Battery string and photovoltaic module

Abstract

A battery string and a photovoltaic module, belonging to the technical field of photovoltaic modules. The battery string comprises: battery cells; connecting lines, which are arranged on at least one surface of each battery cell, wherein the surface comprises a first edge and a second edge, the ends of the connecting lines close to the first edge extend beyond the surface, and the ends of the connecting lines close to the second edge are located inside the surface; and a first adhesive layer, which is laid on the sides of the connecting lines away from each battery cell, wherein the first adhesive layer is configured to fix the connecting lines to the surface of each battery cell, and covers the ends of the connecting lines close to the second edge. By means of fixing the connecting lines to the surface of each battery cell by means of the first adhesive layer, a higher efficiency and lower costs are achieved; and the connection and fixing between the connecting lines and the battery cells are realized at a relatively low temperature, such that a thermal impact is small, and thus the probability that the battery cells are subjected to microcracks, hot spots, etc. is low.

Description

Battery string and photovoltaic module

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on September 13, 2023, with application number 202322490402.1 and invention name “A battery string and photovoltaic module”, and the Chinese patent application filed with the Patent Office of China on September 26, 2023, with application number 202322627653.X and invention name “A multi-layer film photovoltaic module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of photovoltaic modules, and in particular to a battery string and a photovoltaic module. Background Art

[0003] PV panels are equipped with cell strings, the core components of which convert solar energy into electricity. A cell string typically consists of multiple cells spaced apart, with connecting wires connecting two adjacent cells in series to collect the current generated by the cells.

[0004] In the prior art, a connection wire is usually welded to the surface of a battery cell by welding to collect the current in the battery cell.

[0005] However, the existing method of welding the connecting wires to the surface of the battery cell has low welding efficiency and high welding cost. In addition, due to the high welding temperature, it is easy to cause defects such as hidden cracks and hot spots in the battery cell.

[0006] Summary of the Invention

[0007] The present application discloses a battery string and a photovoltaic module to solve or at least partially solve the problems existing in the prior art of welding connecting wires to the surface of battery cells, which have low welding efficiency, high welding costs, and defects such as hidden cracks and hot spots on the battery cells.

[0008] In order to solve the above technical problems, this application is implemented as follows:

[0009] In a first aspect, the present application discloses a battery string, comprising:

[0010] Battery cells;

[0011] a connecting wire disposed on at least one surface of the battery cell; the surface comprising a first edge and a second edge; the first edge and the second edge being opposite and parallel to each other and perpendicular to the extending direction of the battery string; an end of the connecting wire proximate the first edge extending outside the surface, and an end proximate the second edge being located inside the surface;

[0012] A first adhesive layer is laid on a side of the connecting wire away from the battery cell, and is used to fix the connecting wire to the surface of the battery cell; the first adhesive layer covers an end of the connecting wire close to the second edge.

[0013] Optionally, the orthographic projection of the first end portion of the first adhesive layer close to the second edge on a plane perpendicular to the direction in which the battery cells and the connecting wires are stacked is located inside the surface of the battery cells on which the connecting wires are provided;

[0014] One end of the connecting wire close to the second edge is located inside the surface of the battery cell where the connecting wire is provided;

[0015] The distance between the end of the connecting line close to the second edge and the second edge is d5;

[0016] The distance between the first end and the second edge is d3; d5>d3.

[0017] Optionally, the orthographic projection of the second end portion of the first adhesive layer close to the first edge on a plane perpendicular to the direction in which the battery cells and the connecting wires are stacked is located inside the surface of the battery cells on which the connecting wires are provided;

[0018] The distance between the second end and the first edge is d4; 1mm≤d4≤5mm.

[0019] Optionally, the surface further includes: a third edge and a fourth edge; the third edge and the fourth edge are opposite and parallel to each other, and are also parallel to the extension direction of the battery string;

[0020] The orthographic projections of the third end of the first adhesive layer close to the third edge and the fourth end of the first adhesive layer close to the fourth edge on a plane perpendicular to the direction in which the battery cells and the connecting wires are stacked are both located inside the surface of the battery cells on which the connecting wires are provided;

[0021] The distance between the third end and the third edge is d1, 0mm≤d1≤5mm;

[0022] A distance between the fourth end portion and the fourth edge is d2, 0 mm ≤ d2 ≤ 5 mm.

[0023] Optionally, both opposite surfaces of the cell have electrode patterns, 0mm≤d3≤3mm; or,

[0024] The cell is a back contact cell, with 1mm≤d3≤5mm.

[0025] Optionally, a distance between an end of the connecting line close to the second edge and the second edge is d5;

[0026] The cell is a back contact cell, d5>d4.

[0027] Optionally, the number of the connecting lines is greater than 1;

[0028] The first adhesive layer is arranged in strip shape, and the area between adjacent connection lines on the surface is at least partially exposed; or,

[0029] The first adhesive layer is arranged in a plane, and covers the area between adjacent connection lines on the surface.

[0030] Optionally, the first adhesive layer includes a pre-crosslinked polymer adhesive material layer.

[0031] Optionally, the pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer is greater than 40%; and / or,

[0032] The pre-crosslinked polymer adhesive material layer directly contacts the battery cell; and / or,

[0033] The pre-crosslinked polymer adhesive material layer includes at least one of an EVA layer, a POE layer and a PVB layer; and / or,

[0034] The first adhesive layer is a single-layer structure, and the first adhesive layer of the single-layer structure is an EVA layer; and / or,

[0035] The first adhesive layer is a multi-layer structure; and / or,

[0036] The first adhesive layer has a double-layer structure, and the first adhesive layer of the double-layer structure includes an EVA layer and a POE layer, wherein the EVA layer is arranged on a side of the first adhesive layer close to the battery cell so that the EVA layer directly contacts the battery cell.

[0037] Optionally, the connecting wire includes: a connecting wire base and a bonding layer attached to a surface of the connecting wire base, and the connecting wire is electrically connected to the battery cell through the bonding layer;

[0038] The melting point of the bonding layer is less than 165 degrees, and the bonding layer is one of a tin-lead-bismuth layer, a tin-bismuth-silver layer, or a tin-indium layer.

[0039] Optionally, a transparent oxide conductive layer is provided on the surface of the cell, and the bonding layer is partially connected to the transparent oxide conductive layer.

[0040] Optionally, the length of the battery cell is greater than or equal to 180 mm and less than or equal to 240 mm; the direction of the length is parallel to the first edge; and / or,

[0041] The battery cell includes a battery cell without a main grid.

[0042] In a second aspect, the present application discloses a photovoltaic module, comprising: a cover plate, a back plate, a second adhesive layer, and any one of the aforementioned battery strings, wherein:

[0043] The cover plate is bonded to the first adhesive layer via the second adhesive layer, and / or the back plate is bonded to the first adhesive layer via the second adhesive layer.

