16 is disposed on the finger portion near the main body portion of the opposite conductivity type; the first insulating layer 16 covers the end of the current collector electrode 13, and the first insulating layer 16 is spaced apart from the adjacent isolation region 123 in the second direction Y. The main body includes the P-type main body 121a and the N-type main body 122a described below, and the finger-like part includes the P-type finger-like part 121b and the N-type finger-like part 122b described below.

[0016] In this application, both the N-type doped layer 122 and the P-type doped layer 121 include a main body portion and a finger portion. By providing a first insulating layer 16 on the finger portion, the first insulating layer 16 is located on the finger portion near the main body portion of the opposite conductivity type, and the first insulating layer 16 covers the end of the current collector electrode 13 on the finger portion, so that when the battery cell 1 is connected in series using the interconnect 2 (as shown in FIG. 10), the first insulating layer 16 can insulate the current collector electrode 13 from the interconnect 2 on the main body portion of the opposite conductivity type, thereby avoiding the occurrence of short circuit problems. Furthermore, in the second direction Y, the first insulating layer 16 is spaced apart from the adjacent isolation area 123. This ensures that the first insulating layer 16 provides insulation and isolation while reducing the area of ​​the first insulating layer 16 blocking the surface of the substrate 11, thereby increasing the light absorption rate of the surface of the cell 1 and helping to improve the conversion efficiency of the cell 1. At the same time, when using the interconnect 2 for series connection, it can also avoid the problem of the interconnect 2 being raised due to the first insulating layer 16 partially extending under the interconnect 2, thus preventing the interconnect 2 from being poorly connected locally.

[0017] The solar cell 1 in this application can be a back-contact solar cell 1. The substrate 11 has a front side and a back side disposed opposite to each other. The front side of the substrate 11 is the side that faces sunlight when in use, and the back side of the substrate 11 is provided with two doped layers 12 of opposite conductivity types. The back-contact solar cell 1 includes, but is not limited to: back-contact heterojunction solar cell (HBC cell), back-contact tunnel oxide passivated contact cell (TBC cell), composite passivated back-contact cell (HPBC cell), back-contact hybrid cell (HTBC cell), etc.

[0018] Specifically, the two doped layers 12 with opposite conductivity types disposed on the surface of the substrate 11 are a P-type doped layer 121 and an N-type doped layer 122, and an isolation region 123 is provided between the P-type doped layer 121 and the N-type doped layer 122. Furthermore, the P-type doped layer 121 and the N-type doped layer 122 are arranged in an interdigitated pattern, and an isolation region 123 is provided between the P-type doped layer 121 and the N-type doped layer 122 to isolate the P-type doped layer 121 and the N-type doped layer 122.

[0019] As shown in Figures 3 and 4, both the P-type doped layer 121 and the N-type doped layer 122 include a main body portion and finger-shaped portions. The main body portion of the P-type doped layer 121 is designated as P-type main body portion 121a, and the finger-shaped portions are designated as P-type finger-shaped portions 121b. Similarly, the main body portion of the N-type doped layer 122 is designated as N-type main body portion 122a, and the finger-shaped portions are designated as N-type finger-shaped portions 122b. Both the P-type main body portion 121a and the N-type main body portion 122a extend along the first direction X, and the P-type finger-shaped portions 121b and N-type finger-shaped portions 122b are arranged in an interdigitated pattern.

[0020] Furthermore, as shown in FIG4, a first insulating layer 16 is provided at the end of the P-type finger portion 121b near the N-type main body portion 122a, and an isolation region 123 is provided between the P-type finger portion 121b and the N-type main body portion 122a in the second direction Y, so that the first insulating layer 16 and the isolation region 123 are spaced apart, that is, the first insulating layer 16 does not cover the isolation region 123 in the second direction Y.

[0021] Accordingly, as shown in FIG3, a first insulating layer 16 may also be provided at the end of the N-type finger portion 122b near the P-type main body portion 121a, and an isolation region 123 is provided between the N-type finger portion 122b and the P-type main body portion 121a in the second direction Y, so that the first insulating layer 16 and the isolation region 123 are spaced apart.

[0022] It should be understood that on the surface of the substrate 11, the P-type doped layers 121 and N-type doped layers 122 can be arranged in an interdigitated pattern in all regions, or only in some regions (such as the edge region 11b described later) can the P-type doped layers 121 and N-type doped layers 122 be arranged in an interdigitated pattern, while the doped layers 12 in other regions can adopt other arrangements. Of course, the specific arrangement of the P-type doped layers 121 and N-type doped layers 122 on the surface of the substrate 11 can be flexibly set according to actual needs, and is not limited here.

[0023] In some embodiments, as shown in FIG13, the solar cell 1 further includes a passivation layer 18, which covers the doped layer 12 and the isolation region 123. A first insulating layer 16 located on the finger portion is connected to the passivation layer 18. The passivation layer 18 includes, but is not limited to, materials such as silicon oxide, silicon nitride, and aluminum oxide covering the surface of the doped layer 12 to prevent the doped layer 12 from being oxidized or corroded, and also to reduce carrier recombination on the surface of the solar cell 1.

[0024] In some embodiments, the first insulating layer 16 may be made of insulating materials such as silicone, polyester, polyimide, polyurethane, polyamide, epoxy resin, ethylene-vinyl acetate copolymer, etc. Of course, other types of insulating materials may also be used to form the first insulating layer 16, which is not limited here.

