Battery string and photovoltaic module
By setting a carrier film on the pads and arranging the interconnect structure in an alternating manner, the problems of unreliable interconnect structure and excessive carrier film usage in battery strings are solved, achieving more reliable connections and lower production costs.
Patent Information
- Application Number
- CN202423085797.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-13
AI Technical Summary
The existing battery string interconnection structure and welding are unreliable, and there is also the problem of excessive use of carrier film.
By setting a carrier film on the pads and arranging the interconnect structures in an interleaved manner to reduce the coverage area of the carrier film, reliable connection is ensured by utilizing the cross arrangement of the carrier film and the interconnect structures.
This improved the reliability of the interconnect structure, reduced the amount of carrier film used, lowered production costs, and improved the regularity and stability of the battery string.
Smart Images
Figure CN223626250U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of photovoltaic technology, and in particular to a battery string and a photovoltaic module. Background Technology
[0002] As the core component of photovoltaic modules, the solar cell string converts solar energy into electrical energy. A solar cell string consists of multiple solar cells arranged at intervals. These cells are connected in series and parallel through an interconnecting structure to form the solar cell string.
[0003] In existing technologies, the interconnect structure and the battery cells are welded together using a dedicated infrared welding machine at high infrared temperatures, typically between 220 and 350°C. The tin and lead melt at this high temperature, fusing the solder strip and the silver on the battery surface together. However, traditional battery strings suffer from unreliable welding techniques. Utility Model Content
[0004] This invention provides a battery string and a photovoltaic module. By setting a carrier film on the pads where the first interconnection structure is provided, the interconnection structure can be more reliably connected to the pads.
[0005] In a first aspect, this utility model provides a battery string, comprising: N battery cells connected in series, M first interconnect structures, and P carrier films; N is an integer greater than or equal to 2, M is an integer greater than or equal to 1, and P is equal to N or an integer multiple of N; each battery cell is provided with multiple pads, including first pads and second pads; the first pads and second pads are arranged alternately along a first direction; at least one first interconnect structure is provided between each pair of adjacent battery cells, the first interconnect structure being used to connect at least one second pad of the i-th battery cell connected in series with at least one first pad of the (i+1)-th battery cell connected in series; wherein i is an integer greater than or equal to 1 and less than N; the P carrier films are spaced apart along a second direction, and the carrier films cover at least a portion of the area of the pads provided with the first interconnect structures; wherein the first direction intersects the second direction.
[0006] Optionally, the carrier film and the battery cell are arranged in a one-to-one correspondence. The battery cell has a first edge and a second edge arranged opposite to each other in the second direction. The first distance and the second distance are equal or unequal. The first distance is the distance between the carrier film and the first edge, and the second distance is the distance between the carrier film and the second edge.
[0007] Optionally, each of the solar cells has a first edge and a second edge disposed opposite to each other in the second direction; the second edge of the i-th solar cell is adjacent to the first edge of the (i+1)-th solar cell; the first pad is disposed on the side closer to the first edge, and the second pad is disposed on the side closer to the second edge.
[0008] Optionally, the first pads are arranged in rows to form at least two rows of first pads, and the second pads are arranged in rows to form at least two rows of second pads. The first pad rows and the second pad rows are staggered along a first direction, and the polarities of the pad rows of two adjacent cells that are on the same straight line are opposite.
[0009] Optionally, the battery string further includes multiple second interconnect structures and multiple third interconnect structures; the second interconnect structures are disposed on at least one pad in the odd-numbered rows of the first battery cell in series; the third interconnect structures are disposed on at least one pad in the even-numbered rows of the last battery cell in series; the carrier film corresponding to the first battery cell in series also covers a portion of the area of the pads on which the second interconnect structures are disposed, and the carrier film corresponding to the last battery cell in series also covers a portion of the area of the pads on which the third interconnect structures are disposed.
[0010] Optionally, the carrier membrane includes a plurality of carrier membrane blocks arranged along a first direction; the carrier membrane blocks are configured to correspond one-to-one with the pads provided with the first interconnection structure.
[0011] Optionally, the carrier film covers at least 80% of the area of the pads.
[0012] Optionally, the pads are disposed on one side of the solar cell; the first interconnect structure is disposed on the side of the pads away from the solar cell; and the carrier film is disposed on the side of the first interconnect structure away from the solar cell.
[0013] Optionally, the carrier film may be in the shape of a block or a strip, and / or the area of each pad may be not less than 20um*0.1mm.
[0014] Secondly, this utility model provides a photovoltaic module, including multiple battery strings provided in any embodiment of this utility model, and also including an outer encapsulation film, a front cover plate and a back cover plate; the multiple battery strings are interconnected, and the outer encapsulation film connects the front cover plate, the interconnected battery strings and the back cover plate to each other.
