Back contact solar cells, cell assemblies, and photovoltaic systems

Abstract

The application is suitable for the field of photovoltaic technology, and provides a back contact solar cell, a cell module and a photovoltaic system, which comprises a cell piece, the cell piece has a light receiving surface and a back light surface arranged oppositely; an isolation layer is arranged on the light receiving surface of the cell piece to protect the surface of the cell piece, the isolation layer specifically comprises a plurality of isolation protrusions, so that a plurality of stacked cell pieces can be isolated from each other, the isolation protrusion specifically comprises a first isolation part and a second isolation part, the first isolation part is arranged to be widened and thickened in the edge scratch area (contact area with a belt and a roller) of the cell piece, a stepped structure is formed between the first isolation part and the second isolation part, the use amount of the isolation glue can be reduced while the surface of the cell piece is protected from scratching, in addition, the use amount of the isolation glue is reduced, the light reflection on the surface of the cell piece is also reduced, and the photoelectric conversion efficiency of the cell piece is improved.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic technology, and in particular relates to a back-contact solar cell, a battery module and a photovoltaic system. Background Technology

[0002] A photovoltaic (PV) cell is a thin film of photovoltaic semiconductors (also known as a solar cell or photovoltaic cell) that directly generates electricity using sunlight. As long as the illuminance meets certain conditions, it can output voltage and generate current when a circuit is present. Currently, crystalline silicon solar cells operating on the photovoltaic effect are the mainstream type of PV cell, which directly convert light energy into electrical energy through the photoelectric effect.

[0003] In back-contact battery design, both the positive and negative electrodes are located on the back of the battery. Due to the gridless structure of back-contact solar cells, to avoid damage to the gridless surface of the finished cells, separator paper or separator adhesive is usually used to protect adjacent cells during stacking, transportation and use. However, this method will affect the stacking efficiency of the cells and increase the transportation cost of the cells.

[0004] Application content This application provides a back-contact solar cell, which aims to solve the problem that using separator paper or separator adhesive to protect two adjacent cells affects the stacking efficiency of the cells and increases the transportation cost of the cells.

[0005] This application is implemented as follows: a back-contact solar cell includes: a solar cell having a light-receiving surface and a back-lighting surface disposed opposite to each other; an insulating layer disposed on the light-receiving surface, the insulating layer including a plurality of first insulating protrusions spaced apart along a first direction and extending in a second direction; at least a portion of the first insulating protrusions includes a first insulating portion and a second insulating portion, in the second direction, the first insulating portion is closer to a first edge of the solar cell relative to the second insulating portion, and in the first direction, the width of the first insulating portion is greater than the width of the second insulating portion, and the thickness of the first insulating portion is greater than the thickness of the second insulating portion.

[0006] Optionally, the first isolation section includes a plurality of first sub-isolation sections, which are spaced apart in the second direction.

[0007] Optionally, the second isolation section includes a plurality of second sub-isolation sections, which are spaced apart in the second direction.

[0008] Optionally, the first isolation protrusion includes a third isolation portion disposed between the first isolation portion and the second isolation portion, wherein the width of the third isolation portion gradually decreases in the first direction away from the first isolation portion.

[0009] Optionally, the thickness of the third isolation portion gradually decreases in the direction away from the first isolation portion.

[0010] Optionally, the backlight surface of the battery cell has a marking area, and a marking layer is provided in the marking area.

[0011] Optionally, there are multiple identification areas, and the multiple identification areas are aligned in the first direction.

[0012] Optionally, the identification layer includes an identification portion and a peripheral portion surrounding the identification portion, wherein the peripheral portion and the identification portion are spaced apart.

[0013] Optionally, the thickness of the identification part is less than the thickness of the isolation layer.

[0014] Optionally, the thickness of the identification part is less than or equal to 1 micrometer.

[0015] Optionally, in the first direction, the width of the first isolation portion is greater than or equal to 300 micrometers and less than or equal to 400 micrometers.

[0016] Optionally, in the first direction, the width of the second isolation portion is greater than or equal to 200 micrometers and less than or equal to 300 micrometers.

