Battery piece and photovoltaic module

Abstract

The invention discloses a battery piece and a photovoltaic module, the battery piece comprises a substrate, the surface of the substrate is provided with two doping layers of opposite conduction types, and an isolation region is arranged between the two doping layers; the doping layer comprises a main body part extending along the first direction and a finger-shaped part arranged on at least one side of the main body part along the second direction; the main body part close to the first edge of the substrate along the second direction is a first main body part, the finger-shaped part connected with the first main body part is a first finger-shaped part, and the first finger-shaped part is provided with a first collector electrode; the main body part which is adjacent to the first main body part and is opposite to the first main body part in conduction type is a second main body part, the finger-shaped part connected with the second main body part is a second finger-shaped part, and the second finger-shaped part is provided with a second collector electrode; the distance from one end of the first collector electrode facing the second body portion to the adjacent isolation region is greater than the distance from one end of the second collector electrode facing the first body portion to the adjacent isolation region. The current collection efficiency of the edge of the substrate can be improved, and the cost of the battery piece can be reduced.

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] A back-contact battery is a type of battery in which both P-type and N-type doped layers are disposed on the back side. In a back-contact battery, alternating current-collecting electrodes and alternating current-combining electrodes are arranged on the back side, with the current-collecting electrodes and current-combining electrodes interleaved. In related technologies, structural defects such as microcracks easily appear in the edge region of the battery cell, and charge carriers at the edge of the battery cell are prone to recombination. This results in poor current collection in the edge region of the battery cell, thus affecting the cell's efficiency. Summary of the Invention

[0003] This application aims to provide a solar cell and photovoltaic module that can solve the problem of poor current collection effect in the edge area of ​​the solar cell in the back contact cell of the related technology.

[0004] To solve the above-mentioned technical problems, this application provides the following: Firstly, an embodiment of this application proposes a battery cell, comprising: a substrate, the surface of which is provided with two doped layers of opposite conductivity types, the two doped layers of opposite conductivity types being arranged in an interdigitated pattern, and an isolation region being provided between the two doped layers of opposite conductivity types; each of the two doped layers of opposite conductivity types includes a main body portion and a finger-like portion, the main body portion extending along a first direction, and the finger-like portion disposed on at least one side of the main body portion along a second direction, the second direction intersecting the first direction; the substrate includes a first edge and a second side disposed opposite to each other along the second direction. The first body portion is the main body portion located near the first edge along the second direction, and the finger-shaped portion connected to the first body portion is the first finger-shaped portion, which is provided with a first current collector electrode; the second body portion is the main body portion adjacent to the first body portion and having the opposite conductivity type, and the finger-shaped portion connected to the second body portion is the second finger-shaped portion, which is provided with a second current collector electrode; wherein, along the second direction, the distance from the end of the first current collector electrode facing the second body portion to the adjacent isolation region is greater than the distance from the end of the second current collector electrode facing the first body portion to the adjacent isolation region.

[0005] Secondly, this application provides a photovoltaic module, including: a front panel, a back panel, an encapsulation film layer, and solar cells. The front panel and the back panel are stacked, and the solar cells and the encapsulation film layer are both disposed between the front panel and the back panel. The solar cells are embedded in the encapsulation film layer, and the solar cells are the type described in the first aspect.

[0006] In the embodiments of this application, by setting the distance from the end of the first current collector electrode facing the second main body to the adjacent isolation region to be greater than the distance from the end of the second current collector electrode facing the first main body to the adjacent isolation region, the distance from the end of the second current collector electrode to the corresponding isolation region is relatively small. This allows the end of the second current collector electrode to be as close as possible to the first edge of the substrate, thereby increasing the current collection efficiency of the second current collector electrode in the substrate edge region. Simultaneously, making the distance from the end of the first current collector electrode to the corresponding isolation region relatively large reduces the risk of short circuits between the first current collector electrode and the interconnects provided on the first main body when connecting the battery cells in series using interconnects. It also reduces the material cost of the first current collector electrode, thereby reducing the cost of using the battery cells.

[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, the following are specific embodiments of this application. 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: FIG1 is a schematic diagram of a battery cell according to an embodiment of this application; FIG2 is an enlarged view of part A circled in FIG1; FIG3 is an enlarged view of part B circled in FIG1; FIG4 is an enlarged view of part C circled in FIG1; FIG5 is an enlarged view of part D circled in FIG1; FIG6 is an enlarged view of one embodiment of the structure of part E circled in FIG1; FIG7 is an enlarged view of another embodiment of the structure of part E circled in FIG1; FIG8 is a partial structural schematic diagram of a battery cell corresponding to the interconnection member provided on the second main body according to an embodiment of this application; FIG9 is a schematic diagram of a photovoltaic module according to an embodiment of this application.

