Solar cell and photovoltaic module

Abstract

The embodiment of the present application relates to the photovoltaic technical field, provide a kind of solar cell and photovoltaic module, solar cell includes: cell body, the first face of cell body has multiple first grid lines extending along first direction and arranged along second direction, first face includes first area and second area arranged along second direction, at least the first grid line of first area includes first main part and first connecting part arranged alternately;Multiple first pad structures are provided on the first face, each column of first pad structure includes multiple first pads, first pad is electrically contacted with corresponding first grid line, first pad in first area is located on first connecting part, and the orthographic projection of first connecting part on the first face is located in the orthographic projection of first pad on the first face, the orthographic projection area of first pad in first area on the first face is greater than the orthographic projection area of first pad of second area on the first face.The solar cell and photovoltaic module provided by the embodiment of the present application are at least beneficial to improve the welding tension between solar cell pieces.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of photovoltaics, and particularly relate to a solar cell and a photovoltaic module. BACKGROUND

[0002] With the widespread use of solar energy, the solar photovoltaic panel industry is also booming, and efficiency improvement and cost reduction are the main research and development direction in the industry at present. The mainstream photovoltaic module technology is usually to weld the busbars and solder strips of the cell pieces by high-temperature infrared, and then connect the positive and negative electrodes of the adjacent two cell pieces in series, arrange the series, connect the circuit, and then encapsulate to form a module. SUMMARY

[0003] The embodiments of the present application provide a solar cell and a photovoltaic module, which at least have the advantages of improving the welding tension between solar cell pieces.

[0004] According to some embodiments of the present application, the embodiments of the present application provide a solar cell, which includes: a cell body, a first surface of the cell 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 region and a second region arranged along the second direction, at least the first grid lines located in the first region include alternately arranged first main body parts and first connecting parts, the first main body parts are in electrical contact with adjacent first connecting parts, and in the second direction, the width of the first main body part is less than the width of the first connecting part; 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 first pad structures includes a plurality of first pads, and the first pads are in electrical contact with corresponding first grid lines, wherein the first 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 within the orthographic projection of the first pads on the first surface, and the orthographic projection area of the first pads in the first region on the first surface is greater than the orthographic projection area of the first pads in the second region on the first surface.

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

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

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

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

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

[0010] In some embodiments, the area of the first pad in the first region gradually decreases in the direction from the first region to the second region.

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

[0012] In some embodiments, the second surface opposite to the first surface of the battery body is provided with second grid lines, the second grid lines extend along the first direction, and a plurality of second grid lines are arranged along the second direction, the second surface includes a third region and a fourth region arranged along the second direction, the third region and the first region are located on the same side of the battery body, the fourth region and the second region are located on the same side of the battery body, at least the second grid lines located in the fourth region include second main body portions and second connecting portions arranged alternately, the second main body portion is in electrical contact with the adjacent second connecting portion, and the width of the second main body portion is less than the width of the second connecting portion in the second direction; a plurality of second pad structures located on the second surface are arranged at intervals along the first direction, each second pad structure includes a plurality of second pads, the second pad is in electrical contact with the corresponding second grid line, wherein the second pad located in the fourth region is located on the second connecting portion, 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 area of the orthographic projection of the second pad on the second surface in the fourth region is greater than the area of the orthographic projection of the second pad on the second surface in the third region.

[0013] According to some embodiments of the present application, another aspect of the embodiments of the present application further provides a photovoltaic module, including: a plurality of solar cells as in the above embodiments; a solder strip connecting the pads of two adjacent solar cells; a film covering the surface of the solar cell; and a cover plate covering the surface of the film away from the solar cell.

