Photovoltaic module and preparation method thereof

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a photovoltaic module and a preparation method thereof, the photovoltaic module comprises a battery string, the battery string comprises a plurality of electrically connected battery pieces, and each battery piece comprises a substrate; a plurality of fine grids arranged at intervals along a first direction, wherein the fine grids are located on the substrate; the conductive material layer is positioned on the battery piece, and the conductive material layer is electrically connected with the plurality of fine grids; the two ends of the connecting structure are located at the first end of the first battery piece and the second end of the second battery piece which are adjacently arranged respectively, the connecting structure is located on part of the conductive material layer, and the overlapping length of the connecting structure and the conductive material layer is smaller than or equal to 1 / 15 of the length of the conductive material layer; wherein the battery piece comprises a first battery piece and a second battery piece. The photovoltaic module and the preparation method thereof at least can improve the yield of the module.

Description

Technical Field

[0001] The embodiments of the present application relate to the photovoltaic field, and in particular to a photovoltaic module and a method for preparing the same. Background Art

[0002] The photovoltaic module includes a battery string group, which includes multiple battery strings. Multiple battery cells in the battery string are connected in series through welding strips. Generally, the current collected by the grid lines (electrodes) of the battery is collected through the welding strip and finally led to the outer end of the photovoltaic module. The welding strip and the grid lines of the battery form an alloy contact through the welding process, that is, some elements of the welding strip and some elements of the grid lines melt each other and form an alloy layer.

[0003] The soldering ribbon includes a copper substrate and a tin layer coated on the outer surface of the copper substrate. At present, in order to reduce the series resistance of the battery string, the cross-section of the copper substrate of the soldering ribbon is designed to be larger, such as designing the cross-section of the copper substrate of the soldering ribbon to be a regular polygon. However, wider and narrower flat soldering ribbons increase the shielding area, thereby reducing the photoelectric conversion efficiency; secondly, the longer stretching distance of wider and narrower flat soldering ribbons will cause the soldering ribbon to twist, thereby affecting the yield of photovoltaic modules. Summary of the invention

[0004] The embodiments of the present application provide a photovoltaic module and a method for preparing the same, which are at least beneficial to improving the yield of the photovoltaic module.

[0005] According to some embodiments of the present application, on one hand, the embodiments of the present application provide a photovoltaic component, including: a battery string, the battery string including: a plurality of electrically connected battery cells, each of the battery cells including: a substrate; a plurality of fine grids spaced apart along a first direction, the fine grids being located on the substrate; a conductive material layer, the conductive material layer being located on the battery cell, the conductive material layer being electrically connected to the plurality of fine grids; a connecting structure, the two ends of the connecting structure being respectively located at a first end of a first battery cell and a second end of a second battery cell disposed adjacent to each other, the connecting structure being located on a portion of the conductive material layer, and a length by which the connecting structure overlaps with the conductive material layer is less than or equal to 1 / 15 of a length of the conductive material layer; wherein the battery cells include a first battery cell and a second battery cell.

[0006] In some embodiments, there is a gap between the first battery cell and the second battery cell; the connecting structure is a conductive tape, and the conductive tape is located on the gap.

[0007] In some embodiments, along the first direction, the conductive tape overlaps the conductive material layer by a length ranging from 1.2 cm to 3.0 cm.

[0008] In some embodiments, the conductive ribbon is a flat solder ribbon.

[0009] In some embodiments, the first end is located on the second end, the first battery cell overlaps with the second battery cell to form an overlapping area, the connecting structure and the conductive material layer are continuous film layers; adjacent battery cells are electrically contacted through the conductive material layer located in the overlapping area to form the battery string.

[0010] In some embodiments, the battery cell is a back contact battery cell, and the conductive material layer is also located on the side of the second battery cell, so that adjacent battery cells are electrically contacted through the conductive material layer located in the overlapping area and the side of the second battery cell to form the battery string.