[0044] Optionally, the water vapor permeability of the first adhesive layer is greater than the water vapor permeability of the second adhesive layer.

[0045] Optionally, the battery cell has a rectangular structure, wherein the coverage area of ​​the second adhesive layer exceeds the edge of the first adhesive layer, and the coverage area of ​​the second adhesive layer exceeds the edge of the battery cell.

[0046] Optionally, the second adhesive layer is a single-layer structure; or,

[0047] The second adhesive layer is a multi-layer structure.

[0048] Optionally, when the first adhesive layer is a single-layer structure and the second adhesive layer is a multi-layer structure, the material of the layer of the second adhesive layer closest to the battery cell is the same as that of the first adhesive layer; or

[0049] In the case where the first adhesive layer is a multi-layer structure and the second adhesive layer is a single-layer structure, the material of the layer of the first adhesive layer closest to the second adhesive layer is the same as the material of the second adhesive layer; or

[0050] When the first adhesive layer is a multi-layer structure and the second adhesive layer is a multi-layer structure, the material of the layer of the first adhesive layer closest to the second adhesive layer is the same as the material of the layer of the second adhesive layer closest to the first adhesive layer.

[0051] Optionally, the second adhesive layer is a single-layer structure, and the second adhesive layer includes one of an EVA layer and a POE layer; or,

[0052] The second adhesive layer is a double-layer structure, and the double-layer structure includes an EVA layer and a POE layer stacked in sequence; or,

[0053] The second adhesive layer has a three-layer structure, and the three-layer structure includes an EVA layer, a POE layer and an EVA layer stacked in sequence.

[0054] Optionally, the height of the connecting line is greater than the thickness of the first adhesive layer; and the directions of the height and the thickness are both parallel to the stacking direction of the cover plate and the second adhesive layer.

[0055] The battery string disclosed in this application secures the connecting wires to the surface of the battery cell via a first adhesive layer. Compared to spot welding the connecting wires to the surface of the battery cell, the method of securing the connecting wires to the surface of the battery cell via the first adhesive layer in this application is more efficient and less costly. The connection and securing of the connecting wires to the battery cell is achieved at a lower temperature, resulting in less thermal impact and a lower probability of hidden cracks and hot spots on the battery cell. Furthermore, the first adhesive layer covers the end of the connecting wire near the second edge, allowing the connecting wire to be more securely secured to the surface of the battery cell.

[0056] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical aspects of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0058] FIG1 shows a structural schematic diagram 1 of a battery string according to an embodiment of the present application;

[0059] FIG2 shows a second structural diagram of the battery string described in an embodiment of the present application;

[0060] FIG3 shows a top view of the battery string according to an embodiment of the present application;

[0061] FIG4 shows a partial enlarged view AA of the battery string described in an embodiment of the present application;

[0062] FIG5 shows a second top view of the battery string according to an embodiment of the present application;

[0063] FIG6 shows a partial enlarged view BB of the battery string described in an embodiment of the present application;

[0064] FIG7 is a schematic structural diagram of a first photovoltaic module according to an embodiment of the present application;

[0065] FIG8 is a schematic structural diagram of a second photovoltaic module according to an embodiment of the present application;

[0066] FIG9 shows a cross-sectional view 1 of the photovoltaic module according to an embodiment of the present application;

[0067] FIG10 shows a second cross-sectional view of the photovoltaic module according to an embodiment of the present application;

[0068] FIG11 shows a third cross-sectional view of the photovoltaic module according to an embodiment of the present application;

[0069] FIG12 shows a top view of a photovoltaic module in another embodiment of the present application;

[0070] FIG13 shows a cross-sectional view of a photovoltaic module according to another embodiment of the present application.

[0071] Explanation of reference numerals: 10 - battery cell; 11 - first edge; 12 - second edge; 13 - third edge; 14 - fourth edge; 20 - connecting wire; 30 - first adhesive layer; 40 - cover plate; 50 - back plate; 60 - second adhesive layer; 70 - EVA layer; 80 - POE layer. Specific embodiments

[0072] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0073] As shown in Figures 1 to 6, the present application discloses a battery string, which includes: a battery cell 10 and a connecting wire 20 arranged on at least one surface of the battery cell 10; a first adhesive layer 30, which is laid on the side of the connecting wire 20 away from the battery cell 10, and the first adhesive layer 30 is used to fix the connecting wire 20 to the surface of the battery cell 10.

[0074] The solar cell 10 is used to absorb solar energy and convert it into electrical energy. A battery string typically includes multiple solar cells 10, which are arranged at intervals. A connecting wire 20 is provided on at least one surface of the solar cell 10, and two adjacent solar cells 10 are electrically connected via the connecting wire 20. Specifically, a portion of the connecting wire 20 can be laid on the surface of one solar cell 10, the connecting wire 20 can be extended to another adjacent solar cell 10, and another portion of the connecting wire 20 can be laid on the surface of another adjacent solar cell 10. In this way, the two adjacent solar cells 10 can be electrically connected together through the connecting wire 20 to collect the current generated by the two adjacent solar cells 10.

[0075] It should be noted that the connecting wire 20 in the embodiment of the present application is conductive. Specifically, the connecting wire 20 may be a soldering ribbon or any other type of connecting wire that can electrically connect two adjacent battery cells 10. The specific type of connecting wire 20 is not limited, and in actual use, technicians can select it as needed.

[0076] As shown in Figures 1 to 6, a first adhesive layer 30 is applied to the side of the connecting wire 20 away from the battery cell 10, and the connecting wire 20 is fixed to the surface of the battery cell 10 via the first adhesive layer 30 to secure the connecting wire 20. Compared to spot welding the connecting wire 20 to the surface of the battery cell 10, the method of fixing the connecting wire 20 to the surface of the battery cell 10 via the first adhesive layer 30 in this application is more efficient and less costly. Furthermore, there is no high welding temperature, so the thermal impact is minimal, and the probability of hidden cracks and hot spots in the battery cell is reduced.

[0077] It should be noted that during the processing of the battery string, after the first adhesive layer 30 is laid on the side of the connecting wire 20 away from the battery cell 10, the first adhesive layer 30 is adhered to the surface of the battery cell 10 through processes such as thermal curing or light curing, so that the connecting wire 20 can be fixed to the surface of the battery cell 10 through the first adhesive layer 30. At this time, the connecting wire 20 and the battery cell 10 are mainly in physical contact, and there are fewer locations for electrical contact. After lamination, the connecting wire 20 can be electrically connected to the surface of the battery cell 10. Even if processes such as thermal curing or light curing are used here, the temperature of processes such as thermal curing or light curing is significantly lower than the welding temperature. Compared with welding, this application still has less thermal impact, and the probability of hidden cracks, hot spots, etc. on the battery cell is small.