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

[0015] In the solar cell provided by the embodiment of the present application, the first grid line in the first area on the first surface of the cell body comprises a first main body part and a first connecting part connected alternately, the width of the first main body part is smaller than the width of the first connecting part in the second direction, meanwhile, the first pad in the first area is located on the first connecting part, and the area of the orthographic projection of the first pad in the first area on the first surface is larger than the area of the orthographic projection of the first pad in the second area on the first surface. In this way, after the solder strip is welded with the solar cell, the first grid line in the first area has greater welding strength and higher carrier transmission efficiency with the solder strip. When the solder strip is welded with the solar cell, the head of one end of the solder strip is welded from the first pad on the side closest to the edge of the second area to the first pad on the side closest to the edge of the first area, and the other end of the solder strip is used to connect another solar cell, and a plurality of solar cells are connected in series to form a cell string. For the solder strips corresponding to the adjacent two solar cells connected with each other, the solder strip between the two solar cells is not welded, and a certain tension is generated due to the relative movement between the two solar cells. Since the first pad and the first grid line in the first area are closer to another solar cell, the tension between the first pad and the first grid line in the first area and the solder strip is relatively larger than that between the first pad and the first grid line in the second area and the solder strip. In the solar cell provided by the embodiment of the present application, the first grid line in the first area has a first connecting part with a larger size, and the first connecting part has a first pad with a larger area, so that the first grid line in the first area has greater welding strength and higher carrier transmission efficiency with the solder strip, thereby facilitating the stability of the connection between the first grid line in the first area and the solder strip and the stability of carrier transmission, and meanwhile, the welding tension between the solar cells in the cell string formed by connecting the solar cells in series is higher. In addition, the solar cell provided by the embodiment of the present application and the solder strip form a main grid-free structure after being welded, and the main grid-free structure facilitates the reduction of the use cost of main grid paste. BRIEF DESCRIPTION OF DRAWINGS

[0016] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are illustrative of various embodiments of devices, systems, and methods. In the drawings, like references indicate similar elements in the various figures. Unless otherwise noted, the drawings provided herein are not to scale and are shown as simple schematic illustrations of embodiments of the present application. As will be realized, the application is capable of modifications in various obvious aspects, all without departing from the scope of the present application. Accordingly, the drawings are to be regarded as illustrative and not restrictive in nature.

[0017] Figure 1 A top view of the first surface of the cell body provided by the embodiment of the present application;

[0018] Figure 2A first gate line and a first pad of a first region correspond to a local enlarged structure diagram provided by the embodiment of the present application;

[0019] Figure 3 For Figure 2 A cross-sectional structure diagram along the AA1 direction;

[0020] Figure 4 And Figure 5 Two first gate lines and first pads of a first region correspond to a local enlarged structure diagram provided by the embodiment of the present application;

[0021] Figure 6 A second surface of a battery body corresponds to a top view provided by the embodiment of the present application;

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

[0023] Figure 8 Another first surface of a battery body corresponds to a top view provided by the embodiment of the present application;

[0024] Figure 9 Another structure diagram of a battery string provided by the embodiment of the present application. DETAILED DESCRIPTION

[0025] In photovoltaic module technology, the main grid of the solar cell is usually welded with the solder strip, and the positive and negative electrodes of the adjacent two solar cells are connected through the solder strip to form a battery string. Then the battery string is arranged and connected in a circuit, and then encapsulated with an encapsulating material to form a photovoltaic module. The welding of the main grid and the solder strip is usually performed by arranging a certain number of infrared lamp tubes to form a high-temperature area, so that the tin-lead alloy on the surface of the solder strip melts at high temperature, and the silver paste of the solder strip and the surface main grid of the battery is fused together. With the increase in the number of grid line structures, the number of main grids also increases, resulting in an increase in silver consumption of the grid line structure, which limits the efficiency improvement of the photovoltaic cell to some extent.

[0026] To reduce silver consumption, the grid lines on adjacent solar cells can be directly connected by the solder strip to form a main grid-free structure, reduce the laying of the main grid lines, and reduce the manufacturing cost of the solar cell. The design of the main grid-free can shorten the carrier transport path and reduce the series resistance, thereby increasing the front light receiving area and improving the component power. However, due to the insufficient welding tension between the solder strip and the grid line, after the adjacent solar cells are welded to form a battery string, the relative movement between the adjacent solar cells during the handling or transfer process will cause the solder strip and the fine grid to be pulled apart, which will cause the solder strip and the fine grid to fall off.