[0011] In some embodiments, the fine grid is a layer of electroplated material, and the conductive material layer includes a first part and a second part arranged alternately, the first part corresponds to the fine grid, and the second part corresponds to the grid spacing between adjacent fine grids; the first width of the first part along the second direction is less than or equal to the second width of the second part along the second direction.

[0012] In some embodiments, the conductive material layer is formed by solidifying solder paste.

[0013] According to some embodiments of the present application, on the other hand, the embodiments of the present application further provide a method for preparing a photovoltaic module, including: providing a battery cell, the battery cell including: a substrate; a plurality of fine grids arranged at intervals along a first direction, the fine grids being located on the substrate; printing a paste on the substrate, the paste being located on the plurality of fine grids; performing a curing treatment so that the paste is cured into a conductive material layer; assembling a battery string, including: arranging a plurality of first battery cells and a second battery cell having a conductive material layer in sequence; placing a connecting structure, the two ends of the connecting structure being respectively located at a first end of an adjacent first battery cell and a second end of a second battery cell, the connecting structure being located on a portion of the conductive material layer, and a length of overlap between the connecting structure and the conductive material layer being less than or equal to 1 / 15 of a length of the conductive material layer; wherein the battery cell includes a first battery cell and a second battery cell; performing a heating treatment so that the connecting structure is electrically connected to the conductive material layer.

[0014] In some embodiments, the process steps of printing the paste on the substrate include: performing dot printing on each of the fine grids to form a plurality of connecting paste dots; and performing flow treatment to connect adjacent connecting paste dots to each other.

[0015] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0016] The photovoltaic module provided in the embodiment of the present application includes a battery string, which includes: a plurality of electrically connected battery cells, each battery cell includes: a substrate; a plurality of fine grids arranged at intervals along a first direction, the fine grids are located on the substrate; a conductive material layer, the conductive material layer is located on the battery cell, and the conductive material layer is electrically connected to the plurality of fine grids; a connection structure, the two ends of the connection structure are respectively located at the first end of the first battery cell and the second end of the second battery cell arranged adjacently, the connection structure is located on part of the conductive material layer, and the length of the connection structure overlapping the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the battery cell includes a first battery cell and a second battery cell. A conductive material layer is provided, and the electrical connection between the fine grids is achieved through the conductive material layer, thereby forming a battery string. In this way, the distortion problem caused by the welding strip can be avoided, and the efficiency of the component can be improved. The conductive material layer can also reduce the probability of hidden cracks caused by the welding strip, thereby improving the yield of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily illustrated by the figures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the figures 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 creative work.

[0018] Figure 1 A schematic diagram of the structure of a battery string in a photovoltaic module provided in one embodiment of the present application;

[0019] Figure 2 A partial cross-sectional view of a cell string in a photovoltaic module provided in one embodiment of the present application;

[0020] Figure 3 Another structural schematic diagram of a battery string in a photovoltaic module provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of another structure of a battery string in a photovoltaic module provided in an embodiment of the present application;

[0022] Figure 5 A schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present application;

[0023] Figure 6 A schematic diagram of a structure of a battery string in a photovoltaic module provided in another embodiment of the present application;

[0024] Figure 7A partial top view of a cell string in a photovoltaic module provided in another embodiment of the present application;

[0025] Figure 8 Another structural schematic diagram of a battery string in a photovoltaic module provided in another embodiment of the present application

[0026] Fig. 9 A partial cross-sectional view of a cell string in a photovoltaic module provided in another embodiment of the present application;

[0027] Fig.10 A schematic structural diagram of a photovoltaic assembly provided in another embodiment of the present application. DETAILED DESCRIPTION

[0028] As can be seen from the background technology, the yield rate of current photovoltaic modules is poor.

[0029] The embodiment of the present application provides a photovoltaic module, which can achieve electrical connection between fine grids by printing a conductive material layer on the battery cell, and then form a battery string through a connecting structure, which can reduce a series of problems caused by welding strips and thus improve the yield of the photovoltaic module.

[0030] In the description of the embodiments of the present application, the technical terms "first", "second", etc. 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. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0031] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0033] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0034] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0035] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0036] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layer are magnified for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component can be "directly" located on the surface of another component, or there can be a third component 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 "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.