[0009] Reference numerals: 1: Solar cell; 11: Substrate; 101: First edge; 102: Second edge; 11a: Middle region; 11b: Edge region; 12: Doped layer; 121: P-type doped layer; 122: N-type doped layer; 1210: First main body; 1211: First bus electrode; 1220: First finger; 1221: First current collector; 1230: Second main body; 1231: Second bus electrode; 1240: Second finger; 1241: Second current collector; 1251: Third bus electrode; 123: Isolation region; 131: P-region current collector; 132: N-region current collector; 14: First insulating layer; 15: Bridging electrode; 16: Second insulating layer; 17: Junction; 2: Interconnector; 3: Front plate; 4: Back plate; 5: Encapsulation film; 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 Figures 1 to 3, the battery cell 1 according to some embodiments of this application includes: a substrate 11, the substrate 11 including a first edge 101 and a second edge 102 disposed opposite to each other along a first direction, the surface of the substrate 11 being provided with two doped layers 12 of opposite conductivity types, the two doped layers 12 of opposite conductivity types being arranged in an interdigitated manner, and an isolation region 123 being provided between the two doped layers 12 of opposite conductivity types; each of the two doped layers 12 of opposite conductivity types includes a main body portion and a finger-like portion, the main body portion extending along the first direction X, the finger-like portion being disposed on at least one side of the main body portion along the second direction Y, the second direction Y intersecting the first direction X; the main body portion along the second direction Y near the first edge 101 is the first edge 102. The main body 1210 has a finger-shaped portion connected to it called a first finger-shaped portion 1220, which has a first current collector electrode 1221. The main body 1230 is adjacent to the first main body 1210 and has the opposite conductivity type. The finger-shaped portion connected to the second main body 1230 is called a second finger-shaped portion 1240, which has a second current collector electrode 1241. Along the second direction Y, the distance W1 from the end of the first current collector electrode 1221 facing the second main body 1230 to the adjacent isolation region 123 is greater than the distance W2 from the end of the second current collector electrode 1241 facing the first main body 1210 to the adjacent isolation region 123.

[0016] In this embodiment, by setting the distance W1 from the end of the first current collector 1221 facing the second main body 1230 to the adjacent isolation region 123 to be greater than the distance W2 from the end of the second current collector 1241 facing the first main body 1210 to the adjacent isolation region 123, the distance from the end of the second current collector 1241 to the corresponding isolation region 123 is relatively small. This allows the end of the second current collector 1241 to be as close as possible to the first edge 101 of the substrate 11, thereby increasing the current collection efficiency of the second current collector 1241 in the edge region of the substrate 11. At the same time, making the distance from the end of the first current collector 1221 to the corresponding isolation region 123 relatively large reduces the risk of short circuit between the first current collector 1221 and the interconnect 2 provided on the first main body 1210 when the battery cells 1 are connected in series using the interconnect 2. It also reduces the material usage of the first current collector 1221, thereby reducing the cost of using the battery cells.

[0017] Specifically, the battery cell 1 includes a substrate 11, and the surface of the substrate 11 is provided with two doped layers 12 of opposite conductivity types. The doped layer 12 that is close to the first edge 101 of the substrate 11 along the second direction Y is designated as the edge doped layer, and the doped layer 12 that is adjacent to the edge doped layer along the second direction Y and has the opposite conductivity type is designated as the secondary edge doped layer.

[0018] It should be understood that the base 11 includes a first edge 101 and a second edge 102 disposed opposite to each other along a first direction. As shown in FIG2, the right edge of the base 11 can be used as the first edge 101, or, as shown in FIG3, the left edge of the base 11 can be used as the first edge 101.

[0019] As shown in Figures 2 and 3, Figure 2 corresponds to an enlarged view of the right edge region in Figure 1, and Figure 3 corresponds to an enlarged view of the left edge region in Figure 1. The edge doped layer includes a first main body 1210 and a plurality of first finger-shaped portions 1220. The first main body 1210 extends along a first direction X. The plurality of first finger-shaped portions 1220 are disposed on the side of the first main body 1210 away from the first edge 101 along a second direction Y. The plurality of first finger-shaped portions 1220 are arranged at intervals along the first direction X. One end of each first finger-shaped portion 1220 is connected to the first main body 1210, and the other end extends along the second direction Y in a direction away from the first edge 101. The first main body 1210 is provided with a first bus electrode 1211 extending along the first direction X, and the first finger-shaped portions 1220 are provided with a first collector electrode 1221 extending along the second direction Y. The first collector electrode 1221 is electrically connected to the first bus electrode 1211.

[0020] The sub-edge doped layer includes a second main body portion 1230 and a plurality of second finger portions 1240. The second main body portion 1230 is located on the side of the first main body portion 1210 opposite to the first edge 101 and is spaced apart from the first main body portion 1210. The second main body portion 1230 extends along a first direction X, and a plurality of second finger portions 1240 are provided on both sides of the second main body portion 1230 along a second direction Y. The plurality of second finger portions 1240 located on the same side are arranged at intervals along the first direction X. Between the first main body portion 1210 and the second main body portion 1230, a plurality of first finger portions 1220 and a plurality of second finger portions 1240 are alternately spaced along the first direction X to form an interdigitated arrangement. A second bus electrode 1231 extending along the first direction X is provided on the second main body portion 1230, and a second collector electrode 1241 extending along the second direction Y is provided on the second finger portions 1240. The second collector electrode 1241 is electrically connected to the second bus electrode 1231.

