Photovoltaic module

Abstract

The invention discloses a photovoltaic module. The photovoltaic module comprises a conductive back plate and a battery layer arranged on the conductive back plate, the battery layer comprises a plurality of battery strings arranged at intervals in the first direction, each battery string comprises a plurality of battery pieces arranged at intervals in the second direction, the first direction is perpendicular to the second direction, and each battery piece comprises a middle area and edge areas located on the two sides of the middle area in the first direction; a plurality of fine grids which are arranged at intervals in the second direction are arranged on the battery pieces, the fine grids extend in the first direction, main grids are arranged in the edge area, and the main grids extend in the second direction and are connected with the corresponding fine grids; a plurality of connecting parts which are arranged at intervals in the first direction are arranged at the part, located in the middle region, of the fine grid; the conductive backboard is provided with a conductive layer, and the connecting part and the main grid are electrically connected with the conductive layer. Furthermore, the main grid is arranged in the edge area of the battery piece, the damp-heat resistance of the battery piece can be improved, and the fine grid part in the middle area of the battery piece is directly and electrically connected with the conductive layer through the connecting part, so that the production cost can be reduced.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic technology, specifically relating to a photovoltaic module. Background Technology

[0002] Back-contact solar cells, by placing all the grid lines on the back, avoid the grid lines from blocking the front of the cell, thereby improving the conversion efficiency of solar cells and gaining widespread application and attention.

[0003] In related technologies, to reduce battery production costs, low-cost base metal pastes, such as copper paste, are used to replace silver paste to prepare the grid lines on the solar cells. However, because the grid lines prepared with base metal pastes are formed using low-temperature technology, the bonding force between the grid lines and the solar cells is relatively weak. This results in poor resistance to damp heat in the final photovoltaic module product, making it easy for external moisture to penetrate into the photovoltaic module and cause localized failures inside the solar cells, thus reducing the performance of the photovoltaic module. Summary of the Invention

[0004] This application aims to provide a photovoltaic module that can solve the problem of poor resistance to damp heat in existing photovoltaic modules that use base metal grids.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose a photovoltaic module, including: a conductive backsheet and a battery layer disposed on the conductive backsheet; the battery layer includes a plurality of battery strings spaced apart along a first direction, the battery strings include a plurality of battery cells spaced apart along a second direction, the first direction being perpendicular to the second direction, and the battery cells including a central region and edge regions located on both sides of the central region along the first direction.

[0007] The battery cell has a plurality of fine grids spaced apart along the second direction, the fine grids extending along the first direction, the edge region has a main grid, the main grid extends along the second direction and overlaps with the fine grids of the same conductivity type, and the main grid is insulated from the fine grids of the opposite conductivity type; the portion of the fine grid located in the middle region has a plurality of connecting portions spaced apart along the first direction; the conductive backplate has a patterned conductive layer and an insulating layer for separating the conductive layer from the battery cell, the insulating layer has an opening structure, and the connecting portions of the main grid and the fine grids are provided with conductive structures, the conductive structures passing through the opening structure and electrically connected to the conductive layer.

[0008] Optionally, the main gate is provided with a plurality of pads arranged at intervals along the second direction, and the conductive structure is provided on the pads.

[0009] Optionally, the opening structure comprises a first via hole arranged in the insulating layer corresponding to the edge region, and a second via hole arranged in the insulating layer corresponding to the intermediate region, the first via hole is arranged in plurality, the plurality of first via holes are arranged in the second direction, and the conductive structure on the main grid is electrically connected with the conductive layer through the first via hole; the second via hole is a strip-shaped hole extending in the second direction, and the conductive structure on the connecting part is electrically connected with the conductive layer through the second via hole.

[0010] Optionally, the conductive structure is arranged at the intersection of the main grid and the fine grid of the same conductive type.

[0011] Optionally, the opening structure comprises a first via hole arranged in the insulating layer corresponding to the edge region, and a second via hole arranged in the insulating layer corresponding to the intermediate region, the first via hole and the second via hole are both strip-shaped holes extending in the second direction, the conductive structure on the main grid is electrically connected with the conductive layer through the first via hole, and the conductive structure on the fine grid is electrically connected with the conductive layer through the second via hole.

[0012] Optionally, in the first direction, the distance between the main grid located at the edge of the cell and the edge of the cell is D1, and 3mm≤D1≤10mm is satisfied.

[0013] And / or, the number of main grids arranged in each edge region is 1-4.

[0014] Optionally, in the first direction, the distance between the main grid located at the edge of the cell and the edge of the cell is D1, and the distance between two adjacent connecting parts in the intermediate region in the first direction is D2, and D1

[0015] And / or, in the first direction, the distance between the main grid located at the edge of the cell and the adjacent main grid or connecting part is D3, and the distance between two adjacent connecting parts in the intermediate region in the first direction is D2, and D3

[0016] Optionally, an insulating layer is further arranged between the main grid and the fine grid of the opposite conductive type, and the thickness of the main grid is greater than or equal to 15μm.

[0017] Optionally, the conductive layer comprises a plurality of electric connection portions arranged along the first direction, each electric connection portion corresponding to one of the battery strings, the electric connection portion comprising a plurality of conductive strips arranged along the second direction, the conductive strips being used to connect the battery pieces adjacent along the second direction in series, two adjacent conductive strips being in a finger structure; a first insulating gap is present between two adjacent electric connection portions, and a second insulating gap is present between two adjacent conductive strips; the width of the first insulating gap is less than the width of the second insulating gap.

[0018] Optionally, the width of the first insulating gap is L0, satisfying: 0.3mm≤L0≤1.5mm.

[0019] Optionally, the main grid located at the edge of the battery piece is an edge main grid, the distance between the edge main grid and the nearest first insulating gap along the first direction is L1, and the distance between the edge main grid and the nearest second insulating gap along the first direction is L2, satisfying: L1>L2.

[0020] Optionally, the distance between the edge main grid and the nearest first insulating gap along the first direction is L1, satisfying: 3mm≤L1≤12mm.

[0021] And / or, the ratio L1 / L2 of the distance L1 between the edge main grid and the nearest first insulating gap along the first direction to the distance L2 between the edge main grid and the nearest second insulating gap along the first direction satisfies: 1

[0022] Optionally, a third gap is present between two adjacent battery strings along the first direction, and the width of the first insulating gap is less than the width of the third gap.

[0023] Optionally, two adjacent battery pieces along the second direction are a first battery piece and a second battery piece, the main grid on the first battery piece close to the second battery piece is a first main grid, and the main grid on the second battery piece close to the first battery piece is a second main grid; the distance from the first main grid to the edge of the first battery piece is not equal to the distance from the second main grid to the edge of the second battery piece.

[0024] Optionally, the material of the fine grid is a base metal; and / or, the material of the main grid is a base metal.