[0037] In the description of the embodiments of the present application, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it may be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may exist in between. In addition, when a component such as a layer, film, region, or plate is "directly located on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located in between.

[0038] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the part" is also intended to include the plural form unless the context clearly indicates otherwise. Among them, a component includes a layer, a film, a region, or a plate.

[0039] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0040] According to some embodiments of the present application, on one hand, a photovoltaic module is provided in the embodiments of the present application to improve the yield and efficiency of the photovoltaic module.

[0041] Figure 1 A schematic diagram of the structure of a battery string in a photovoltaic module provided in one embodiment of the present application; Figure 2 A partial cross-sectional view of a cell string in a photovoltaic module provided in one embodiment of the present application.

[0042] refer to Figure 1 and Figure 2 The photovoltaic module includes: a battery string, the battery string includes: a plurality of electrically connected battery cells 10, each battery cell 10 includes: a substrate 100; a plurality of fine grids 101 arranged at intervals along a first direction X, the fine grids 101 are located on the substrate 100; a conductive material layer 110, the conductive material layer 110 is located on the battery cell 10, and the conductive material layer 110 is electrically connected to the plurality of fine grids 101; a connecting structure 120, the two ends of the connecting structure 120 are respectively located at the first end 111 of the first battery cell 11 and the second end 112 of the second battery cell 12 arranged adjacently, the connecting structure 120 is located on part of the conductive material layer 110, and the overlapping length of the connecting structure 120 and the conductive material layer 110 is less than or equal to 1 / 15 of the length of the conductive material layer 110; wherein the battery cell 10 includes a first battery cell 11 and a second battery cell 12. In this way, the conductive material layer 110 is provided, and the electrical connection between the fine grids 101 and the fine grids 101 is achieved through the conductive material layer 110, thereby forming a battery string. In this way, the distortion problem caused by the soldering strip can be avoided, thereby improving the efficiency of the module. The conductive material layer 110 can also reduce the probability of hidden cracks caused by the soldering strip, thereby improving the yield of the photovoltaic module.

[0043] In some embodiments, the cell 10 is a whole cell or a split cell. The split cell may be a half cell, a three-cell cell, a four-cell cell, or an eight-cell cell, etc. The present application embodiment takes the solar cell as a half-cell as an example, and the half-cell cell can also be understood as a half-cell or a two-cell cell.

[0044] refer to Figure 3 The cell 10 includes, but is not limited to, one or any combination of PERC cells (Passivated Emitter Rear Cell), IBC (Interdigitated Back Contact), TOPCon cells (Tunnel Oxide Passivated Contact), HIT / HJT cells (Heterojunction Technology), solar thin-film cells, and stacked cells. Among them, solar thin-film cells include, but are not limited to, perovskite solar thin-film cells, copper indium selenide solar thin-film cells, gallium arsenide solar thin-film cells, and cadmium sulfide solar thin-film cells. Stacked cells include, but are not limited to, perovskite cells superimposed on crystalline silicon cells, perovskite cells superimposed on perovskite cells, and perovskite cells superimposed on thin-film cells.

[0045] The cell 10 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.

[0046] In some embodiments, the P-type structure and the N-type structure of the cell 10 are located on two opposite surfaces of the substrate 100, for example, a PERC cell, a TOPCon cell, a HIT / HJT cell, a solar thin-film cell, and a stacked cell. The grid lines of two different polarities of the cell are located on two opposite sides of the substrate 100. Figure 2 , grid lines of different polarities can be defined as a first grid line 121 and a second grid line 122, the first grid line 121 has a positive polarity, and the second grid line 122 has a negative polarity. Wherein, the P-type structure is a P-type semiconductor, as the P-type region in the solar cell, the positively charged holes move to the P-type structure, and are finally collected by the first grid line 121 of positive polarity; the N-type structure is an N-type semiconductor, as the N-type region in the solar cell, the negatively charged electrons move to the N-type structure, and are finally collected by the second grid line 122 of negative polarity.