[0021] Isolation regions 123 are provided between the first finger portion 1220 and the second main body portion 1230, between the second finger portion 1240 and the first main body portion 1210, and between the first finger portion 1220 and the second finger portion 1240. As shown in Figures 2 and 3, along the second direction Y, the distance from the end of the first collector electrode 1221 near the second main body portion 1230 to the corresponding isolation region 123 is W1, and the distance from the end of the second collector electrode 1241 near the first main body portion 1210 to the corresponding isolation region 123 is W2. By setting the distance W1 to be greater than the distance W2, since the end of the second collector electrode 1241 extends towards the first edge 101 of the substrate 11, by reducing the distance W2, the end of the second collector electrode 1241 can be brought as close as possible to the first edge 101 of the substrate 11, thereby improving the current collection efficiency in the edge region of the substrate 11. When connecting the battery cells 1 in series using the interconnecting member 2, the interconnecting member 2 is provided on the second main body 1230. By appropriately increasing the distance between the end of the first current collector 1221 and the corresponding isolation area 123, the safe distance between the end of the first current collector 1221 and the interconnecting member 2 on the second main body 1230 is increased, reducing the possibility of short circuit between the two.

[0022] It is understood that the solar cell 1 in this embodiment can be a back-contact solar cell, and 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 the 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 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.

[0023] Specifically, the substrate 11 has two doped layers 12 with opposite conductivity types, one of which can be a P-type doped layer and the other an N-type doped layer. The specific doping types of the two doped layers 12 can be flexibly set and are not limited here.

[0024] It should be noted that the aforementioned edge doped layer can be a P-type doped layer, in which case the next edge doped layer is an N-type doped layer; or, the edge doped layer can also be an N-type doped layer, in which case the next edge doped layer is a P-type doped layer. As shown in Figures 2 and 3, edge doped layers are provided on both sides of the surface of the substrate 11 along the second direction Y. The doping types of the edge doped layer corresponding to the first edge 101 and the edge doped layer corresponding to the second edge 102 can be the same or different, and can be flexibly set according to the specific structural design needs of the solar cell 1, without limitation here.

[0025] Furthermore, in all regions of the surface of the substrate 11, the two doped layers 12 of opposite conductivity types can be arranged in an interdigitated pattern. Alternatively, the two doped layers 12 of opposite conductivity types can be arranged in an interdigitated pattern only in a portion of the surface of the substrate 11, while the doped layers 12 in other regions can adopt other arrangements.

[0026] For example, as shown in Figure 1, the surface of the substrate 11 includes a central region 11a and an edge region 11b surrounding the central region 11a. Two doped layers 12 of opposite conductivity types are a P-type doped layer 121 and an N-type doped layer 122. Within the edge region 11b, the P-type doped layer 121 and the N-type doped layer 122 are arranged in an interdigitated pattern. Within the central region 11a, as shown in Figure 6, the P-type doped layer 121 and the N-type doped layer 122 can be arranged in an interdigitated pattern, or, as shown in Figure 7, both the P-type doped layer 121 and the N-type doped layer 122 are continuously disposed along the second direction Y, and the P-type doped layer 121 and the N-type doped layer 122 are alternately arranged along the first direction X.

[0027] It is understood that Figure 6 shows an enlarged view of one embodiment of the structure of the circled part E in Figure 1, and Figure 7 shows an enlarged view of another embodiment of the structure of the circled part E in Figure 1. The difference between the two structures is that in the structure shown in Figure 6, the doped layer in the part without a bus electrode adopts an interdigitated structure, while in the structure shown in Figure 7, the doped layer in the part without a bus electrode is a strip structure that extends continuously along the second direction Y. The specific arrangement of the two doped layers can be flexibly set according to actual needs and is not limited here.

[0028] In some embodiments, as shown in Figures 2 and 3, the distance W1 from one end of the first collector electrode 1221 toward the second main body portion 1230 to the adjacent isolation region 123 along the second direction Y is 0.2 mm to 0.6 mm. For example, the distance W1 can be set to 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, etc.

[0029] In this application, by setting the distance W1 between 0.2mm and 0.6mm, a certain safe distance is ensured between the end of the first current collector 1221 and the corresponding isolation area 123. This avoids the risk of short circuit between the first current collector 1221 and the interconnect 2 provided on the second main body 1230 when the battery cell 1 is connected in series using the interconnect 2. At the same time, it avoids the distance between the end of the first current collector 1221 and the isolation area 123 being too large, which would result in a large area on the first finger portion 1220 not having grid lines, thus preventing the current from being effectively collected.

[0030] In some embodiments, along the second direction Y, the distance W2 from one end of the second current collector 1241 toward the first main body portion 1210 to the adjacent isolation region 123 is 0.1 mm to 0.5 mm. For example, the distance W2 can be set to: 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0031] In this application, by setting the distance W2 to be greater than or equal to 0.1 mm, a certain safe distance is ensured between the end of the second collector electrode 1241 and the first bus electrode 1211 on the first main body 1210, so as to avoid the risk of short circuit; at the same time, the distance W2 is set to be less than or equal to 0.5 mm, so as to avoid the end of the second collector electrode 1241 being too far from the first edge 101 of the substrate 11 and thus failing to effectively collect the current in the edge region of the substrate 11.