[0015] In this embodiment of the technical solution, at least one first interconnection structure is provided between each pair of adjacent battery cells. The first interconnection structure is used to connect at least one second pad of the i-th battery cell connected in series with at least one first pad of the (i+1)-th battery cell connected in series. By providing a carrier film on the pads where the first interconnection structure is provided, the interconnection structure can be reliably connected to the pads. In addition, since the carrier film and the first interconnection structure are arranged crosswise (e.g., perpendicularly), and when the carrier film is arranged perpendicularly to the first interconnection structure, the carrier film passes laterally through the interconnection structure, the carrier film only needs to be laid at the position of the pad where the first interconnection structure is provided, and does not need to cover the entire length direction of the interconnection structure as a large area as when the carrier film is arranged parallel to the interconnection structure, thereby reducing the amount of carrier film used.
[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of a battery string structure provided in an embodiment of the present invention;
[0019] Figure 2 This is a schematic diagram of another battery string structure provided in this embodiment of the present invention;
[0020] Figure 3 This is a schematic diagram of another battery string structure provided in this embodiment of the present invention;
[0021] Figure 4 This is a schematic diagram of another battery string structure provided in this embodiment of the present invention;
[0022] Figure 5 This is a schematic diagram of another battery string structure provided in this embodiment of the present invention;
[0023] Figure 6 This is a schematic diagram of another battery string structure provided in this embodiment of the present invention;
[0024] Figure 7 This is a cross-sectional structural diagram of a battery cell provided in an embodiment of the present utility model;
[0025] Figure 8 This is a cross-sectional structural diagram of a photovoltaic module provided in an embodiment of this utility model. Detailed Implementation
[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.
[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.
[0028] As mentioned in the background section, existing battery strings suffer from problems such as excessive interconnection structures and excessive use of carrier films. After careful research, the inventors discovered that the cause of this technical problem is:
[0029] Figure 1 This is a schematic diagram of the structure of a battery string provided in an embodiment of this utility model. Figure 2 This is a schematic diagram of another battery string structure provided in this embodiment of the utility model. Figure 3 This is a schematic diagram of another battery string structure provided in this embodiment of the utility model. Figure 4 This is a schematic diagram of another battery string structure provided in this embodiment of the utility model. Figure 5 This is a schematic diagram of another battery string structure provided in an embodiment of this utility model. See also... Figures 1 to 5 The battery string includes: N series-connected battery cells 10, M first interconnect structures 20 and P carrier films 30; N is an integer greater than or equal to 2, M is an integer greater than or equal to 1, and P is equal to N or an integer multiple of N. Figures 1 to 3 The case where P=1 is illustrated. Figure 4 The case where P = 2 is illustrated. Figure 5 The case where P=3 is illustrated.
[0030] Each solar cell 10 has multiple pads 11, including first pads 110 and second pads 120, which are staggered along a first direction Y. At least one first interconnect structure 20 is provided between every two adjacent solar cells 10, connecting at least one second pad of the i-th solar cell 11 connected in series with at least one first pad of the (i+1)-th solar cell 11 connected in series; where i is an integer greater than or equal to 1 and less than N. P carrier films 30 are spaced apart along a second direction X, covering at least a portion of the area of the pads 11 with the first interconnect structures 20; where the first direction Y intersects the second direction X. Optionally, the first direction Y is perpendicular to the second direction X.
[0031] Specifically, the solar cell 10, as the core component of the battery string, converts solar energy into electrical energy. The solar cell 10 has a front side facing sunlight, also known as the light-receiving surface. The solar cell 10 also has a back side facing away from sunlight, also known as the back-lighting surface. It should be noted that the solar cell 10 in this embodiment can be a whole solar cell or a half solar cell. No specific limitation is made in this embodiment. In practical applications, those skilled in the art can configure it as needed.
[0032] It should be noted that the first interconnect structure 20 in this embodiment can be a solder strip or any other interconnect structure that can electrically connect two adjacent solar cells 10. Here, no further restrictions are placed on the specific type of the first interconnect structure 20. When the second solder pad of one solar cell is connected to the first solder pad of an adjacent solar cell through the first interconnect structure 20, electrons can flow between the solar cells in a direction from the negative electrode to the positive electrode, realizing the series connection of multiple solar cells. This series connection method allows the voltage of the solar cell string to accumulate, meeting the voltage requirements of different application scenarios. For example, in photovoltaic modules, the number of solar cells connected in series is determined according to the required output voltage, thereby constructing a suitable solar cell string through this connection principle.