[0078] In addition, the first adhesive layer 30 in the embodiment of the present application is typically a transparent adhesive layer. Furthermore, the first adhesive layer 30 can have insulating properties, i.e., be an insulating adhesive layer, or it can have conductive properties, i.e., be a conductive adhesive layer. In the embodiment of the present application, there are no additional restrictions on the specific properties of the first adhesive layer 30. In actual use, technicians can select according to their needs.

[0079] The edge of the surface of the battery cell 10 on which the connecting wire 20 is provided refers to the boundary line or contour line of the surface. The extension direction of the battery string refers to the direction in which the individual battery cells in the battery string are arranged in sequence, or the direction in which the length of the battery string is located. In Figures 3 to 6, the extension direction of the battery string can be parallel to the extension direction of the connecting wire 20. As shown in Figures 3 and 5, the surface of the battery cell 10 on which the connecting wire 20 is provided includes: a first edge 11 and a second edge 12 arranged opposite to each other. The first edge 11 and the second edge 12 are opposite and parallel to each other and are also perpendicular to the extension direction of the battery string. The first edge 11 and the second edge 12 here are the contour line portions extending in the up-down direction. The end of the connecting wire 20 close to the first edge 11 extends outside the surface of the battery cell 10 on which the connecting wire 20 is provided, and the end of the connecting wire 20 close to the second edge 12 is located inside the battery cell 10 on which the connecting wire 20 is provided. It should be noted here that for a double-sided battery cell shown in Figure 3, the first edge 11 and the second edge 12 corresponding to each connecting wire 20 are the same. For a back-contact cell shown in FIG5 , the first edge 11 and second edge 12 corresponding to the connecting line 20 connecting the n-type gate line are different from those corresponding to the connecting line 20 connecting the p-type gate line. For example, in FIG5 , the marked first edge 11 and second edge 12 refer to the connecting line 20 whose end near the first edge 11 extends outside the surface and whose end near the second edge 12 is located inside the surface. In other words, in FIG5 , the marked first edge 11 and second edge 12 refer to the connecting line 20 whose left end is located inside the surface of the cell where the connecting line is provided and whose right end extends outside the surface where the connecting line is provided. In FIG5 , for the connecting line 20 whose left end extends outside the surface where the connecting line is provided and whose right end is located inside the surface where the connecting line is provided, the left side marked 12 is the first edge, and the right side marked 11 is the second edge.

[0080] 3 to 6 , the first adhesive layer 30 covers the end of the connecting wire 20 close to the second edge 12 . The first adhesive layer 30 can firmly fix the end of the connecting wire 20 close to the second edge, thereby more firmly fixing the connecting wire 20 to the surface of the battery cell 10 .

[0081] The direction in which the battery cells and the connecting wires are stacked is parallel to the thickness direction of the battery cells. Optionally, referring to Figures 3 to 6, the first end portion of the first adhesive layer 30 close to the second edge 12 refers to the end portion of the first adhesive layer 30 closest to the second edge 12. The first end portion of the first adhesive layer 30 close to the second edge 12, the orthographic projection on the plane perpendicular to the direction in which the battery cells 10 and the connecting wires 20 are stacked, is located inside the surface of the battery cell 10 where the connecting wires 20 are set, thereby avoiding the first adhesive layer 30 being too large, resulting in problems such as glue overflow during the lamination process of the photovoltaic module, resulting in defective photovoltaic modules. The end of the connecting wire 20 near the second edge 12 is located inside the surface of the battery cell 10 where the connecting wire 20 is provided. The distance between the end of the connecting wire 20 near the second edge 12 and the second edge 12 is d5. The distance between the first end of the first adhesive layer 30 near the second edge 12 and the second edge 12 is d3. d5>d3. The first adhesive layer 30 fully covers the end of the connecting wire 20 near the second edge 12. The first adhesive layer 30 can fully and firmly fix the end of the connecting wire 20 near the second edge, thereby more securely fixing the connecting wire 20 to the surface of the battery cell 10. The difference between d5 and d3 is not specifically limited herein.

[0082] Optionally, referring to Figures 3 to 6, the second end of the first adhesive layer 30 near the first edge 11 refers to the end of the first adhesive layer 30 closest to the second edge 12. The orthographic projection of the second end of the first adhesive layer 30 near the first edge 11, on a plane perpendicular to the direction in which the cells 10 and the connecting wires 20 are stacked, is located within the surface of the cell where the connecting wires are located. This prevents the first adhesive layer 30 from being too large, which could lead to problems such as adhesive overflow during the lamination process of the photovoltaic module and cause photovoltaic module defects. The distance d4 between the second end and the first edge 11 is 1mm≤d4≤5mm, and d4 is set to be greater than or equal to 1mm and less than or equal to 5mm to facilitate repair of the cell string if there is a problem with the cell string.

[0083] For example, d4 can be set to 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc. Of course, the above is only an example of d4 and is not intended to be limiting of this application. In actual production processes, technicians can set d4 to any value between greater than or equal to 1 mm and less than or equal to 5 mm.

[0084] Optionally, the surface of the cell where the connecting wires are provided further includes: a third edge 13 and a fourth edge 14. These third and fourth edges 13 and 14 are located between the first and second edges 11 and 12. These third and fourth edges 13 and 14 are opposite and parallel to each other and parallel to the direction in which the cell string extends. Here, the third and fourth edges 13 and 14 are the contour lines extending in the left-right direction. The orthographic projections of the third end of the first adhesive layer 30 near the third edge 13 and the fourth end of the first adhesive layer 30 near the fourth edge 14, on a plane perpendicular to the direction in which the cells and connecting wires 20 are stacked, are both located within the surface of the cell where the connecting wires are provided. This prevents the first adhesive layer 30 from being too large, which could lead to problems such as adhesive overflow during the lamination process of the photovoltaic module and cause photovoltaic module defects. The third end of the first adhesive layer 30 near the third edge 13 refers to the end of the first adhesive layer 30 closest to the third edge 13. The fourth end of the first adhesive layer 30 near the fourth edge 14 refers to the end of the first adhesive layer 30 closest to the fourth edge 14. The distance between the third end of the first adhesive layer 30 near the third edge 13 and the third edge 13 is d1, where 0 mm ≤ d1 ≤ 5 mm. The distance between the fourth end of the first adhesive layer 30 near the fourth edge 14 and the fourth edge 14 is d2, where 0 mm ≤ d2 ≤ 5 mm. Both d1 and d2 are set to be greater than or equal to 0 mm and less than or equal to 5 mm. This allows the first adhesive layer 30 to cover and secure the connecting wire 20 located near the third edge 13. Furthermore, the first adhesive layer 30 can cover and secure the connecting wire 20 located near the fourth edge 14.

