Photovoltaic module and method of manufacturing the same

Abstract

The embodiment of the present application relates to the field of photovoltaic, and provides a photovoltaic module and a preparation method thereof, the photovoltaic module comprises: a cell string, the cell string comprises: a plurality of electrically connected cell pieces, each cell piece comprises: 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 cell piece, and the conductive material layer is electrically connected with the plurality of fine grids; a connecting structure, two ends of the connecting structure are located at a first end portion of a first cell piece and a second end portion of a second cell piece arranged adjacently, the connecting structure is located on part of the conductive material layer, and the length of the connecting structure overlapping with the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the cell piece comprises the first cell piece and the second cell piece. The provided photovoltaic module and the preparation method thereof can at least improve the yield of the module.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of photovoltaic, and particularly relate to a photovoltaic module and a preparation method thereof. BACKGROUND

[0002] The photovoltaic module includes a cell string group, the cell string group includes a plurality of cell strings, and a plurality of cell pieces in the cell string are connected in series by a solder ribbon. Generally, the current collected by the busbar (electrode) of the cell is collected by the solder ribbon and finally led out to the outer end of the photovoltaic module. The solder ribbon and the busbar of the cell form an alloyed contact through a soldering process, that is, the partial elements of the solder ribbon and the partial elements of the busbar are mutually melted and form an alloy layer.

[0003] The solder ribbon includes a copper base and a tin layer coated on the outer surface of the copper base. At present, in order to reduce the series resistance of the cell string, the cross section of the copper base of the solder ribbon is designed to be larger, such as being designed as a regular polygon. However, the wider and narrower flat solder ribbon increases the shading area, thereby reducing the photoelectric conversion efficiency, and the longer stretching distance of the wider and narrower flat solder ribbon causes the solder ribbon to be twisted, thereby affecting the yield of the photovoltaic module. SUMMARY

[0004] Embodiments of the present application provide a photovoltaic module and a preparation method thereof, which at least facilitate to improve the yield of the photovoltaic module.

[0005] According to some embodiments of the present application, the embodiments of the present application provide a photovoltaic module, which includes: a cell string, the cell string includes: a plurality of electrically connected cell pieces, each of the cell pieces includes: a substrate; a plurality of thin busbars arranged at intervals along a first direction, the thin busbars are located on the substrate; a conductive material layer, the conductive material layer is located on the cell piece, and the conductive material layer is electrically connected with the plurality of thin busbars; and a connecting structure, two ends of the connecting structure are located at a first end portion of a first cell piece and a second end portion of a second cell piece arranged adjacently, the connecting structure is located on part of the conductive material layer, and the length of the connecting structure overlapping with the conductive material layer is less than or equal to 1 / 15 of the length of the conductive material layer; wherein the cell pieces include the first cell piece and the second cell piece.

[0006] In some embodiments, the first cell piece and the second cell piece have a gap therebetween; the connecting structure is a conductive strip, and the conductive strip is located on the gap.

[0007] In some embodiments, along the first direction, the length of the conductive strip overlapping with the conductive material layer ranges from 1.2 cm to 3.0 cm.

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

[0009] In some embodiments, the first end portion is located on the second end portion, the first cell piece and the second cell piece overlap to form an overlapping area, and the connecting structure and the conductive material layer are continuous film layers; adjacent cell pieces are electrically connected through the conductive material layer located in the overlapping area to form the cell string.

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

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

[0012] In some embodiments, the conductive material layer is formed by curing of a tin paste.

[0013] According to some embodiments of the present application, another aspect of the embodiments of the present application further provides a method for manufacturing a photovoltaic module, including: providing a cell piece, the cell piece including: a substrate; a plurality of fine grids arranged at intervals in 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 process to cure the paste into a conductive material layer; assembling a cell string, including: arranging a plurality of first cell pieces and second cell pieces with the conductive material layer in sequence; placing a connecting structure, two ends of the connecting structure being located at a first end portion of an adjacent first cell piece and a second end portion of an adjacent second cell piece respectively, the connecting structure being located on part of the conductive material layer, and the length of the connecting structure overlapping the conductive material layer being less than or equal to 1 / 15 of the length of the conductive material layer; wherein the cell piece includes the first cell piece and the second cell piece; and performing a heating process to electrically connect the connecting structure and the conductive material layer.