[0032] Optionally, as shown in Figures 2 and 3, the first main body 1210 is provided with a first bus electrode 1211 extending along the first direction X, and a first collector electrode 1221 is electrically connected to the first bus electrode 1211; the second main body 1230 is provided with a second bus electrode 1231 extending along the first direction X, and a second collector electrode 1241 is electrically connected to the second bus electrode 1231; along the second direction Y, the distance W3 from the end of the first collector electrode 1221 facing the second main body 1230 to the second bus electrode 1231 is less than the distance W4 from the end of the second collector electrode 1241 facing the first main body 1210 to the first bus electrode 1211.

[0033] In this embodiment of the application, by setting the distance W3 to be less than the distance W4, on the one hand, it can ensure that there is a certain safe distance between the end of the second collector electrode 1241 and the first bus electrode 1211, avoiding the risk of short circuit between the second collector electrode 1241 and the first bus electrode 1211; on the other hand, it can also make the first bus electrode 1211 as close as possible to the first edge 101 of the substrate 11, thereby improving the current collection effect of the edge region of the substrate 11.

[0034] Understandably, in practical applications, to avoid short circuits between the current collector electrode and the opposite polarity bus electrode, an insulating layer (such as the first insulating layer 14 described below) can be provided at the end of the first current collector electrode 1221 facing the second bus electrode 1231, so that the insulating layer covers the end of the first current collector electrode 1221 to improve the insulation effect. However, it is not convenient to provide an insulating layer at the end of the second current collector electrode 1241 facing the first bus electrode 1211 because the end of the second current collector electrode 1241 facing the first bus electrode 1211 is close to the first edge 101 of the substrate 11. If an insulating layer is provided in the corresponding area, the shrinkage rate of the insulating layer material is different from that of the substrate 11, which may easily lead to warping or even damage at the edge of the substrate 11.

[0035] Therefore, in this application, the distance W3 is set to be smaller than the distance W4 so that, without the presence of an insulating layer, the distance W4 can be appropriately increased to ensure a safe distance between the second collector electrode 1241 and the first bus electrode 1211, thereby reducing the possibility of a short circuit between them. Furthermore, the insulation between the first collector electrode 1221 and the second bus electrode 1231 can be improved by providing an insulating layer, thus allowing the distance W3 to be set relatively small to improve layout compactness.

[0036] In some embodiments, as shown in Figures 2 and 3, the distance W3 from one end of the first current collector 1221 toward the second main body 1230 to the second bus electrode 1231 along the second direction Y is 0.6 mm to 1.2 mm. For example, the distance W3 can be set to 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, etc.

[0037] In this application, by setting the distance W3 to be greater than or equal to 0.6 mm, a certain safe distance is ensured between the end of the first collector electrode 1221 and the second bus electrode 1231, thereby reducing the risk of short circuit between the first collector electrode 1221 and the second bus electrode 1231. At the same time, by setting the distance W3 to be less than or equal to 1.2 mm, it is to avoid the end of the first collector electrode 1221 being too far from the second bus electrode 1231, which would result in a large area of ​​current between the first collector electrode 1221 and the second bus electrode 1231 not being effectively collected.

[0038] In some embodiments, along the second direction Y, the distance W4 from one end of the second current collector 1241 facing the first main body 1210 to the first bus electrode 1211 is 0.8 mm to 1.6 mm. For example, the distance W4 can be set to 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, etc.

[0039] In this application, by setting the distance W4 to be greater than or equal to 0.8 mm, a certain safe distance is ensured between the end of the second collector electrode 1241 and the first bus electrode 1211, so as to reduce the risk of short circuit between the second collector electrode 1241 and the first bus electrode 1211; at the same time, the distance W4 is set to be less than or equal to 1.6 mm, so as to avoid the end of the second collector electrode 1241 being too far from the first bus electrode 1211, which would prevent the second collector electrode 1241 from effectively collecting current in the edge region of the substrate 11.

[0040] Optionally, as shown in Figures 2 and 3, along the second direction Y, the width W6 of the first main body portion 1210 is greater than the width W5 of the second main body portion 1230. By setting the width of the first main body portion 1210 to be wider, the distance from the outermost isolation region 123 on the substrate 11 to the first edge 101 of the substrate 11 is increased, thereby reducing damage to the edge of the substrate 11 during the formation of the isolation region 123. At the same time, the relatively wide first main body portion 1210 can collect charge carriers in the edge region of the battery, making the edge region of the battery an effective power generation region, thereby increasing the utilization rate of the edge region of the battery cell. Furthermore, by setting the relatively wide first main body portion 1210, the risk of microcracks appearing at the edge of the battery cell 1 due to printed electrodes can be reduced. In addition, it is also convenient to set the first bus electrode 1211 on the first main body portion 1210, and the wider first main body portion 1210 can reduce the risk of misalignment of the first bus electrode 1211.

[0041] In some embodiments, as shown in Figures 2 and 3, the width W5 of the second main body portion 1230 along the second direction Y is 0.5 mm to 1 mm. For example, the width W5 can be set to 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc. By setting the width W5 of the second main body portion 1230 to between 0.5 mm and 1 mm, it is possible to ensure that the second main body portion 1230 has an appropriate width, which facilitates the setting of the second bus electrode 1231. At the same time, it also avoids the second main body portion 1230 being too wide, which would increase the carrier recombination probability.