[0025] In some embodiments, as shown in Figures 3 and 4, the distance between the first insulating layer 16 and the adjacent isolation region 123 in the second direction Y is 0.1 mm to 0.5 mm. For example, the distance can be set to 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc. It should be understood that the distance in the embodiments of this application includes the distance W1 in Figure 3 and the distance W2 in Figure 4.

[0026] Understandably, if the distance between the first insulating layer 16 and the adjacent isolation region 123 in the second direction Y is too small, it would be inconvenient for actual processing due to the high precision requirements. Simultaneously, since the first insulating layer 16 covers the end of the current collector 13, meaning the end of the current collector 13 on the finger-like portion does not exceed the area covered by the first insulating layer 16, if the distance between the first insulating layer 16 and the adjacent isolation region 123 is too large, a large area between the first insulating layer 16 and the isolation region 123 would not have a current collector 13, resulting in the current in that area not being effectively collected, thus affecting the conversion efficiency of the solar cell.

[0027] In this application, by setting the distance between the first insulating layer 16 and the adjacent isolation region 123 along the second direction Y to be between 0.1mm and 0.5mm, it can ensure that the edge of the first insulating layer 16 and the isolation region 123 are separated by a certain distance in the second direction Y, thereby avoiding the first insulating layer 16 from blocking the isolation region 123 and avoiding the first insulating layer 16 from affecting the connection of the interconnect 2; at the same time, it can also ensure the current collection capability of the collector electrode 13 in the area between the first insulating layer 16 and the isolation region 123.

[0028] The distance between the first insulating layer 16 and the isolation region 123 refers to the straight-line distance between the edge of the first insulating layer 16 facing the isolation region 123 along the second direction Y and the edge of the isolation region 123 facing the first insulating layer 16.

[0029] In some embodiments, as shown in Figures 1, 2, and 6, the battery cell 1 further includes a bus electrode 14, which is located on the main body and extends along a first direction X; wherein, the bus electrode 14 adjacent to the edge of the substrate 11 along a second direction Y is an edge bus electrode 14a, and the bus electrode 14 adjacent to the edge bus electrode 14a and having the same conductivity type is a secondary edge bus electrode 14b; the current collector electrode 13 further includes a bridging electrode 15, which extends along the second direction Y and electrically connects the edge bus electrode 14a and the secondary edge bus electrode 14b.

[0030] In this application, a bridging electrode 15 is provided to electrically connect the edge bus electrode 14a and the secondary edge bus electrode 14b. When the battery cell 1 is connected in series using the interconnect 2, due to space limitations, it is not convenient to set the interconnect 2 at the outermost edge of the substrate 11. The current collected by the edge bus electrode 14a can be gathered to the secondary edge bus electrode 14b by the bridging electrode 15, and then the current is discharged by the interconnect 2 connected to the secondary edge bus electrode 14b. In this way, the current collection capability of the edge area of ​​the battery cell 1 is improved.

[0031] In some embodiments, as shown in FIG5, the width of the bridging electrode 15 in the first direction X is greater than the width of the other current collector electrodes 13 in the first direction X. Since the bridging electrode 15 needs to connect two bus electrodes (FIG14a and FIG14b), the current transmission path in the bridging electrode 15 is relatively long. By widening the bridging electrode 15, the conductivity of the bridging electrode 15 can be increased, thereby improving the current collection capability of the bridging electrode 15 for the edge region of the cell 1.

[0032] In some embodiments, the width of the bridging electrode 15 is 0.05 mm to 0.15 mm. For example, the width of the bridging electrode 15 can be set to 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm, 0.15 mm, etc.

[0033] In this application, the width of the bridging electrode 15 is set between 0.05mm and 0.15mm. This ensures that the bridging electrode 15 has a certain current-carrying area, thereby improving the current transmission capability of the bridging electrode 15. At the same time, it also avoids the bridging electrode 15 being too wide, which would result in a large internal resistance and increase the loss in current transmission.

[0034] It should be understood that, because the bridging electrode 15 needs to electrically connect the edge bus electrode and the sub-edge bus electrode of the same conductivity type, the bridging electrode 15 must cross at least one main body portion of the opposite conductivity type in the second direction Y. Therefore, the length of the bridging electrode 15 in the second direction Y is longer than that of the other collector electrodes 13 of the same conductivity type. At the same time, by setting the width of the bridging electrode 15 in the first direction X to be wider than that of the other collector electrodes 13 of the same conductivity type, the current carrying capacity of the bridging electrode 15 is improved.

[0035] Specifically, if the bridging electrode 15 is disposed on the P-type doped layer 121, then the bridging electrode 15 belongs to the P-region collector electrode 131; and if the bridging electrode 15 is disposed on the N-type doped layer 122, then the bridging electrode 15 belongs to the N-region collector electrode 132. The configuration can be flexibly set according to actual needs and is not limited here.

[0036] In some embodiments, the width of the collector electrode 13, excluding the bridging electrode 15, can be set to 0.02 mm-0.08 mm. For example, the width can be set to 0.02 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.08 mm, etc. The collector electrode 13 here includes a P-region collector electrode 131 and an N-region collector electrode 132. In some embodiments, the widths of the P-region collector electrode 131 and the N-region collector electrode 132 are different, with the width of the P-region collector electrode 131 being greater than the width of the N-region collector electrode 132.

