Solar cell and photovoltaic module

Abstract

The embodiment of the invention relates to the field of photovoltaic technology, and provides a solar cell and a photovoltaic module, and the solar cell comprises a cell body, a first surface of the cell body is provided with a plurality of first grid lines which extend along a first direction and are arranged along a second direction, and the first surface comprises a first region and a second region which are arranged along the second direction, the first grid line at least located in the first region comprises a first main body part and a first connecting part which are alternately arranged; a plurality of columns of first bonding pad structures are arranged on the first surface, each column of first bonding pad structure comprises a plurality of first bonding pads, the first bonding pads are in electric contact with the corresponding first grid lines, the first bonding pads located in the first region are located on the first connecting parts, and the orthographic projection of the first connecting parts on the first surface is located in the orthographic projection of the first bonding pads on the first surface; the orthographic projection area of the first bonding pad in the first region on the first surface is larger than the orthographic projection area of the first bonding pad in the second region on the first surface. The solar cell and the photovoltaic module provided by the embodiment of the invention are at least beneficial to improving the welding tension between the solar cells.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Art

[0002] With the widespread application of solar energy, the solar photovoltaic panel industry has also flourished. Improving efficiency and reducing costs are the main research and development directions in the industry. The current mainstream photovoltaic module technology usually uses infrared high temperature to weld the main grid and welding ribbon of the battery cell. At the same time, the positive and negative poles of two adjacent battery cells are connected into a string. The strings are then arranged in a certain way and connected to the circuit. They are then packaged with packaging materials to form modules. Summary of the Invention

[0003] The embodiments of the present application provide a solar cell and a photovoltaic module, which are at least beneficial for improving the welding tension between solar cell sheets.

[0004] According to some embodiments of the present application, on the one hand, the embodiments of the present application provide a solar cell, comprising: a battery body, a first surface of the battery body having a plurality of first grid lines, the first grid lines extending along a first direction, and the plurality of first grid lines arranged along a second direction, the first surface comprising a first region and a second region arranged along the second direction, at least the first grid line located in the first region comprising alternating first main portions and first connecting portions, the first main portions being electrically contacted with adjacent first connecting portions, and along the second direction, the width of the first main portions being smaller than the width of the first connecting portions; a plurality of columns of first soldering pad structures located on the first surface, the plurality of columns of first soldering pad structures being arranged at intervals along the first direction, each column of the first soldering pad structures comprising a plurality of first soldering pads, the first soldering pads being electrically contacted with corresponding first grid lines, wherein the first soldering pad located in the first region is located on the first connecting portion, and the orthographic projection of the first connecting portion on the first surface is located within the orthographic projection of the first soldering pad on the first surface, and the orthographic projection area of ​​the first soldering pad in the first region on the first surface is larger than the orthographic projection area of ​​the first soldering pad in the second region on the first surface.

[0005] In some embodiments, in a direction perpendicular to the first surface, a height of the first connecting portion relative to the first surface is greater than a height of the first main body portion relative to the first surface.

[0006] In some embodiments, the first pad includes a first portion and a second portion, the first portion is located on the top surface of the first connecting portion, the second portion is located on the side of the first connecting portion, and the top surface of the first portion is flush with the top surface of the second portion.

[0007] In some embodiments, the first pad includes a hollow portion, and the hollow portion exposes a top surface of the first connection portion.

[0008] In some embodiments, the orthographic projection of the first connecting portion on the first surface is located within the orthographic projection of the hollow portion on the first surface.

[0009] In some embodiments, a top surface of the first pad is higher than or flush with a top surface of the first connecting portion.

[0010] In some embodiments, in a direction from the first region to the second region, an orthographic projection area of ​​the first pad located in the first region on the first surface gradually decreases.

[0011] In some embodiments, in the direction from the first zone to the second zone, the first pad in the first zone is divided into a first sub-pad and a second sub-pad arranged in sequence, the area of ​​the first sub-pad is larger than the area of ​​the second sub-pad, the number of first sub-pads is 2 to 3, and the number of second sub-pads is 2 to 8.

[0012] In some embodiments, a second grid line is provided on a second surface of the battery body opposite to the first surface, the second grid line extends along the first direction, and a plurality of second grid lines are arranged along the second direction, the second surface includes a third area and a fourth area arranged along the second direction, the third area and the first area are located on the same side of the battery body, and the fourth area and the second area are located on the same side of the battery body, at least the second grid line located in the fourth area includes alternating second main body portions and second connecting portions, the second main body portions are electrically contacted with adjacent second connecting portions, and along the second direction, the width of the second main body portions is smaller than the width of the second connecting portions; multiple columns of second welding pad structures are located on the second surface, the multiple columns of second welding pad structures are arranged at intervals along the first direction, each column of second welding pad structures includes multiple second welding pads, and the second welding pads are electrically contacted with corresponding second grid lines, wherein the second welding pad located in the fourth area is located on the second connecting portion, and the orthographic projection of the second connecting portion on the second surface is located within the orthographic projection of the second welding pad on the second surface, and the orthographic projection area of ​​the second welding pad in the fourth area on the second surface is larger than the orthographic projection area of ​​the second welding pad in the third area on the second surface.