[0025] In the embodiments of the present application, by laying a plurality of battery pieces on the conductive back plate, the conductive interconnection of the plurality of battery pieces can be realized by using the conductive layer in the conductive back plate, and the insulating layer is arranged to separate the conductive layer and the battery piece. The battery piece is provided with a plurality of fine grids arranged in the second direction. Then, the main grid is arranged in the edge area of the battery piece, the main grid extends in the second direction and is connected with the fine grid of the same conductive type, and the main grid is not arranged in the middle area of the battery piece. In order to electrically connect the conductive structure on the main grid with the conductive layer through the opening structure in the insulating layer in the edge area, and the conductive structure on the connecting part of the grid line directly with the conductive layer in the conductive back plate through the opening structure in the insulating layer in the middle area. By arranging the main grid in the edge area of the battery piece, the main grid is connected with the fine grid in the edge area and the conductive layer. Since the main grid is a through structure and relatively thick, it can better resist the erosion of water vapor, thereby effectively slowing down the failure rate. Even if there is local connection failure, since the main grid is still in a through state, the charge carriers collected by the fine grid in the edge area can still be transmitted outward through the main grid, avoiding the problem that the charge carriers in the local area of the battery piece cannot be effectively collected and transmitted due to local connection failure.

[0026] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiment description, wherein:

[0028] Figure 1 is a schematic view of a photovoltaic module according to an embodiment of the present application;

[0029] Figure 2 is a schematic view of a battery piece according to an embodiment of the present application;

[0030] Figure 3 is a schematic view of a battery piece according to an embodiment of the present application;

[0031] Figure 4 is a schematic view of another battery piece according to an embodiment of the present application;

[0032] Figure 5 is a schematic view of a battery piece according to an embodiment of the present application;

[0033] Figure 6 is a side sectional view of a photovoltaic module according to an embodiment of the present application;

[0034] Figure 7 is a schematic diagram of an opening structure of an insulating layer in a conductive backsheet according to an embodiment of the present application;

[0035] Figure 8 is a schematic diagram of another opening structure of an insulating layer in a conductive backsheet according to an embodiment of the present application;

[0036] Figure 9 is a schematic diagram of a conductive layer according to an embodiment of the present application;

[0037] Figure 10 is a schematic diagram of a cooperation structure of an edge main grid and a first insulating gap according to an embodiment of the present application;

[0038] Figure 11 is a schematic diagram of another cooperation structure of an edge main grid and a first insulating gap according to an embodiment of the present application;

[0039] Figure 12 is a schematic diagram of a connection structure of a main grid and a fine grid according to an embodiment of the present application;

[0040] Figure 13 is a schematic diagram of a conductive sheet according to an embodiment of the present application.

[0041] Reference signs:

[0042] 10: battery layer; 11: battery string; 111: battery sheet; A: middle area; B: edge area; 112: fine grid; 1121: connection part; 113: main grid; 1130: solder pad; 113a: edge main grid; 111a: first battery sheet; 113a: first main grid; 111b: second battery sheet; 113b: second main grid; 114: insulating glue; 115: conductive structure; 20: conductive backsheet; 21: conductive layer; 211: electrical connection part; 2111: conductive sheet; 2111a: base part; 2111B: electrode part; M1: first insulating gap; M2: second insulating gap; M3: third gap; 22: substrate; 23: glue film layer; 24: insulating layer; 241: opening structure; 2411: first through hole; 2412: second through hole; 30: encapsulation glue film; 40: front plate; X: first direction; Y: second direction. DETAILED DESCRIPTION

[0043] Embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0044] The terms "first", "second" in the specification and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0045] In the description of the present application, it should be understood that the 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 based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element 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 present application.

[0046] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] Before explaining the photovoltaic module provided by the embodiments of the present application, the application scenario of the photovoltaic module provided by the embodiments of the present application will be described in detail:

[0048] Back contact (BC) cell is a kind of solar cell which sets PN junction and grid line on the back surface of solar cell. This kind of solar cell has no grid line on the front surface, so as to increase the area of the cell for absorbing solar radiation, and improve the photoelectric conversion efficiency of the cell.

[0049] In a conventional solar cell, the grid lines (including main grid and fine grid) are usually made by high-temperature metallization process, that is, by printing high-temperature silver paste on the dielectric layer of the cell, and then by high-temperature sintering to make the paste penetrate the dielectric layer on the surface of the cell sheet and form a good ohmic connection with the lower doped semiconductor layer. Based on the overall cost reduction needs of the photovoltaic industry, the demand for replacing silver paste with other low-cost paste is increasing, among which, the use of low-cost base metal paste such as copper paste can greatly reduce the cost. However, due to the use of base metal paste to prepare grid lines, low-temperature metallization process is usually used, and the grid lines formed mainly rely on resin for bonding with the cell sheet substrate, unlike silver paste which can form a good silver-silicon interface with the cell sheet substrate. The bonding force between the base metal grid lines and the cell sheet substrate is relatively low, making the cell sheet sensitive to moisture and prone to local failure in a humid environment.

[0050] For base metal grid line cells, due to their poor resistance to heat and humidity, when external moisture penetrates into the photovoltaic module, it is easy to cause local connection failure of the grid lines on the cell, and the failure position is often located near the solder joints at the periphery of the cell sheet. Therefore, the embodiments of the present application provide a photovoltaic module to solve the problem of poor resistance to heat and humidity in the prior art.

[0051] The photovoltaic module provided by the embodiments of the present application will be described in detail below in combination with the drawings and specific embodiments and their application scenarios.

[0052] As shown in Figures 1 to 3 According to some embodiments of the present application, the photovoltaic module includes a conductive back sheet 20 and a cell layer 10 disposed on the conductive back sheet 20; the cell layer 10 includes a plurality of cell strings 11 arranged at intervals along a first direction X, the cell string 11 includes a plurality of cell sheets 111 arranged at intervals along a second direction Y, the first direction X is perpendicular to the second direction Y, and the cell sheet 111 includes a middle area A and an edge area B located on both sides of the middle area A along the first direction X; a plurality of fine grids 112 are arranged at intervals along the second direction Y on the cell sheet 111, the fine grid 112 extends along the first direction X, the edge area B is provided with a main grid 113, the main grid 113 extends along the second direction Y and overlaps with the fine grid 112 of the same conductive type, and the main grid 113 is insulated and separated from the fine grid 112 of the opposite conductive type; the part of the fine grid 112 located in the middle area A is provided with a plurality of connection parts 1121 arranged at intervals along the first direction X; the conductive back sheet 20 is provided with a patterned conductive layer 21 and an insulating layer 24 for spacing the conductive layer 21 and the cell sheet 111, the insulating layer 24 is provided with an opening structure 241, and the connection part 1121 of the main grid 113 and the fine grid 112 is provided with a conductive structure 115, the conductive structure 115 is electrically connected with the conductive layer 21 through the opening structure 241.

[0053] In the embodiment of the present application, by laying a plurality of battery pieces 111 on the conductive back plate 20, the conductive interconnection of the plurality of battery pieces 111 can be realized by using the conductive layer 21 in the conductive back plate 20, and the insulating layer 24 is arranged to separate the conductive layer 21 and the battery piece 111. The battery piece 111 is provided with a plurality of fine grids 112 arranged at intervals along the second direction Y, and a main grid 113 is arranged at the edge area B of the battery piece 111. The main grid 113 extends along the second direction Y and is connected with the fine grid 112 of the same conductive type. No main grid 113 is arranged in the middle area A of the battery piece 111, so that the conductive structure 115 on the main grid 113 in the edge area B is electrically connected with the conductive layer 21 through the opening structure 241 in the insulating layer 24, and the conductive structure 115 on the connecting part 1121 of the fine grid 112 in the middle area A is electrically connected with the conductive layer 21 in the conductive back plate 20 through the opening structure 241 in the insulating layer 24. By arranging the main grid 113 at the edge area B of the battery piece 111 and connecting the main grid 113 with the fine grid 112 in the edge area B and the conductive layer 21, the main grid 113 can better resist the erosion of water vapor due to its through structure and relatively thick thickness, thereby effectively slowing down the failure rate. Even if there is local connection failure, since the main grid 113 is still in a through state, the charge carriers collected by the fine grid 112 in the edge area B can still be transmitted outward through the main grid 113, avoiding the problem that the charge carriers in the local area of the battery piece 111 cannot be effectively collected and transmitted due to local connection failure.