[0047] refer to Figure 1In some embodiments, each battery cell has a first surface 103 and a second surface 104 that are opposite to each other, and a gap 105 is formed between the first battery cell 11 and the second battery cell 12 .

[0048] refer to Figure 2 , the first surface 103 of the first battery cell 11 has a first grid line 121, and the second surface 104 of the first battery cell 11 has a second grid line 122; the first surface 103 of the second battery cell 12 has a first grid line 121, and the second surface 104 of the second battery cell 12 has a second grid line 122. According to the alternating arrangement of the first surface 103 of the first battery cell 11 and the first surface 103 of the second battery cell 12, one end of the connection structure 120 is located on the first surface 103 of the first battery cell 11 and the other end is located on the second surface 104 of the second battery cell 12, and the connection structure 120 is naturally bent and connected to the first grid line 121 of the first battery cell 11 and the second grid line 122 of the second battery cell 12.

[0049] Figure 3 Another schematic diagram of the structure of a battery string in a photovoltaic module provided in one embodiment of the present application.

[0050] refer to Figure 3 In other embodiments, there is a gap 105 between the first battery cell 11 and the second battery cell 12, and the first surface 103 of the first battery cell 11 and the second surface 104 of the second battery cell 12 are alternately arranged, that is, the gate lines of the first battery cell 11 and the gate lines of the second battery cell 12 facing the same side have different polarities, and the connecting structure 120 is horizontally placed on the first surface 103 of the first battery cell 11 and the second surface 104 of the second battery cell 12.

[0051] Figure 4 A schematic diagram of another structure of a battery string in a photovoltaic module provided in an embodiment of the present application.

[0052] In some other embodiments, reference Figure 4 The first end 111 is located on the second end 112, and the first battery cell 11 and the second battery cell 12 overlap to form an overlapping area. The first surface 103 of the first battery cell 11 and the first surface 103 of the second battery cell 12 are arranged alternately, and the second battery cell 12 is stacked on the surface of the first battery cell 11, that is, the first surface 103 of the first battery cell 11 is in contact with the second surface 104 of the second battery cell 12, and the connection structure 120 is located between the first surface 103 of the first battery cell 11 and the second surface 104 of the second battery cell 12.

[0053] In some embodiments, the battery cell can be a main grid-less battery, and the first grid line 121 and the second grid line 122 refer to the secondary grids of the battery cell 10, and their extension direction intersects with the extension direction of the conductive material layer 110. One conductive material layer 110 is electrically connected to multiple first grid lines 121 / one conductive material layer 110 is electrically connected to multiple second grid lines 122, thereby reducing the use of silver-aluminum paste and further reducing the preparation cost.

[0054] Continue to refer Figure 1 , the thickness of the conductive material layer 110 is 200 μm to 300 μm. The thickness range of the conductive material layer 110 is used to ensure that the conductive material layer 110 has a low resistivity, thereby improving the carrier transmission efficiency; the thickness range of the conductive material layer 110 can avoid the problem of battery cell rupture caused by the excessive thickness of the conductive material layer 110.

[0055] The thickness of the conductive material layer 110 in the vertical direction Z is 200-220 μm, 200-220 μm, 200-220 μm, 200-220 μm or 200-220 μm. The thickness of the conductive material layer 110 is 205 μm, 215 μm, 225 μm, 235 μm, 245 μm, 255 μm, 265 μm, 275 μm, 285 μm or 298 μm.

[0056] Continue to refer Figure 1 , the width of the conductive material layer 110 along the second direction Y is 0.6 mm to 1.2 mm, and the second direction Y is perpendicular to the first direction X. When the thickness of the conductive material layer 110 is within the above range, the conductive material layer 110 and the fine grid 101 have a larger contact area, thereby reducing the contact resistance between the conductive material layer 110 and the fine grid and reducing electrical losses. When the thickness of the conductive material layer 110 is within the above range, the shielding loss of the conductive material layer 110 can also be reduced, thereby improving the optical conversion efficiency of the solar cell.