[0013] According to some embodiments of the present application, on the other hand, the embodiments of the present application further provide a photovoltaic assembly, including: a plurality of solar cells as in the above embodiments; a welding ribbon, the welding ribbon connecting the welding pads of two adjacent solar cells; an adhesive film, the adhesive film covering the surface of the solar cell; and a cover plate, the cover plate covering the surface of the adhesive film away from the solar cell.

[0014] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0015] In the solar cell provided in the embodiment of the present application, on the first surface of the battery body, the first grid line in the first area includes a first main body portion and a first connecting portion that are alternately connected. In the second direction, the width of the first main body portion is smaller than the width of the first connecting portion. At the same time, the first soldering pad in the first area is located on the first connecting portion, and the orthographic projection area of ​​the first soldering pad in the first area on the first surface is larger than the orthographic projection area of ​​the first soldering pad in the second area on the first surface. In this way, after the soldering ribbon is welded to the solar cell, there is a greater welding strength and higher carrier transfer efficiency between the first grid line in the first area and the soldering ribbon. When the soldering ribbon is welded to the solar cell, the head of one end of the soldering ribbon starts welding from the first soldering pad on the side closest to the edge of the second area until the welding ends at the first soldering pad on the side closest to the edge of the first area. The other end of the soldering ribbon is used to connect to another solar cell. Multiple solar cells are connected in series to form a cell string. For the soldering tapes corresponding to two adjacent solar cells connected, the unwelded portion of the soldering tape between the two solar cells will generate a certain amount of tension due to the relative movement between the two adjacent solar cells. Since the first soldering pad and the first grid line in the first zone are closer to the other solar cell, the tension between the first soldering pad and the first grid line in the first zone and the soldering tape is relatively large relative to the first soldering pad and the first grid line in the second zone. In the solar cell provided in the embodiment of the present application, the first grid line located in the first zone has a first connecting portion with a larger size, and the first connecting portion has a first soldering pad with a larger area, so that the first grid line in the first zone and the soldering tape have a greater welding strength and a higher carrier transfer efficiency, which is conducive to maintaining the connection stability and carrier transfer stability between the first grid line and the soldering tape in the first zone. At the same time, after the solar cells are connected in series to form a battery string, the welding tension between the solar cells is higher. In addition, the solar cell provided in the embodiment of the present application forms a structure without a main grid after being welded to the soldering tape. The structure without a main grid is conducive to reducing the cost of using the main grid slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A top view corresponding to the first surface of a battery body provided in an embodiment of the present application;

[0018] Figure 2A schematic diagram of a partially enlarged structure corresponding to a first gate line and a first pad in a first region provided by an embodiment of the present application;

[0019] Figure 3 for Figure 2 Schematic diagram of the cross-section structure along the AA1 direction;

[0020] Figure 4 and Figure 5 Schematic diagram of the partially enlarged structure corresponding to the first gate lines and first pads of the two first regions provided in the embodiments of the present application;

[0021] Figure 6 A top view corresponding to the second side of a battery body provided in an embodiment of the present application;

[0022] Figure 7 A schematic diagram of the structure of a battery string provided in an embodiment of the present application;

[0023] Figure 8 A top view corresponding to the first surface of another battery body provided in an embodiment of the present application;

[0024] Figure 9 A schematic structural diagram of another battery string provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In photovoltaic module technology, the main grid of a solar cell is typically welded to a soldering ribbon. The positive and negative electrodes of two adjacent solar cells are connected via the soldering ribbon to form a cell string. The cell string is then arranged and connected to the circuit before being packaged with packaging materials to create a photovoltaic module. The welding of the main grid to the soldering ribbon is typically done using a certain number of infrared lamps arranged to form a high-temperature zone. This melts the tin-lead alloy on the surface of the soldering ribbon, fusing the soldering ribbon with the silver paste of the main grid on the cell surface. As the number of busbar structures increases, the number of busbars also increases, leading to a continuous increase in silver consumption in the grid structure, which to some extent limits the efficiency of photovoltaic cells.

[0026] To reduce silver consumption, the grid lines on adjacent solar cells can be directly connected electrically via welding ribbons to form a busbar-free structure, reducing the laying of busbars and lowering the manufacturing cost of solar cells. The busbar-free design can shorten the carrier transport path and reduce the series resistance, thereby increasing the front light-receiving area and improving the module power. However, due to insufficient welding tension between the welding ribbon and the grid line, after adjacent solar cells are welded to form a cell string, the relative movement between adjacent solar cells during transportation or transfer will pull on the welding ribbon, which can easily cause the welding ribbon to fall off from the fine grid.