[0017] Optionally, the thickness of the first isolation portion is greater than or equal to 4 micrometers and less than or equal to 8 micrometers.

[0018] Optionally, the thickness of the second isolation portion is greater than or equal to 3 micrometers and less than or equal to 5 micrometers.

[0019] Optionally, the insulating layer further includes a second insulating protrusion, which is located closer to the second edge of the battery cell in the first direction than the first insulating protrusion, and the width of the second insulating protrusion is greater than the width of the first insulating protrusion in the first direction.

[0020] Optionally, the second isolation protrusion includes a plurality of second sub-isolation protrusions, which are spaced apart in the second direction.

[0021] Optionally, the surface of the first isolation protrusion has a pit or a through hole, and / or the surface of the second isolation protrusion has a pit or a through hole.

[0022] Optionally, the first isolation protrusion includes a main body region and an edge region disposed on at least one side of the main body region in the first direction, and the thickness of the first isolation protrusion in the main body region is greater than the thickness of the first isolation protrusion in the edge region.

[0023] Optionally, the thickness of the first isolation protrusion in the edge region is greater than 0 and less than or equal to 1 micrometer.

[0024] Optionally, the insulating layer further includes a third insulating protrusion, which extends in the first direction and is disposed near the first edge of the battery cell.

[0025] Optionally, the third isolation protrusion includes a plurality of third sub-isolation protrusions, which are spaced apart in the first direction.

[0026] Optionally, the thickness of the third isolation protrusion is greater than or equal to the thickness of the first isolation portion.

[0027] This application provides an isolation layer on the light-receiving surface of the solar cell to protect its surface. The isolation layer specifically includes multiple isolation protrusions, which can isolate multiple stacked solar cells from each other. The isolation protrusions specifically include a first isolation portion and a second isolation portion. The first isolation portion is widened and thickened in the easily scratched area of ​​the edge of the solar cell (the area in contact with the belt or roller). A stepped structure is formed between the first isolation portion and the second isolation portion. This can reduce the amount of isolation adhesive used while protecting the surface of the solar cell from scratches. In addition, the reduction in the amount of isolation adhesive will also reduce the light reflection on the surface of the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell.

[0028] A battery assembly includes the aforementioned back-contact solar cell. The technical effects of this application are the same as those of the aforementioned back-contact solar cell, and will not be repeated here.

[0029] A photovoltaic system includes the aforementioned battery module. The technical effects of this application are the same as those of the aforementioned battery module, and will not be repeated here. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the first type of back-contact solar cell provided in this application; Figure 2 This is a schematic diagram of the structure of the second type of back-contact solar cell provided in the current application; Figure 3 This is a schematic diagram of the structure of the third type of back-contact solar cell provided in the current application; Figure 4 This is a schematic diagram of the structure of the fourth type of back-contact solar cell provided in the current application; Figure 5 This is a schematic diagram of the structure of the fifth type of back-contact solar cell provided in the current application; Figure 6 This is a schematic diagram of the structure of the sixth type of back-contact solar cell provided in the current application; Figure 7 This is a schematic diagram of the structure of the seventh type of back-contact solar cell provided in the current application.