[0037] Furthermore, as shown in FIG5, the surface of the substrate 11 is also provided with a second insulating layer 17, which at least covers the portion of the bridging electrode 15 in the area where it intersects with the main body portion of the opposite conductivity type.

[0038] In this application, a second insulating layer 17 is provided in the area where the bridging electrode 15 intersects with the main body of the opposite conductivity type, so that when the interconnecting member 2 is used for series connection, the bridging electrode 15 and the interconnecting member 2 of the opposite conductivity type are insulated and isolated, thereby avoiding the risk of short circuit between the two.

[0039] It is understood that at least one main body portion of opposite conductivity type is provided between the edge bus electrode 14a and the sub-edge bus electrode 14b connected to the bridging electrode 15. If the main body portion of opposite conductivity type is set as the target main body portion (e.g., the P-type main body portion 121a in FIG. 5), then a second insulating layer 17 is provided on the bridging electrode 15 so that the second insulating layer 17 covers the portion of the bridging electrode 15 in the area where it intersects with the target main body portion. In this way, when the interconnecting member 2 is provided on the target main body portion, the problem of short circuit between the interconnecting member 2 and the bridging electrode 15 can be avoided.

[0040] In some embodiments, the second insulating layer 17 may be made of insulating materials such as silicone, polyester, polyimide, polyurethane, polyamide, epoxy resin, ethylene-vinyl acetate copolymer, etc. Of course, other types of insulating materials may also be used to form the second insulating layer 17, and this is not limited. The materials of the second insulating layer 17 and the first insulating layer 16 may be the same or different, and this is not limited.

[0041] In some embodiments, as shown in FIG5, the width of the second insulating layer 17 in the first direction X is 0.2mm-1.5mm. For example, the width of the second insulating layer 17 can be set to 0.2 mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 1mm, 1.2mm, 1.5mm, etc.

[0042] In this application, by setting the width of the second insulating layer 17 between 0.2mm and 1.5mm, it can ensure that the second insulating layer 17 fully covers the bridging electrode 15 in the first direction X, avoiding short circuit problems when the interconnecting member 2 is connected. At the same time, it can also avoid the second insulating layer 17 being too wide, which would result in too much of the interconnecting member 2 being raised, easily leading to poor connection problems.

[0043] In some embodiments, the length of the second insulating layer 17 in the second direction Y is 1.8 mm to 3 mm. For example, the length of the second insulating layer 17 can be set to 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 2.7 mm, 3 mm, etc.

[0044] In this application, by setting the length of the second insulating layer 17 between 1.8mm and 3mm, it is possible to ensure that the second insulating layer 17 can cover a certain length of the bridging electrode 15 in the second direction Y, thereby allowing a certain offset in the placement position of the interconnect 2 when connecting, thus reducing the requirements for connection accuracy; at the same time, it also avoids the second insulating layer 17 being too long, which would cause excessive shading of the surface of the substrate 11, and also saves material costs.

[0045] In some embodiments, as shown in FIG5, a bus electrode 14 is provided on the main body portion located on both sides of the bridging electrode 15 along the first direction X, and the bus electrode 14 is connected to at least two collector electrodes 13 of the same conductivity type.

[0046] It is understandable that when the interconnect 2 is used to electrically connect the collector electrodes 13 on both sides of the bridging electrode 15, the interconnect 2 passes over the bridging electrode 15, and a part of the interconnect 2 is raised by the bridging electrode 15 and the second insulating layer 17, which may easily lead to poor connection between the interconnect 2 and the collector electrodes 13 on both sides of the bridging electrode 15.

[0047] In this application, by providing busbar electrodes 14 on both sides of the main body of the bridging electrode 15, the multiple collector electrodes 13 are electrically connected using the busbar electrodes 14. Thus, when the interconnecting member 2 is provided, the interconnecting member 2 is connected to the busbar electrodes 14, and the current of the connected collector electrodes 13 can be collected and guided to the interconnecting member 2 through the busbar electrodes 14, avoiding the problem of poor connection of the interconnecting member 2 caused by the interconnecting member 2 being partially raised by the bridging electrode 15.

[0048] In some embodiments, as shown in Figures 1 and 7, the surface of the substrate 11 includes a central region 11a and an edge region 11b surrounding the central region 11a; both the N-type doped layer 122 and the P-type doped layer 121 are interdigitated within the edge region 11b and the central region 11a. Furthermore, the bus electrode 14 may not be provided on the main body portion located in the central region 11a; instead, a junction portion 133 may be provided on the portion of the current collector 13 corresponding to the main body portion to facilitate connection with the interconnect 2.

[0049] In some embodiments, as shown in Figures 1 and 8, the surface of the substrate 11 includes a central region 11a and an edge region 11b surrounding the central region 11a; within the edge region 11b, an N-type doped layer 122 and a P-type doped layer 121 are arranged in an interdigitated manner; within the central region 11a, both the N-type doped layer 122 and the P-type doped layer 121 are continuously disposed along the second direction Y and alternately disposed along the first direction X.

[0050] In this application, by setting the doped layer 12 in the edge region 11b into an interdigitated arrangement, the current collector 13 and the current bus 14 are simultaneously set on the doped layer 12 in the edge region 11b. This ensures the current collection capability at the edge of the cell 1. At the same time, when connecting the interconnect 2, the interconnect 2 can be connected to the current bus 14 instead of connecting the interconnect 2 to each current collector 13 in the edge region 11b. This facilitates the actual connection operation and reduces the occurrence of connection failures.