[0027] The present application provides a solar cell and a photovoltaic module, which at least helps to improve the welding tension between solar cells.

[0028] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0029] In the description of the embodiments of the present application, “multiple” means more than two, unless otherwise clearly and specifically defined.

[0030] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0032] In the description of the embodiments of the present application, technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present application.

[0033] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0034] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layers are magnified for better understanding and ease of description. When describing a component on another component or on the surface of another component, the component can be "directly" located on the surface of the other component, or a third component can be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a partial edge of the entire surface.

[0035] In the description of the embodiments of the present application, when a component “includes” another component, unless otherwise stated, other components are not excluded, and other components may be further included.

[0036] The terms used in the description of the various embodiments described herein are for describing specific embodiments only and are not intended to be limiting. As used in the description of the various embodiments described and the appended claims, "components" are also intended to include plural forms unless the context clearly indicates otherwise.

[0037] The following detailed description of the various embodiments of the present application is provided in conjunction with the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in the various embodiments of the present application to facilitate a better understanding of the present application. However, even without these technical details and the various variations and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0038] Figure 1 A top view corresponding to the first surface of a battery body provided in an embodiment of the present application; Figure 2 This is a schematic diagram of a partially enlarged structure corresponding to a first gate line and a first pad in a first region provided in an embodiment of the present application.

[0039] Combined with reference Figure 1 and Figure 2In one aspect, an embodiment of the present application provides a solar cell, comprising: a cell body 100; a first surface 101 of the cell body 100 having a plurality of first gridlines 111 extending along a first direction X and arranged along a second direction Y; and the first surface 101 including a first region and a second region arranged along the second direction Y. At least the first gridlines 111 located in the first region include alternating first main portions 1111 and first connecting portions 1112, wherein the first main portions 1111 are in electrical contact with adjacent first connecting portions 1112. In the second direction Y, the width of the first main portions 1111 is smaller than the width of the first connecting portions 1112. The first surface 101 of the cell body 100 has a plurality of columns of first solder pad structures 201, which are arranged at intervals along the first direction X. Each column of the first solder pad structures 201 includes a plurality of first solder pads 211, which are in electrical contact with corresponding first gridlines 111. The first solder pad 211 located in the first zone is located on the first connecting portion 1112, and the orthographic projection of the first connecting portion 1112 on the first surface 101 is located within the orthographic projection of the first solder pad 211 on the first surface 101. The orthographic projection area of ​​the first solder pad 211 in the first zone on the first surface is greater than the orthographic projection area of ​​the first solder pad 211 in the second zone on the first surface 101.

[0040] In the solar cell provided in the embodiment of the present application, on the first surface 101 of the cell body 100, the first grid line 111 in the first region includes a first main portion 1111 and a first connecting portion 1112 that are alternately connected. In the second direction Y, the width of the first main portion 1111 is smaller than the width of the first connecting portion 1112. At the same time, the first soldering pad 211 in the first region is located on the first connecting portion 1112, and the orthographic projection area of ​​the first soldering pad 211 in the first region on the first surface is larger than the orthographic projection area of ​​the first soldering pad 211 in the second region on the first surface 101. In this way, after the soldering ribbon is welded to the solar cell, there is greater welding strength and higher carrier transfer efficiency between the first grid line 111 in the first region and the soldering ribbon. When the soldering ribbon is welded to the solar cell, the head of one end of the soldering ribbon starts welding from the first soldering pad 211 closest to the edge of the second region until the welding ends at the first soldering pad 211 closest to the edge of the first region. The other end of the soldering ribbon is used to connect to another solar cell. Multiple solar cells are connected in series to form a cell string. For the soldering tapes corresponding to two adjacent solar cells connected, the unwelded portion of the soldering tape between the two solar cells will generate a certain amount of tension due to the relative movement between the two adjacent solar cells. Since the first soldering pad 211 and the first grid line 111 in the first area are closer to the other solar cell, the tension between the first soldering pad 211 and the first grid line 111 in the first area and the soldering tape is relatively large compared to the first soldering pad 211 and the first grid line 111 in the second area. In the solar cell provided in the embodiment of the present application, the first grid line 111 located in the first area has a first connecting portion 1112 with a larger size, and the first connecting portion 1112 has a first soldering pad 211 with a larger area. This makes the first grid line 111 in the first area have a greater welding strength and a higher carrier transfer efficiency with the soldering tape, which is conducive to maintaining the connection stability and carrier transfer stability between the first grid line 111 in the first area and the soldering tape. At the same time, after the solar cells are connected in series to form a cell string, the welding tension between the solar cells is higher. In addition, the solar cell provided in the embodiment of the present application forms a busbar-free structure after being welded to the welding ribbon. The busbar-free structure is beneficial for reducing the cost of using busbar slurry.