[0031] Explanation of reference numerals in the attached figures: 100, Battery cell; 101, Backlight surface; 102, Light-receiving surface; 103, First edge; 104, Second edge; 200, Insulation layer; 201, First isolation protrusion; 201a, First isolation portion; 201a1, First sub-isolation portion; 201b, Second isolation portion; 201b1, Second sub-isolation portion; 201c, Third isolation portion; 201d, Main body area; 201e, Edge area; 202, Second isolation protrusion; 2021, Second sub-isolation protrusion; 203, Third isolation protrusion; 2031, Third sub-isolation protrusion; 300, Identification area; 400, Identification layer; 401, Identification portion; 402, Peripheral portion. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0033] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this 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.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] 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, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0038] like Figure 1As shown in this embodiment, a back-contact solar cell includes a cell 100, which has a light-receiving surface 102 and a back-lighting surface 101 disposed opposite to each other. Typically, the cell 100 has a sheet-like structure; the side that absorbs light energy and converts it into electrical energy is called the light-receiving surface 102, and the other side is called the back-lighting surface 101. Furthermore, the light-receiving surface 102 of the back-contact cell 100 has no grid structure; both positive and negative grid lines are disposed on the back-lighting surface 101. Therefore, when cells 100 are stacked, the grid structure of the back-lighting surface 101 of the upper cell 100 can easily damage the light-receiving surface 102 of the lower cell 100. For example, the grid structure of the back-lighting surface 101 of the upper cell 100 causes damage to the passivation layer of the light-receiving surface 102 of the lower cell 100, directly leading to a decrease in the efficiency of the cell 100, accelerated power decay, and severe deterioration of long-term reliability. The solar cell 100 is essentially rectangular. This essentially rectangular shape can be, for example, a square or another type of rectangle, and can have standard corners, cut corners, or rounded corners, depending on actual production needs. No specific limitations are made here. The solar cell 100 can be a whole cell or a half cell. For example, from... Figure 7 A half-cell is a cell that is cut from a whole cell. Cell 100 can also be a three- or four-segment cell that is cut from a whole cell.

[0039] Furthermore, an isolation layer 200 is provided on the light-receiving surface 102. The isolation layer 200 can be formed by screen printing or spraying, with the isolation adhesive applied to the light-receiving surface 102 of the battery cell 100 according to a predetermined shape. Specifically, the isolation layer 200 includes a plurality of first isolation protrusions 201 spaced apart along a first direction and extending in a second direction. For example, the first isolation protrusions 201 can be a single isolation strip structure. Multiple first isolation protrusions 201 protrude from the light-receiving surface 102 of the battery cell 100, preventing direct contact with the grid structures of other battery cells 100, thus protecting the light-receiving surface 102 of the battery cell 100. In other embodiments, such as... Figure 4 and Figure 5As shown, the first isolation protrusion 201 has a multi-segment discrete structure. For example, the first isolation portion 201a includes multiple first sub-isolation portions 201a1, which are spaced apart in the second direction. And / or, the second isolation portion 201b includes multiple second sub-isolation portions 201b1, which are spaced apart in the second direction. This reduces the amount of insulating adhesive used while ensuring the isolation effect. The isolation layer 200 can be installed during the solar cell 100 manufacturing process. Specifically, the isolation layer 200 can be installed after the passivation layer of the light-receiving surface 102 of the solar cell 100 is formed. This avoids damage to the light-receiving surface 102 of the solar cell 100 during subsequent metallization processes, such as belt wear during cell transport, thus ensuring the finished product quality of the solar cell 100. Furthermore, it eliminates the need for insulating paper or insulating adhesive between adjacent cells 100 during stacking, transportation, and use, reducing transportation costs.

[0040] like Figure 2 As shown, at least a portion of the first isolation protrusion 201 includes a first isolation portion 201a and a second isolation portion 201b. In the second direction, the first isolation portion 201a is closer to the first edge 103 of the battery cell 100 relative to the second isolation portion 201b. In the first direction, the width of the first isolation portion 201a is greater than the width of the second isolation portion 201b, and the thickness of the first isolation portion 201a is greater than the thickness of the second isolation portion 201b. Understandably, the battery cell 100 has two opposing first edges 103 in the second direction. In this embodiment, the two first edges 103 are arranged left and right opposite each other. Based on the positional relationship between different portions of the first isolation protrusion 201 and the first edge 103, the first isolation protrusion 201 is configured as a first isolation portion 201a and a second isolation portion 201b. The first isolation portion 201a is closer to the first edge 103, and the second isolation portion 201b is farther from the first edge 103. Because in the production line of the solar cell 100 (such as texturing, diffusion, coating, etc.), the solar cell 100 is usually conveyed by rollers or guide rails. The edge of the solar cell 100 is the part that is in direct contact and friction. The first isolation part 201a is widened and thickened compared to the second isolation part 201b. This design can effectively strengthen the protection of the edge of the solar cell 100, while reducing the overall amount of isolation adhesive used and reducing production costs.