[0085] Exemplarily, d1 can be set to 0mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc. d2 can be set to 0mm, 0.4mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc. It should be noted that d1 in the embodiment of the present application can be equal to d2 or unequal to d2. In this regard, the embodiment of the present application does not impose too many restrictions. In actual use, technicians can set it as needed. Among them, d1 and d2 should be less than half of the spacing distance between two adjacent connecting wires 20, and should both be greater than or equal to 1mm. This can prevent the edge of the first adhesive layer 30 from extending beyond the edge of the battery cell due to errors, and can reduce the twisting of the edge connecting wire 20.

[0086] Optionally, the coverage area of ​​the first adhesive layer 30 at least does not exceed the two third edges 13 and the fourth edge 14 of the battery cell 10 that are relatively arranged, so that the length of the first adhesive layer 30 is equivalent to or slightly shorter than the length of the battery string. Multiple battery cells 10 of a battery string are placed on one first adhesive layer 30, and the first adhesive layer 30 spans the battery cell spacing of the battery string, while the first adhesive layer 30 does not exceed the two opposite sides of the battery cell that are parallel to the extension direction of the corresponding battery string.

[0087] Alternatively, the coverage area of ​​the first adhesive layer 30 does not exceed the edge of the cell 10. In this case, the first adhesive layer 30 is only provided on the surface of the cell and not within the cell spacing or string spacing. That is, each cell 10 corresponds to a first adhesive layer 30, and the boundary of the first adhesive layer 30 is located within the boundaries of the cell 10.

[0088] Optionally, as shown in Figures 3 and 4 , the cell 10 in the embodiment of the present application has two opposing surfaces, namely, a first surface and a second surface disposed opposite each other, each of which has an electrode pattern. Here, one of the first surface and the second surface is a light-facing surface and the other is a light-reflecting surface. During normal operation of the cell, the surface that primarily receives light is the light-facing surface. Both opposing surfaces of the cell have electrode patterns, and the cell is a bifacial cell. The distance between the first end of the first adhesive layer 30 near the second edge 12 and the second edge 12 is d3, where 0 mm ≤ d3 ≤ 3 mm. As shown in Figures 3 and 4 , it can be understood that a portion of the connecting wire 20 in the present application connects to the first surface of one cell 10, while another portion passes through the gap between two adjacent cells 10 and connects to the second surface of another adjacent cell 10. In the embodiment of the present application, d3 is set to be greater than or equal to 0 mm and less than or equal to 3 mm. In this way, the first adhesive layer 30 can cover more connecting wires 20 along the extending direction of the connecting wires 20 , so as to more firmly connect the connecting wires 20 to the surface of the battery cell 10 .

[0089] Exemplarily, both opposite surfaces of the battery cell have electrode patterns, and d3 can be set to 0 mm, 0.4 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0090] Optionally, as shown in Figures 5 and 6, the cell 10 is a back-contact cell, meaning that the electrode patterns of the cell are all disposed on its backlight side. The distance between the first end portion of the first adhesive layer 30 near the second edge 12 and the second edge 12 is d3, where 1mm≤d3≤5mm. In other words, a portion of the connecting wire 20 is connected to the back side of one cell 10, and another portion is connected to the back side of another adjacent cell 10. For back-contact cells, d3 is set to be greater than or equal to 1mm and less than or equal to 5mm. This allows d3 to be equal to or nearly equal to d4, the distance between the edge of the first projection near the first edge 11 and the first edge 11, simplifying the process.

[0091] For example, for a back contact cell, d3 can be set to 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0092] Optionally, the distance between the end of the connecting wire 20 near the second edge 12 and the second edge 12 is d5, and the battery cell is a back-contact battery cell, d5>d4, and the first adhesive layer 30 is ensured to cover the end of the connecting wire 20 near the second edge 12, thereby more securely fixing the connecting wire 20 to the surface of the battery cell 10. The difference between d5 and d4 is not specifically limited here.

[0093] Optionally, referring to Figures 3 to 5 , the number of connecting wires on the surface of a cell where the connecting wires are provided is greater than one, that is, multiple connecting wires are provided. The first adhesive layer 30 is provided in a strip shape, and the area between adjacent connecting wires 20 on the surface of the cell where the connecting wires are provided is at least partially exposed, thereby reducing light blocking caused by the first adhesive layer 30. Alternatively, referring to Figures 3 to 5 , the first adhesive layer 30 is provided in a planar shape, and the first adhesive layer 30 covers the area between adjacent connecting wires 20 on the surface of the cell where the connecting wires are provided. This allows for the simultaneous fixing of multiple connecting wires, resulting in more efficient fixing of the connecting wires and easier alignment.

[0094] Optionally, in the case where the first adhesive layer 30 is arranged in a planar manner, the area of ​​the orthographic projection of the first adhesive layer 30 on a plane perpendicular to the direction in which the battery cell 10 and the connecting wire 20 are stacked accounts for 75% or more of the area of ​​the surface of the battery cell on which the connecting wire is arranged, so that the first adhesive layer 30 can cover a larger portion of the connecting wire 20, thereby fixing the connecting wire 20 more firmly to the surface of the battery cell 10, thereby avoiding the connection wire 20 from being offset during the processing of the battery string, thereby affecting the photoelectric conversion efficiency of the battery cell 10.

[0095] Optionally, in the case where the first adhesive layer 30 is provided in a planar manner, the area of ​​the orthographic projection of the first adhesive layer 30 on a plane perpendicular to the direction in which the battery cells 10 and the connecting wires 20 are stacked accounts for less than 95% of the area of ​​the surface of the battery cells on which the connecting wires are provided. If the area covered by the first adhesive layer 30 is too large, the first adhesive layer 30 may easily deviate during lamination and extend beyond the edge of the battery cells 10. If this extended portion is located at the spacing position between battery strings, it may cause the battery cells 10 to shift, adversely affecting the electrical connection between the battery cells 10 and affecting the photoelectric conversion efficiency of the battery cells 10. Similarly, if this extended portion is located at the spacing position between the battery cells 10, it may cause a large pulling force on the connecting wires 20 located between the spacing of the battery cells 10 during lamination, affecting the extension length of the connecting wires 20 on the battery cells 10 and resulting in poor collection of current at the edges of the battery cells 10.

[0096] For example, in the case where the first adhesive layer 30 is provided in a planar manner, the area of ​​the orthographic projection of the first adhesive layer 30 on a plane perpendicular to the direction in which the battery cells 10 and the connecting wires 20 are stacked is 75%, 78.2%, 80%, 83.1%, 85%, 87%, 90%, 93.9%, 95%, etc. of the area of ​​the surface of the battery cells on which the connecting wires are provided. This embodiment of the present application does not impose excessive restrictions on this. In actual use, technicians can set it according to needs.

[0097] Optionally, the battery cell is roughly rectangular, and the shape of the battery cell is relatively regular, which is convenient for transportation and packaging.