[0051] Meanwhile, the doped layer 12 of the intermediate region 11a is configured to extend continuously along the second direction Y, and the two doped layers 12 with opposite conductivity types are arranged alternately. Therefore, only the collector electrode 13 needs to be provided on the doped layer 12 of the intermediate region 11a, without the need to provide a separate bus electrode 14. Furthermore, a bonding portion 133 (e.g., a pad) can be provided on the collector electrode 13 located in the intermediate region 11a, which can be used to directly connect to the interconnect 2. This can save material for the bus electrode 14 and reduce processing costs.

[0052] The joint 133 can be formed by thickening a local area of ​​the current collector 13, or it can be formed by separately depositing a conductive material layer on the current collector 13. It can be flexibly set according to actual needs and is not limited here. In addition, the joint 133 can also be provided at the junction of the current collector 13 and the current bus 14 in the edge region 11b, so as to facilitate connection with the interconnect 2 through the joint 133.

[0053] In some embodiments, the junction 133 and the current collector 13 can be separately molded structures, with the junction 133 and the current collector 13 at least partially overlapping. The width of the junction 133 along the first direction X is greater than the width of the current collector 13 along the first direction X, so as to increase the effective connection area of ​​the junction 133 and facilitate a stable connection with the interconnect 2. The junction 133 can be made of the same material as the bus electrode 14 to reduce material costs.

[0054] Furthermore, the joint 133 includes a connecting portion and an overlapping portion. The overlapping portion is located at both ends of the connecting portion along the second direction Y, and overlaps with the current collector 13. The width of the connecting portion along the first direction X is greater than the width of the current collector 13 along the first direction X. The width of the overlapping portion along the first direction X gradually decreases in the direction away from the connecting portion, so that the joint 133 has a spindle-shaped structure that is thicker in the middle and thinner at both ends. In this way, it can be ensured that the joint 133 has sufficient connection area to form a stable connection with the interconnect 2, and at the same time, the dimensions of the joint 133 and the current collector 13 at the connection point are smoothly transitioned, avoiding the increase in current loss caused by abrupt size changes. In addition, the current collector 13 can also be disconnected at the position corresponding to the joint 133 to save material costs for the current collector 13.

[0055] In some embodiments, as shown in Figures 3 and 4, the P-type doped layer 121 includes a P-type body portion 121a and a P-type finger portion 121b, and the N-type doped layer 122 includes an N-type body portion 122a and an N-type finger portion 122b; wherein, the P-type finger portion 121b is provided with a P-region collector electrode 131, and the N-type finger portion 122b is provided with an N-region collector electrode 132; the P-type finger portion 121b is provided with a first insulating layer 16 near the N-type body portion 122a, the first insulating layer 16 covers the end of the P-region collector electrode 131, and the first insulating layer 16 is spaced apart from the adjacent isolation region 123 in the second direction Y; correspondingly, the N-type finger portion 122b is provided with a first insulating layer 16 near the P-type body portion 121a, the first insulating layer 16 covers the end of the N-region collector electrode 132; the first insulating layer 16 is spaced apart from the adjacent isolation region 123 in the second direction Y.

[0056] Specifically, the substrate 11 can be an N-type silicon substrate. The N-type doped layer 122 has the same doping type as the substrate 11, and the P-type doped layer 121 has the opposite doping type to the substrate 11, so as to form a PN junction between the P-type doped layer 121 and the substrate 11. Furthermore, as shown in Figures 3 and 4, the P-type doped layer 121 includes a P-type body portion 121a and a P-type finger portion 121b. A P-region bus electrode 141 is provided on the P-type body portion 121a, and a P-region collector electrode 131 is provided on the P-type finger portion 121b. The N-type doped layer 122 includes an N-type body portion 122a and an N-type finger portion 122b. An N-region bus electrode 142 is provided on the N-type body portion 122a, and an N-region collector electrode 132 is provided on the N-type finger portion 122b.

[0057] In this application, by providing a first insulating layer 16 near the N-type main body 122a in the P-type finger portion 121b, insulation isolation between the P-region current collector 131 and the adjacent N-region bus electrode 142 can be achieved. Correspondingly, as shown in FIG3, by providing a first insulating layer 16 near the P-type main body 121a in the N-type finger portion 122b, insulation isolation between the N-region current collector 132 and the adjacent P-region bus electrode 141 can be achieved. Furthermore, by spacing the first insulating layer 16 from the adjacent isolation region 123, the occlusion of the first insulating layer 16 on the surface of the substrate 11 can be reduced, thereby improving light absorption efficiency. Simultaneously, the first insulating layer 16 is prevented from affecting the connection between the P-region bus electrode 141 and the N-region bus electrode 142 and the corresponding interconnect 2.

[0058] It should be noted that the shape and size of the first insulating layer 16 provided on the P-type finger portion 121b and the N-type finger portion 122b can be the same or different, and can be flexibly set according to actual needs, without limitation here.

[0059] In some embodiments, as shown in Figures 3 and 4, the width W3 of the P-type main body portion 121a in the second direction Y is greater than the width W4 of the N-type main body portion 122a in the second direction Y. That is, by making the width of the P-type main body portion 121a wider, the light-receiving area of ​​the P-type main body portion 121a can be increased. Since a PN junction is formed between the P-type main body portion 121a and the substrate 11, increasing the light-receiving area of ​​the P-type main body portion 121a helps to improve the power generation capacity of the solar cell 1.