[0041] In this embodiment, the second direction intersects the first direction. Specifically, the second direction can be perpendicular to the first direction. For example, the first direction can be the length direction of the battery cell 100, and the second direction can be the width direction of the battery cell 100.

[0042] In some embodiments, the first isolation protrusion 201 includes a third isolation portion 201c, which is disposed between the first isolation portion 201a and the second isolation portion 201b. In the direction away from the first isolation portion 201a, the width and thickness of the third isolation portion 201c gradually decrease in a first direction. Specifically, the third isolation portion 201c connects the first isolation portion 201a and the second isolation portion 201b. Since there is a difference in width and thickness between the first isolation portion 201a and the second isolation portion 201b, the third isolation portion 201c serves as a transition portion between them. The gradual decrease in width and thickness in the direction away from the first isolation portion 201a ensures a smooth transition in the overall width and thickness of the first isolation protrusion 201 in the extending direction. This facilitates fabrication and avoids stress concentration caused by excessive structural differences between different parts of the first isolation protrusion 201.

[0043] In some embodiments, the backlight surface 101 of the solar cell 100 has an identification area 300, within which an identification layer 400 is disposed. Exemplarily, the identification area 300 can be a hollowed-out area within the isolation layer 200, with the isolation protrusion interrupted at the identification area 300, forming an exposed surface of the solar cell 100 within the identification area 300, facilitating subsequent printing of the identification layer 400 within the identification area 300. Understandably, the identification layer 400 can have an identification code, which may include any information from the solar cell fabrication process, such as the size specifications of the solar cell 100, the film color information of the solar cell 100, etc. This facilitates the unified scheduling of solar cells 100 of the same type during subsequent assembly of the solar cell module, providing corresponding data support for intelligent quality control.

[0044] like Figure 1 As shown, in some embodiments, there are multiple identification areas 300, which are aligned in the first direction. Preferably, identification areas 300 are provided at both ends of the battery cell 100 in the first direction, so that the information of the battery cell can be quickly identified from either end when it enters the preparation equipment, thus improving the identification efficiency. Of course, in other embodiments, the multiple identification areas 300 can also be staggered in the first direction, and the position of the identification areas 300 can be flexibly set. This application does not limit this.

[0045] In some embodiments, the identification layer 400 includes an identification portion 401 and a peripheral portion 402 surrounding the identification portion 401, with the peripheral portion 402 and the identification portion 401 spaced apart. This spaced arrangement between the peripheral portion 402 and the identification portion 401 creates an isolation between the isolation protrusion and the identification portion 401, providing redundant space for printing the isolation protrusion on the outer side of the peripheral portion 402, preventing damage to the identification portion 401 due to printing deviations in the isolation protrusion, and ensuring the structural integrity of the identification portion 401. Understandably, the isolation protrusion and the peripheral portion 402 can be in direct contact or spaced apart, depending on the requirements. Preferably, the isolation protrusion and the peripheral portion 402 can be spaced apart to further effectively ensure the structural integrity of the identification portion, facilitating subsequent information reading and improving component production efficiency. Furthermore, since the identification portion 401 is only used for information identification or information writing, its thickness can be set to be less than the thickness of the isolation layer 200 to reduce the use of isolation adhesive and improve the light absorption capacity of the surface of the battery cell 100. Preferably, the thickness of the identification portion 401 is less than or equal to 1 micrometer. The thickness of the identification part 401 is within this range, which can effectively hide the identification part from the user's perspective and improve the appearance of the battery assembly.

[0046] In some embodiments, in the first direction, the width of the first insulating portion 201a is greater than or equal to 300 micrometers and less than or equal to 400 micrometers. In such embodiments, the width of the first insulating portion 201a can be 300 micrometers, 310 micrometers, 330 micrometers, 350 micrometers, 370 micrometers, 380 micrometers, 400 micrometers, or any value between 300 and 400 micrometers, without any specific limitation herein. With the width of the first insulating portion 201a within this range, the first insulating portion 201a can have a larger contact area with the surface of the battery cell 100, achieving more comprehensive protection for the edge region 201e of the battery cell 100.