[0042] In some embodiments, the width W6 of the first main body portion 1210 along the second direction Y is 0.5 mm to 1.6 mm. For example, the width W6 can be set to 0.5 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, etc. By setting the width W6 of the first main body portion 1210 between 0.5 mm and 1.6 mm, it is possible to ensure that the first main body portion 1210 has an appropriate width, enabling effective separation and migration of photogenerated carriers, thereby improving the current collection efficiency of the edge region 11b of the substrate 11. At the same time, it also avoids the first main body portion 1210 being too wide, which would increase the carrier recombination probability.

[0043] Optionally, as shown in FIG2, the first main body 1210 has a centerline extending along a first direction X, and the first bus electrode 1211 is located on the side of the centerline away from the second bus electrode 1231 and close to the first edge 101. By offsetting the first bus electrode 1211 relative to the centerline of the first main body 1210 toward the side away from the second bus electrode 1231, the first bus electrode 1211 is brought as close as possible to the first edge 101 of the substrate 11, reducing the transport distance of charge carriers in the edge region of the substrate 11, for example, reducing the distance of charge carriers in the doped layer 12 near the first edge 101 to the first bus electrode 1211, thereby improving the current collection efficiency in the edge region of the substrate 11.

[0044] Optionally, as shown in Figures 2 and 3, the first finger portion 1220 is provided with a first insulating layer 14 near the second main body portion 1230, and the first insulating layer 14 covers the end of the first collector electrode 1221.

[0045] In this embodiment of the application, by providing a first insulating layer 14 near the second main body 1230 on the first finger portion 1220, the first insulating layer 14 covers the end of the first current collector electrode 1221 on the first finger portion 1220, so that when the battery cell 1 is connected in series using the interconnect 2, the first insulating layer 14 can insulate the first current collector electrode 1221 from the interconnect 2 on the second main body 1230, thereby avoiding the risk of short circuit between the interconnect 2 and the first current collector electrode 1221.

[0046] In some embodiments, the first insulating layer 14 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 14, which is not limited here.

[0047] Optionally, as shown in Figures 2 and 3, the first insulating layer 14 is spaced apart from the adjacent isolation zone 123 along the second direction Y.

[0048] In this embodiment, by spacing the first insulating layer 14 from the adjacent isolation area 123, the first insulating layer 14 can effectively provide insulation while reducing the area of ​​the first insulating layer 14 blocking the surface of the substrate 11. This improves the light absorption rate of the cell 1 surface and helps to improve the conversion efficiency of the cell 1. At the same time, when using the interconnecting member 2 for series connection, it can also avoid the problem of the interconnecting member 2 being raised due to the first insulating layer 14 partially extending under the interconnecting member 2, thus preventing poor local connection of the interconnecting member 2.

[0049] Optionally, as shown in FIG1, the battery cell 1 further includes a bridging electrode 15, and the surface of the substrate 11 is also provided with a third bus electrode 1251 extending along the first direction X. The third bus electrode 1251 is located on the side of the second bus electrode 1231 away from the first bus electrode 1211, and the third bus electrode 1251 and the first bus electrode 1211 have the same conductivity type. The bridging electrode 15 extends along the second direction Y and electrically connects the first bus electrode 1211 and the third bus electrode 1251, and the second bus electrode 1231 is disconnected at the bridging electrode 15.

[0050] In this embodiment, by setting a first bus electrode 1211 and multiple first current collector electrodes 1221 at the edge of the substrate 11, the current at the edge of the substrate 11 can be collected by the first current collector electrodes 1221 and gathered to the first bus electrode 1211. However, due to space limitations, it is not convenient to set the interconnect 2 at the outermost edge of the substrate 11. Therefore, the first bus electrode 1211 at the edge of the substrate 11 is electrically connected to the third bus electrode 1251 by the bridging electrode 15. In this way, the current collected by the first bus electrode 1211 can be gathered to the third bus electrode 1251 by the bridging electrode 15, and then the current is discharged by the interconnect 2 connected to the third bus electrode 1251. This improves the current collection capability of the edge region of the battery cell 1.

[0051] Specifically, in the process of fabricating photovoltaic modules using solar cells 1, the solar cells 1 can be connected in series using interconnecting elements 2. The interconnecting elements 2 can be provided on the main body portion other than the first main body portion 1210. For example, the interconnecting elements 2 can be provided on the second main body portion 1230 (as shown in Figure 8), and the interconnecting elements 2 are electrically connected to the second bus electrode 1231. However, since the first main body portion 1210 is located close to the first edge 101 of the substrate 11, space constraints make it inconvenient to install the interconnecting elements 2. As shown in Figure 1, in this application, a bridging electrode 15 is provided, which connects the first bus electrode 1211 to an adjacent third bus electrode 1251 of the same conductivity type, thereby achieving the collection and extraction of current generated in the edge region of the substrate 11.

[0052] It should be noted that, because the bridging electrode 15 needs to electrically connect the first bus electrode 1211 and the third bus electrode 1251 of the same conductivity type, the bridging electrode 15 must cross at least one main body portion of 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 other current collector electrodes 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 other current collector electrodes of the same conductivity type, the current carrying capacity of the bridging electrode 15 is improved.