[0041] refer to Figure 2 In some embodiments, the first solder pad 211 covers the surface of the first connection portion 1112 .

[0042] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along direction AA1.

[0043] Combined with reference Figures 1 to 3When the first solder pad 211 covers the surface of the first connecting portion 1112, the height of the first connecting portion 1112 relative to the first surface 101 can be greater than the height of the first main portion 1111 relative to the first surface 101 in a direction perpendicular to the first surface 101. In this way, the side surface of the first connecting portion 1112 can contact the first solder pad 211, thereby increasing the contact area between the first gate line 111 and the first solder pad 211, thereby facilitating improvement in the soldering tension between the soldering ribbon and the first gate line 111 and in improving carrier transfer efficiency.

[0044] exist Figure 3 In the embodiment, the first pad 211 includes a first portion and a second portion. The first portion is located on the top surface of the first connecting portion 1112, and the second portion is located on the side of the first connecting portion 1112. The top surface of the first portion is flush with the top surface of the second portion. This makes the top surface of the first pad 211 relatively flat, which facilitates sufficient contact between the soldering ribbon and the first pad 211 during subsequent soldering.

[0045] In other embodiments, the top surface of the first portion may be lower than the top surface of the second portion; or, the top surface of the first portion may be higher than the top surface of the second portion.

[0046] Figure 4 and Figure 5 This is a schematic diagram of the locally enlarged structure corresponding to the first gate lines and first pads of the two first regions provided in the embodiments of the present application.

[0047] refer to Figure 4 and Figure 5 In other embodiments, the first pad 211 may include a hollow portion 2113, which exposes the top surface of the first connection portion 1112. In this way, when soldering a solder ribbon to the first pad 211, the solder ribbon can be directly soldered to the first connection portion 1112 using solder paste, thereby increasing the welding tension between the first gate line 111 and the solder ribbon.

[0048] refer to Figure 4 and Figure 5 , the orthographic projection of the first connecting portion 1112 on the first surface 101 may be located within the orthographic projection of the hollow portion 2113 on the first surface 101. In one example, referring to Figure 4 , the orthographic projection of the first connecting portion 1112 on the first surface 101 coincides with the orthographic projection of the hollow portion 2113 on the first surface 101, that is, the orthographic projection area of ​​the first connecting portion 1112 on the first surface 101 is equal to the orthographic projection area of ​​the hollow portion 2113 on the first surface 101. In another example, referring to Figure 5The orthographic projection of the first connecting portion 1112 on the first surface 101 can be completely located inside the orthographic projection of the hollow portion 2113 on the first surface 101, that is, the orthographic projection area of ​​the first connecting portion 1112 on the first surface 101 is smaller than the orthographic projection area of ​​the hollow portion 2113 on the first surface 101.

[0049] The top surface of the first connecting portion 1112 is completely exposed by the hollow portion 2113. Thus, the first solder pads 211 located around the first connecting portion 1112 can serve to confine the solder paste, thereby preventing the solder paste from flowing excessively over the surface of the battery body 100 after melting, thereby reducing the light absorption area of ​​the battery body 100. When the orthographic projection of the first connecting portion 1112 on the first surface 101 is completely within the orthographic projection of the hollow portion 2113 on the first surface 101, the solder paste can contact the side of the first connecting portion 1112 after melting, thereby increasing the welding tension between the solder ribbon and the first grid line 111, and further increasing the carrier transmission area between the solder ribbon and the first grid line 111, thereby facilitating improved carrier transmission efficiency between the solder ribbon and the first grid line 111.

[0050] exist Figure 4 or Figure 5 In the direction perpendicular to the first surface 101, the top surface of the first soldering pad 211 relative to the first surface 101 can be higher than or flush with the top surface of the first connecting portion 1112 relative to the first surface 101. This is more conducive to the first soldering pad 211 confining the melted solder paste within the hollow portion 2113, preventing the melted solder paste from flowing over a large surface area on the battery body 100, thereby reducing the light absorption area of ​​the battery body 100.

[0051] refer to Figure 1 , the orthographic projection area of ​​the first soldering pad 211 located in the first region on the first surface 101 gradually decreases in the direction from the first region to the second region. In the direction from the first region to the second region, the distance between the first soldering pad 211 and the edge of another solar cell gradually increases, and the pulling force exerted on the first soldering pad 211 and the first grid line 111 by the soldering ribbon between adjacent solar cells gradually decreases. Therefore, the orthographic projection area of ​​the first soldering pad 211 located in the first region on the first surface 101 gradually decreases, which can maintain sufficient soldering tension for the first soldering pad 211 in the first region while reducing the paste usage cost of the first soldering pad 211.