[0060] It is understandable that solar cell power generation is based on the photovoltaic effect, which converts solar energy into electrical energy. The core structure of a solar cell is the PN junction structure. Under the photovoltaic effect, the solar cell generates electron-hole pairs, i.e., charge carriers. An internal electric field exists in the space charge region of the PN junction. This internal electric field drives free electrons to move towards the N-region and holes to move towards the P-region, preventing them from recombinating. Ultimately, electrons (negatively charged) accumulate in the N-region and holes (positively charged) accumulate in the P-region, forming a potential difference (voltage) across the PN junction, thus generating current. Charge carriers far from the PN junction are more likely to recombine during their migration towards the PN junction. Therefore, increasing the light-receiving area of ​​the corresponding region of the PN junction is beneficial to improving the power generation capacity of the solar cell.

[0061] For example, as shown in FIG3, the width W3 of the P-type main body 121a in the second direction Y is set to 0.4mm-0.8mm. For example, the width W3 of the P-type main body 121a can be set to 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc.

[0062] For example, as shown in FIG4, the width W4 of the N-type main body 122a in the second direction Y is set to 0.2mm-0.6mm. For example, the width W4 of the N-type main body 122a can be set to 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc.

[0063] In some embodiments, as shown in FIG4, the width D1 of the P-type finger portion 121b in the first direction X is greater than the width D2 of the N-type finger portion 122b in the first direction X. That is, by making the width of the P-type finger portion 121b wider, the light-receiving area of ​​the P-type finger portion 121b is increased, and a PN junction is formed between the P-type finger portion 121b and the substrate 11, thereby improving the power generation capacity of the solar cell 1.

[0064] For example, as shown in FIG4, the width D1 of the P-type finger portion 121b in the first direction X is 0.3mm-0.6mm. For example, the width D1 can be set to 0.3 mm, 0.4mm, 0.5 mm, 0.6 mm, etc.

[0065] For example, as shown in FIG4, the width D2 of the N-type finger portion 122b in the first direction X is 0.2 mm-0.5 mm. For example, the width D2 can be set to 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0066] In some embodiments, as shown in FIG3, in the second direction Y, the distance from the first insulating layer 16 on the N-type finger portion 122b to the adjacent isolation region 123 is W1, and as shown in FIG4, the distance from the first insulating layer 16 on the P-type finger portion 121b to the adjacent isolation region 123 is W2, satisfying: W1≤W2.

[0067] In this application, the distance W2 from the first insulating layer 16 on the P-type finger 121b to the adjacent isolation region 123 is made greater than or equal to the distance W1 from the first insulating layer 16 on the N-type finger 122b to the adjacent isolation region 123. That is, the area of ​​the end of the P-type finger 121b not covered by the first insulating layer 16 is made larger, so that the end of the P-type finger 121b has a larger area for receiving light. A PN junction is formed between the P-type finger 121b and the substrate 11, which helps to increase the light absorption rate in the area near the PN junction, thereby improving the power generation capacity of the solar cell 1.

[0068] For example, in the second direction Y, the distance W1 is set to 0.1mm-0.4mm. For instance, the distance W1 can be set to 0.1mm, 0.2mm, 0.3mm, 0.4mm, etc.

[0069] For example, in the second direction Y, the distance W2 is set to 0.1mm - 0.5mm. For instance, the distance W2 can be set to 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

[0070] In some embodiments, along the second direction Y, the distance from the end of the current collector 13 to the edge of the corresponding first insulating layer 16 near the isolation region 123 is greater than or equal to 0.1 mm. By setting the distance from the end of the current collector 13 to the edge of the corresponding first insulating layer 16 to be greater than or equal to 0.1 mm, it is ensured that the end of the current collector 13 is fully covered by the first insulating layer 16, avoiding the risk of short circuit between the current collector 13 and the interconnect 2.

[0071] In some embodiments, as shown in FIG3, the first insulating layer 16 located on the N-type finger 122b partially covers the isolation region 123 adjacent to the first insulating layer 16 along the first direction X. In this embodiment, by providing the first insulating layer 16 on the N-type finger 122b to partially cover the isolation region 123 adjacent along the first direction X, sufficient coverage of the N-type finger 122b is formed in the first direction X, thereby improving the insulation and isolation effect on the N-region current collector electrode 132.

[0072] In some embodiments, as shown in FIG4, the first insulating layer 16 located on the P-type finger portion 121b does not overlap with the isolation region 123 adjacent to the first insulating layer 16 along the first direction X.

[0073] In this application, by setting the first insulating layer 16 on the P-type finger portion 121b to not overlap with the adjacent isolation region 123 along the first direction X, the shading area of ​​the first insulating layer 16 on the P-type finger portion 121b is reduced. A PN junction is formed between the P-type finger portion 121b and the substrate 11, which helps to increase the light absorption rate in the area near the PN junction, thereby improving the power generation capacity of the battery cell 1.

[0074] In some embodiments, as shown in FIG9, the width of the first insulating layer 16 at the end near the N-type main body portion 122a along the first direction X is greater than the width of the first insulating layer 16 at the end away from the N-type main body portion 122a along the first direction X.