[0057] The width of the conductive material layer 110 along the second direction Y is 0.6 mm to 0.8 mm, 0.8 mm to 1.0 mm, or 1.0 mm to 1.2 mm. The width of the conductive material layer 110 along the second direction Y may be 0.7 mm, 0.9 mm, or 1.1 mm.

[0058] In some embodiments, the conductive material layer 110 is formed by solidifying solder paste, so that a good alloy layer is formed between the conductive material layer 110 and the fine grid 101 , thereby reducing the contact resistance between the conductive material layer 110 and the fine grid 101 .

[0059] In some embodiments, reference Figure 1 or Figure 3The connection structure 120 is a conductive tape, and the conductive tape is located on the gap 105 .

[0060] In some embodiments, the conductive tape is a flat solder tape. In this way, the thickness of the conductive tape is relatively thin. When the conductive tape is located on the battery cell 10 and connected to the conductive material layer 110, the conductive tape has a larger surface area, thereby alleviating and improving the stress problem applied to the battery cell 10, thereby avoiding the problem of cracking the battery cell 10, thereby improving the yield of the photovoltaic module.

[0061] In some embodiments, the overlapping length L of the conductive tape and the conductive material layer 110 is in the range of 1.2 cm to 3.0 cm along the first direction X. The contact length between the conductive tape and the conductive material layer 110 is within this range, and the contact area between the conductive tape and the conductive material layer 110 is large enough to avoid edge cracking and insufficient welding tension.

[0062] The overlapping length L of the conductive tape and the conductive material layer 110 ranges from 1.2 cm to 1.5 cm, 1.5 cm to 1.7 cm, 1.7 cm to 2.0 cm, 2.0 cm to 2.5 cm, 2.5 cm to 2.7 cm or 2.7 cm to 3.0 cm. The overlapping length L of the conductive tape and the conductive material layer 110 can be 1.3 cm, 1.6 cm, 1.9 cm, 2.2 cm, 2.6 cm or 2.8 cm.

[0063] In some embodiments, reference Figure 4 , the connection structure 120 and the conductive material layer 110 are continuous film layers; adjacent battery cells 10 are electrically contacted through the conductive material layer 110 located in the overlapping area to form a battery string.

[0064] In some embodiments, the fine gate 101 is a layer of electroplated material, and the conductive material layer 110 includes a first part and a second part arranged alternately, the first part corresponds to the fine gate, and the second part corresponds to the gate spacing of adjacent fine gates; the first width of the first part along the second direction is less than or equal to the second width of the second part along the second direction.

[0065] In some embodiments, the width of the second portion decreases along the middle of the second portion in a direction toward the first portion.

[0066] In some embodiments, the thickness of the first portion is greater than the thickness of the second portion.

[0067] In some embodiments, the thickness of the conductive material layer 110 decreases along a direction from the first portion to the second portion.

[0068] In some embodiments, the thickness of the first portion ranges from 0.3 mm to 0.5 mm, the width of the first portion ranges from 0.1 mm to 0.3 mm, and the length of the first portion ranges from 0.6 mm to 1.2 mm.

[0069] The thickness of the first part may be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 μm. The width of the first part may be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm. The length of the first part may be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm or 1.2 mm.

[0070] In some embodiments, the thickness of the second portion ranges from 50 μm to 80 μm, the width of the second portion ranges from 0.1 mm to 0.3 mm, and the length of the second portion ranges from 0.3 mm to 0.6 mm.

[0071] The thickness of the second portion may be 50 μm, 60 μm, 70 μm or 80 μm. The width of the second portion may be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm or 0.3 mm. The length of the second portion may be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm or 0.8 mm.

[0072] In some embodiments, the battery cell further includes: a main grid connection line extending along a first direction and connected to at least a portion of the fine grids near an edge of the substrate; and a conductive material layer located on the main grid connection line.

[0073] Figure 5 A schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present application.

[0074] refer to Figure 5 The photovoltaic module further includes: a packaging film 13 for covering the surface of the battery string; and a cover plate 14 for covering the surface of the packaging film 13 away from the battery string.