[0054] In addition, by arranging the conductive back plate 20, the packaging and conductive interconnection of the battery piece 111 can be realized. Compared with the traditional solder ribbon photovoltaic module, the process of laying and soldering the solder ribbon is saved, and the production efficiency of the photovoltaic module can be improved. Moreover, by using the conductive back plate 20 to package the battery piece 111, since the conductive layer 21 in the conductive back plate 20 is water-tight, most of the water vapor can be prevented from penetrating into the photovoltaic module, thereby reducing the failure risk of the battery piece 111.

[0055] In some embodiments, the solar cell in the embodiment of the present application can be a back contact cell (BC cell). The grid lines of the back contact cell are arranged on the back surface. The back contact cell includes but is not limited to a back contact heterojunction solar cell (HBC cell), a back contact tunnel oxide passivated contact solar cell (TBC cell), a hybrid passivated back contact solar cell (HPBC cell), a back contact hybrid solar cell (HTBC cell), etc.

[0056] Since the grid lines of the BC battery are all arranged on the back surface, during the preparation of the photovoltaic module, a more optimal module packaging technology can be realized in combination with the conductive back plate 20. The conductive back plate 20 is provided with a patterned conductive layer 21, which can be made of conductive metal, such as copper foil. A plurality of battery pieces 111 are laid on the conductive back plate 20, and the patterned conductive layer 21 can realize the conductive interconnection between the plurality of battery pieces 111. Then, the bus bar is connected with the conductive layer 21 to lead the current generated by the battery pieces 111 out of the photovoltaic module. Compared with the conventional photovoltaic module using solder strips to connect the battery pieces 111 in series, the laying and welding process of the solder strips can be saved, the process flow can be simplified, the production efficiency can be improved, and the production cost can be reduced.

[0057] In some embodiments, as shown in Figure 6 The photovoltaic module includes a front plate 40, a conductive back plate 20, an encapsulation adhesive film 30, and a battery layer 10. The front plate 40 and the conductive back plate 20 are stacked, the encapsulation adhesive film 30 is arranged between the front plate 40 and the conductive back plate 20, and the battery layer 10 is embedded in the encapsulation adhesive film 30. The battery layer 10 is electrically connected with the conductive layer 21 in the conductive back plate 20.

[0058] The conductive back plate 20 includes a substrate 22, an adhesive film layer 23, a conductive layer 21, and an insulating layer 24 which are sequentially stacked. The adhesive film layer 23 is arranged on the surface of the substrate 22, the conductive layer 21 is arranged on the side of the adhesive film layer 23 away from the substrate 22, and the insulating layer 24 covers the conductive layer 21. The battery layer 10 includes a plurality of battery pieces 111, which can be laid on the surface of the insulating layer 24 away from the conductive layer 21. The back surface of the battery piece 111 is provided with a plurality of fine grids 112 arranged along the second direction Y, and a main grid 113 extending along the first direction X is arranged in the edge area B of the battery piece, so that the main grid 113 is electrically connected with the fine grid 112 in the edge area B. Part of the fine grid 112 in the middle area A is provided with a connecting portion 1121. As shown in Figure 5 and Figure 9 The conductive layer 21 is formed with a patterned conductive circuit, and the insulating layer 24 is provided with an opening structure 241. The opening structure 241 is provided with a conductive structure 115, and the conductive structure 115 penetrates the insulating layer 24. During the assembly of the photovoltaic module, a plurality of battery pieces 111 are laid on the conductive back plate 20. The connecting portion 1121 on the fine grid 112 and the main grid 113 are respectively electrically connected with the conductive circuit in the conductive layer 21 through the corresponding conductive structure 115. In this way, the series and / or parallel connection between the plurality of battery pieces 111 can be realized by using the conductive circuit in the conductive layer 21.

[0059] It should be noted that the patterned conductive layer 21 can be obtained by the following method: a whole metal foil is laid on the substrate 22, then a laser etching or the like is used to draw a separation pattern, and then the waste silk in the drawn area is removed to form an insulating gap, so as to obtain the patterned conductive layer 21. Alternatively, the patterned conductive layer 21 can also be obtained by the following method: the metal foil is cut into a plurality of separate electrically connected pieces with a predetermined shape, and then the plurality of electrically connected pieces are laid on the substrate 22 with a certain insulating gap between adjacent two electrically connected pieces, so as to form the patterned conductive layer 21. Of course, the processing technology of the conductive layer 21 in the conductive back plate 20 can be flexibly set according to actual needs, which is not limited herein.

[0060] The conductive structure 115 can be formed by using conductive glue, tin paste or the like conductive material, and the conductive structure 115 is arranged in the opening structure 241 of the insulating layer 24, so that the main grid 113 and the fine grid 112 can be electrically connected with the conductive layer 21 through the insulating layer 24. The conductive structure 115 can contain silver, copper, lead, bismuth, zinc, nickel or the like metal component, and the specific component of the conductive structure 115 is not limited herein.

[0061] In the present application, the conductive back plate 20 is used for packaging and conductive interconnection of the battery piece 111. During use of the photovoltaic module, when water vapor penetrates from the back of the photovoltaic module to the inside, the water vapor can only penetrate through the insulating gap in the conductive layer 21 to reach the surface of the battery piece 111, because the conductive layer 21 is water-proof. The insulating gap in the conductive layer 21 is relatively narrow, and the area ratio of the insulating gap to the whole back of the battery piece 111 is relatively small, for example, it can be controlled within 2.5% to 15%, so that the penetration amount of water vapor can be greatly limited, the failure risk of the battery piece 111 can be reduced, and the moisture resistance of the photovoltaic module can be improved.

[0062] Further, the inventors have found through research and analysis that, in the photovoltaic module packaged by the conductive back plate 20, when failure occurs due to water vapor erosion, it is usually located at the edge of the battery piece 111, especially the welding point near the interval between the adjacent two battery strings 11, which is more prone to failure. This is because, when the conductive layer 21 in the conductive back plate 20 is used to realize the conductive interconnection of the plurality of battery pieces 111, the insulating gap is arranged in the conductive layer 21 corresponding to the interval between the adjacent two battery strings, and the welding point of the fine grid 112 at the edge of the battery piece 111 is close to the insulating gap, so that this place becomes a weak point of failure. When water vapor penetrates from the insulating gap in the conductive layer 21 corresponding to the interval between the two battery strings 11, the distance of the water vapor flowing to the welding point at the edge of the battery piece 111 on both sides is short, so that the welding point at the edge of the battery piece 111 is more prone to failure.