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

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

[0016] The photovoltaic module provided by the embodiment of the present application comprises a cell string, and the cell string comprises: a plurality of electrically connected cell pieces, each cell piece comprising: a substrate; a plurality of thin grids arranged at intervals in a first direction, the thin grids being located on the substrate; a conductive material layer, the conductive material layer being located on the cell piece, and the conductive material layer being electrically connected with the plurality of thin grids; and a connecting structure, two ends of the connecting structure being located at a first end portion of a first cell piece and a second end portion of a second cell piece arranged adjacently, the connecting structure being located on part of the conductive material layer, and the length of the connecting structure overlapping with the conductive material layer being less than or equal to 1 / 15 of the length of the conductive material layer; wherein the cell piece comprises the first cell piece and the second cell piece. The conductive material layer is arranged, the electrical connection between the thin grids is realized through the conductive material layer, and then the cell string is formed. In this way, the distortion problem caused by the solder strip can be avoided, and then the efficiency of the module can be improved. The conductive material layer can also reduce the probability of hidden cracks caused by the solder strip, thereby improving the yield of the photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0017] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are shown by way of illustration in the drawings. Together with the description, the drawings serve to explain principles of embodiments. In the drawings:

[0018] Figure 1 A structural schematic diagram of a cell string in a photovoltaic module provided by an embodiment of the present application;

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

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

[0021] Figure 4 Still another structural schematic diagram of a cell string in a photovoltaic module provided by an embodiment of the present application;

[0022] Figure 5 A structural schematic diagram of a photovoltaic module provided by an embodiment of the present application;

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

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

[0025] Figure 8 Another structural schematic view of a cell string in a photovoltaic module according to another embodiment of the present application

[0026] Figure 9 A partial sectional view of a cell string in a photovoltaic module according to another embodiment of the present application;

[0027] Figure 10 A structural schematic view of a photovoltaic module according to another embodiment of the present application. DETAILED DESCRIPTION

[0028] As known from the background art, the yield of the current photovoltaic module is poor.

[0029] Embodiments of the present application provide a photovoltaic module, which can realize the electrical connection between the fine grids by printing a conductive material layer on the cell sheet, and then form a cell string through the connecting structure, so as to reduce the problems caused by the solder strips, and thus improve the yield of the photovoltaic module.

[0030] In the description of embodiments of the present 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. In the description of embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0031] In this document, the reference to "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean that the same embodiments are referred to, nor does it mean that the embodiments are mutually exclusive or alternative to each other. The skilled person explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0032] In the description of embodiments of the present application, the term "and / or" is only used to describe 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 three cases of A, A and B, and B. In addition, the character " / " in this document generally represents a "or" relationship between the front and rear associated objects.

[0033] In the description of embodiments of the present application, the term "a plurality of" means two or more (including two), and similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of pieces" means two or more pieces (including two pieces).

[0034] In the description of the embodiments of the present application, the technical terms "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 shown in the 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 devices or elements referred to 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 present application.

[0035] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0036] In the corresponding drawings of the embodiments of the present application, in order to better understand and facilitate the description, the thickness and area of the layer are enlarged. When describing a component (such as a layer, a film, a region or a substrate) on or on the surface of another component, the component can be "directly" on the surface of the other 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 a component surface forming or providing another component, it means that there is no third component between the two components. In addition, when a component is described as "formed substantially" on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on the edge of the entire surface.

[0037] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded and other components can also be further included. In addition, when a layer, film, region or plate and the like is referred to as "on / over" another component, it can be "directly on" another component (i.e. between the surface of another component and another component without other components), or another component can exist therebetween. In addition, when a layer, film, region, plate and the like is "directly on" another component, or when a layer, film, region, plate and the like is on the surface of another component, it means that there is no other component therebetween.

[0038] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments of the disclosure and the appended claims, the phrase "the part" is intended to also include plural forms unless the context clearly indicates otherwise. Among other things, parts include components such as layers, films, regions, or plates.

[0039] The embodiments of the present application will be described in detail with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be realized even without these technical details and various changes and modifications based on the following embodiments.

[0040] According to some embodiments of the present application, the embodiments of the present application provide a photovoltaic module for improving the yield and efficiency of the photovoltaic module.

[0041] Figure 1 A structural schematic diagram of a cell string in a photovoltaic module according to an embodiment of the present application is provided. Figure 2 A partial sectional view of a cell string in a photovoltaic module according to an embodiment of the present application is provided.