[0047] In some embodiments, in the first direction, the width of the second insulating portion 201b is greater than or equal to 200 micrometers and less than or equal to 300 micrometers. In such embodiments, the width of the second insulating portion 201b can be any value between 200 micrometers, 210 micrometers, 230 micrometers, 250 micrometers, 270 micrometers, 280 micrometers, 300 micrometers, or 200 to 300 micrometers, without any specific limitation. The width of the second insulating portion 201b within this range ensures sufficient bonding strength between the second insulating portion 201b and the battery cell 100, ensuring that the second insulating portion 201b remains undeformed on the surface of the battery cell 100, thus protecting the surface of the battery cell 100.

[0048] In some embodiments, the thickness of the first isolation portion 201a is greater than or equal to 4 micrometers and less than or equal to 8 micrometers. In such embodiments, the thickness of the first isolation portion 201a can be any value between 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, or 4 to 8 micrometers, and is not specifically limited herein. The thickness of the first isolation portion 201a within this range ensures that the first isolation portion 201a possesses sufficient structural strength and high wear resistance.

[0049] In some embodiments, the thickness of the second isolation portion 201b is greater than or equal to 3 micrometers and less than or equal to 5 micrometers. In such embodiments, the thickness of the second isolation portion 201b can be any value between 3 micrometers, 4 micrometers, 5 micrometers, or 3 to 5 micrometers, and is not specifically limited herein. With the thickness of the second isolation portion 201b within this range, the surface of the solar cell 100 can be isolated from the grid structure on the back of adjacent solar cells 100, preventing damage to the surface of the solar cell 100.

[0050] It should be noted that when the light-receiving surface 102 of the solar cell 100 is a velvety pyramid structure, the height of the velvety pyramid is usually between 1 micrometer and 3 micrometers. The insulating adhesive fills the gaps between the velvety pyramids and covers the pyramids on the surface of the solar cell 100 to form an insulating protrusion. The thickness of the insulating part is the distance between the base of the velvety pyramid structure and the top surface of the insulating part.

[0051] In some embodiments, the insulating layer 200 further includes a second insulating protrusion 202. In a first direction, the second insulating protrusion 202 is closer to the second edge 104 of the battery cell 100 relative to the first insulating protrusion 201. In the first direction, the width of the second insulating protrusion 202 is greater than the width of the first insulating protrusion 201. Understandably, the battery cell 100 has two opposing second edges 104 in the first direction. In this embodiment, the two second edges 104 are vertically opposed. In the region of the battery cell 100 near the second edges 104, the insulating protrusion is widened to enhance edge protection of the battery cell 100 in the first direction. It should be noted that the width of the second insulating protrusion 202 being greater than the width of the first insulating protrusion 201 can mean that the average width of the second insulating protrusion 202 is greater than the average width of the first insulating protrusion 201, or that the minimum width of the second insulating protrusion 202 is greater than the minimum width of the first insulating protrusion 201. This application does not impose any limitations on this. For example, the second isolation protrusion 202 can be a single isolation strip structure to effectively protect the edge area of ​​the battery cell, or the second isolation protrusion 202 can include multiple second sub-isolation protrusions 2021, which are spaced apart in the second direction to reduce the amount of isolation adhesive used while ensuring the isolation effect.

[0052] like Figure 6 As shown, in some embodiments, the insulating layer 200 further includes a third insulating protrusion 203. The third insulating protrusion 203 extends in a first direction and is located near the first edge 103 of the battery cell 100. The extending direction of the third insulating protrusion 203 intersects the extending directions of the first insulating protrusion 201 and the second insulating protrusion 202, and the third insulating protrusion 203 is located at the edge of the battery cell 100. It can be understood that the ends of the third insulating protrusion 203 and the first insulating protrusion 201, as well as the ends of the second insulating protrusion 202, are spaced apart to further enhance the isolation and protection of the edge of the battery cell 100. Preferably, the thickness of the third insulating protrusion 203 is greater than or equal to the thickness of the first insulating portion 201a, thus ensuring effective isolation and protection of the edge of the battery cell 100. For example, the third insulating protrusion 203 can be a single insulating strip structure for effective protection of the edge area of ​​the battery cell. Alternatively, the third isolation protrusion 203 may include multiple third sub-isolation protrusions 2031, which are spaced apart in the first direction. This reduces the amount of isolation adhesive used while ensuring the isolation effect.