[0063] Furthermore, for a single solar cell 111, the edges are more susceptible to stress and more prone to failure. This is because during the lamination process of a photovoltaic module, there are certain gaps between solar cells or between solar strings. These gaps are not filled with material equivalent to the thickness of the solar cell. During lamination, the adhesive film is squeezed and flows to fill these gaps. Since the gaps between solar strings 11 correspond to the insulating gaps in the conductive layer 21, the total height at the locations between solar strings 11 is equivalent to a deficiency of the thickness of the conductive layer 21 plus the thickness of the solar cell 111. Therefore, in high-temperature environments or environments subject to thermal shock, the solar cells 111 inside the photovoltaic module will exhibit a certain degree of bending due to the creep and shrinkage of the adhesive film material, resulting in stress concentration at the edges of the solar cells 111. Meanwhile, since the conductive layer 21 is welded to the grid lines on the solar cell 111 via conductive materials such as adhesive during the lamination process, the welding stress at the edge of the solar cell 111 is greater due to the flow of material at the edge of the solar cell 111 during lamination. Furthermore, when the solar cell 111 bends, the crystalline silicon cell itself is brittle, and under bending stress, the welding stress between the fine grid 112 at the edge of the solar cell 111 and the conductive layer 21 is superimposed, making the connection point between the fine grid 112 and the conductive layer 21 at the edge of the solar cell 111 more susceptible to stress.

[0064] Therefore, such as Figure 2 and Figure 3 As shown, in this application, along the arrangement direction of the battery string 11 (i.e., the first direction X), the back surface of the battery cell 111 is divided into a middle region A and an edge region B located on both sides of the middle region A. By setting a main grid 113 extending along the second direction Y in the edge region B, the main grid 113 is connected to the corresponding fine grid 112, and then the main grid 113 is electrically connected to the conductive layer 21 in the conductive backplate 20. Since the main grid 113 extends along the second direction Y and is electrically connected to multiple fine grids 112, on the one hand, the main grid 113 has a certain thickness and strong resistance to water vapor erosion; on the other hand, the main grid 113 is a continuous through structure, so even if a local connection fails, the main grid 113 can still maintain a continuous state and can still transmit the collected charge carriers to the conductive layer 21, thereby avoiding the problem of local failure. In this way, the resistance to damp heat in the edge region B of the battery cell 111 can be improved, and the risk of battery cell 111 failure can be reduced. In the middle zone A, no main grid 113 is provided. Instead, a connecting part 1121 is provided on the fine grid 112 to form an electrical connection with the conductive layer 21, thereby reducing the number of main grids 113. This facilitates the processing of photovoltaic modules and saves material costs.

[0065] It should be noted that the connecting portion 1121 can be formed by thickening or widening part of the positions of the fine grid 112, so as to increase the connection strength of the fine grid 112 and the conductive layer 21 at the connecting portion 1121. Alternatively, the connecting portion 1121 can also be a separately provided conductive connecting structure on the fine grid 112, so as to be connected and fixed with the conductive layer 21 by the connecting portion 1121. The specific structure of the connecting portion 1121 on the fine grid 112 can be flexibly set according to actual needs, which is not limited here.

[0066] It can be understood that the plurality of fine grids 112 on the battery piece 111 include a plurality of positive fine grids and a plurality of negative fine grids, and the positive fine grids and the negative fine grids are alternately arranged at intervals along the second direction Y. The main grid 113 located in the edge area B includes a positive main grid and a negative main grid, for example, the positive main grid is arranged at one side edge area B of the battery piece 111, and the negative main grid is arranged at the other side edge area B of the battery piece 111, and the positive main grid and the negative main grid both extend along the second direction Y; the positive main grid is connected with the plurality of positive fine grids, and the positive main grid and the negative fine grid are insulated and separated; and the negative main grid is connected with the plurality of negative fine grids, and the negative main grid and the positive fine grid are insulated and separated.

[0067] As shown in Figure 12 , the insulating glue 114 can be arranged between the main grid 113 and the fine grid 112 of the opposite conductive type, so as to realize the insulation and separation between the main grid 113 and the fine grid 112 of the opposite conductive type. Alternatively, the main grid 113 can be arranged to be disconnected at the intersection with the fine grid 112 of the opposite conductive type, so as to realize the insulation and separation between the main grid 113 and the fine grid 112 of the opposite conductive type. The specific insulation and separation mode can be flexibly set according to actual needs, which is not limited here.

[0068] In some embodiments, as shown in Figure 12 , the main grid 113 in the present application is provided as a suspended main grid structure, that is, the main grid 113 is arranged on the side away from the battery piece 111 of the fine grid 112 and extends along the second direction Y, the main grid 113 is connected with the fine grid 112 of the same conductive type, and the insulating glue 114 is arranged between the main grid 113 and the fine grid 112 of the opposite conductive type, so as to insulate and separate the main grid 113 and the fine grid 112 of the opposite conductive type by the insulating glue 114, without the need to disconnect the fine grid 112 of the opposite conductive type and the main grid 113 at the intersection, so as to ensure that the fine grid 112 is in a continuous and through structure, which helps to improve the carrier collection capability of the fine grid 112 at different positions of the battery piece 111.

[0069] Specifically, the main grid 113 includes a positive main grid and a negative main grid. The positive main grid is connected to the side of the positive fine grid opposite to the solar cell 111, and an insulating adhesive 114 is provided between the positive main grid and the negative fine grid to provide insulation between them. Correspondingly, the negative main grid is connected to the side of the negative fine grid opposite to the solar cell 111, and an insulating adhesive 114 is provided between the negative main grid and the positive fine grid to provide insulation between them.

[0070] In some embodiments, the thickness of the main gate 113 is set to be greater than or equal to 15 μm. Preferably, the thickness of the main gate 113 is set to 15 μm-50 μm. By setting the thickness of the main gate 113 to be greater than or equal to 15 μm, a certain thickness is ensured for the main gate 113, thereby improving its resistance to moisture erosion and reducing the risk of connection failure of the main gate 113 in humid and hot environments.

[0071] In other embodiments, such as Figure 2 As shown, one to four main grids 113 can be provided in the edge region B on each side of the solar cell 111. For example, the number of main grids 113 in the edge region B is 1, 2, 3, or 4. Based on the foregoing analysis, the edge region B of the solar cell 111 is a weak point for failure. Therefore, in this application, one to four main grids 113 are provided in the edge region B on each side of the solar cell 111, so that the main grids 113 connect the corresponding fine grids 112 and the conductive layer 21. The main grids 113 can collect the charge carriers collected by the fine grids 112 and transfer them to the conductive layer 21. In this way, the resistance of the edge region B of the solar cell 111 to damp heat can be improved, and the problem of local failure at the edge of the solar cell 111 can be avoided. At the same time, the positive and negative fine grids are provided with multiple connecting parts 1121 in the middle region A. The positive and negative fine grids are electrically connected to the conductive layer 21 through the connecting parts 1121.

[0072] It should be noted that the number of main grids 113 located on both sides of the edge region B of the solar cell 111 can be the same or different. The conductivity type of the main grids 113 and the specific connection structure between the main grids 113 and the fine grids 112 can be flexibly set according to the specific structural design of the photovoltaic module, and are not limited here.