[0075] In this application, the first insulating layer 16 provided on the P-type finger portion 121b has two opposite ends along the second direction Y. By setting the width of the end of the first insulating layer 16 near the N-type main body portion 122a to be greater than the width of the end of the first insulating layer 16 away from the N-type main body portion 122a, the electrical isolation effect of the first insulating layer 16 between the P-region collector electrode 131 and the N-region bus electrode 142 (or interconnect 2) on the N-type main body portion 122a can be improved.

[0076] In some embodiments, the width of the first insulating layer 16 at the end near the P-type body portion 121a along the first direction X is greater than the width of the first insulating layer 16 at the end away from the P-type body portion 121a along the first direction X.

[0077] In this application, the first insulating layer 16 disposed on the N-type finger portion 122b has two opposite ends along the second direction Y. By setting the width of the end of the first insulating layer 16 near the P-type main body portion 121a to be greater than the width of the end away from the P-type main body portion 121a, the electrical isolation effect of the first insulating layer 16 between the N-region collector electrode 132 and the P-region bus electrode 141 (or interconnect 2) on the P-type main body portion 121a can be improved.

[0078] In some embodiments, the surface of the substrate 11 is provided with a plurality of welding areas extending along a first direction X and spaced apart along a second direction Y. Each welding area is used to provide interconnects so as to connect the battery cells 1 in series using the interconnects. Specifically, as shown in FIG1, from right to left, a first welding area 101, a second welding area 102, a third welding area 103 and a fourth welding area 104 are provided on the surface of the substrate 11. The interconnects 2 provided in the first welding area 101 and the third welding area 103 have the same conductivity type, and the interconnects 2 provided in the second welding area 102 and the fourth welding area 104 have the same conductivity type.

[0079] As shown in Figure 1, the first welding area 101 and the second welding area 102 are located in the edge region 11b of the substrate 11 surface. At corresponding positions in the first welding area 101 and the second welding area 102, the N-type doped layer 122 and the P-type doped layer 121 are arranged in an interdigitated pattern. Both the first welding area 101 and the second welding area 102 are provided with bus electrodes 14. The bus electrodes 14 in each welding area are intermittently arranged along the first direction X to facilitate flexible connection with multiple collector electrodes 13. Furthermore, a joint portion 133 (e.g., a pad) can be provided at the intersection of the bus electrode 14 and the collector electrode 13 to connect and fix the interconnect 2 to the joint portion 133.

[0080] Furthermore, as shown in Figures 1 and 2, edge bus electrodes 14a and multiple edge current collectors connected to the edge bus electrodes 14a are provided on both sides of the battery cell 1 along the second direction Y. Current from the edge of the substrate 11 can be collected through the edge bus electrodes 14a and the edge current collectors. Since it is inconvenient to install interconnects 2 at the edge of the substrate 11, bridging electrodes 15 extending along the second direction Y are provided on both sides of the battery cell 1 along the second direction Y. The bridging electrodes 15 electrically connect the edge bus electrodes 14a to adjacent bus electrodes 14 of the same conductivity type. For example, in the right-hand region of Figure 1, the edge bus electrode 14a on the right edge is electrically connected to the bus electrode 14 in the second welding area 102 through the bridging electrodes 15.

[0081] As shown in Figures 1, 2, and 8, the third welding area 103 and the fourth welding area 104 are partially located in the edge area 11b and partially in the middle area 11a. The doped layer 12 in the edge area 11b adopts an interdigitated arrangement structure. The N-type doped layer 122 and P-type doped layer 121 in the middle area 11a both extend along the second direction Y and are alternately arranged along the first direction X. In this way, the bus electrode 14 does not need to be set in the middle area 11a. The collector electrode 13 is provided with a joint 133, and the interconnect is directly connected to the joint 133. The heterogeneous collector electrode 13 is disconnected at the corresponding welding area position. Furthermore, the end of the collector electrode 13 at the disconnection point can be covered with an insulating layer for insulation isolation. The material and size of the insulating layer can be set with reference to the first insulating layer 16.

[0082] It should be noted that the first welding area 101 and the second welding area 102 are only set at the two sides of the edge of the battery cell 1 along the second direction Y, while the third welding area 103 and the fourth welding area 104 can be set in multiple sets. Figure 1 is only used as a schematic structure. The specific setting of the welding area can be flexibly set according to the actual layout needs of the battery cell 1, and is not limited here.

[0083] This application also provides a photovoltaic module, including a battery string, the battery string including a plurality of battery cells 1 and an interconnecting element 2, the plurality of battery cells 1 being connected together in series through the interconnecting element 2, the battery cells 1 being the battery cells 1 in the above embodiments.

[0084] In this application, both the N-type doped layer 122 and the P-type doped layer 121 include a main body and finger-shaped portions. A first insulating layer 16 is provided on the finger-shaped portion, positioned near the main body with the opposite conductivity type, and covering the end of the current collector electrode 13 on the finger-shaped portion. This ensures that when connecting the battery cell 1 in series using the interconnect 2, the first insulating layer 16 can insulate the current collector electrode 13 from the interconnect 2 on the main body with the opposite conductivity type, thus preventing short circuits. Furthermore, in the second direction Y, the first insulating layer 16 is spaced apart from the adjacent isolation region 123. This ensures that the first insulating layer 16 provides insulation while reducing the area of ​​the substrate 11 surface obstructed by the substrate 11, thereby increasing the light absorption rate of the battery cell 1 surface and improving its conversion efficiency. Simultaneously, when connecting in series using the interconnect 2, it also prevents the first insulating layer 16 from partially extending below the interconnect 2, which could cause the interconnect 2 to be raised and lead to poor local connections.