[0042] Reference Figure 1 And Figure 2 The photovoltaic module includes a cell string, and the cell string includes a plurality of electrically connected cell pieces 10, each of which includes a substrate 100, a plurality of fine grids 101 arranged at intervals along a first direction X, the fine grids 101 being located on the substrate 100, a conductive material layer 110 located on the cell piece 10, the conductive material layer 110 being electrically connected to the plurality of fine grids 101, and a connection structure 120, two ends of the connection structure 120 being located at a first end portion 111 of a first cell piece 11 and a second end portion 112 of a second cell piece 12 respectively, the connection structure 120 being located on part of the conductive material layer 110, and the length of the connection structure 120 overlapping the conductive material layer 110 being less than or equal to 1 / 15 of the length of the conductive material layer 110; wherein the cell piece 10 includes the first cell piece 11 and the second cell piece 12. In this way, the conductive material layer 110 is provided, and the electrical connection between the fine grids 101 is realized through the conductive material layer 110, thereby forming the cell string. In this way, the distortion problem caused by the solder 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 solder strip, thereby improving the yield of the photovoltaic module.

[0043] In some embodiments, the battery piece 10 is a whole piece battery or a split piece battery. The split piece battery can be a half piece battery, a third piece battery, a fourth piece battery, or an eighth piece battery, etc. The embodiments of the present application take the solar cell as an example of a half piece battery, which can also be understood as a cut half battery or a two-piece battery.

[0044] Reference Figure 3 The battery piece 10 includes but is not limited to one or any combination of a PERC (Passivated Emitter Rear Cell) battery, an IBC (Interdigitated Back Contact) battery, a TOPCon (Tunnel Oxide Passivated Contact) battery, a HIT / HJT (Heterojunction Technology) battery, a solar thin film battery, and a stacked battery. The solar thin film battery includes but is not limited to a perovskite solar thin film battery, a copper indium selenium solar thin film battery, a gallium arsenide solar thin film battery, and a cadmium sulfide solar thin film battery. The stacked battery includes but is not limited to a perovskite battery stacked with a crystalline silicon battery, a perovskite battery stacked with a perovskite battery, and a perovskite battery stacked with a thin film battery.

[0045] The battery piece 10 can be a single-crystal silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-element compound solar cell, which can be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenium solar cell, or a perovskite solar cell.

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

[0047] Reference Figure 1In some embodiments, each of the battery pieces has a first surface 103 and a second surface 104 arranged oppositely, and the first battery piece 11 and the second battery piece 12 have a gap 105 therebetween.

[0048] With reference to Figure 2 The first surface 103 of the first battery piece 11 has a first grid line 121, and the second surface 104 of the first battery piece 11 has a second grid line 122; the first surface 103 of the second battery piece 12 has a first grid line 121, and the second surface 104 of the second battery piece 12 has a second grid line 122. The first surface 103 of the first battery piece 11 and the first surface 103 of the second battery piece 12 are arranged alternately, one end of the connecting structure 120 is located on the first surface 103 of the first battery piece 11, and the other end is located on the second surface 104 of the second battery piece 12, the connecting structure 120 naturally bends and connects the first grid line 121 of the first battery piece 11 and the second grid line 122 of the second battery piece 12.

[0049] Figure 3 Another structure diagram of the battery string in the photovoltaic module is provided for an embodiment of the present application.

[0050] With reference to Figure 3 In other embodiments, the first battery piece 11 and the second battery piece 12 have a gap 105 therebetween, and the first surface 103 of the first battery piece 11 and the second surface 104 of the second battery piece 12 are arranged alternately, that is, the grid lines of the first battery piece 11 and the grid lines of the second battery piece 12 on the same side have different polarities, and the connecting structure 120 is horizontally placed on the first surface 103 of the first battery piece 11 and the second surface 104 of the second battery piece 12.

[0051] Figure 4 Another structure diagram of the battery string in the photovoltaic module is provided for an embodiment of the present application.

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

[0053] In some embodiments, the battery piece can be a non-main grid battery, the first grid line 121 and the second grid line 122 refer to the sub-grid of the battery piece 10, the extension direction of which intersects with the extension direction of the conductive material layer 110, one conductive material layer 110 is electrically connected with a plurality of first grid lines 121 / one conductive material layer 110 is electrically connected with a plurality of second grid lines 122, thereby reducing the amount of silver-aluminum paste, thereby reducing the preparation cost.