[0073] In some embodiments, the fine grid 112 and the main grid 113 in this application may be made of a base metal material. By using a base metal material to make the fine grid 112 and / or the main grid 113, the material cost of fabricating the grid lines can be reduced, thereby reducing the manufacturing cost of the photovoltaic module.

[0074] It can be understood that the base metal here mainly refers to a metal material not containing silver, gold and platinum. Exemplarily, the base metal material includes one or a combination of two or more of copper, aluminum, sodium, calcium, magnesium, nickel, copper, tungsten, zinc and the like. Compared with noble metals such as silver, gold and platinum, the base metal is relatively common in industrial production and has a lower price. Therefore, the fine grid 112 and / or the main grid 113 are made of a base metal material, which can reduce the material cost of the grid line (including the fine grid 112 and the main grid 113) compared with the traditional silver paste grid line, thereby reducing the production cost of the photovoltaic module.

[0075] In addition, compared with the traditional silver paste grid line, the base metal paste is used to prepare the grid line, which not only can reduce the material cost, but also belongs to a non-burn-through type paste. The low-temperature metallization process can be used to realize the forming processing of the grid line under low-temperature conditions (lower than 300 DEG C, such as about 200 DEG C), without the need for high-temperature furnace sintering, which can reduce the process complexity, facilitate the processing and preparation of the grid line, and also can reduce the heat influence brought into the cell.

[0076] Optionally, as shown in Figure 4 and Figure 5 It is shown that the main grid 113 is provided with a plurality of pads 1130 arranged at intervals along the second direction Y, and the conductive structure 115 is arranged on the pad 1130.

[0077] In the embodiment of the application, the plurality of pads 1130 arranged at intervals along the second direction Y are arranged on the main grid 113, and the conductive structure 115 is arranged on the pad 1130, so that the main grid 113 forms an electrical connection with the conductive layer 21 through the pad 1130 and the conductive structure 115. Since the surface area of the pad 1130 is relatively larger, more conductive material can be arranged on the pad 1130 to form the conductive structure 115 for connecting with the conductive layer 21, so as to improve the connection reliability of the main grid 113 and the conductive layer 21.

[0078] Optionally, as shown in Figure 7 It is shown that the opening structure 241 includes a first through hole 2411 arranged in the insulating layer 24 corresponding to the edge area B, and a second through hole 2412 arranged in the insulating layer 24 corresponding to the middle area A. The first through hole 2411 is provided with a plurality of first through holes 2411 arranged at intervals along the second direction Y. The conductive structure 115 on the main grid 113 passes through the first through hole 2411 to be electrically connected with the conductive layer 21. The second through hole 2412 is a strip-shaped hole extending along the second direction Y. The conductive structure 115 on the connecting part 1121 passes through the second through hole 2412 to be electrically connected with the conductive layer 21.

[0079] In the embodiment of the present application, the first through holes 2411 are arranged in the part of the insulating layer 24 corresponding to the edge area B, so that the plurality of conductive structures 115 on the main grid 113 are respectively connected to the conductive layer 21 through the corresponding first through holes 2411, and the first through holes 2411 are arranged in the part of the insulating layer 24 corresponding to the middle area A and are arranged as strip-shaped holes, so that the conductive structures 115 on the connecting part 1121 of the fine grid 112 in the middle area A are connected to the conductive layer 21 through the second through holes 2412. In this way, while meeting the connection requirements of the main grid 113 and the fine grid 112 to the conductive layer 21, the waste amount of the insulating layer 24 can be reduced, so that the structural strength of the insulating layer 24 corresponding to the edge area B is greater and is less likely to be deformed.

[0080] In some embodiments, the positions and number of the first through holes 2411 can correspond to the positions and number of the pads 1130 on the main grid 113, the first through holes 2411 can be arranged as regular-shaped hole structures such as circular holes, elliptical holes, polygonal holes, etc., or other irregular-shaped hole structures, and the shape of the first through holes 2411 is not limited.

[0081] It should be noted that the second through holes 2412 are arranged as strip-shaped holes, the strip-shaped holes simultaneously span a plurality of fine grids 112, the plurality of fine grids 112 include two kinds of grid lines with opposite conductive types, and then the conductive structures 115 are arranged between the conductive layer 21 and the fine grid 112 with the same conductive type in the second through holes 2412, and the insulating glue 114 is arranged between the conductive layer 21 and the fine grid 112 with the opposite conductive type for insulation and isolation, and the specific arrangement structure can be flexibly arranged according to actual needs, which is not limited here.

[0082] Optionally, as shown in Figure 2 and Figure 3 , the conductive structure 115 is arranged at the intersection of the main grid 113 and the fine grid 112 with the same conductive type.

[0083] In the embodiment of the present application, the conductive structure 115 is arranged at the intersection of the main grid 113 and the fine grid 112 with the same conductive type, so that the conductive structure 115 realizes the electrical connection of the main grid 113 and the conductive layer 21 through the insulating layer 24, and arranging the conductive structure 115 at the intersection of the main grid 113 and the fine grid 112 with the same conductive type can avoid the problem of broken grid at the intersection of the main grid 113 and the fine grid 112, and at the same time, using this structure can increase the number of connection points of the main grid 113 and the conductive layer 21, thereby improving the connection performance and reducing the power loss.

[0084] It should be noted that the intersection refers to the position where the main grid 113 and the fine grid 112 with the same conductive type intersect with each other.

[0085] Optionally, as shown inFigure 8 As shown, the opening structure 241 includes a first through hole 2411 arranged in the insulating layer 24 corresponding to the edge region B, and a second through hole 2412 arranged in the insulating layer 24 corresponding to the middle region A, the first through hole 2411 and the second through hole 2412 are both strip-shaped holes extending along the second direction Y, the conductive structure 115 on the main grid 113 is electrically connected with the conductive layer 21 through the first through hole 2411, and the conductive structure 115 on the fine grid 112 is electrically connected with the conductive layer 21 through the second through hole 2412.

[0086] In the embodiment of the present application, the opening structure 241 corresponding to the edge region B and the middle region A in the insulating layer 24 is arranged as a strip-shaped hole, so that the opening modes of the opening structure 241 in the conductive layer 21 are consistent, thereby facilitating actual opening processing, and thus the processing efficiency can be improved.

[0087] Optionally, as shown, Figure 3 The main grid 113 located at the most edge of the battery piece 111 along the first direction X is arranged as an edge main grid 113a, and the distance between the edge main grid 113a and the edge of the adjacent battery piece 111 is D1, which satisfies: 3mm≤D1≤10mm.

[0088] In the embodiment of the present application, when the water vapor seeps into the inside of the photovoltaic module from the insulating gap between the two battery strings 11 in the conductive layer 21 (i.e., the first insulating gap M1 described in the above), Figure 9 the water vapor will diffuse from the insulating gap to the edge region B of the battery piece 111 on both sides. In the embodiment of the present application, the distance between the edge main grid 113a and the edge of the adjacent battery piece 111 is greater than or equal to 3mm, so as to ensure that there is a certain distance between the edge main grid 113a and the edge of the battery piece 111, thereby increasing the diffusion distance of the water vapor from the first insulating gap M1 in the conductive layer 21 to the edge main grid 113a on both sides of the battery piece 111, and further slowing down the failure rate of the battery piece 111 at the edge main grid 113a. Further, the distance between the edge main grid 113a and the edge of the battery piece 111 is less than or equal to 10mm, so as to ensure the collection ability of the edge main grid 113a to the carriers in the edge region B of the battery piece 111, reduce the loss of the carriers collected by the fine grid 112 in the edge region B during the transmission to the main grid 113, and also reduce the interference of the connection structure of the main grid 113 to the part of the fine grid 112 in the middle region A and the conductive layer 21.