[0053] If the bridging electrode 15 is disposed on the P-type doped layer, then the bridging electrode 15 belongs to the P-region collector electrode; and if the bridging electrode 15 is disposed on the N-type doped layer, then the bridging electrode 15 belongs to the N-region collector electrode. The bridging electrode 15 can be flexibly set according to actual needs, and no limitation is made here.

[0054] In some embodiments, as shown in FIG5, a bus electrode or a collector electrode is provided on the doped layer 12. A joint portion 17 can be provided on the bus electrode or collector electrode corresponding to the connection position with the interconnect 2, so that the joint portion 17 is connected and fixed to the interconnect 2, thereby improving the connection stability. The collector electrode is used to collect current, and the bus electrode is used to collect the current collected by the collector electrode.

[0055] Optionally, as shown in FIG4, the surface of the substrate 11 is further provided with a second insulating layer 16, which covers the portion of the bridging electrode 15 corresponding to the second bus electrode 1231.

[0056] In this embodiment of the application, by providing a second insulating layer 16 on the bridging electrode 15 at the position corresponding to the second bus electrode 1231, the bridging electrode 15 and the second bus electrode 1231 are insulated and isolated by the second insulating layer 16 when the battery cells 1 are connected in series using the interconnecting member 2, so as to avoid the risk of short circuit between the two.

[0057] It is understandable that when the bridging electrode 15 connects the first bus electrode 1211 and the third bus electrode 1251, it needs to cross the second bus electrode 1231. By disconnecting the second bus electrode 1231, a short circuit between the second bus electrode 1231 and the bridging electrode 15 can be avoided. When the battery cell 1 is connected in series using the interconnect 2, the interconnect 2 corresponding to the second bus electrode 1231 extends along the first direction X and passes through the bridging electrode 15. By providing a second insulating layer 16 at the corresponding position on the bridging electrode 15, the bridging electrode 15 and the interconnect 2 on the second bus electrode 1231 are insulated from each other.

[0058] For example, the second insulating layer 16 can 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 can also be used to form the second insulating layer 16, which is not limited here. The materials of the second insulating layer 16 and the first insulating layer 14 can be the same or different, which is not limited here.

[0059] In some embodiments, the width of the second insulating layer 16 in the first direction X is 0.2 mm to 1.5 mm. For example, the width of the second insulating layer 16 can be set to 0.2 mm, 0.5 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, etc.

[0060] In this embodiment, by setting the width of the second insulating layer 16 between 0.2mm and 1.5mm, it is possible to ensure that the second insulating layer 16 has a certain width, which can fully cover the bridging electrode 15 in the first direction X, thus avoiding short circuits when the interconnecting member 2 is connected. At the same time, it is also to avoid the second insulating layer 16 being too wide, which would result in too much raised area for the interconnecting member 2 and easily lead to poor connection problems.

[0061] In some embodiments, the length of the second insulating layer 16 in the second direction Y is 1.8 mm to 3 mm. For example, the length of the second insulating layer 16 can be set to 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 2.7 mm, 3 mm, etc.

[0062] In this embodiment, by setting the length of the second insulating layer 16 to be between 1.8 mm and 3 mm, it is possible to ensure that the second insulating layer 16 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 16 being too long, which would cause excessive shading of the surface of the substrate 11, and also saves material costs.

[0063] Optionally, the width of the bridging electrode 15 in the first direction X is greater than the width of the first collector electrode 1221 and / or the second collector electrode 1241 in the first direction X.

[0064] It is understandable that, since the bridging electrode 15 needs to connect the first bus electrode 1211 and the third bus electrode 1251 to transmit the current in the first bus electrode 1211 to the third bus electrode 1251, the transmission path of the current 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.

[0065] For example, along the first direction X, the width of the bridging electrode 15 is 0.05mm-0.15mm. For instance, 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. By setting the width of the bridging electrode 15 between 0.05mm and 0.15mm, it is possible to ensure 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, resulting in a large internal resistance and increased losses during current transmission.

[0066] Optionally, as shown in FIG6, the two doped layers with opposite conductivity types are a P-type doped layer 121 and an N-type doped layer 122. The P-type doped layer 121 includes a P-type main body and a P-type finger portion, and the N-type doped layer 122 includes an N-type main body and an N-type finger portion. The P-type finger portion is provided with a P-region collector electrode 131, and the N-type finger portion is provided with an N-region collector electrode 132. The distance between the ends of the P-region collector electrodes 131 located on both sides of the N-type main body along the second direction Y is a first distance L1. The portion of the N-region collector electrode 132 located on the N-type main body has a first break portion. The width of the first break portion in the second direction Y is a second distance L2. The first distance L1 is greater than the second distance L2.

[0067] In this embodiment, by providing a first disconnection portion on the N-type main body of the N-region current collector electrode 132, i.e., the portion of the N-region current collector electrode 132 on the N-type main body is disconnected, the material cost of the N-region current collector electrode 132 can be saved, and the printing preparation of the N-region current collector electrode 132 can be facilitated, thereby improving the electrode printing quality and the service life of the printing screen. Furthermore, the second distance between the two P-region current collector electrodes 131 on both sides of the N-type main body is set to be greater than the disconnection distance of the N-region current collector electrode 132. This ensures, on the one hand, that there is a certain gap between the end of the P-region current collector electrode 131 and the N-type main body for electrical isolation; on the other hand, it avoids the disconnection distance of the first disconnection portion being too large, which would affect the current collection and transmission effect of the N-region current collector electrode 132.