[0054] With reference to Figure 1 , the thickness of the conductive material layer 110 is 200-300 μm. The thickness range of the conductive material layer 110 is used to ensure that the conductive material layer 110 has a lower resistivity, thereby improving the transmission efficiency of the carriers; the thickness range of the conductive material layer 110 can avoid the problem of battery piece rupture caused by the thickness of the conductive material layer 110 being too high.

[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] With reference to Figure 1 , the width of the conductive material layer 110 along the second direction Y is 0.6-1.2 mm, and the second direction Y is perpendicular to the first direction X. The thickness of the conductive material layer 110 is within the above range, and the conductive material layer 110 has a larger contact area with the fine grid 101, thereby reducing the contact resistance between the conductive material layer 110 and the fine grid, reducing electrical loss. The thickness of the conductive material layer 110 is within the above range, which can also reduce the shading loss of the conductive material layer 110, 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 0.6-0.8 mm, 0.8-1.0 mm, or 1.0-1.2 mm. The width of the conductive material layer 110 along the second direction Y can be 0.7 mm, 0.9 mm, or 1.1 mm.

[0058] In some embodiments, the conductive material layer 110 is solidified by tin paste. In this way, 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, with reference to Figure 1 or Figure 3The connecting structure 120 is a conductive strip, which is located on the gap 105.

[0060] In some embodiments, the conductive strip is a flat ribbon. In this way, the thickness of the conductive strip is thin, and when the conductive strip is located on the cell 10 and connected with the conductive material layer 110, the conductive strip has a large surface area, thereby relieving and improving the stress problem applied to the cell 10, thereby avoiding the problem of cell 10 cracking, thereby improving the yield of the photovoltaic module.

[0061] In some embodiments, along the first direction X, the length L of the conductive strip overlapping with the conductive material layer 110 ranges from 1.2 cm to 3.0 cm. Within this range, the contact length between the conductive strip and the conductive material layer 110 is large enough, so that the problem of edge cracking and the problem of insufficient soldering tension can be avoided.

[0062] The length L of the conductive strip overlapping with 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 length L of the conductive strip overlapping with 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, referring to Figure 4 The connecting structure 120 and the conductive material layer 110 are continuous film layers; adjacent cells 10 are electrically connected through the conductive material layer 110 located in the overlapping area to form a cell string.

[0064] In some embodiments, the fine grid 101 is a plated material layer, the conductive material layer 110 includes first portions and second portions arranged alternately, the first portions correspond to the fine grids, and the second portions correspond to the grid spacings of adjacent fine grids; the first portions have a first width along the second direction that is less than or equal to a second width along the second direction of the second portions.

[0065] In some embodiments, along a direction of the second portion pointing to the first portion, the width of the second portion decreases.

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

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

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

[0069] The first portion can have a thickness of 0.3mm, 0.35mm, 0.4mm, 0.45mm, or 0.5mm. The first portion can have a width of 0.1mm, 0.15mm, 0.2mm, 0.25mm, or 0.3mm. The first portion can have a length of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, or 1.2mm.

[0070] In some embodiments, the second portion has a thickness ranging from 50mm to 80mm, a width ranging from 0.1mm to 0.3mm, and a length ranging from 0.3mm to 0.6mm.

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

[0072] In some embodiments, the battery piece further comprises a main grid connecting line extending along the first direction, the main grid connecting line being connected to at least a portion of the plurality of fine grids close to the edge of the substrate, and a layer of conductive material on the main grid connecting line.

[0073] Figure 5 A structural schematic diagram of a photovoltaic module according to an embodiment of the present application is provided.

[0074] Reference Figure 5 The photovoltaic module further comprises an encapsulation adhesive film 13 covering a surface of the battery string, and a cover plate 14 covering a surface of the encapsulation adhesive film 13 away from the battery string.

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

[0076] It is worth mentioning that the first encapsulation layer and the second encapsulation layer have a boundary before the lamination process, and after the lamination process, the photovoltaic module is formed, and there is no 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 adhesive film.

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

[0078] In the photovoltaic module provided by the embodiments of the present application, the conductive material layer 110 is arranged, and the electrical connection between the fine grids 101 and the fine grids 101 is realized through the conductive material layer 110, thereby forming a cell string. In this way, the distortion problem caused by the solder 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 solder strip, thereby improving the yield of the photovoltaic module.