[0027] The application provides a solar cell and a photovoltaic module, and at least improves the welding tension between the solar cells.

[0028] In the description of the embodiments of the application, the technical terms "first", "second" and the like 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 application, the meaning of "a plurality of" is more than two, unless otherwise explicitly and specifically limited.

[0030] In this paper, "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment to other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments of the application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are A, A and B, and B. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0032] In the description of the embodiments of the application, the technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the application.

[0033] In the description of the embodiments of the application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the application can be understood according to the specific circumstances.

[0034] In the drawings corresponding to the embodiments of the present application, the thickness and area of the layers are exaggerated for better understanding and ease of description. When it is described that one component is on or on the surface of another component, the component can be "directly" on the surface of the other component, or a third component can exist between the two components. On the contrary, when it is described that one component is on the surface of another component or one component surface forms or is provided with another component, it means that there is no third component between the two components. In addition, when it is described that one component is "approximately" 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 part of the edge of the entire surface.

[0035] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components can also be included, and other components can also be further included.

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

[0037] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present application, many technical details are presented in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be implemented even without these technical details and based on various changes and modifications of the following embodiments.

[0038] Figure 1 A first plan view corresponding to a first surface of a battery body provided by an embodiment of the present application; Figure 2 A first gate line and a first pad of a first region corresponding to a partial enlarged structure diagram provided by an embodiment of the present application.

[0039] In combination with reference Figure 1 And Figure 2The embodiment of the present application provides a solar cell, which comprises: a cell body 100, a first surface 101 of the cell body 100 has a plurality of first grid lines 111, the first grid lines 111 extend along a first direction X, and the plurality of first grid lines 111 are arranged along a second direction Y, and the first surface 101 comprises a first area and a second area arranged along the second direction Y. The first grid lines 111 located at least in the first area comprise first main body parts 1111 and first connecting parts 1112 arranged alternately, the first main body part 1111 is in electrical contact with the adjacent first connecting part 1112, and the width of the first main body part 1111 is smaller than the width of the first connecting part 1112 along the second direction Y. The first surface 101 of the cell body 100 has a plurality of columns of first pad structures 201, the plurality of columns of first pad structures 201 are arranged at intervals along the first direction X, each column of first pad structures 201 comprises a plurality of first pads 211, and the first pad 211 is in electrical contact with the corresponding first grid line 111. The first pad 211 located in the first area is located on the first connecting part 1112, and the orthographic projection of the first connecting part 1112 on the first surface 101 is located in the orthographic projection of the first pad 211 on the first surface 101, and the orthographic projection area of the first pad 211 in the first area on the first surface is greater than the orthographic projection area of the first pad 211 in the second area on the first surface 101.

[0040] In the solar cell provided by the embodiment of the present application, the first grid line 111 in the first area on the first surface 101 of the cell body 100 comprises the first main body part 1111 and the first connecting part 1112 connected alternately, the width of the first main body part 1111 is smaller than the width of the first connecting part 1112 along the second direction Y, meanwhile, the first pad 211 in the first area is located on the first connecting part 1112, and the area of the orthographic projection of the first pad 211 in the first area on the first surface is larger than the area of the orthographic projection of the first pad 211 in the second area on the first surface 101, thus, after the solder strip is welded with the solar cell, the first grid line 111 in the first area has greater welding strength and higher carrier transmission efficiency between the solder strip. When the solder strip is welded with the solar cell, the head of one end of the solder strip is welded from the first pad 211 closest to the edge of the second area to the first pad 211 closest to the edge of the first area, and the other end of the solder strip is used to connect another solar cell, and the plurality of solar cells are connected in series to form a cell string. For the solder strips corresponding to the adjacent two solar cells connected with each other, the solder strip between the two solar cells is not welded, and a certain tension is generated due to the relative movement between the two solar cells, since the first pad 211 and the first grid line 111 in the first area are closer to the other solar cell, compared with the first pad 211 and the first grid line 111 in the second area, the tension between the first pad 211 and the first grid line 111 in the first area and the solder strip is relatively large. In the solar cell provided by the embodiment of the present application, the first grid line 111 in the first area has the first connecting part 1112 with a larger size, and the first pad 211 with a larger area is arranged on the first connecting part 1112, thus, the first grid line 111 in the first area has greater welding strength and higher carrier transmission efficiency between the solder strip, so as to facilitate the stability of the connection between the first grid line 111 in the first area and the solder strip and the stability of the carrier transmission, meanwhile, after the solar cell string is connected to form a cell string, the welding tension between the solar cells is high. In addition, the solar cell provided by the embodiment of the present application and the solder strip welded together form a main grid-free structure, which is conducive to reducing the use cost of the main grid paste.