[0075] The encapsulation film 13 includes a first encapsulation layer and a second encapsulation layer, the first encapsulation layer covers one of the front side or the back side of the solar cell, and the second encapsulation layer covers the other of the front side or the back side of the solar cell. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyethylene terephthalate (PET) film.

[0076] It is worth noting that there is a boundary line between the first encapsulation layer and the second encapsulation layer before the lamination process. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film.

[0077] In some embodiments, the cover plate 14 may be a glass cover plate, a plastic cover plate or the like with a light-transmitting function. Specifically, the surface of the cover plate 14 facing the encapsulation film 13 may be a concave-convex surface, thereby increasing the utilization rate of the incident light. The cover plate 14 includes a first cover plate and a second cover plate, the first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer; or the first cover plate is opposite to one side of the solar cell, and the second cover plate is opposite to the other side of the solar cell.

[0078] In the photovoltaic module provided in the embodiment of the present application, a conductive material layer 110 is provided, and the electrical connection between the fine grids 101 and the fine grids 101 is achieved through the conductive material layer 110, thereby forming a battery string. In this way, the distortion problem caused by the welding strip can be avoided, thereby improving the efficiency of the module. The conductive material layer 110 can also reduce the probability of hidden cracks caused by the welding strip, thereby improving the yield of the photovoltaic module.

[0079] Correspondingly, another embodiment of the present application further provides a photovoltaic module, which is different from the previous embodiment in that, in the previous embodiment, the first gate line and the second gate line are located on both sides of the substrate, while in another embodiment, the first gate line and the second gate line are located on the same side of the substrate. The technical features that are the same or corresponding to the above-mentioned embodiments will not be described in detail here.

[0080] Figure 6 A schematic diagram of the structure of a battery string in a photovoltaic module provided in another embodiment of the present application.

[0081] refer to Figure 6 The photovoltaic module includes: a battery string, the battery string includes: a plurality of electrically connected battery cells 20, each battery cell 20 includes: a substrate 200; a plurality of fine grids 201 arranged at intervals along a first direction X, the fine grids 201 are located on the substrate 200; a conductive material layer 210, the conductive material layer 210 is located on the battery cell 20, and the conductive material layer 210 is electrically connected to the plurality of fine grids 201; a connecting structure 220, the two ends of the connecting structure 220 are respectively located at a first end 211 of a first battery cell 21 and a second end 212 of a second battery cell 22 arranged adjacent to each other, the connecting structure 220 is located on a portion of the conductive material layer 210, and the length of the overlapping between the connecting structure 220 and the conductive material layer 210 is less than or equal to 1 / 15 of the length of the conductive material layer 210; wherein the battery cell 20 includes a first battery cell 21 and a second battery cell 22.

[0082] In some embodiments, the battery cell 20 is a back contact battery cell, and the back contact battery cell may be an interdigitated back contact battery (IBC).

[0083] Figure 7 A partial top view of a cell string in a photovoltaic module provided in another embodiment of the present application.

[0084] In some embodiments, reference Figure 7 The battery cell 20 includes: a plurality of first gate lines 221 spaced apart along a first direction X and a plurality of second gate lines 222 spaced apart along the first direction X, and the first gate lines 221 and the second gate lines 222 are staggered along a second direction Y so that gate lines of different polarities are disconnected from each other.

[0085] In some embodiments, the battery cell includes a first gate line and a second gate line extending along a first direction, and a portion of the surface of the first gate line and a portion of the surface of the second gate line have an insulating film, which is used to avoid electrical insulation between conductive material layers of different polarities and the gate lines, thereby achieving open circuit.