[0079] Correspondingly, another embodiment of the present application also provides a photovoltaic module, which is different from the above embodiment in that the first grid line and the second grid line are located on the same side of the substrate in the above embodiment, and the first grid line and the second grid line are located on the same side of the substrate in the other embodiment. The same or corresponding technical features as the above embodiment will not be described in detail here.

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

[0081] Reference Figure 6 The photovoltaic module includes: a cell string, the cell string includes: a plurality of electrically connected cell pieces 20, each cell piece 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 cell piece 20, the conductive material layer 210 is electrically connected with the plurality of fine grids 201; a connection structure 220, two ends of the connection structure 220 are located at a first end portion 211 of a first cell piece 21 and a second end portion 212 of a second cell piece 22 arranged adjacently, respectively, the connection structure 220 is located on part of the conductive material layer 210, and the length of the connection structure 220 overlapping with the conductive material layer 210 is less than or equal to 1 / 15 of the length of the conductive material layer 210; wherein the cell piece 20 includes the first cell piece 21 and the second cell piece 22.

[0082] In some embodiments, the battery piece 20 is a back contact battery piece, which can be an Interdigitated Back Contact (IBC) battery piece.

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

[0084] In some embodiments, referring to Figure 7 , the battery piece 20 includes a plurality of first grid lines 221 arranged along a first direction X and a plurality of second grid lines 222 arranged along the first direction X, and the first grid lines 221 and the second grid lines 222 are staggered along a second direction Y so that grid lines of different polarities are electrically disconnected.

[0085] In some embodiments, the battery piece includes first grid lines and second grid lines extending along a first direction, and part of the surface of the first grid lines and part of the surface of the second grid lines have an insulating film, which is used to avoid electrical insulation between layers of conductive materials of different polarities and grid lines, thereby achieving electrical disconnection.

[0086] In some embodiments, the fine grid 201 is a layer of electroplated material, the conductive material layer 210 includes first portions 231 and second portions 232 arranged alternately, the first portions 231 correspond to the fine grid 201, and the second portions 232 correspond to the grid spacing between the fine grid 201 and the fine grid 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. 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, along the direction of the second portion 232 pointing to the first portion 231, the width of the second portion 232 decreases.

[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, along the direction of the first portion 231 pointing to the second portion 232, the thickness of the conductive material layer 210 decreases.

[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 second portion 232 has a thickness ranging from 50 μm to 80 μm, a width ranging from 0.1 mm to 0.3 mm, and a length ranging from 0.3 mm to 0.6 mm.

[0092] Figure 8 Another structural schematic diagram of a cell string in a photovoltaic module according to another embodiment of the present application is provided. Figure 9 A partial sectional view of a cell string in a photovoltaic module according to another embodiment of the present application is provided.

[0093] Reference is made to Figure 8 and Figure 9 , the first end portion 211 is located on the second end portion 212, and the first cell 21 overlaps with the second cell 22 to form an overlapping area. The first surface 203 of the first cell 21 and the first surface 203 of the second cell 22 are arranged alternately, and the second cell 22 is stacked on the surface of the first cell 21, i.e., the first surface 203 of the first cell 21 is in contact with the second surface 204 of the second cell 22, and the connecting structure 220 is located between the first surface 203 of the first cell 21 and the second surface 204 of the second cell 22.

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

[0095] Figure 10 A structural schematic diagram of a photovoltaic module according to another embodiment of the present application is provided.

[0096] Reference is made to Figure 10 , the photovoltaic module further comprises: an encapsulation adhesive film 23 for covering the surface of the cell string; and a cover plate 24 for covering the surface of the encapsulation adhesive film 23 away from the cell string.

[0097] Correspondingly, another aspect of the embodiments of the present application further provides a preparation method of a photovoltaic module, which is used for preparing the photovoltaic module provided in the above embodiments, and has the same or corresponding technical features as the above embodiments, which will not be described in detail here.

[0098] Reference is made to Figure 1 , the preparation method comprises: providing a cell, the cell comprising: a substrate; and a plurality of thin grids arranged at intervals in a first direction, the thin grids being located on the substrate.

[0099] The preparation method comprises: printing a paste on the substrate, the paste being located on the plurality of thin grids.

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

[0101] The preparation method includes: performing a curing treatment to cure the paste into the conductive material layer.