[0041] Reference Figure 2 In some embodiments, the first pad 211 covers the surface of the first connecting part 1112.

[0042] Figure 3 For Figure 2 The cross-sectional structure schematic diagram along the AA1 direction.

[0043] Combined with reference Figure 1 to Figure 3When the first pad 211 covers the surface of the first connecting part 1112, the height of the first connecting part 1112 relative to the first surface 101 can be greater than the height of the first main body part 1111 relative to the first surface 101 in the direction perpendicular to the first surface 101. In this way, the side surface of the first connecting part 1112 can be in contact with the first pad 211, so as to increase the contact area between the first gate line 111 and the first pad 211, and thus facilitate the increase of the welding tensile force between the solder and the first gate line 111 and the carrier transport efficiency.

[0044] In Figure 3 , the first pad 211 includes a first part and a second part, the first part is located on the top surface of the first connecting part 1112, and the second part is located on the side surface of the first connecting part 1112. The top surface of the first part is flush with the top surface of the second part. In this way, the top surface of the first pad 211 is relatively flat, which is conducive to the full contact between the solder and the first pad 211 in the subsequent welding process.

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

[0046] Figure 4 And Figure 5 The partial enlarged structure diagram of the first pad and the first gate line of the first area provided in the embodiments of the present application.

[0047] Referring to Figure 4 and Figure 5 , in some other embodiments, the first pad 211 can include a hollow part 2113, and the hollow part 2113 exposes the top surface of the first connecting part 1112. In this way, when the solder is welded on the first pad 211, the solder can be directly welded with the first connecting part 1112 through the solder paste, so as to increase the welding tensile force between the first gate line 111 and the solder.

[0048] Referring to Figure 4 and Figure 5 , the orthographic projection of the first connecting part 1112 on the first surface 101 can be located within the orthographic projection of the hollow part 2113 on the first surface 101. In one example, referring to Figure 4 , the orthographic projection of the first connecting part 1112 on the first surface 101 coincides with the orthographic projection of the hollow part 2113 on the first surface 101, that is, the area of the orthographic projection of the first connecting part 1112 on the first surface 101 is equal to the area of the orthographic projection of the hollow part 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 hollowed portion 2113 on the first surface 101, that is, the area of the orthographic projection of the first connecting portion 1112 on the first surface 101 is less than the area of the orthographic projection of the hollowed portion 2113 on the first surface 101.

[0049] The top surface of the first connecting portion 1112 is completely exposed by the hollowed portion 2113, and thus the first pads 211 located around the first connecting portion 1112 can limit the solder paste, so as to avoid the solder paste from flowing too much on 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 located inside the orthographic projection of the hollowed portion 2113 on the first surface 101, the solder paste can also contact the side surface of the first connecting portion 1112 after melting, thereby improving the welding tension between the solder strip and the first grid line 111, and further improving the carrier transport area between the solder strip and the first grid line 111, thereby facilitating the carrier transport efficiency between the solder strip and the first grid line 111.