[0052] exist Figure 1In the embodiment, the width of the first pad 211 along the first direction X gradually decreases from the first region to the second region, and the width of the first pad 211 along the second direction Y gradually decreases. In other embodiments, the width of the first pad 211 along the first direction X may remain unchanged from the first region to the second region, and the width of the first pad 211 along the second direction Y gradually decreases; or the width of the first pad 211 along the first direction X decreases, and the width of the first pad 211 along the second direction Y may remain unchanged.

[0053] In some embodiments, in a direction from the first region to the second region, the orthographic projection area of ​​the first pad 211 in the first region on the first surface 101 gradually decreases in a step-wise manner.

[0054] For example, reference Figure 1 In the direction from the first zone to the second zone, the first pad 211 in the first zone is divided into a plurality of first sub-pads 2111 and a plurality of second sub-pads 2112 arranged in sequence, with the area of ​​the first sub-pads 2111 being larger than the area of ​​the second sub-pads 2112. The number of first sub-pads 2111 is 2 to 3, for example, 2 or 3; the number of second sub-pads 2112 is 2 to 8, for example, 2, 3, 4, 5, 6, 7, or 8. The number of first sub-pads 2111 and second sub-pads 2112 within an appropriate range can maintain sufficient soldering tension for the first pad 211 in the first zone, while also helping to reduce the paste cost of the first pad 211.

[0055] When the soldering ribbon is to be soldered using infrared soldering, the number of first sub-pads 2111 is 1-2, and the number of second sub-pads 2112 is 2-5. The width of the first sub-pad 2111 along the first direction X is 0.8 mm to 1.2 mm, for example, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. The width of the first sub-pad 2111 along the second direction Y is 0.3 mm to 0.6 mm, for example, 0.3 mm, 0.4 mm, 0.5 mm, or 0.6 mm. The width of the second sub-pad 2112 along the first direction X is 0.5 mm to 0.8 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, or 0.8 mm. The width of the second sub-pad 2112 along the second direction Y is 0.15 mm to 0.5 mm, for example, 0.15 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. The width of the first pad 211 in the second area along the first direction X is 0.4mm-0.7mm, for example, 0.4mm, 0.5mm, 0.6mm or 0.7mm; the width of the first pad 211 in the second area along the second direction Y is 0.05mm-0.15mm, for example, 0.05mm, 0.1mm or 0.15mm.

[0056] When the soldering ribbon is soldered using a low-temperature soldering mode, the number of first sub-pads 2111 is 2 to 3, and the number of second sub-pads 2112 is 3 to 8. The width of the first sub-pads 2111 along the first direction X is 0.4 mm to 0.6 mm, for example, 0.4 mm, 0.5 mm, or 0.6 mm; the width of the first sub-pads 2111 along the second direction Y is 0.2 mm to 0.3 mm, for example, 0.2 mm, 0.23 mm, 0.25 mm, 0.28 mm, or 0.3 mm. The width of the second sub-pad 2112 along the first direction X is 0.3 mm to 0.5 mm, for example, 0.3 mm, 0.35 mm, 0.4 mm, 0.46 mm, or 0.5 mm. The width of the second sub-pad 2112 along the second direction Y is 0.1 mm to 0.3 mm, for example, 0.1 mm, 0.16 mm, 0.2 mm, 0.24 mm, or 0.3 mm. The width of the first pad 211 in the second region along the first direction X is 0.15 mm to 0.3 mm, for example, 0.15 mm, 0.2 mm, 0.25 mm, or 0.3 mm. The width of the first pad 211 in the second region along the second direction Y is 0.05 mm to 0.1 mm, for example, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, or 0.1 mm.

[0057] exist Figure 1In a column of first pad structures 201, the number of first sub-pads 2111 and the number of second sub-pads 2112 do not constitute a limitation on the first sub-pads 2111 and the second sub-pads 2112. The number of first sub-pads 2111 and the number of second sub-pads 2112 can be adjusted in combination with the total number of first gate lines 111.

[0058] refer to Figure 1 The size of the first connection portion 1112 is smaller than that of the first pad 211 in the first region, which can reduce the slurry usage cost of the first connection portion 1112 and at the same time increase the welding tension between the welding strip and the first gate line 111 with the help of the first pad 211.

[0059] In some embodiments, the first gate line in the second region may also include a first connecting portion and a first main portion.