[0085] In this battery string, the battery cell 1 can be a whole battery cell or a segmented battery cell, such as a two-segmented battery cell, a three-segmented battery cell, a four-segmented battery cell, or other multi-segmented battery cells. In addition, adjacent battery cells 1 can be spaced apart in the battery string, or the edges of adjacent battery cells 1 can overlap to form a stacked structure.

[0086] In some embodiments, as shown in Figures 13 and 14, the interconnect 2 includes a body portion 21 and a bonding layer 22. The bonding layer 22 covers at least a portion of the outer peripheral surface of the body portion 21 and is electrically connected to at least one of the current collector electrode 13, the bus electrode 14, or the junction portion 133. In this embodiment, the body portion 21 plays a primary role in connection and conductivity. Providing the bonding layer 22 on the body portion 21 can improve the connectability of the interconnect 2.

[0087] The body 21 of the interconnect 2 can be made of a metal material with good electrical conductivity, such as pure copper, brass, aluminum alloy, or copper-aluminum composite material. The bonding layer 22 may include at least one element selected from Sn, Bi, Ag, Pb, and Zn to improve the solderability of the bonding layer 22.

[0088] In some embodiments, the thickness of the bonding layer 22 can be set to 0.01mm-0.03mm. This ensures that the bonding layer 22 on the body 21 has a certain thickness to improve the connectability of the interconnect 2, while avoiding the bonding layer 22 being too thick, which would cause the resistivity of the interconnect 2 to increase and affect the power of the photovoltaic module.

[0089] In some embodiments, the interconnecting element 2 can be a solder strip. For example, the interconnecting element 2 can be a flat solder strip with a width of 0.4 mm to 1 mm and a thickness of 0.18 mm to 0.3 mm. Alternatively, the interconnecting element 2 can be a round solder strip with a diameter of 0.15 mm to 0.5 mm, specifically 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.3 mm, 0.31 mm, or 0.32 mm. Yet another example is the interconnecting element 2 using other irregularly shaped solder strips with a cross-sectional area of ​​0.02 mm². 2 -0.3mm 2 Of course, the specific selection of interconnect component 2 can be flexibly chosen according to actual needs, and no restrictions are imposed here.

[0090] In some embodiments, the interconnect 2 extends along the first direction X and is electrically connected to the collector electrode 13 of the same conductivity type. The distance between the two first insulating layers 16 located on both sides of the interconnect 2 is M1, and the width of the interconnect 2 in the second direction Y is M2, satisfying: M1≥3M2.

[0091] In this application, the distance M1 between the two first insulating layers 16 on both sides of the interconnect 2 is set to be greater than or equal to three times the width M2 of the interconnect 2, so as to prevent the first insulating layer 16 from raising the interconnect 2 during the connection of the interconnect 2, which would cause a cold solder joint problem between the interconnect 2 and the collector electrode 13.

[0092] In some embodiments, as shown in FIG12, the photovoltaic module further includes an adhesive 3, through which the interconnect 2 and the solar cell 1 are bonded and fixed. By setting the adhesive 3, the interconnect 2 and the solar cell 1 can be bonded and fixed, thereby pre-fixing the interconnect 2 and preventing the interconnect 2 from shifting during lamination welding.

[0093] Specifically, when laying the interconnect component 2, adhesive can be applied first between two adjacent joints 133 on the battery cell 1, and then the interconnect component 2 can be placed in the welding area, with the adhesive between the interconnect component 2 and the battery cell 1; alternatively, the interconnect component 2 can be placed in the welding area first, and then adhesive can be applied to the interconnect component 2, covering part of the outer periphery of the interconnect component 2; subsequently, the adhesive can be cured by heating, light, or other methods to form the adhesive component 3. For example, the adhesive can be a UV adhesive, and a UV lamp can be used for curing.

[0094] In some embodiments, as shown in FIG11, a fixing film 4 is provided on the surface of the battery cell 1. The fixing film 4 covers the interconnect 2 and is connected to the battery cell 1. By providing the fixing film 4 on the surface of the battery cell 1, so that the fixing film 4 covers the interconnect 2 and is connected to the battery cell 1, a pre-fixing effect is achieved on the interconnect 2, so as to prevent the interconnect 2 from shifting during lamination welding.

[0095] Specifically, when laying the interconnect 2, the interconnect 2 is first placed in the welding area, and then a fixing film 4 is laid on the surface of the battery cell 1, covering the interconnect 2, so that the interconnect 2 is pre-fixed to the battery cell 1 by the fixing film 4. The fixing film 4 can be a low-flow film that operates at 80-120℃, such as POE or EVA. The thickness of the fixing film 4 is 0.1mm-0.5mm.

[0096] In some embodiments, as shown in FIG15, the photovoltaic module further includes a front panel 5, a back panel 6, an encapsulation film layer 7, and a solar cell 1. The front panel 5 and the back panel 6 are stacked, and the solar cell 1 and the encapsulation film layer 7 are both disposed between the front panel 5 and the back panel 6. The solar cell 1 is embedded in the encapsulation film layer 7, and the solar cell 1 is the solar cell 1 in the above embodiments.