[0050] In the embodiment, the first connecting portion 1112 can be located in the first area. Figure 4 Alternatively, the first connecting portion 1112 can be located in the second area. Figure 5 In the embodiment, in the direction perpendicular to the first surface 101, the top surface of the first 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. In this way, the first pad 211 is more conducive to limiting the melted solder paste inside the hollowed portion 2113, thereby avoiding the solder paste from flowing too much on the surface of the battery body 100 after melting, thereby reducing the light absorption area of the battery body 100.

[0051] In the embodiment, the first pad 211 in the first area can be located in the first area. Figure 1 In the embodiment, in the direction from the first area to the second area, the orthographic projection area of the first pad 211 on the first surface 101 gradually decreases. In the direction from the first area to the second area, the distance between the edge of the first pad 211 adjacent to another solar cell gradually increases, and the pulling force of the solder strip between the adjacent solar cells on the first pad 211 and the first grid line 111 gradually decreases. Therefore, the orthographic projection area of the first pad 211 on the first surface 101 gradually decreases, which can maintain the first pads 211 in the first area having sufficient welding tension while reducing the paste use cost of the first pads 211.

[0052] In the embodiment, the first pad 211 in the second area can be located in the second area. Figure 1For example, in the direction from the first region to the second region, the width of the first pad 211 in the first direction X gradually decreases, and the width of the first pad 211 in the second direction Y gradually decreases.

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

[0054] For example, referring to Figure 1 In the direction from the first region to the second region, the first pad 211 in the first region is divided into a plurality of first sub-pads 2111 and a plurality of second sub-pads 2112 arranged in sequence, and the area of the first sub-pad 2111 is greater than the area of the second sub-pad 2112. The number of first sub-pads 2111 is 2-3, for example, 2 or 3; the number of second sub-pads 2112 is 2-8, for example, 2, 3, 4, 5, 6, 7, or 8. The number of first sub-pads 2111 and second sub-pads 2112 can be kept within a reasonable range to ensure that the first pad 211 of the first region has sufficient soldering tension, while reducing the cost of paste used by the first pad 211.

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

[0056] When the solder strip needs to be welded in the low-temperature welding mode, the number of the first sub-pads 2111 is 2-3, and the number of the second sub-pads 2112 is 3-8. The width of the first sub-pad 2111 along the first direction X is 0.4mm-0.6mm, for example, it can be 0.4mm, 0.5mm or 0.6mm; the width of the first sub-pad 2111 along the second direction Y is 0.2mm-0.3mm, for example, it can be 0.2mm, 0.23mm, 0.25mm, 0.28mm or 0.3mm. The width of the second sub-pad 2112 along the first direction X is 0.3mm-0.5mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.46mm or 0.5mm; the width of the second sub-pad 2112 along the second direction Y is 0.1mm-0.3mm, for example, it can be 0.1mm, 0.16mm, 0.2mm, 0.24mm or 0.3mm. The width of the first pad 211 in the second area along the first direction X is 0.15mm-0.3mm, for example, it can be 0.15mm, 0.2mm, 0.25mm or 0.3mm; the width of the first pad 211 in the second area along the second direction Y is 0.05mm-0.1mm, for example, it can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm or 0.1mm.

[0057] In Figure 1In a column of first pad structure 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 conjunction with the total number of first gate lines 111.

[0058] refer to Figure 1 The size of the first connecting part 1112 is smaller than the size of the first pad 211 in the first area, which can reduce the cost of paste used in the first connecting part 1112, while the first pad 211 can be used to increase the welding pull between the solder strip and the first gate line 111.

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

[0060] In some embodiments, the solar cell can 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 cell), a HIT / HJT cell (Heterojunction Technology cell), or a BC cell (Back Contact cell). In some embodiments, the solar cell can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell can 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 This application provides a top view of the second side of a battery body according to an embodiment of the present application; Figure 7 This is a schematic diagram of a battery string structure provided in an embodiment of this application.