[0068] In some embodiments, a joint 17 may also be provided at the first break, such that the orthographic projection of the joint 17 on the surface of the substrate 11 covers the first break, and the joint 17 is electrically connected to the N-region current collector electrode 132 so as to achieve connection with the interconnect 2 through the joint 17.

[0069] Correspondingly, the distance between the ends of the N-region collector electrodes 132 located on both sides of the P-type main body along the second direction Y is the third distance, the portion of the P-region collector electrode 131 located on the P-type main body has a second break, the width of the second break in the second direction Y is the fourth distance, and the third distance is greater than the fourth distance.

[0070] In this embodiment, by providing a second disconnection portion on the P-type main body of the P-region collector electrode 131, i.e., the P-region collector electrode 131 is partially disconnected on the P-type main body, the material cost of the P-region collector electrode 131 is saved. Furthermore, the fourth distance between the two N-region collector electrodes 132 on both sides of the P-type main body is set to be greater than the disconnection distance of the P-region collector electrode 131 (i.e., the third distance). This ensures, on the one hand, that there is a certain gap between the end of the N-region collector electrode 132 and the P-type main body to achieve electrical isolation; on the other hand, it avoids the second disconnection distance being too large, which would affect the current collection and transmission effect of the P-region collector electrode 131.

[0071] In some embodiments, a joint 17 may be provided at the second break, such that the orthographic projection of the joint 17 on the surface of the substrate 11 covers the second break, and the joint 17 is electrically connected to the P-region current collector electrode 131 so as to achieve connection with the interconnect 2 through the joint 17.

[0072] It is understandable that when connecting batteries in series using interconnect 2, the welding capability between the current collector electrode (including N-region current collector electrode 132 and P-region current collector electrode 131) and interconnect 2 is less than that between the junction 17 and the bus electrode. Therefore, by providing a break (including a first break and a second break) in the current collector electrode and providing the junction 17 at the break, welding and fixing with interconnect 2 can be achieved through the junction 17, thereby improving the welding effect. At the same time, by making the current collector electrode disconnected at the connection with the junction 17, the current collector electrode will not penetrate through the surface of the junction 17, which can reduce the unevenness of the surface of the junction 17 and reduce the obstruction of the surface of the junction 17, thereby reducing the possibility of poor welding between interconnect 2 and junction 17.

[0073] Furthermore, the current collector electrode is prepared using a screen printing process. By incorporating a break in the current collector electrode, its continuous extension length can be reduced. When printing the current collector electrode using a screen printing plate, the break corresponds to a solid connection segment in the screen. This reduces the opening length in the screen, thereby mitigating uneven stress distribution during electrode printing, lowering the probability of screen deformation, and ultimately improving electrode printing quality and increasing screen lifespan. This is particularly important in processes using steel plate screen printing. Because the steel plate screen has a fully open structure in the printing area, if the continuous extension length of the electrode to be printed is too long, the corresponding slit opening structure in the steel plate screen will be too long, which can weaken the strength of the steel plate screen and cause it to easily deform.

[0074] Optionally, the bridging electrode 15 has a third disconnection portion at a position corresponding to the second bus electrode 1231, and a connecting portion 17 is provided at the third disconnection portion. The bridging electrode 15 is connected through the connecting portion 17 at the third disconnection portion, and the second insulating layer 16 at least covers the third disconnection portion and the corresponding connecting portion 17. In this way, by providing a third disconnection portion in the bridging electrode 15, the probability of deformation of the corresponding screen can be reduced when the bridging electrode 15 is prepared using a screen printing process, thereby improving the electrode printing quality and increasing the service life of the screen.

[0075] Optionally, as shown in FIG9, this application embodiment also provides a photovoltaic module, including a front panel 3, a back panel 4, an encapsulation film layer 5, and a solar cell 1. The front panel 3 and the back panel 4 are stacked, and the solar cell 1 and the encapsulation film layer 5 are both disposed between the front panel 3 and the back panel 4. The solar cell 1 is embedded in the encapsulation film layer 5, and the solar cell 1 is the solar cell 1 in the above embodiment.

[0076] In this embodiment, by setting the distance W1 from the end of the first current collector 1221 facing the second main body 1230 to the adjacent isolation region 123 to be greater than the distance W2 from the end of the second current collector 1241 facing the first main body 1210 to the adjacent isolation region 123, the distance from the end of the second current collector 1241 to the corresponding isolation region 123 is relatively small. This allows the end of the second current collector 1241 to be as close as possible to the first edge 101 of the substrate 11, thereby increasing the current collection efficiency of the second current collector 1241 in the edge region of the substrate 11. At the same time, making the distance from the end of the first current collector 1221 to the corresponding isolation region 123 relatively large reduces the risk of short circuit between the first current collector 1221 and the interconnect 2 provided on the first main body 1210 when the battery cells 1 are connected in series using the interconnect 2. It also reduces the material usage of the first current collector 1221, thereby reducing the cost of using the battery cells.