[0086] In some embodiments, the fine grid 201 is a plating material layer, and the conductive material layer 210 includes a first portion 231 and a second portion 232 that are alternately arranged, the first portion 231 corresponds to the fine grid 201, and the second portion 232 corresponds to the grid spacing between the fine grids 201 and the fine grids 201; the first width of the first portion 231 along the second direction Y is less than or equal to the second width of the second portion 232 along the second direction Y. Among them, for the conductive material layer 210 connected to the first grid line 221, the first portion 231 corresponds to the first grid line 221, and the second portion 232 corresponds to the second grid line 222; conversely, for the conductive material layer connected to the second grid line, the first portion corresponds to the second grid line, and the second portion corresponds to the first grid line.

[0087] In some embodiments, the width of the second portion 232 decreases along the middle of the second portion 232 in a direction pointing toward the first portion 231 .

[0088] In some embodiments, the thickness of the first portion 231 is greater than the thickness of the second portion 232 .

[0089] In some embodiments, the thickness of the conductive material layer 210 decreases along a direction from the first portion 231 to the second portion 232 .

[0090] In some embodiments, the thickness of the first portion 231 ranges from 0.3 mm to 0.5 mm, the width of the first portion 231 ranges from 0.1 mm to 0.3 mm, and the length of the first portion 231 ranges from 0.6 mm to 1.2 mm.

[0091] In some embodiments, the thickness of the second portion 232 ranges from 50 μm to 80 μm, the width of the second portion 232 ranges from 0.1 mm to 0.3 mm, and the length of the second portion 232 ranges from 0.3 mm to 0.6 mm.

[0092] Figure 8 Another structural schematic diagram of a battery string in a photovoltaic module provided in another embodiment of the present application; Fig. 9 A partial cross-sectional view of a cell string in a photovoltaic module provided in another embodiment of the present application.

[0093] refer to Figure 8 and Fig. 9 The first end 211 is located on the second end 212, and the first battery cell 21 and the second battery cell 22 overlap to form an overlapping area. The first surface 203 of the first battery cell 21 and the first surface 203 of the second battery cell 22 are arranged alternately, and the second battery cell 22 is stacked on the surface of the first battery cell 21, that is, the first surface 203 of the first battery cell 21 is in contact with the second surface 204 of the second battery cell 22, and the connection structure 220 is located between the first surface 203 of the first battery cell 21 and the second surface 204 of the second battery cell 22.

[0094] In some embodiments, reference Fig. 9 The battery cell 20 is a back contact battery cell, and the conductive material layer 210 is also located on the side of the second battery cell 22, so that adjacent battery cells are electrically contacted through the conductive material layer located in the overlapping area and the side of the second battery cell 22 to form a battery string.

[0095] Fig.10 A schematic structural diagram of a photovoltaic assembly provided in another embodiment of the present application.

[0096] refer to Fig.10 The photovoltaic module further includes: a packaging film 23 for covering the surface of the battery string; and a cover plate 24 for covering the surface of the packaging film 23 away from the battery string.

[0097] Correspondingly, on the other hand, an embodiment of the present application further provides a method for preparing a photovoltaic module, which is used to prepare the photovoltaic module provided by the above embodiment. The technical features that are the same as or corresponding to the above embodiment will not be described in detail here.

[0098] refer to Figure 1 The preparation method includes: providing a battery cell, the battery cell includes: a substrate; a plurality of fine grids arranged at intervals along a first direction, the fine grids are located on the substrate.

[0099] The preparation method comprises: printing slurry on a substrate, wherein the slurry is located on a plurality of fine grids.

[0100] In some embodiments, the process steps of printing the paste on the substrate include: performing dot printing on each fine grid to form a plurality of connecting paste dots; and performing flow treatment to connect adjacent connecting paste dots to each other.

[0101] The preparation method comprises: performing a curing treatment to solidify the slurry into a conductive material layer.

[0102] In some embodiments, the process parameters of the curing treatment include: a curing temperature of 110° C. to 150° C., and a curing belt conveying speed of 3000 mm / min to 5000 mm / min.

[0103] The curing temperature may be 110° C., 120° C., 130° C., 140° C. or 150° C. The curing belt conveying speed may be 3000 mm / min, 3500 mm / min, 4000 mm / min, 4500 mm / min or 5000 mm / min.