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

[0063] refer to Figure 6On the second surface 102, the second grid lines 112 extend along the first direction X, and a plurality of the second grid lines 112 are arranged along the second direction Y, the second surface 102 comprises a third region and a fourth region arranged along the second direction Y, the third region is located on the same side of the battery body 100 as the first region, and the fourth region is located on the same side of the battery body 100 as the second region. At least the second grid lines 112 located in the fourth region comprise second main body parts and second connecting parts arranged alternately, the second main body part is in electrical contact with the adjacent second connecting part, and the width of the second main body part is smaller than the width of the second connecting part along the second direction Y. The second surface 102 has a plurality of columns of second pad structures 202, the plurality of columns of second pad structures 202 are arranged at intervals along the first direction X, each column of second pad structures 202 comprises a plurality of second pads 212, the second pad 212 is in electrical contact with the corresponding second grid line 112, wherein the second pad 212 located in the fourth region is located on the second connecting part, and the orthographic projection of the second connecting part on the second surface 102 is located within the orthographic projection of the second pad 212 on the second surface 102, and the orthographic projection area of the second pad 212 in the fourth region on the second surface 102 is greater than the orthographic projection area of the second pad 212 in the third region on the second surface 102.

[0064] In combination with reference Figure 1 , Figure 6 and Figure 7 , the first surface 101 of the two connected solar cells 10 is arranged upward, the solder strip 20 extends from the first surface 101 of one solar cell 10 to the second surface 102 of the other solar cell 10, the area of the first pad 211 near the first region of the other solar cell 10 on the first surface 101 is relatively large, and the first grid line 111 comprises a first connecting part with a relatively large size, the area of the second pad 212 near the fourth region of the other solar cell 20 on the second surface 102 is relatively large, and the second grid line 112 comprises a second connecting part with a relatively large size, in this way, the welding tension between the adjacent two solar cells 10 is mainly borne by the first pad 211 in the first region and the first connecting part and the second pad 212 in the fourth region and the second connecting part, under the joint action of the first pad 211 in the first region and the first connecting part and the second pad 212 in the fourth region and the second connecting part, the welding tension between the adjacent solar cells 20 is increased, and the welding stability of the cell string is improved.

[0065] Figure 8 Another top view of a first surface of a battery body provided by an embodiment of the present application; Figure 9 Another structure diagram of a cell string provided by an embodiment of the present application.

[0066] In combination with reference Figure 8In some embodiments, the first surface 101 of the battery body 100 is provided with a first grid line 111 and a second grid line 112, the first grid line 111 and the second grid line 112 have different polarities. The first grid line 111 and the second grid line 112 both extend along a first direction X, and a plurality of first grid lines 111 and a plurality of second grid lines 112 are arranged alternately along a second direction Y. The first surface 101 includes a first region, a second region and a third region arranged along the second direction Y. The first grid line 111 located at least in the first region includes a first main body portion and a first connecting portion arranged alternately, the first main body portion is in electrical contact with the adjacent first connecting portion, and the width of the first main body portion is smaller than the width of the first connecting portion along the second direction Y. The second grid line 112 located at least in the third region includes a second main body portion and a second connecting portion arranged alternately, the second main body portion is in electrical contact with the adjacent second connecting portion, and the width of the second main body portion is smaller than the width of the second connecting portion along the second direction Y. The first surface 101 has a plurality of first pad structures 201 and a plurality of second pad structures 202, the first pad structures 201 and the second pad structures 202 are arranged alternately along the first direction X. Each column of first pad structures 201 includes a plurality of first pads 211, the first pad 211 is in electrical contact with the corresponding first grid line 111; each column of second pad structures 202 includes a plurality of second pads 212, the second pad 212 is in electrical contact with the corresponding second grid line 112. Among them, the first pad 211 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 101 is located in the orthographic projection of the first pad 211 on the first surface 101, the orthographic projection area of the first pad 211 in the first region on the first surface is greater than the orthographic projection area of the first pad 211 in the second region on the first surface 101; the second pad 212 located in the third region is located on the second connecting portion, and the orthographic projection area of the second connecting portion on the first surface 101 is located in the orthographic projection of the second pad 212 on the first surface 101, the orthographic projection area of the second pad 212 in the third region on the first surface 101 is greater than the orthographic projection area of the second pad 212 in the second region on the first surface 101.