[0053] In some embodiments, the surface of the first isolation protrusion 201 has a pit or a through hole, and / or the surface of the second isolation protrusion 202 has a pit or a through hole. Providing pits or through holes on the surface of the isolation protrusion can improve the light-trapping effect of the isolation protrusion surface and enhance the light absorption capacity of the light-receiving surface 102 of the solar cell 100.

[0054] like Figure 3As shown, in some embodiments, the first isolation protrusion 201 includes a main body region 201d and an edge region 201e disposed on at least one side of the main body region 201d in a first direction. The thickness of the first isolation protrusion 201 in the main body region 201d is greater than the thickness of the first isolation protrusion 201 in the edge region 201e. In this application, the film thickness in the width direction of the isolation protrusion (perpendicular to the extension direction of the isolation protrusion) is designed to be unequal. The curved surface of the isolation protrusion facing away from the light-receiving surface 102 of the battery cell 100 can be a circular arc surface, an ellipsoidal surface, a parabolic surface, or other curved surface structures. This achieves natural adhesion of the isolation protrusion to the surface of the battery cell 100, forming a natural transition connection on the light-receiving surface 102 of the battery cell 100, and improving the connection strength between the isolation protrusion and the battery cell 100. Preferably, the thickness of the first isolation protrusion 201 in the edge region 201e is greater than 0 and less than or equal to 1 micrometer. The thickness of the edge region 201e of the first isolation protrusion 201 is within this range, resulting in good light transmittance and enhancing the absorption of sunlight by the light-receiving surface 102 of the solar cell 100. Since the film thickness of the edge region 201e of the first isolation protrusion 201 is relatively small at this time, when the light-receiving surface 102 of the solar cell 100 has a velvety pyramid structure, the thickness of the edge region 201e of the first isolation protrusion 201 is insufficient to cover the velvety pyramid structure. In this case, the thickness of the edge region 201e of the first isolation protrusion 201 is the film thickness adhered to the surface of the velvety pyramid.

[0055] A battery assembly includes the aforementioned back-contact solar cell. Based on the described solar cell, those skilled in the art will understand that a corresponding battery assembly can be obtained using multiple such solar cells and / or other corresponding existing accessories.

[0056] In this embodiment, multiple solar cells in the battery module can be connected in series to form a battery string, thereby achieving series current collection and output. For example, the series connection of the cells can be achieved by setting solder strips (busbars, interconnecting strips), conductive backsheets, etc. It is understood that in such an embodiment, the battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the front and back of the back contact cells, the photovoltaic glass, adjacent cells, etc. As a filler, it can be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film can be EVA film or POE film, and the specific choice can be made according to the actual situation, without limitation.

[0057] A photovoltaic system includes the aforementioned battery modules. The technical effects of this application are the same as those of the aforementioned battery modules, and will not be repeated here. In this embodiment, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules. For example, multiple battery modules may form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to realize solar power supply.

[0058] In the description of this specification, the use of terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., refers to specific features, structures, materials, or characteristics described in connection with the embodiments or examples, which are 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 embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A back-contact solar cell, characterized in that, include: A battery cell having a light-receiving surface and a backlighting surface disposed opposite to each other; an insulating layer disposed on the light-receiving surface, the insulating layer including a plurality of first insulating protrusions spaced apart along a first direction and extending in a second direction; at least a portion of the first insulating protrusions includes a first insulating portion and a second insulating portion, in the second direction, the first insulating portion is closer to a first edge of the battery cell relative to the second insulating portion, in the first direction, the width of the first insulating portion is greater than the width of the second insulating portion, and the thickness of the first insulating portion is greater than the thickness of the second insulating portion.