[0089] It should be noted that the distance D1 refers to the minimum straight line distance between the edge main grid 113a and the edge of the adjacent battery piece 111 along the first direction X, which can be obtained by measuring the straight line distance from the center point of the edge main grid 113a to the side edge of the battery piece 111, and selecting the minimum value from a plurality of measurement values as the final measurement of the distance D1.

[0090] Specifically, the distance D1 can be set as 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, or any value or range between any two values.

[0091] Optionally, as shown in FIG. 1B, the distance between the edge main grid 113a and the edge of the battery sheet 111 is D1, and the distance between the edge main grid 113a and the adjacent main grid 113 or the adjacent connecting part 1121 is D3. Figure 3 As shown in FIG. 1B, along the first direction X, the distance between the edge main grid 113 (i.e., the edge main grid 113a) of the battery sheet 111 and the edge of the battery sheet 111 is D1, and the distance between the adjacent two connecting parts 1121 in the middle area A along the first direction X is D2, satisfying D1

[0092] In the embodiments of the present application, the distance D1 between the edge main grid 113a and the edge of the battery sheet 111 is less than the distance D2 between the adjacent two connecting parts 1121 in the middle area A along the first direction X, so as to reduce the loss of the carriers collected by the fine grid 112 part of the edge area B in the transmission process to the main grid 113, while facilitating the reasonable layout of the connecting parts 1121 on the fine grid 112 in the middle area A, thereby improving the anti-humid heat capability of the battery sheet 111 and ensuring the conversion efficiency of the battery sheet 111.

[0093] Optionally, as shown in FIG. 1B, the distance between the edge main grid 113a and the edge of the battery sheet 111 is D1, and the distance between the edge main grid 113a and the adjacent main grid 113 or the adjacent connecting part 1121 is D3. Figure 3 As shown in FIG. 1B, the distance between the edge main grid 113a and the edge of the battery sheet 111 is D1, and the distance between the edge main grid 113a and the adjacent main grid 113 or the adjacent connecting part 1121 is D3.

[0094] It can be understood that when the battery sheet 111 without main grid 113 is connected with the conductive layer 21 in the conductive back plate 20, the connecting parts 1121 on the fine grid 112 are uniformly arranged, whether in the edge area B or the middle area A of the battery sheet 111, and the distance between any two adjacent connecting parts 1121 along the first direction X is equal, so as to ensure the uniformity of the current transmission at different positions on the battery sheet 111.

[0095] In the embodiments of the present application, the main grid 113 is arranged in the edge area B of the battery sheet 111, and the distance D3 between the edge main grid 113a and the adjacent main grid 113 or the adjacent connecting part 1121 is less than the distance D2 between the adjacent two connecting parts 1121 in the middle area A along the first direction X, which is equivalent to moving the position of the main grid 113 in the edge area B towards the middle area A of the battery sheet 111, so as to increase the distance between the edge main grid 113a and the edge of the battery sheet 111, and further increase the diffusion distance of the water vapor from the first insulating gap M1 of the conductive layer 21 to the edge main grid 113a, thereby slowing down the failure rate at the edge main grid 113a.

[0096] When two main grids 113 are arranged in the edge area B, the distance D3 refers to the interval between the two main grids 113 along the first direction X; when one main grid 113 is arranged in the edge area B, the distance D3 refers to the interval between the main grid 113 and the adjacent connecting part 1121 along the first direction X.

[0097] It should be noted that the interval between any two adjacent connecting parts 1121 in the middle area A along the first direction X can be equal or unequal, and can be flexibly set according to actual needs. When the interval between any two adjacent connecting parts 1121 in the middle area A along the first direction X is unequal, the distance D2 in the above embodiment refers to the minimum interval between any two adjacent connecting parts 1121 along the first direction X.

[0098] Optionally, as shown in Figure 9 The conductive layer 21 includes a plurality of electric connecting parts 211 arranged along the first direction X, each electric connecting part corresponding to one battery string 11. The electric connecting part 211 includes a plurality of conductive pieces 2111 arranged at intervals along the second direction Y, and the conductive pieces 2111 are used to connect the battery pieces 111 adjacent along the second direction Y in series. Adjacent two conductive pieces 2111 are in a plug-in structure. There is a first insulating gap M1 between adjacent two electric connecting parts 211, and a second insulating gap M2 between adjacent conductive pieces 2111. The width of the first insulating gap M1 is smaller than the width of the second insulating gap M2.

[0099] As shown in Figure 9 In the conductive back plate 20, the conductive layer 21 is arranged by a plurality of conductive pieces 2111, and the plurality of conductive pieces 2111 are arranged at intervals along the second direction Y to form the electric connecting part 211. The conductive layer 21 has a plurality of electric connecting parts 211 arranged at intervals along the first direction X, each electric connecting part 211 corresponding to one battery string 11 in the battery layer 10. There is a first insulating gap M1 between adjacent two electric connecting parts 211 along the first direction X. Adjacent two conductive pieces 2111 are in a plug-in structure along the second direction Y, and the adjacent two conductive pieces 2111 are separated by a second insulating gap M2. The first insulating gap M1 and the second insulating gap M2 can be a hollow structure formed in the conductive layer 21.

[0100] It is understandable that the first insulation gap M1 corresponds to the position between two adjacent battery strings 11. Therefore, by setting the width of the first insulation gap M1 to be smaller than the width of the second insulation gap M2, that is, by reducing the width of the first insulation gap M1 in the conductive layer 21 corresponding to the position between two adjacent battery strings 11, and the arrangement position of the two adjacent battery strings 11 is fixed, when the width of the first insulation gap M1 is reduced, it can increase the difficulty of water vapor passing through the first insulation gap M1, and also increase the distance from the edge main grid 113a to the first insulation gap M1. When water vapor seeps in from the back of the photovoltaic module through the first insulation gap M1, it can increase the diffusion distance of water vapor from the first insulation gap M1 to the two edge main grids 113a, thereby slowing down the failure rate at the edge main grid 113a on the upper edge of the battery cell 111.

[0101] In addition, such as Figure 9 As shown, in the conductive layer 21, the first insulating gap M1 has a straight-line extending hollow structure, and the second insulating gap M2 has a curved extending hollow structure. In the patterning process of the conductive layer 21, whether the waste wire is removed by engraving or the pattern is spliced, the processing difficulty of the first insulating gap M1 is less than that of the second insulating gap M2, and the precision requirement is lower. Therefore, in this application, by setting the width of the first insulating gap M1 to be smaller than the width of the second insulating gap M2, it is also convenient for actual processing.