[0067] By way of reference Figure 8 And Figure 9When the solar cell 10 is a back contact cell, the first busbar 111 and the second busbar 112 are both located on the same side surface of the solar cell 10. For the middle solar cell 10, the first busbar 111 on the first surface 101 is connected to the second busbar 112 on the left solar cell 10 through the left solder ribbon 20, and the second busbar 112 on the first surface 101 is connected to the first busbar 111 on the right solar cell 10 through the right solder ribbon 20. Therefore, the two solder ribbons 20 on the first surface 101 of the middle solar cell 10 are pulled by the two adjacent solar cells 10 respectively, and when the first pad 211 in the first area and the second pad 212 in the third area have a large area, and the first busbar 111 in the first area includes a first connecting portion and the second busbar in the third area includes a second connecting portion, the soldering tension between the middle solar cell 10 and the adjacent solar cells 10 can be improved, and the carrier transport efficiency between the first busbar 111 and the second busbar 112 and the corresponding solder ribbon 20 is also improved.

[0068] The second connecting portion and the second main portion are the same as the first connecting portion 1112 and the first main portion 1111 in the foregoing embodiments, or the corresponding parts can refer to the foregoing embodiments, which will not be described here.

[0069] The second pad 212 is the same as the first pad 211 in the foregoing embodiments, or the corresponding parts can refer to the foregoing embodiments, which will not be described here.

[0070] In the solar cell provided by the embodiment of the present application, the first grid line 111 in the first area on the first surface 101 of the cell body 100 comprises the first main body part 1111 and the first connecting part 1112 connected alternately, the width of the first main body part 1111 is smaller than the width of the first connecting part 1112 along the second direction Y, meanwhile, the first pad 211 in the first area is located on the first connecting part 1112, and the area of the orthographic projection of the first pad 211 in the first area on the first surface is larger than the area of the orthographic projection of the first pad 211 in the second area on the first surface 101, so that the first grid line 111 in the first area and the solder ribbon have greater welding strength and higher carrier transmission efficiency after the solder ribbon is welded with the solar cell. When the solder ribbon is welded with the solar cell, the head of one end of the solder ribbon is welded from the first pad 211 closest to the edge of the second area to the first pad 211 closest to the edge of the first area, and the other end of the solder ribbon is used to connect another solar cell, and a plurality of solar cells are connected in series to form a cell string. For the solder ribbons corresponding to the adjacent two solar cells, the solder ribbon between the two solar cells is not welded, and a certain tension is generated due to the relative movement between the two solar cells. Since the first pad 211 and the first grid line 111 in the first area are closer to the other solar cell, the tension between the first pad 211 and the first grid line 111 in the first area and the solder ribbon is relatively larger than that between the first pad 211 and the first grid line 111 in the second area and the solder ribbon. In the solar cell provided by the embodiment of the present application, the first grid line 111 in the first area has the first connecting part 1112 with a larger size, and the first pad 211 with a larger area is arranged on the first connecting part 1112, so that the first grid line 111 in the first area and the solder ribbon have greater welding strength and higher carrier transmission efficiency, thereby facilitating the stability of the connection between the first grid line 111 in the first area and the solder ribbon and the stability of the carrier transmission, and meanwhile, the welding tension between the solar cells in the cell string is higher after the solar cells are connected in series to form the cell string. In addition, the solar cell provided by the embodiment of the present application and the solder ribbon form a main grid-free structure after being welded, and the main grid-free structure facilitates the reduction of the use cost of the main grid paste.

[0071] Correspondingly, another embodiment of the present application further provides a photovoltaic module, comprising: a plurality of solar cells as in the above embodiments, a solder ribbon, a film and a cover plate, the solder ribbon connects the pads of two adjacent solar cells; the film covers the surface of the solar cell; and the cover plate covers the surface of the film away from the solar cell. The same or corresponding parts as in the previous embodiment can refer to the corresponding description of the previous embodiment, and will not be described in detail hereinafter.