[0098] As an optional embodiment, the first adhesive layer 30 includes a pre-crosslinked polymer adhesive layer. For example, the pre-crosslinked polymer adhesive layer may include a pre-crosslinked EVA layer. The pre-crosslinked EVA layer has advantages such as low fluidity and low cost. EVA is an ethylene-vinyl acetate copolymer. As another example, the pre-crosslinked polymer adhesive layer may also include a pre-crosslinked POE layer. The pre-crosslinked POE layer has the advantage of good resistance to PID effects. POE is divided into two types: one is a polymer of ethylene and butene, and the other is a polymer of ethylene and octene.

[0099] Of course, the pre-crosslinked polymer adhesive layer may also include any other pre-crosslinked polymer adhesive layer. In this regard, the present application embodiment does not impose specific restrictions, and in actual use, technicians can select as needed.

[0100] As an optional embodiment, the pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer is greater than 40%. In the embodiment of the present application, the pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer refers to the degree to which the polymer molecules in the pre-crosslinked polymer adhesive material layer reach an insoluble gel solidification through a cross-linking reaction. It can also be understood as the mass ratio of the linear molecules in the pre-crosslinked polymer adhesive material layer to cross-linked network molecules. In other words, the higher the pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer, the stronger its adhesion. In the embodiment of the present application, the pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer is set to be greater than 40%. In the process of battery string production, the connecting wire 20 is more firmly bonded to the surface of the battery cell 10 through the pre-crosslinked polymer adhesive material layer.

[0101] For example, the degree of pre-crosslinking of the pre-crosslinked polymer adhesive material layer can be 40%, 42.3%, 44%, 45%, 48%, 49.2%, 50%, 52%, 54.3%, 55%, 56.7%, or 60%.

[0102] As an optional embodiment, as shown in Figures 1, 2, and 7, the pre-crosslinked polymer adhesive material layer directly contacts the battery cell 10. In other words, the pre-crosslinked polymer adhesive material layer is disposed on the side of the first adhesive layer 30 close to the battery cell 10, thereby bonding the connecting wire 20 to the surface of the battery cell 10 through the pre-crosslinked polymer adhesive material layer, thereby improving the reliability of the connection between the connecting wire 20 and the battery cell 10.

[0103] As an optional embodiment, the pre-crosslinked polymer adhesive layer includes at least one of an EVA layer, a POE layer, and a PVB layer. Specifically, the pre-crosslinked polymer adhesive layer can be provided as a single layer structure, and the pre-crosslinked polymer adhesive layer of the single layer structure can be a pre-crosslinked EVA layer. The pre-crosslinked EVA layer has advantages such as low fluidity and low cost.

[0104] Of course, the pre-crosslinked polymer adhesive material layer can also be provided as a multi-layer structure. The pre-crosslinked polymer adhesive material layer of the multi-layer structure can include one or more of an EVA layer, a POE layer and a PVB layer.

[0105] For example, the pre-crosslinked polymer adhesive material layer of the multi-layer structure can be configured as a double-layer structure, wherein the pre-crosslinked polymer adhesive material layer of the double-layer structure includes an EVA layer and a POE layer, wherein the aforementioned EVA layer is disposed on the side of the first adhesive layer 30 close to the cell 10, so that the EVA layer directly contacts the cell 10. The connecting wire 20 is bonded to the surface of the cell 10 through the EVA layer to improve the reliability of the connection between the connecting wire 20 and the cell 10. The POE layer has good resistance to the PID effect. By disposing the POE layer on the side of the first adhesive layer 30 away from the cell 10, the photovoltaic module can improve its resistance to the PID effect.

[0106] As an optional embodiment, the connecting wire 20 includes a connecting wire substrate and a bonding layer attached to the surface of the connecting wire substrate. The connecting wire 20 is electrically connected to the battery cell 10 through the bonding layer. The melting point of the bonding layer is less than 165 degrees. The bonding layer is one of a tin-lead-bismuth layer, a tin-bismuth-silver layer, or a tin-indium layer. The connecting wire substrate is conductive and is usually a copper strip. For example, the connecting wire substrate is an oxygen-free copper strip. Of course, the connecting wire substrate can also be other metal strips, such as aluminum strips. This application does not impose specific restrictions on this. In actual use, technicians can make choices as needed.

[0107] In the embodiment of the present application, the connecting wires 20 are electrically connected to the cell 10 via a bonding layer. The bonding layer has a melting point of less than 165°C. During the battery string manufacturing process, the bonding layer can alloy and interconnect with the metal grid lines on the surface of the cell 10. This electrically connects the connecting wires 20 to the surface of the cell 10, thereby collecting the current generated by the cell 10 through the connecting wires 20.

[0108] It should be noted that the bonding layer in the embodiments of the present application also has electrical conductivity. Specifically, the bonding layer can be a tin-lead-bismuth layer, a tin-bismuth-silver layer, or a tin-indium layer. Of course, the bonding layer can also be other conductive metal layers with a melting point less than 165 degrees. In this regard, the present application does not impose too many restrictions. In actual use, technicians can set a suitable bonding layer as needed.

[0109] As an optional embodiment, a transparent conductive oxide layer is provided on the surface of the cell 10, and the aforementioned bonding layer is partially connected to the transparent conductive oxide layer, and the current generated by the cell 10 is collected through the transparent conductive oxide layer. For example, the transparent conductive oxide layer can be a tin oxide layer or an indium tin oxide layer. Of course, the transparent conductive oxide layer can also be a transparent conductive oxide layer of other materials. In the embodiments of the present application, there are no excessive restrictions on the specific material of the transparent conductive oxide layer. In actual use, technicians can set it as needed.

[0110] The bonding layer is partially connected to the transparent conductive oxide layer. That is, the bonding layer at least partially directly contacts the transparent conductive oxide layer and is electrically connected to the transparent conductive oxide layer. This allows for electrical connection between the connecting wire 20 and the cell 10, allowing the current generated by the cell 10 to be collected via the connecting wire 20.

[0111] As an optional embodiment, the length of the battery cell 10 is greater than or equal to 180 mm and less than or equal to 240 mm, and the direction of the length of the battery cell 10 is parallel to the direction of the first edge 11 and the direction of the second edge 12. For example, the length of the battery cell 10 can be 180 mm, 182 mm, 191.6 mm, 191.75 mm, 192, 210 mm, 220 mm, 230 mm, 240 mm, etc.

[0112] For example, the battery cell 10 may be a rectangular structure, and the specific dimensions of the rectangular structure battery cell 10 may include: (182±2) mm×(96±1) mm, (192±2) mm×(91±1) mm, (182±2) mm×(91±1) mm, (182±2) mm×(105±1) mm, etc.

[0113] Of course, in the embodiment of the present application, there are no excessive restrictions on the specific structure and size of the battery cell 10. Battery cells 10 of any structure and any size fall within the scope of protection of the present application. In actual use, technicians can select a suitable battery cell as the battery cell 10 as needed.

[0114] It should also be noted that the battery cell 10 in the embodiment of the present application can be a battery cell without a busbar or a battery cell with a busbar. In actual use, technicians can choose according to their needs.