[0060] In some embodiments, the solar cell may be any one of a PERC cell (Passivated Emitter and Rear Cell), a PERT cell (Passivated Emitter and Rear Totally-diffused cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Heterojunction Technology), or a BC cell (Back Contact). In some embodiments, the solar cell may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-compound solar cell. The multi-compound solar cell may specifically be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0061] Figure 6 A top view corresponding to the second side of a battery body provided in an embodiment of the present application; Figure 7 A schematic diagram of the structure of a battery string provided in an embodiment of the present application.

[0062] Combined with reference Figure 1 and Figure 6 In some embodiments, a first grid line 111 is provided on the first surface 101 of the battery body 100, and a second grid line 112 is provided on the second surface 102 of the battery body 100 opposite to the first surface 101. The polarities of the first grid line 111 and the second grid line 112 are different.

[0063] refer to Figure 6On second surface 102, second fingerlines 112 extend along a first direction X, and multiple second fingerlines 112 are arranged along a second direction Y. Second surface 102 includes a third region and a fourth region arranged along second direction Y. The third region and the first region are located on the same side of battery body 100, and the fourth region and the second region are located on the same side of battery body 100. At least the second fingerlines 112 located in the fourth region include alternating second main portions and second connecting portions. The second main portions are in electrical contact with adjacent second connecting portions, and along second direction Y, the width of the second main portions is smaller than the width of the second connecting portions. The second surface 102 has multiple columns of second pad structures 202, which are arranged at intervals along the first direction X. Each column of the second pad structures 202 includes multiple second pads 212, and the second pads 212 are electrically contacted with the corresponding second gate lines 112. The second pads 212 located in the fourth area are located on the second connecting portion, and the orthographic projection of the second connecting portion on the second surface 102 is located within the orthographic projection of the second pads 212 on the second surface 102. The orthographic projection area of ​​the second pads 212 in the fourth area on the second surface 102 is greater than the orthographic projection area of ​​the second pads 212 in the third area on the second surface 102.

[0064] Combined with reference Figure 1 、 Figure 6 and Figure 7 The first surfaces 101 of the two connected solar cells 10 are both arranged upward, and the welding ribbon 20 extends from the first surface 101 of one solar cell 10 to the second surface 102 of the other solar cell 10. The first welding pad 211 in the first area close to the other solar cell 10 on the first surface 101 has a larger area and the first grid line 111 includes a first connecting portion with a larger size. The second welding pad 212 in the fourth area close to the other solar cell 20 on the second surface 102 has a larger area and the second grid line 112 includes a second connecting portion with a larger size. In this way, the welding tension of the welding ribbon 20 between the two adjacent solar cells 10 is mainly borne by the first welding pad 211 and the first connecting portion in the first area and the second welding pad 212 and the second connecting portion in the fourth area. Under the joint action of the first welding pad 211 and the first connecting portion in the first area and the second welding pad 212 and the second connecting portion in the fourth area, the welding tension between the adjacent solar cells 20 is increased, thereby improving the welding stability of the battery string.

[0065] Figure 8 A top view corresponding to the first surface of another battery body provided in an embodiment of the present application; Figure 9 A schematic structural diagram of another battery string provided in an embodiment of the present application.

[0066] refer to Figure 8In some embodiments, a first gate line 111 and a second gate line 112 are provided on the first surface 101 of the battery body 100, and the polarity of the first gate line 111 and the second gate line 112 are different. The first gate line 111 and the second gate line 112 both extend along the first direction X, and a plurality of first gate lines 111 and a plurality of second gate lines 112 are alternately arranged along the second direction Y. The first surface 101 includes a first area, a second area, and a third area arranged along the second direction Y. At least the first gate line 111 located in the first area includes a first main body portion and a first connecting portion alternately arranged, the first main body portion is in electrical contact with the adjacent first connecting portion, and along the second direction Y, the width of the first main body portion is smaller than the width of the first connecting portion. At least the second gate line 112 located in the third area includes a second main body portion and a second connecting portion alternately arranged, the second main body portion is in electrical contact with the adjacent second connecting portion, and along the second direction Y, the width of the second main body portion is smaller than the width of the second connecting portion. The first surface 101 has multiple columns of first pad structures 201 and multiple columns of second pad structures 202, which are alternately arranged along the first direction X. Each column of the first pad structures 201 includes multiple first pads 211, which are electrically connected to the corresponding first gate lines 111; each column of the second pad structures 202 includes multiple second pads 212, which are electrically connected to the corresponding second gate lines 112. Among them, the first solder pad 211 located in the first zone is located on the first connecting portion, and the orthographic projection of the first connecting portion on the first surface 101 is located within the orthographic projection of the first solder pad 211 on the first surface 101, and the orthographic projection area of ​​the first solder pad 211 in the first zone on the first surface is greater than the orthographic projection area of ​​the first solder pad 211 in the second zone on the first surface 101; the second solder pad 212 located in the third zone is located on the second connecting portion, and the orthographic projection area of ​​the second connecting portion on the first surface 101 is located within the orthographic projection of the second solder pad 212 on the first surface 101, and the orthographic projection area of ​​the second solder pad 212 in the third zone on the first surface 101 is greater than the orthographic projection area of ​​the second solder pad 212 in the second zone on the first surface 101.