[0104] The preparation method includes: assembling a battery string, including: arranging a plurality of first battery cells and second battery cells having a conductive material layer in sequence; placing a connection structure, wherein two ends of the connection structure are respectively located at a first end of a first battery cell and a second end of a second battery cell that are adjacently arranged, the connection structure is located on a portion of the conductive material layer, and the length of overlap between the connection structure and the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the battery cells include a first battery cell and a second battery cell; and performing a heating treatment to electrically connect the connection structure to the conductive material layer.

[0105] The preparation method comprises: laying a packaging film 13, the packaging film 13 is used to cover the surface of the battery string; laying a cover plate 14, which is used to cover the surface of the packaging film 13 away from the battery string.

[0106] The preparation method comprises: performing lamination processing to make alloy contact between the conductive material layer and the fine grid, and connecting the conductive material layer with the connection structure.

[0107] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail 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, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that: include: A battery string, the battery string comprising: a plurality of electrically connected battery cells, each of the battery cells comprising: a substrate; a plurality of fine grids spaced apart along a first direction, the fine grids being located on the substrate; A conductive material layer, the conductive material layer is located on the battery cell, and the conductive material layer is electrically connected to the plurality of fine grids; A connecting structure, wherein the two ends of the connecting structure are respectively located at the first end of a first battery cell and the second end of a second battery cell that are adjacent to each other, the connecting structure is located on a portion of the conductive material layer, and the overlapping length of the connecting structure and the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the battery cells include the first battery cell and the second battery cell.

2. The photovoltaic module according to claim 1, characterized in that: There is a gap between the first battery cell and the second battery cell; the connecting structure is a conductive tape, and the conductive tape is located in the gap.

3. The photovoltaic module according to claim 2, characterized in that: Along the first direction, the overlapping length of the conductive tape and the conductive material layer is in the range of 1.2 cm to 3.0 cm.

4. The photovoltaic module according to claim 2, characterized in that: The conductive strip is a flat solder strip.

5. The photovoltaic module according to claim 1, characterized in that: The first end is located on the second end, the first battery cell overlaps with the second battery cell to form an overlapping area, the connection structure and the conductive material layer are continuous film layers; adjacent battery cells are electrically contacted through the conductive material layer located in the overlapping area to form the battery string.

6. The photovoltaic module according to claim 5, characterized in that: The battery cell is a back contact battery cell, and the conductive material layer is also located on the side of the second battery cell, so that the adjacent battery cells are electrically contacted through the conductive material layer located in the overlapping area and the side of the second battery cell to form the battery string.

7. The photovoltaic module according to claim 1, characterized in that: The fine grid is a layer of electroplated material, and the conductive material layer includes a first part and a second part that are alternately arranged, the first part corresponds to the fine grid, and the second part corresponds to the grid spacing of adjacent fine grids; the first width of the first part along the second direction is less than or equal to the second width of the second part along the second direction.

8. The photovoltaic module according to claim 1, characterized in that: The conductive material layer is formed by solidifying solder paste.

9. A method for preparing a photovoltaic module, characterized in that: include: A battery cell is provided, the battery cell comprising: a substrate; a plurality of fine grids arranged at intervals along a first direction, the fine grids being located on the substrate; Printing a paste on the substrate, wherein the paste is located on a plurality of the fine grids; Performing a curing treatment to cure the slurry into a conductive material layer; Assembling a battery string, comprising: arranging a plurality of first battery cells and second battery cells having a conductive material layer in sequence; placing a connection structure, wherein two ends of the connection structure are respectively located at a first end of a first battery cell and a second end of a second battery cell arranged adjacent to each other, the connection structure is located on a portion of the conductive material layer, and the length of overlap between the connection structure and the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the battery cells comprise a first battery cell and a second battery cell; and performing a heating treatment to electrically connect the connection structure to the conductive material layer.

10. The preparation method according to claim 9, characterized in that: The process steps of printing the paste on the substrate include: performing dot printing on each of the fine grids to form a plurality of connection paste dots; and performing flow treatment to connect adjacent connection paste dots to each other.

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