[0115] As shown in Figures 7 to 11, an embodiment of the present application also discloses a photovoltaic module, which includes: a cover plate 40, a back plate 50, a second adhesive layer 60 and the battery string described in the above embodiments, wherein the cover plate 40 is bonded to the first adhesive layer 30 through the second adhesive layer 60, and / or the back plate 50 is bonded to the first adhesive layer 30 through the second adhesive layer 60.

[0116] As shown in Figures 7 to 11, the photovoltaic module in the embodiment of the present application further includes a second adhesive layer 60, a cover plate 40, and a back plate 50. The second adhesive layer 60 is disposed between the first adhesive layer 30 and the cover plate 40 to bond the cover plate 40 to one side of the cell 10 via the second adhesive layer 60, and / or the second adhesive layer 60 is disposed between the first adhesive layer 30 and the back plate 50 to bond the back plate 50 to the other side of the cell 10 via the second adhesive layer 60. Thus, the cell 10 can be fixed and protected by the cover plate 40 and the back plate 60.

[0117] It should be noted that the battery string included in the photovoltaic assembly described in the embodiment of the present application has the same structure as the battery string described in the above embodiment, and its beneficial effects are also similar, which will not be described in detail here.

[0118] Optionally, the first adhesive layer 30 is closer to the surface of the cell 10 than the second adhesive layer 60. Furthermore, the water vapor permeability of the first adhesive layer 30 is greater than that of the second adhesive layer 60. In this embodiment of the present application, components on the surface of the cell 10, such as connecting wires, are secured to the cell 10 surface solely via the first adhesive layer 30, without regard for the water barrier properties of the first adhesive layer 30. Therefore, in this embodiment of the present application, the first adhesive layer 30 can be made of a material with a higher water vapor permeability to reduce the production cost of the photovoltaic module. The second adhesive layer 60, on the other hand, can be made of a material with a lower water vapor permeability. This means that the second adhesive layer 60 has better water barrier properties and can protect the cell 10.

[0119] It should be noted that, in the embodiment of the present application, the water vapor transmittance of the first adhesive layer 30 is generally greater than 25 mg / ㎡-24h, while the water vapor transmittance of the second adhesive layer 60 is less than 25 mg / ㎡-24h.

[0120] The first adhesive layer 30 and the second adhesive layer 60 are typically made of a pre-crosslinked polymer adhesive material. Specifically, the pre-crosslinked polymer adhesive material can be pre-crosslinked EVA. Pre-crosslinked EVA has advantages such as low fluidity and low cost. EVA is ethylene-vinyl acetate copolymer.

[0121] Alternatively, the pre-crosslinked polymer adhesive material may be a pre-crosslinked POE layer, which has the advantages of good resistance to PID effects and good water barrier properties. POE is divided into two types: one is a polymer of ethylene and butene, and the other is a polymer of ethylene and octene.

[0122] Certainly, this pre-crosslinked polymer adhesive material can also be any other pre-crosslinked polymer adhesive material.Here, the concrete material of pre-crosslinked polymer adhesive material is not done too much restriction, in actual use, technical personnel can select suitable material as needed.

[0123] In the embodiment of the present application, the second adhesive layer 60 is adhered to the side of the first adhesive layer 30 away from the battery cell 10, so that the cover plate 40 or the back plate 50 is connected to the battery cell 10 through the second adhesive layer 60, thereby fixing and protecting the battery cell 10 through the cover plate 40 or the back plate 50.

[0124] The cover plate 40 can be made of transparent glass or a transparent organic material. Furthermore, the surface of the cover plate 40 is provided with an anti-reflection layer or an embossed structure. The back plate 50 can be made of transparent glass or a transparent organic material. Furthermore, the surface of the back plate 50 is provided with an embossed structure. The cover plate is typically located on the light-facing side of the cell, while the back plate is located on the backlight-facing side of the cell.

[0125] As an optional implementation, the battery cell 10 in the embodiment of the present application is generally a rectangular structure, and the coverage area of ​​the second adhesive layer 60 exceeds the edge of the battery cell 10 .

[0126] The second adhesive layer 60 in the embodiment of the present application is not only required to adhere the cover plate 40 or the back plate 50 to the side of the first adhesive layer 30 away from the battery cell 10 to fix and protect the battery cell 10. At the same time, the second adhesive layer 60 is also required to block water to waterproof the battery cell 10 and prevent a large amount of water vapor from entering the battery cell 10 and affecting the life of the battery cell 10. Based on the above considerations, the coverage area of ​​the second adhesive layer 60 in the embodiment of the present application is set to exceed the edge of the battery cell 10. This allows the second adhesive layer 60 to reliably adhere the cover plate 40 or the back plate 50 to the side of the first adhesive layer 30 away from the battery cell 10. At the same time, the second adhesive layer 60 can waterproof the entire plurality of battery cells 10 to prevent water vapor from entering the battery cell 10.

[0127] It should be noted that in the actual production process, along the thickness direction of the battery cell or the stacking direction of the battery cell and the connecting wires, the projection area of ​​the second adhesive layer 60 on the plane where the multiple battery cells 10 are located is usually adapted to the area of ​​the multiple battery cells 10 arranged at intervals.

[0128] The second adhesive layer 60 in the embodiment of the present application can be a single-layer structure or a multi-layer structure. For example, as shown in Figure 9, when the second adhesive layer 60 is a single-layer structure, the single-layer structure can be one of an EVA layer or a POE layer. As shown in Figure 10, when the second adhesive layer 60 is a double-layer structure, the double-layer structure can be an EVA layer and a POE layer stacked in sequence. As shown in Figure 11, when the second adhesive layer 60 is a three-layer structure, the three-layer structure can be an EVA layer, a POE layer, and an EVA layer stacked in sequence.

[0129] Of course, in the embodiment of the present application, there is no limitation on the specific number of layers of the second adhesive layer 60 , and in actual use, technicians can set it as needed.

[0130] Optionally, when the first adhesive layer 30 is a single-layer structure and the second adhesive layer 60 is a multi-layer structure, the material of the layer of the second adhesive layer 60 closest to the battery cell 10 is the same as the material of the first adhesive layer 30. As shown in FIG10 , in an embodiment of the present application, the first adhesive layer 30 can be set to a single-layer structure, and the second adhesive layer 60 can be set to a double-layer structure. For example, the first adhesive layer 30 of the single-layer structure can be an EVA layer, and the second adhesive layer 60 of the double-layer structure can be an EVA layer and a POE layer, and the EVA layer in the second adhesive layer 60 is arranged on the side of the second adhesive layer 60 close to the first adhesive layer 30, so that the material of the layer of the second adhesive layer 60 closest to the battery cell 10 is the same as the material of the first adhesive layer 30 or the same as the main material, so that during the lamination process of the photovoltaic module, the second adhesive layer 60 can be better integrated with the first adhesive layer 30 to improve the reliability of the photovoltaic module.