[0067] Combined with reference Figure 8 and Figure 9When the solar cell 10 is a back-contact cell, the first gridline 111 and the second gridline 112 are both located on the same side surface of the solar cell 10. For the solar cell 10 in the middle, the first gridline 111 on the first surface 101 is connected to the second gridline 112 on the left solar cell 10 via the left soldering ribbon 20, and the second gridline 112 on the first surface 101 is connected to the first gridline 111 on the right solar cell 10 via the right soldering ribbon 20. Therefore, the soldering ribbons 20 on both sides of the first surface 101 of the middle solar cell 10 are pulled by the solar cells 10 on both sides respectively. When the first soldering pad 211 in the first region and the second soldering pad 212 in the third region are larger in area, and the first gridline 111 in the first region includes a first connecting portion and the second gridline in the third region includes a second connecting portion, the welding tension between the middle solar cell 10 and the adjacent solar cells 10 can be increased. At the same time, the carrier transmission efficiency between the first gridline 111 and the second gridline 112 and the corresponding soldering ribbons 20 is higher.

[0068] The parts of the second connecting portion and the second main body portion that are identical or corresponding to the first connecting portion 1112 and the first main body portion 1111 in the aforementioned embodiment can be referred to the aforementioned embodiment and will not be repeated here.

[0069] The same or corresponding parts of the second pad 212 and the first pad 211 in the aforementioned embodiment can be referred to the aforementioned embodiment and will not be described again here.

[0070] In the solar cell provided in the embodiment of the present application, on the first surface 101 of the cell body 100, the first grid line 111 in the first region includes a first main portion 1111 and a first connecting portion 1112 that are alternately connected. In the second direction Y, the width of the first main portion 1111 is smaller than the width of the first connecting portion 1112. At the same time, the first soldering pad 211 in the first region is located on the first connecting portion 1112, and the orthographic projection area of ​​the first soldering pad 211 in the first region on the first surface is larger than the orthographic projection area of ​​the first soldering pad 211 in the second region on the first surface 101. In this way, after the soldering ribbon is welded to the solar cell, there is greater welding strength and higher carrier transfer efficiency between the first grid line 111 in the first region and the soldering ribbon. When the soldering ribbon is welded to the solar cell, the head of one end of the soldering ribbon starts welding from the first soldering pad 211 closest to the edge of the second region until the welding ends at the first soldering pad 211 closest to the edge of the first region. The other end of the soldering ribbon is used to connect to another solar cell. Multiple solar cells are connected in series to form a cell string. For the soldering tapes corresponding to two adjacent solar cells connected, the unwelded portion of the soldering tape between the two solar cells will generate a certain amount of tension due to the relative movement between the two adjacent solar cells. Since the first soldering pad 211 and the first grid line 111 in the first area are closer to the other solar cell, the tension between the first soldering pad 211 and the first grid line 111 in the first area and the soldering tape is relatively large compared to the first soldering pad 211 and the first grid line 111 in the second area. In the solar cell provided in the embodiment of the present application, the first grid line 111 located in the first area has a first connecting portion 1112 with a larger size, and the first connecting portion 1112 has a first soldering pad 211 with a larger area. This makes the first grid line 111 in the first area have a greater welding strength and a higher carrier transfer efficiency with the soldering tape, which is conducive to maintaining the connection stability and carrier transfer stability between the first grid line 111 in the first area and the soldering tape. At the same time, after the solar cells are connected in series to form a cell string, the welding tension between the solar cells is higher. In addition, the solar cell provided in the embodiment of the present application forms a busbar-free structure after being welded to the welding ribbon. The busbar-free structure is beneficial for reducing the cost of using busbar slurry.

[0071] Accordingly, another embodiment of the present application provides a photovoltaic module comprising: a plurality of solar cells as described in the above embodiment; a soldering ribbon, an adhesive film, and a cover plate, wherein the soldering ribbon connects the soldering pads of two adjacent solar cells; the adhesive film covers the surface of the solar cells; and the cover plate covers the surface of the adhesive film away from the solar cells. For portions identical or corresponding to the previous embodiment, reference may be made to the corresponding description of the previous embodiment and will not be repeated in detail below.

[0072] In some embodiments, the material of the film may be an organic encapsulation film such as ethylene vinyl acetate (EVA) film, polyethylene octene co-elastomer (POE) film or polyvinyl butyral (PVB) film.