[0097] In this application, the photovoltaic module includes multiple solar cells 1. The multiple solar cells 1 are connected in series to form a solar cell string through interconnecting components 2. Then, multiple solar cell strings are connected in series and parallel using busbars to form a solar cell unit. A front encapsulating film and a front panel 5 are sequentially laid on the front side of the solar cell unit, and a back encapsulating film and a back panel 6 are sequentially laid on the back side of the solar cell unit to form a laminate. The laminate is then placed in a laminator for lamination. The front encapsulating film and the back encapsulating film are fused to form an encapsulation film layer 7 to encapsulate the solar cells 1. At the same time, the encapsulation film layer 7 can be used to bond and fix the front panel 5 and the back panel 6.

[0098] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0099] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A type of battery cell, characterized in that, The substrate includes: an N-type doped layer and a P-type doped layer on its surface, with an isolation region between the N-type and P-type doped layers; the N-type and P-type doped layers are arranged in an interdigitated pattern, each including a main body and a finger-like portion; the main body extends along a first direction, and the finger-like portion is disposed on at least one side of the main body along a second direction, the second direction intersecting the first direction; a current collector electrode extending along the second direction is provided on the finger-like portion. A first insulating layer is disposed on the finger portion near the main body portion of the opposite conductivity type; the first insulating layer covers the end of the current collector electrode, and is spaced apart from the adjacent isolation region in the second direction.

2. The battery cell according to claim 1, characterized in that, In the second direction, the distance between the first insulating layer and the adjacent isolation area is 0.1mm-0.5mm.

3. The battery cell according to claim 1, characterized in that, Also includes: A bus electrode is located on the main body and extends along a first direction; wherein the bus electrode adjacent to the edge of the substrate along the second direction is an edge bus electrode, and the bus electrode adjacent to the edge bus electrode and having the same conductivity type is a secondary edge bus electrode; the current collector electrode includes a bridging electrode, which extends along the second direction and electrically connects the edge bus electrode and the secondary edge bus electrode.

4. The battery cell according to claim 3, characterized in that, The surface of the substrate is further provided with a second insulating layer, which at least covers the portion of the bridging electrode that intersects with the body portion of the opposite conductivity type.

5. The battery cell according to claim 4, characterized in that, The width of the second insulating layer in the first direction is: 0.2mm-1.5mm; and / or, the length of the second insulating layer in the second direction is 1.8mm-3mm.

6. The battery cell according to claim 3, characterized in that, The width of the bridging electrode in the first direction is greater than the width of the other current collector electrodes in the first direction; and / or, the width of the bridging electrode is 0.05mm-0.15mm.

7. The battery cell according to claim 3, characterized in that, Along the first direction, a bus electrode is provided on each of the main body portions located on both sides of the bridging electrode, and the bus electrode is connected to at least two current collector electrodes of the same conductivity type.

8. The battery cell according to claim 1, characterized in that, The surface of the substrate includes a central region and an edge region surrounding the central region; within the edge region, the N-type doped layer and the P-type doped layer are arranged in an interdigitated pattern; within the central region, both the N-type doped layer and the P-type doped layer extend along the second direction and are arranged alternately along the first direction.

9. The battery cell according to any one of claims 1-8, characterized in that, The P-type doped layer includes a P-type body portion and a P-type finger portion, and the N-type doped layer includes an N-type body portion and an N-type finger portion; wherein, the P-type finger portion is provided with a P-region collector electrode, the N-type finger portion is provided with an N-region collector electrode, and the P-type finger portion is provided with a first insulating layer near the N-type body portion, the first insulating layer covering the end of the P-region collector electrode; and / or, the N-type finger portion is provided with a first insulating layer near the P-type body portion, the first insulating layer covering the end of the N-region collector electrode.

10. The battery cell according to claim 9, characterized in that, In the second direction, the distance from the first insulating layer on the N-type finger to the adjacent isolation area is W1, and the distance from the first insulating layer on the P-type finger to the adjacent isolation area is W2, satisfying: W1≤W2; and / or, the width of the P-type main body in the second direction is greater than the width of the N-type main body in the second direction.

11. The battery cell according to claim 9, characterized in that, The first insulating layer located on the N-type finger portion partially covers the isolation area adjacent to the first insulating layer along the first direction; and / or, the first insulating layer located on the P-type finger portion does not overlap with the isolation area adjacent to the first insulating layer along the first direction.

12. The battery cell according to claim 9, characterized in that, The width of the first insulating layer at the end near the P-type body portion along the first direction is greater than the width of the first insulating layer at the end away from the P-type body portion along the first direction; and / or, the width of the first insulating layer at the end near the N-type body portion along the first direction is greater than the width of the first insulating layer at the end away from the N-type body portion along the first direction.

13. A photovoltaic module, characterized in that, It includes multiple battery strings, each battery string comprising multiple battery cells and interconnects, the multiple battery cells being connected together in series via the interconnects, the battery cells being the type of battery cells as described in any one of claims 1-12.

14. The photovoltaic module according to claim 13, characterized in that, The interconnect extends along a first direction and is electrically connected to the current collector electrode of the same conductivity type. The distance between the two first insulating layers located on both sides of the interconnect is M1, and the width of the interconnect in the second direction is M2, satisfying: M1≥3*M2.

15. The photovoltaic module according to claim 13, characterized in that, It also includes an adhesive component, through which the interconnect component is bonded and fixed to the battery cell; and / or, the surface of the battery cell is provided with a fixing film, which covers the interconnect component and is connected to the battery cell.

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