[0131] It should be noted that, when the first adhesive layer 30 is a single-layer structure, and the single-layer structure is an EVA layer, and the second adhesive layer 60 is a double-layer structure, and the double-layer structure is an EVA layer and a POE layer, the water vapor permeability of the first adhesive layer 30 is greater than 25 mg / ㎡-24h, while the water vapor permeability of the second adhesive layer 60 is less than 15 mg / ㎡-24h.

[0132] As shown in Figure 11, the first adhesive layer 30 can be set as a single-layer structure, and the second adhesive layer 60 can be set as a three-layer structure. For example, the first adhesive layer 30 of the single-layer structure can be an EVA layer, and the second adhesive layer 60 of the three-layer structure can be an EVA layer, a POE layer, and an EVA layer stacked in sequence.

[0133] It should be noted that, when the first adhesive layer 30 is a single-layer structure, and the single-layer structure is an EVA layer, and the second adhesive layer 60 is a three-layer structure, and the three-layer structure is an EVA layer, a POE layer and an EVA layer stacked in sequence, the water vapor permeability of the first adhesive layer 30 is greater than 25 mg / ㎡-24h, while the water vapor permeability of the second adhesive layer 60 is less than 15 mg / ㎡-24h.

[0134] Optionally, when the first adhesive layer 30 has a multi-layer structure and the second adhesive layer 60 has a single-layer structure, the material of the layer of the first adhesive layer 30 closest to the second adhesive layer 60 is the same as the material of the second adhesive layer 60. For example, the first adhesive layer 30 can be configured as a double-layer structure, and the first adhesive layer 30 of the double-layer structure can be an EVA layer and a POE layer. The second adhesive layer 60 of the single-layer structure can be an EVA layer or a POE layer. When the second adhesive layer 60 is an EVA layer, the EVA layer in the first adhesive layer 30 is positioned adjacent to the second adhesive layer 60. When the second adhesive layer 60 is a POE layer, the POE layer in the first adhesive layer 30 is positioned adjacent to the second adhesive layer 60. By ensuring that the material of the layer of the first adhesive layer 30 closest to the second adhesive layer 60 is the same as the material of the second adhesive layer 60, the second adhesive layer 60 can be better integrated with the first adhesive layer 30 during the lamination process of the photovoltaic module, thereby improving the reliability of the photovoltaic module.

[0135] It should be noted that when the first adhesive layer 30 has a double-layer structure, and the double-layer structure is an EVA layer and a POE layer, and the second adhesive layer 60 has a single-layer structure, and the single-layer structure is an EVA layer or a POE layer, the water vapor permeability of the first adhesive layer 30 is greater than 15 mg / ㎡-24h, while the water vapor permeability of the second adhesive layer 60 is less than 15 mg / ㎡-24h.

[0136] Optionally, when the first adhesive layer 30 is a multi-layer structure and the second adhesive layer 60 is a multi-layer structure, the material of the layer of the first adhesive layer 30 closest to the second adhesive layer 60 is the same as the material of the layer of the second adhesive layer 60 closest to the first adhesive layer 30. For example, the first adhesive layer 30 can be set as a double-layer structure, and the first adhesive layer 30 of the double-layer structure includes an EVA layer and a POE layer. The second adhesive layer 60 is set as a three-layer structure, and the second adhesive layer 60 of the three-layer structure includes an EVA layer, a POE layer, and an EVA layer. The EVA layer in the first adhesive layer 30 is set on the side of the first adhesive layer 30 close to the second adhesive layer 60, so that the material of the layer of the first adhesive layer 30 closest to the second adhesive layer 60 is the same as the material of the side of the second adhesive layer 60 closest to the first adhesive layer 30 or the same as the main material. Therefore, during the lamination process of the photovoltaic module, the second adhesive layer 60 can be better integrated with the first adhesive layer 30 to improve the reliability of the photovoltaic module.

[0137] Alternatively, as shown in Figures 5, 12, and 13, the cell 10 in the embodiment of the present application may be a back-contact cell. In the case of a back-contact cell 10, one end of the connecting wire 20 is laid on the backlight surface of one cell 10, and the other end extends to and is laid on the backlight surface of another adjacent cell 10. A first adhesive layer 30 is provided on the side of the connecting wire 20 away from the cell 10, so that the connecting wire 20 is fixed to the surface of the cell 10 via the first adhesive layer 30.

[0138] As shown in Figures 8 and 9, the cell 10 in the embodiment of the present application may also be a heterojunction cell. In the case of a heterojunction cell, one end of the connecting wire 20 is laid on the light-receiving surface of one cell 10, and the other end passes through the gap between two adjacent cells 10, extends to the backlight surface of the other adjacent cell 10, and is laid on the backlight surface of the other adjacent cell 10. A first adhesive layer 30 is then provided on the side of the connecting wire 20 away from the cell 10, so that the connecting wire 20 is fixed to the surface of the cell 10 through the first adhesive layer 30.

[0139] Of course, the above types of battery cells 10 are only examples of battery cells 10 in this application and are not intended to be limiting of this application. In actual use, technicians can select appropriate battery cells 10 as needed.

[0140] Optionally, as shown in FIG. 9 to FIG. 11 , along a direction perpendicular to the plane where the battery cell 10 is located, the height of the connecting wire 20 is greater than the thickness of the first adhesive layer 30 .

[0141] As shown in Figures 9 to 11, in the embodiment of the present application, along the stacking direction of the cover plate and the second adhesive layer, the height of the connecting wire 20 is greater than the thickness of the first adhesive layer 30, so that when the connecting wire 20 is fixed to the surface of the battery cell 10 through the first adhesive layer 30, the first adhesive layer 30 is in a curved and undulating state, the concave portion of the first adhesive layer 30 is adhered to the surface of the battery cell 10, and the convex portion of the first adhesive layer 30 abuts against the connecting wire 20, so as to form a curved structure of the first adhesive layer 30, which is wrapped around the surface of the connecting wire 20.

[0142] The height of the connecting line 20 along the stacking direction of the cover plate and the second adhesive layer is typically 0.2 mm to 0.4 mm. For example, the height of the connecting line 20 can be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, etc. The thickness of the first adhesive layer 30 is typically 0.1 mm to 0.2 mm. For example, the thickness of the first adhesive layer 30 can be 0.1 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, etc.

[0143] Of course, the above data are only examples of the height of the connecting line 20 and the thickness of the first adhesive layer 30, and are not limitations of this application. In actual use, technicians can set the height of the connecting line 20 and the thickness of the first adhesive layer 30 as needed.