[0077] Specifically, the photovoltaic module includes multiple solar cells 1, which are connected in series by interconnecting components 2 to form a solar cell string. Then, multiple solar cell strings are connected in series and parallel by a busbar to form a solar cell unit. A front encapsulating film and a front panel 3 are sequentially laid on the front side of the solar cell unit, and a back encapsulating film and a back panel 4 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 5 to encapsulate the solar cell 1. At the same time, the encapsulation film layer 5 can be used to bond and fix the front panel 3 and the back panel 4.

[0078] 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.

[0079] 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: a substrate having two doped layers of opposite conductivity types on its surface, the two doped layers of opposite conductivity types being arranged in an interdigitated pattern, and an isolation region being provided between the two doped layers of opposite conductivity types; each of the two doped layers of opposite conductivity types includes a main body portion and a finger portion, the main body portion extending along a first direction, and the finger portion being disposed on at least one side of the main body portion along a second direction, the second direction intersecting the first direction; the substrate includes a first edge and a second edge disposed opposite to each other along the second direction; The main body portion along the second direction near the first edge is a first main body portion, and the finger-shaped portion connected to the first main body portion is a first finger-shaped portion, with a first current collector electrode provided on the first finger-shaped portion; the main body portion adjacent to the first main body portion and having the opposite conductivity type is a second main body portion, and the finger-shaped portion connected to the second main body portion is a second finger-shaped portion, with a second current collector electrode provided on the second finger-shaped portion; wherein, along the second direction, the distance from the end of the first current collector electrode facing the second main body portion to the adjacent isolation region is greater than the distance from the end of the second current collector electrode facing the first main body portion to the adjacent isolation region.

2. The battery cell according to claim 1, characterized in that, The first main body is provided with a first bus electrode extending along the first direction, and the first current collector electrode is electrically connected to the first bus electrode; the second main body is provided with a second bus electrode extending along the first direction, and the second current collector electrode is electrically connected to the second bus electrode. Along the second direction, the distance from the end of the first collector electrode facing the second main body to the second bus electrode is less than the distance from the end of the second collector electrode facing the first main body to the first bus electrode.

3. The battery cell according to claim 2, characterized in that, Along the second direction, the width of the first main body portion is greater than the width of the second main body portion.

4. The battery cell according to claim 2, characterized in that, The first main body has a centerline extending along a first direction, and the first bus electrode is located on the side of the centerline away from the second bus electrode and close to the first edge.

5. The battery cell according to claim 3, characterized in that, The battery cell satisfies at least one of the following conditions: A. Along the second direction, the distance W1 from the end of the first current collector electrode facing the second main body to the adjacent isolation region is 0.2mm-0.6mm; B. Along the second direction, the distance W2 from the end of the second current collector electrode facing the first main body to the adjacent isolation region is 0.1mm-0.5mm; C. Along the second direction, the distance W3 from the end of the first current collector electrode facing the second main body to the second bus electrode is 0.6mm-1.2mm. D. Along the second direction, the distance W4 from the end of the second collector electrode facing the first main body to the first bus electrode is 0.8mm-1.6mm; E. Along the second direction, the width W5 of the second main body is 0.5mm-1mm; F. Along the second direction, the width W6 of the first main body is 0.5mm-1.6mm.

6. The battery cell according to any one of claims 1-5, characterized in that, The first finger portion has a first insulating layer near the second main body portion, and the first insulating layer covers the end of the first current collector electrode; the first insulating layer is spaced apart from the adjacent isolation region.

7. The battery cell according to any one of claims 2-5, characterized in that, It also includes a bridging electrode, and the surface of the substrate is further provided with a third bus electrode extending along the first direction. The third bus electrode is located on the side of the second bus electrode away from the first bus electrode, and the third bus electrode has the same conductivity type as the first bus electrode. The bridging electrode extends along the second direction and electrically connects the first bus electrode and the third bus electrode, and the second bus electrode is disconnected at the bridging electrode.

8. The battery cell according to claim 7, characterized in that, The surface of the substrate is further provided with a second insulating layer, which covers the portion of the bridging electrode corresponding to the second bus electrode.

9. The battery cell according to claim 7, characterized in that, The width of the bridging electrode in the first direction is greater than the width of the first collector electrode and / or the second collector electrode in the first direction.

10. The battery cell according to any one of claims 1-5, characterized in that, The two doped layers with opposite conductivity types are a P-type doped layer and an N-type doped layer. 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. A P-type collector electrode is provided on the P-type finger portion, and an N-type collector electrode is provided on the N-type finger portion. The distance between the ends of the P-type collector electrodes located on both sides of the N-type body portion along the second direction is a first distance. The portion of the N-type collector electrode located on the N-type body portion has a first break portion, and the width of the first break portion in the second direction is a second distance, which is greater than the second distance. And / or, the distance between the ends of the N-type collector electrodes located on both sides of the P-type body portion along the second direction is a third distance, and the portion of the P-type collector electrode located on the P-type body portion has a second break portion, and the width of the second break portion in the second direction is a fourth distance, which is greater than the fourth distance.

11. A photovoltaic module, characterized in that, include: The device comprises a front panel, a back panel, an encapsulation film, and a battery cell. The front panel and the back panel are stacked together. The battery cell and the encapsulation film are disposed between the front panel and the back panel. The battery cell is embedded in the encapsulation film. The battery cell is any of the battery cells described in claims 1-10.

Images