[0073] In some embodiments, the cover plate can be a glass cover plate, a plastic cover plate, or the like with light-transmitting function. In some embodiments, the surface of the cover plate facing the film can be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0074] In the photovoltaic assembly provided by the embodiment of the present application, the first grid line located in the first zone on the solar cell has a first connecting portion with a larger size, and the first connecting portion has a first soldering pad with a larger area, so that the first grid line in the first zone and the soldering ribbon have a greater welding strength and a higher carrier transfer efficiency, which is conducive to maintaining the connection stability and carrier transfer stability between the first grid line and the soldering ribbon in the first zone. At the same time, after the solar cells are connected in series to form a cell string, the welding tension between the solar cell sheets is higher. In addition, in the photovoltaic assembly provided by the embodiment of the present application, the solar cell and the soldering ribbon are welded to form a main grid-free structure, and the main grid-free structure is conducive to reducing the cost of using the main grid slurry.

[0075] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present application, and that in actual applications, various changes in form and detail may be made thereto without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A solar cell, characterized in that: include: A battery body, wherein a first surface of the battery body has a plurality of first grid lines, the first grid lines extend along a first direction, and the plurality of first grid lines are arranged along a second direction, the first surface includes a first area and a second area arranged along the second direction, at least the first grid lines located in the first area include first main body portions and first connecting portions that are alternately arranged, the first main body portions are in electrical contact with adjacent first connecting portions, and along the second direction, the width of the first main body portions is smaller than the width of the first connecting portions; A plurality of columns of first pad structures are located on the first surface, the plurality of columns of first pad structures are arranged at intervals along the first direction, each column of the first pad structures includes a plurality of first pads, the first pads are electrically contacted with the corresponding first gate lines, wherein the first pads located in the first region are located on the first connecting portion, and the orthographic projection of the first connecting portion on the first surface is located within the orthographic projection of the first pad on the first surface, and the orthographic projection area of ​​the first pad in the first region on the first surface is greater than the orthographic projection area of ​​the first pad in the second region on the first surface.

2. The solar cell according to claim 1, characterized in that In a direction perpendicular to the first surface, a height of the first connecting portion relative to the first surface is greater than a height of the first main body portion relative to the first surface.

3. The solar cell according to claim 2, characterized in that: The first pad includes a first portion and a second portion, the first portion is located on the top surface of the first connecting portion, the second portion is located on the side surface of the first connecting portion, and the top surface of the first portion is flush with the top surface of the second portion.

4. The solar cell according to claim 1 or 2, characterized in that: The first pad includes a hollow portion, and the hollow portion exposes a top surface of the first connecting portion.

5. The solar cell according to claim 4, characterized in that: The orthographic projection of the first connecting portion on the first surface is located within the orthographic projection of the hollow portion on the first surface.

6. The solar cell according to claim 4, characterized in that: The top surface of the first pad is higher than or flush with the top surface of the first connecting portion.

7. The solar cell according to claim 1, characterized in that In a direction from the first region to the second region, an orthographic projection area of ​​the first pad located in the first region on the first surface gradually decreases.

8. The solar cell according to claim 7, characterized in that: In the direction from the first zone to the second zone, the first pad in the first zone is divided into a first sub-pad and a second sub-pad arranged in sequence, the area of ​​the first sub-pad is larger than the area of ​​the second sub-pad, the number of the first sub-pads is 2 to 3, and the number of the second sub-pads is 2 to 8.

9. The solar cell according to claim 1, characterized in that: A second grid line is arranged on a second surface of the battery body opposite to the first surface, the second grid line extends along the first direction, and a plurality of the second grid lines are arranged along the second direction, the second surface includes a third area and a fourth area arranged along the second direction, the third area and the first area are located on the same side of the battery body, the fourth area and the second area are located on the same side of the battery body, at least the second grid line located in the fourth area includes alternately arranged second main body parts and second connecting parts, the second main body parts are in electrical contact with adjacent second connecting parts, and along the second direction, the width of the second main body parts is smaller than the width of the second connecting parts; A plurality of columns of second pad structures are located on the second surface, the plurality of columns of second pad structures are arranged at intervals along the first direction, each column of the second pad structures includes a plurality of second pads, and the second pads are electrically contacted with the corresponding second gate lines, wherein the second pad located in the fourth area is located on the second connecting portion, and the orthographic projection of the second connecting portion on the second surface is located within the orthographic projection of the second pad on the second surface, and the orthographic projection area of ​​the second pad in the fourth area on the second surface is greater than the orthographic projection area of ​​the second pad in the third area on the second surface.

10. A photovoltaic module, characterized in that: include: A plurality of solar cells according to any one of claims 1 to 9; A welding ribbon connecting the welding pads of two adjacent solar cells; An adhesive film, wherein the adhesive film covers the surface of the solar cell; A cover plate covers a surface of the adhesive film away from the solar cell.

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