[0144] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0145] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0146] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0147] In the claims, any reference signs placed between brackets shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery string, characterized in that: include: Battery cells; A connecting line is arranged on at least one surface of the battery cell; the surface includes: a first edge and a second edge; the first edge and the second edge are opposite and parallel to each other and perpendicular to the extension direction of the battery string; in the connecting line: an end close to the first edge extends outside the surface, and an end close to the second edge is located inside the surface; The first adhesive layer is laid on the side of the connecting line away from the battery cell, and the first adhesive layer is used to fix the connecting line to the surface of the battery cell; the first adhesive layer covers one end of the connecting line close to the second edge.

2. The battery string according to claim 1, characterized in that: The orthographic projection of the first end portion of the first adhesive layer close to the second edge on a plane perpendicular to the direction in which the battery cell and the connecting wire are stacked is located inside the surface of the battery cell on which the connecting wire is provided; the end of the connecting wire close to the second edge is located inside the surface of the battery cell on which the connecting wire is provided; The distance between one end of the connecting line close to the second edge and the second edge is d5; The distance between the first end and the second edge is d3; d5>d3.

3. The battery string according to claim 1, characterized in that: The orthographic projection of the second end portion of the first adhesive layer close to the first edge on a plane perpendicular to the direction in which the battery cell and the connecting wire are stacked is located inside the surface of the battery cell on which the connecting wire is set; the distance between the second end portion and the first edge is d4; 1mm≤d4≤5mm.

4. The battery string according to claim 1, characterized in that: The surface further includes: a third edge and a fourth edge; the third edge and the fourth edge are opposite and parallel to each other, and are also parallel to the extension direction of the battery string; the orthographic projections of the third end of the first adhesive layer close to the third edge and the fourth end of the first adhesive layer close to the fourth edge on a plane perpendicular to the direction in which the battery cell and the connecting wire are stacked are both located inside the surface of the battery cell on which the connecting wire is arranged; The distance between the third end and the third edge is d1, 0mm≤d1≤5mm; the distance between the fourth end and the fourth edge is d2, 0mm≤d2≤5mm.

5. The battery string according to claim 4, characterized in that: The number of the connecting lines is greater than 1, and d1 and d2 are both less than half of the spacing between two adjacent connecting lines, and are both greater than or equal to 1 mm.

6. The battery string according to claim 2, characterized in that: The two opposite surfaces of the battery cell both have electrode patterns, 0mm≤d3≤3mm; or, the battery cell is a back contact battery cell, 1mm≤d3≤5mm.

7. The battery string according to claim 3, characterized in that: The distance between one end of the connection line close to the second edge and the second edge is d5; the battery cell is a back contact battery cell, and d5>d4.

8. The battery string according to claim 1, characterized in that: The number of connecting lines is greater than 1; The first adhesive layer is arranged in strip shape, and the area between adjacent connection lines on the surface is at least partially exposed; Alternatively, the first adhesive layer is arranged in an upper plane, and the first adhesive layer covers the area between adjacent connection lines on the surface.

9. The battery string according to any one of claims 1 to 8, characterized in that: The first adhesive layer includes a pre-crosslinked polymer adhesive material layer.

10. The battery string according to claim 9, characterized in that: The pre-crosslinking degree of the pre-crosslinked polymer adhesive material layer is greater than 40%; and / or, The pre-crosslinked polymer adhesive material layer directly contacts the battery cell; and / or, The pre-crosslinked polymer adhesive material layer comprises at least one of an EVA layer, a POE layer and a PVB layer; and / or, The first adhesive layer is a single-layer structure, and the first adhesive layer of the single-layer structure is an EVA layer; and / or, The first adhesive layer is a multi-layer structure; and / or, The first adhesive layer is a double-layer structure, and the first adhesive layer of the double-layer structure includes an EVA layer and a POE layer, wherein the EVA layer is arranged on a side of the first adhesive layer close to the battery cell so that the EVA layer directly contacts the battery cell.

11. The battery string according to any one of claims 1 to 8, characterized in that: The connecting wire comprises: a connecting wire substrate and a bonding layer attached to the surface of the connecting wire substrate, and the connecting wire is electrically connected to the battery cell through the bonding layer; The melting point of the bonding layer is less than 165 degrees, and the bonding layer is one of a tin-lead-bismuth layer, a tin-bismuth-silver layer or a tin-indium layer.

12. The battery string according to claim 11, characterized in that: A transparent oxide conductive layer is disposed on the surface of the cell, and a portion of the bonding layer is connected to the transparent oxide conductive layer.

13. The battery string according to any one of claims 1 to 8, characterized in that: The length of the battery cell is greater than or equal to 180 mm and less than or equal to 240 mm; the direction of the length is parallel to the first edge 11; and / or, The battery cell includes a battery cell without a main grid.

14. A photovoltaic module, characterized in that: include: A cover plate, a back plate, a second adhesive layer, and a battery string as described in any one of claims 1 to 13, wherein: The cover plate is bonded to the first adhesive layer through the second adhesive layer, and / or the back plate is bonded to the first adhesive layer through the second adhesive layer.

15. The photovoltaic module according to claim 14, characterized in that: The water vapor permeability of the first adhesive layer is greater than the water vapor permeability of the second adhesive layer.

16. The photovoltaic module according to claim 14, characterized in that: The battery cell is a rectangular structure, wherein the coverage area of ​​the second adhesive layer exceeds the edge of the first adhesive layer, and the coverage area of ​​the second adhesive layer exceeds the edge of the battery cell.

17. The photovoltaic module according to any one of claims 14 to 16, characterized in that: The second adhesive layer is a single-layer structure; or, The second adhesive layer is a multi-layer structure.

18. The photovoltaic module according to claim 17, characterized in that: In the case where the first adhesive layer is a single-layer structure and the second adhesive layer is a multi-layer structure, the material of a layer of the second adhesive layer closest to the battery cell is the same as that of the first adhesive layer; or, In the case where the first adhesive layer is a multi-layer structure and the second adhesive layer is a single-layer structure, the material of a layer of the first adhesive layer closest to the second adhesive layer is the same as the material of the second adhesive layer; or, When the first adhesive layer is a multi-layer structure and the second adhesive layer is a multi-layer structure, a material of a layer of the first adhesive layer closest to the second adhesive layer is the same as a material of a layer of the second adhesive layer closest to the first adhesive layer.

19. The photovoltaic module according to claim 17, characterized in that: The second adhesive layer is a single-layer structure, and the second adhesive layer includes one of an EVA layer and a POE layer; or, The second adhesive layer is a double-layer structure, and the double-layer structure includes an EVA layer and a POE layer stacked in sequence; or, The second adhesive layer is a three-layer structure, and the three-layer structure includes an EVA layer, a POE layer and an EVA layer stacked in sequence.

20. The photovoltaic module according to any one of claims 14 to 16, characterized in that: The height of the connection line is greater than the thickness of the first adhesive layer; the directions of the height and the thickness are both parallel to the stacking direction of the cover plate and the second adhesive layer.

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