2. The back-contact solar cell as described in claim 1, characterized in that, The first isolation section includes a plurality of first sub-isolation sections, which are spaced apart in the second direction.

3. The back-contact solar cell as described in claim 1, characterized in that, The second isolation section includes a plurality of second sub-isolation sections, which are spaced apart in the second direction.

4. The back-contact solar cell as described in claim 1, characterized in that, The first isolation protrusion includes a third isolation portion disposed between the first isolation portion and the second isolation portion. In the direction away from the first isolation portion, the width of the third isolation portion gradually decreases in the first direction, and the thickness of the third isolation portion gradually decreases.

5. The back-contact solar cell as described in claim 1, characterized in that, The backlight surface of the battery cell has a marking area, and a marking layer is provided in the marking area.

6. The back-contact solar cell as described in claim 5, characterized in that, There are multiple identification areas, and the multiple identification areas are aligned in the first direction.

7. The back-contact solar cell as described in claim 5, characterized in that, The identification layer includes an identification part and a peripheral part surrounding the identification part, the peripheral part and the identification part being spaced apart.

8. The back-contact solar cell as described in claim 7, characterized in that, The thickness of the identification part is less than the thickness of the isolation layer.

9. The back-contact solar cell as described in claim 7, characterized in that, The thickness of the identification part is less than or equal to 1 micrometer.

10. The back-contact solar cell as claimed in claim 1, characterized in that, In the first direction, the width of the first isolation portion is greater than or equal to 300 micrometers and less than or equal to 400 micrometers.

11. The back-contact solar cell as claimed in claim 1, characterized in that, In the first direction, the width of the second isolation portion is greater than or equal to 200 micrometers and less than or equal to 300 micrometers.

12. The back-contact solar cell as claimed in claim 1, characterized in that, The thickness of the first isolation portion is greater than or equal to 4 micrometers and less than or equal to 8 micrometers.

13. The back-contact solar cell as claimed in claim 1, characterized in that, The thickness of the second isolation portion is greater than or equal to 3 micrometers and less than or equal to 5 micrometers.

14. The back-contact solar cell as claimed in claim 1, characterized in that, The insulating layer further includes a second insulating protrusion, which is located closer to the second edge of the battery cell in the first direction than the first insulating protrusion, and the width of the second insulating protrusion is greater than the width of the first insulating protrusion in the first direction.

15. The back-contact solar cell as described in claim 14, characterized in that, The second isolation protrusion includes a plurality of second sub-isolation protrusions, which are spaced apart in the second direction.

16. The back-contact solar cell as described in claim 14, characterized in that, The surface of the first isolation protrusion has a pit or a through hole, and / or the surface of the second isolation protrusion has a pit or a through hole.

17. The back-contact solar cell as claimed in claim 1, characterized in that, The first isolation protrusion includes a main body region and an edge region disposed on at least one side of the main body region in the first direction, and the thickness of the first isolation protrusion in the main body region is greater than the thickness of the first isolation protrusion in the edge region.

18. The back-contact solar cell as claimed in claim 17, characterized in that, The thickness of the first isolation protrusion in the edge region is greater than 0 and less than or equal to 1 micrometer.

19. The back-contact solar cell as claimed in claim 1, characterized in that, The insulating layer further includes a third insulating protrusion, which extends in the first direction and is located near the first edge of the battery cell.

20. The back-contact solar cell as claimed in claim 19, characterized in that, The third isolation protrusion includes a plurality of third sub-isolation protrusions, which are spaced apart in the first direction.

21. The back-contact solar cell as claimed in claim 19, characterized in that, The thickness of the third isolation protrusion is greater than or equal to the thickness of the first isolation portion.

22. A battery assembly, characterized in that, Includes the back-contact solar cell described in any one of claims 1-21.

23. A photovoltaic system, characterized in that, Includes the battery assembly described in claim 22 above.

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