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

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

[0104] The preparation method includes: assembling the battery string, including: arranging a plurality of first battery pieces and second battery pieces in sequence, the first battery pieces and the second battery pieces each having a conductive material layer; placing a connecting structure, two ends of the connecting structure being located at a first end portion of the first battery piece and a second end portion of the second battery piece arranged adjacently, the connecting structure being located on part of the conductive material layer, and an overlapping length of 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 piece includes the first battery piece and the second battery piece; and performing a heating treatment to electrically connect the connecting structure and the conductive material layer.

[0105] The preparation method includes: laying the encapsulation adhesive film 13, the encapsulation adhesive film 13 being used to cover a surface of the battery string; and laying the cover plate 14, the cover plate 14 being used to cover a surface of the encapsulation adhesive film 13 away from the battery string.

[0106] The preparation method includes: performing a laminating treatment to make the conductive material layer and the fine grid alloy contact, and the conductive material layer and the connecting structure be connected.

[0107] Those skilled in the art can understand that the above 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 photovoltaic module, characterized by, The battery string comprises a plurality of electrically connected battery pieces, each of which comprises a substrate and a plurality of thin grids arranged at intervals in a first direction on the substrate; a layer of conductive material on the battery piece, the layer of conductive material being electrically connected to the plurality of thin grids; the layer of conductive material comprises first portions and second portions arranged alternately, the first portions corresponding to the thin grids, and the second portions corresponding to the grid spacing of adjacent thin grids; the first portions have a first width in a second direction that is less than or equal to a second width of the second portions in the second direction; a connecting structure having two ends respectively located at a first end portion of a first battery piece and a second end portion of a second battery piece arranged adjacently, the connecting structure being located on part of the layer of conductive material, and the length of the connecting structure overlapping the layer of conductive material being less than or equal to 1 / 15 of the length of the layer of conductive material; wherein the battery pieces comprise the first battery piece and the second battery piece. The first battery piece and the second battery piece have a gap therebetween; the connecting structure is a conductive strip located in the gap. In the first direction, the length of the conductive strip overlapping the layer of conductive material ranges from 1.2 cm to 3.0 cm. The conductive strip is a flat solder strip.

2. The photovoltaic module of claim 1, wherein, The first end portion is located on the second end portion, the first battery piece and the second battery piece overlap to form an overlapping area, the connecting structure and the layer of conductive material are continuous film layers; adjacent battery pieces are electrically connected through the layer of conductive material located in the overlapping area to form the battery string.

3. The photovoltaic module of claim 2, wherein, The battery piece is a back contact battery piece, the layer of conductive material is also located on the side surface of the second battery piece, so that adjacent battery pieces are electrically connected through the layer of conductive material located in the overlapping area and the side surface of the second battery piece to form the battery string.

4. The photovoltaic module of claim 2, wherein, The thin grids are layers of electroplated material.

5. The photovoltaic module of claim 1, wherein, The layer of conductive material is formed by solidification of tin paste.

6. The photovoltaic module of claim 5, wherein, The battery string comprises a plurality of electrically connected battery pieces, each of which comprises a substrate and a plurality of thin grids arranged at intervals in a first direction on the substrate; a layer of conductive material on the battery piece, the layer of conductive material being electrically connected to the plurality of thin grids; the layer of conductive material comprises first portions and second portions arranged alternately, the first portions corresponding to the thin grids, and the second portions corresponding to the grid spacing of adjacent thin grids; the first portions have a first width in a second direction that is less than or equal to a second width of the second portions in the second direction; a connecting structure having two ends respectively located at a first end portion of a first battery piece and a second end portion of a second battery piece arranged adjacently, the connecting structure being located on part of the layer of conductive material, and the length of the connecting structure overlapping the layer of conductive material being less than or equal to 1 / 15 of the length of the layer of conductive material; wherein the battery pieces comprise the first battery piece and the second battery piece; a heating process is performed to electrically connect the connecting structure and the layer of conductive material.

7. The photovoltaic module of claim 1, wherein, ​ 8. The photovoltaic module of claim 1, wherein, ​ 9. A method of making a photovoltaic module, characterized by, ​ ​ ​ ​ ​ The conductive material layer comprises first parts and second parts arranged alternately, the first parts correspond to the fine grids, and the second parts correspond to the grid spacings of adjacent fine grids; the first parts have a first width in a second direction which is less than or equal to a second width in the second direction of the second parts.

10. The method of claim 9, wherein, The process step of printing the paste on the substrate comprises: performing dot printing on each fine grid to form a plurality of connecting paste dots; and performing flow processing to connect the adjacent connecting paste dots to each other.

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