[0102] It should be noted that, as Figure 9 As shown, the first insulating gap M1 in the conductive layer 21 does not penetrate the entire conductive layer 21 along the second direction Y. At the end of the conductive layer 21 along the second direction Y, two adjacent conductive sheets 2111 along the first direction X are at least partially connected. For example, in Figure 9 At position C, the two conductive plates 2111 are connected to each other so that the two adjacent battery strings 11 can be connected in series through the two interconnected conductive plates 2111.

[0103] In some embodiments, such as Figure 13 As shown, the conductive sheet 2111 includes a base 2111a and an electrode portion 2111b extending from one or both sides of the base along the second direction Y. Multiple electrode portions 2111b are provided, and the multiple electrode portions 2111b are arranged at intervals along the first direction X. The electrode portions 2111b of two adjacent conductive sheets 2111 are connected in an interlocking finger structure. Each battery cell 111 is electrically connected to two adjacent conductive sheets 2111. The electrode portion 2111b of one conductive sheet 2111 is electrically connected to the positive electrode grid on the battery cell 111, and the electrode portion 2111b of the other conductive sheet 2111 is electrically connected to the negative electrode main grid on the battery cell 111.

[0104] Optionally, such as Figure 10As shown, the width of the first insulation gap M1 is L0, which satisfies: 0.3mm≤L0≤1.5mm. By setting the reasonable value range of the width L0 of the first insulation gap M1, it can be ensured that the two adjacent conductive pieces 2111 in the first direction X can be insulated and isolated by the first insulation gap M1, and at the same time, the width L0 is controlled to be less than or equal to 1.5mm, so as to increase the diffusion distance of the water vapor from the first insulation gap M1 to the edge area B of the two adjacent battery pieces 111, thereby helping to slow down the connection failure rate of the edge main grid 113a of the battery piece 111.

[0105] For example, the width L0 of the first insulation gap M1 can be set to: 0.3mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, etc. or a range between any two values.

[0106] In some embodiments, the first insulation gap M1 can overlap with the gap between the adjacent two battery strings 11, that is, the first insulation gap M1 falls in the blank area between the adjacent two battery strings 11. Alternatively, the first insulation gap M1 can also be offset to one side of the battery string 11, that is, the first insulation gap M1 is offset to one of the adjacent two battery strings 11, so that the first insulation gap M1 overlaps with the edge area B of the battery piece 111 on one side in the first direction X. The specific setting position of the first insulation gap M1 can be flexibly set according to actual needs, which is not limited here.

[0107] Optionally, as shown in Figure 10 There is a third gap M3 between the two adjacent battery strings 11 in the first direction X, and the width L0 of the first insulation gap M1 is less than the width L3 of the third gap M3.

[0108] In the embodiments of the present application, by setting the width L0 of the first insulation gap M1 to be less than the width L3 of the third gap M3, the width of the first insulation gap M1 is reduced under the premise of meeting the patterning design requirements of the conductive layer 21, thereby the effective conductive area of the conductive layer 21 can be increased, so as to reduce the resistance and the transmission loss of the current; at the same time, the diffusion distance of the water vapor from the first insulation gap M1 to the edge area B of the two adjacent battery pieces 111 can also be increased.

[0109] Optionally, as shown in Figure 10 The main grid 113 at the edge of the battery piece 111 is set as the edge main grid 113a, the distance between the edge main grid 113a and the nearest first insulation gap M1 in the first direction X is L1, and the distance between the edge main grid 113a and the nearest second insulation gap M2 in the first direction X is L2, which satisfies: L1>L2.

[0110] In the embodiments of the present application, the distance L1 between the edge main grid 113a and the nearest first insulating gap M1 is less than the distance L2 between the edge main grid 113a and the nearest second insulating gap M2, that is, by increasing the distance between the edge main grid 113a on the cell sheet 111 and the first insulating gap M1, the diffusion distance of the water vapor from the first insulating gap M1 to the edge main grid 113a is increased, thereby helping to slow down the failure rate at the edge main grid 113a on the cell sheet 111.

[0111] In some embodiments, as shown in Figure 10 the distance L1 between the edge main grid 113a and the nearest first insulating gap M1 along the first direction X satisfies: 3mm≤L1≤12mm.

[0112] In the embodiments of the present application, the distance L1 between the edge main grid 113a and the nearest first insulating gap M1 is greater than or equal to 3mm, so as to ensure that there is a certain distance between the edge main grid 113a and the first insulating gap M1, thereby increasing the diffusion distance of the water vapor from the first insulating gap M1 to the edge main grid 113a. At the same time, the edge main grid 113a is mainly used to collect carriers in the edge area B of the cell sheet 111, and if the distance L1 is too large, the edge main grid 113a is relatively far from the edge of the cell sheet 111, which will affect the collection of carriers in the edge area B of the cell sheet 111 by the edge main grid 113a. Therefore, by setting the distance L1 to be less than or equal to 12mm, the carrier collection capability of the edge main grid 113a for the edge area B of the cell sheet 111 is considered, thereby ensuring the conversion efficiency of the photovoltaic module.

[0113] Specifically, the distance L1 between the edge main grid 113a and the nearest first insulating gap M1 along the first direction X can be set to: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, etc.

[0114] It should be noted that the distance between the edge main grid 113a and the first insulating gap M1 can be measured by measuring the straight line distance between the center point of the edge main grid 113a and the side wall of the first insulating gap M1 close to the edge main grid 113a, and the minimum value is taken as the distance L1.

[0115] In some embodiments, as shown in Figure 10 the ratio L1 / L2 of the distance L1 between the edge main grid 113a and the nearest first insulating gap M1 along the first direction X to the distance L2 between the edge main grid 113a and the nearest second insulating gap M2 along the first direction X satisfies: 1

[0116] In this embodiment of the application, by setting the ratio of the spacing L1 to the spacing L2, L1 / L2, to be greater than 1 and less than or equal to 20, it can both increase the diffusion distance of water vapor from the first insulating gap M1 to the edge main grid 113a and ensure that there is a certain distance between the edge main grid 113a and the nearest second insulating gap M2, so as to avoid short-circuiting of the edge main grid 113a.

[0117] Specifically, the ratio L1 / L2 can be set to: 1.1, 1.5, 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, etc.

[0118] Among them, such as Figure 10 As shown, the distance L2 between the edge main gate 113a and the nearest second insulating gap M2 along the first direction X is in the range of 0.5mm-8mm. For example, the distance L2 can be set to 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, etc. By setting the distance L2 to 0.5mm-8mm, a certain gap can be ensured between the edge main gate 113a and the nearest second insulating gap M2, avoiding short circuit between the edge main gate 113a and the conductive sheet 2111 of the opposite conductivity type in the conductive layer 21. At the same time, by controlling the distance from the edge main gate to the nearest second insulating gap M2, more space can be reserved between the edge main gate 113a and the first insulating gap M1.

[0119] Optionally, such as Figure 11 As shown, two adjacent battery cells 111 along the second direction Y are respectively the first battery cell 111a and the second battery cell 111b. The main grid 113 on the first battery cell 111a that is close to the second battery cell 111b is the first main grid 113a, and the main grid 113 on the second battery cell 111b that is close to the first battery cell 111a is the second main grid 113b. The distance from the first main grid 113a to the edge of the first battery cell 111a is not equal to the distance from the second main grid 113b to the edge of the second battery cell 111b.