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

[0073] In some embodiments, the cover plate can be a glass cover plate, a plastic cover plate, or the like cover plate having a light transmission 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 incident light.

[0074] In the photovoltaic module provided by the embodiments of the present application, the first grid line in the first area on the solar cell has a first connecting portion with a large size, and the first connecting portion has a first pad with a large area, so that the first grid line in the first area and the solder ribbon have greater welding strength and higher carrier transport efficiency, to facilitate maintaining the connection stability and carrier transport stability between the first grid line in the first area and the solder ribbon, and meanwhile, after the solar cells are connected in series to form a cell string, the welding tension between the solar cells is higher. In addition, in the photovoltaic module provided by the embodiments of the present application, the solar cell and the solder ribbon constitute a main grid-free structure after welding, and the main grid-free structure is conducive to reducing the use cost of main grid paste.

[0075] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present application, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, therefore the protection scope of the present application should be limited by the scope defined in the claims.

Claims

1. A solar cell, characterized in that, include: The battery body has a first surface with multiple first grid lines extending along a first direction and multiple first grid lines arranged along a second direction. The first surface includes a first region and a second region arranged along the second direction. The first region is located on one edge of the first surface along the second direction, and the second region is located on the side of the first region away from the edge. At least the first grid lines located in the first region include alternating first main body portions and first connecting portions. The first main body portions are in electrical contact with adjacent first connecting portions. Along the second direction, the width of the first main body portion is smaller than the width of the first connecting portion. The first pad structure is located on the first surface and is arranged at intervals along the first direction. Each row of the first pad structure includes multiple first pads. The first pads are electrically in contact with the corresponding first gate lines. The first pads located in the first region are located on the first connection portion, and the orthographic projection of the first connection portion on the first surface is located within the orthographic projection of the first pads on the first surface. The orthographic projection area of ​​the first pads in the first region on the first surface is greater than the orthographic projection area of ​​the first pads in the second region on the first surface.

2. The solar cell according to claim 1, characterized in that, Along a direction perpendicular to the first surface, the height of the first connecting portion relative to the first surface is greater than the 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 part and a second part. The first part is located on the top surface of the first connection portion, and the second part is located on the side surface of the first connection portion. The top surface of the first part is flush with the top surface of the second part.

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

5. The solar cell according to claim 4, characterized in that, The orthographic projection of the first connecting portion on the first surface lies 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 connection portion.

7. The solar cell according to claim 1, characterized in that, In the direction from the first region to the second region, the projected 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 region to the second region, the first pad in the first region 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-pad is 2 to 3, and the number of the second sub-pad is 2 to 8.

9. The solar cell according to claim 1, characterized in that, A second grid line is provided on the second surface of the battery body opposite to the first surface. The second grid line extends along the first direction, and multiple second grid lines are arranged along the second direction. The second surface includes a third region and a fourth region arranged along the second direction. The third region and the first region are located on the same side of the battery body, and the fourth region and the second region are located on the same side of the battery body. At least the second grid line located in the fourth region includes an alternately arranged second main body portion and a second connecting portion. The second main body portion is in electrical contact with the adjacent second connecting portion. Along the second direction, the width of the second main body portion is smaller than the width of the second connecting portion. The second pad structure is located on the second surface and is arranged at intervals along the first direction. Each row of the second pad structure includes multiple second pads. The second pads are electrically in contact with the corresponding second gate lines. The second pads located in the fourth region are located on the second connection portion, and the orthographic projection of the second connection portion on the second surface is located within the orthographic projection of the second pads on the second surface. The orthographic projection area of ​​the second pads in the fourth region on the second surface is greater than the orthographic projection area of ​​the second pads in the third region on the second surface.

10. A photovoltaic module, characterized in that, include: Multiple solar cells as described in any one of claims 1 to 9; Solder strips, which connect two adjacent pads of the solar cells; An adhesive film covering the surface of the solar cell; A cover plate that covers the surface of the adhesive film away from the solar cell.

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