[0120] In this embodiment, by setting the distance from the first main grid 113a to the edge of the first battery cell 111a to be unequal to the distance from the second main grid 113b to the edge of the second battery cell 111b, that is, by setting one of the distances of the first main grid 113a and the second main grid 113b to the edge distance of the corresponding battery cell 111, the spacing between the first main grid 113a and the second main grid 113b can be increased. The first insulating gap M1 is located between the first main grid 113a and the second main grid 113b. When the spacing between the first main grid 113a and the second main grid 113b is increased, the diffusion distance of water vapor from the first insulating gap M1 to the first main grid 113a and the second main grid 113b can be increased.

[0121] Specifically, the distance from the first busbar 113a to the edge of the first cell piece 111a can be set to be greater than the distance from the second busbar 113b to the edge of the second cell piece 111b, that is, the first busbar 113a is offset to the middle area A of the first cell piece 111a, and the distance between the first busbar 113a and the second busbar 113b can be increased accordingly. The first insulating gap M1 in the conductive layer 21 can be offset to the first cell piece 111a, and the distance from the first busbar 113a to the first insulating gap M1 can be increased, so that the diffusion distance of the water vapor from the first insulating gap M1 to the first busbar 113a can be increased.

[0122] Similarly, the distance from the first busbar 113a to the edge of the first cell piece 111a can also be set to be less than the distance from the second busbar 113b to the edge of the second cell piece 111b, which will not be described here.

[0123] In addition, in the present application, the distance from the first busbar 113a to the edge of the first cell piece 111a is set to be different from the distance from the second busbar 113b to the edge of the second cell piece 111b, so as to reduce the failure rate of the cell piece 111 edge while facilitating the flexible layout of the plurality of cell pieces 111 in the battery layer 10.

[0124] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0125] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A photovoltaic module, characterized in that, include: A conductive backsheet and a battery layer disposed on the conductive backsheet; the battery layer includes a plurality of battery strings spaced apart along a first direction, the battery strings include a plurality of battery cells spaced apart along a second direction, the first direction being perpendicular to the second direction, and the battery cells including a central region and edge regions located on both sides of the central region along the first direction. The battery cell has a plurality of fine grids spaced apart along the second direction, the fine grids extending along the first direction, the edge region has a main grid, the main grid extends along the second direction and overlaps with the fine grids of the same conductivity type, and the main grid is insulated from the fine grids of the opposite conductivity type; the portion of the fine grid located in the middle region has a plurality of connecting portions spaced apart along the first direction; the conductive backplate has a patterned conductive layer and an insulating layer for separating the conductive layer from the battery cell, the insulating layer has an opening structure, and the connecting portions of the main grid and the fine grids are provided with conductive structures, the conductive structures passing through the opening structure and electrically connected to the conductive layer.

2. The photovoltaic module according to claim 1, characterized in that, The main gate is provided with a plurality of pads arranged at intervals along the second direction, and the conductive structure is provided on the pads.

3. The photovoltaic module according to claim 2, characterized in that, The opening structure includes a first through hole in the insulating layer corresponding to the edge region and a second through hole in the insulating layer corresponding to the middle region. There are multiple first through holes, which are arranged at intervals along the second direction. The conductive structure on the main gate passes through the first through hole and is electrically connected to the conductive layer. The second through hole is a strip-shaped hole extending along the second direction. The conductive structure on the connecting part passes through the second through hole and is electrically connected to the conductive layer.

4. The photovoltaic module according to claim 1, characterized in that, The conductive structure is located at the intersection of the main gate and the fine gate of the same conductivity type.

5. The photovoltaic module according to claim 4, characterized in that, The opening structure includes a first through hole in the insulating layer corresponding to the edge region and a second through hole in the insulating layer corresponding to the middle region. Both the first through hole and the second through hole are strip-shaped holes extending along the second direction. The conductive structure on the main gate passes through the first through hole and is electrically connected to the conductive layer, and the conductive structure on the fine gate passes through the second through hole and is electrically connected to the conductive layer.

6. The photovoltaic module according to any one of claims 1-5, characterized in that, Along the first direction, the distance between the main grid located at the outermost edge of the solar cell and the edge of the solar cell is D1, which satisfies: 3mm≤D1≤10mm; And / or, the number of main gates provided in each of the edge regions is 1-4.

7. The photovoltaic module according to any one of claims 1-5, characterized in that, Along the first direction, the distance between the main grid located at the outermost edge of the battery cell and the edge of the battery cell is D1, and the distance between two adjacent connecting portions along the first direction in the middle area is D2, satisfying: D1 < D2; And / or, along the first direction, the distance between the main grid located at the outermost edge of the battery cell and the adjacent main grid or the connecting portion is D3, and the distance between two adjacent connecting portions in the middle area along the first direction is D2, satisfying: D3 < D2.

8. The photovoltaic module according to any one of claims 1-5, characterized in that, An insulating layer is also provided between the main gate and the fine gate of the opposite conductivity type, and the thickness of the main gate is greater than or equal to 15 μm.

9. The photovoltaic module according to claim 1, characterized in that, The conductive layer includes a plurality of electrical connection portions spaced apart along the first direction, each electrical connection portion corresponding to one of the battery strings. The electrical connection portion includes a plurality of conductive sheets spaced apart along the second direction. The conductive sheets are used to connect adjacent battery cells in series along the second direction, and adjacent conductive sheets are fitted in an interlocking finger structure. A first insulating gap exists between two adjacent electrical connection portions, and a second insulating gap exists between adjacent conductive sheets. The width of the first insulating gap is smaller than the width of the second insulating gap.

10. The photovoltaic module according to claim 9, characterized in that, The width of the first insulation gap is L0, which satisfies: 0.3mm≤L0≤1.5mm.

11. The photovoltaic module according to claim 9, characterized in that, The main grid located at the outermost edge of the battery cell is designated as the edge main grid. The distance between the edge main grid and the nearest first insulating gap along the first direction is L1, and the distance between the edge main grid and the nearest second insulating gap along the first direction is L2, satisfying: L1 > L2.

12. The photovoltaic module according to claim 11, characterized in that, The spacing L1 between the nearest first insulating gap and the edge main grid along the first direction satisfies: 3mm≤L1≤12mm; And / or, the ratio L1 / L2 of the distance L1 between the edge main gate and the nearest first insulating gap along the first direction to the distance L2 between the edge main gate and the nearest second insulating gap along the first direction satisfies: 1 < L1 / L2 ≤ 20.

13. The photovoltaic module according to claim 9, characterized in that, A third gap exists between two adjacent battery strings along the first direction, and the width of the first insulating gap is smaller than the width of the third gap.

14. The photovoltaic module according to any one of claims 1-5, characterized in that, Two adjacent battery cells along the second direction are a first battery cell and a second battery cell, respectively. The main grid on the first battery cell that is closer to the second battery cell is the first main grid, and the main grid on the second battery cell that is closer to the first battery cell is the second main grid. The distance from the first main grid to the edge of the first battery cell is not equal to the distance from the second main grid to the edge of the second battery cell.

15. The photovoltaic module according to any one of claims 1-5, characterized in that, The fine grid is made of base metal; and / or the main grid is made of base metal.

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