[0033] In practical applications, technicians can select a suitable first interconnect structure 20 as needed. When the first interconnect structure 20 is a solder strip, the cross-section of the solder strip can be circular, square, or other irregular shapes. This application does not impose specific limitations on this. In practical applications, technicians can choose according to their needs.
[0034] Additionally, it should be noted that the first interconnect structure 20 may only have an interconnect structure body structure; for example, the first interconnect structure 20 may only have a copper strip body. The first interconnect structure 20 may also include an interconnect structure body and a tin layer structure covering the surface of the interconnect structure body; for example, the first interconnect structure 20 includes a copper strip body and a tin layer structure covering the surface of the copper strip body. This application does not impose specific limitations in this regard, and those skilled in the art can choose according to the actual application scenario.
[0035] In this battery string, each of the first interconnect structures 20 is in a straight line, meaning that each first interconnect structure 20 is entirely located on the same side of the plane formed by the two adjacent battery cells it connects to. Furthermore, the straight line shape of each first interconnect structure 20 reduces its length, thereby lowering the manufacturing cost of the battery string and preventing the first interconnect structure 20 from having its conductivity affected by twisting.
[0036] In this embodiment, the carrier film 30 is stacked on the side of the first interconnect structure 20 away from the battery cell 10, and the first interconnect structure 20 is fixed to the surface of the battery cell 10 by heating the carrier film 30 at low temperature. This arrangement ensures that the first interconnect structure 20 (e.g., solder ribbon) is more reliably soldered onto the pad 11; on the other hand, the cooperation between the battery cell 10 and the carrier film 30 can limit the position of the first interconnect structure 20, preventing the first interconnect structure 20 from shifting during the lamination of the battery string, thereby ensuring the regularity of the battery string.
[0037] The thickness of the carrier membrane 30 is not limited in this embodiment of the invention. Optionally, the thickness of the carrier membrane 20 is 300-900 μm, for example, it can be 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm or 900 μm, etc.
[0038] This embodiment of the invention does not limit the shape of the carrier film 30. Optionally, the carrier film 30 can be in the shape of a block or a strip. Different shapes can adapt to different battery cell designs and process requirements. For example, a block shape may have advantages in terms of large-area coverage and fixation, while a strip shape may be more suitable in certain specific layouts or space-constrained situations.
[0039] The pads 11 are disposed on the electrode area of the solar cell and are used to make electrical connections with the pads 11 on other solar cells 10 through the first interconnect structure 20, thereby realizing series connection between solar cells. Optionally, the area of each pad 11 is not less than 20um*0.1mm. This arrangement ensures that the pads 11 have sufficient contact area to achieve good electrical connection with the first interconnect structure 20, ensuring the stability and efficiency of current transmission.
[0040] Optionally, the first pad 110 and the second pad 120 are arranged alternately and equidistantly along the first direction Y. This ensures that the spacing between adjacent first pads 110 and second pads 120 is equal, guaranteeing uniform current distribution within the solar cell 10. This helps reduce heat concentration caused by uneven current distribution, thereby improving the overall efficiency and stability of the solar cell 10. Furthermore, it simplifies the production process and increases production efficiency.
[0041] In this embodiment of the technical solution, at least one first interconnection structure is provided between each pair of adjacent battery cells. The first interconnection structure is used to connect at least one second pad of the i-th battery cell connected in series with at least one first pad of the (i+1)-th battery cell connected in series. By providing a carrier film on the pads where the first interconnection structure is provided, the interconnection structure can be reliably connected to the pads. In addition, since the carrier film and the first interconnection structure are arranged crosswise (e.g., perpendicularly), and when the carrier film is arranged perpendicularly to the first interconnection structure, the carrier film passes laterally through the interconnection structure, the carrier film only needs to be laid at the position of the pad where the first interconnection structure is provided, and does not need to cover the entire length direction of the interconnection structure as a large area as when the carrier film is arranged parallel to the interconnection structure, thereby reducing the amount of carrier film used.
[0042] Optionally, continue to refer to Figures 1 to 3 The carrier film 30 is configured in a one-to-one correspondence with the battery cell 10. The battery cell 10 has a first edge and a second edge that are configured opposite to each other in the second direction X. The first distance and the second distance may be equal or unequal. The first distance is the distance between the carrier film 30 and the first edge, and the second distance is the distance between the carrier film 30 and the second edge. Figure 1 The illustration shows the case where the second distance is greater than the first distance. Figure 2 The illustration shows the case where the second distance is less than the first distance. Figure 3 The diagram illustrates the case where the second distance is equal to the first distance. The solar cell 10 has opposing first and second edges in the second direction X, and the carrier film 30 is equidistant from these two edges. This results in a more symmetrical arrangement of the carrier film 30 on the solar cell 10, which is beneficial for the uniformity of the battery string in terms of stress and heat dissipation, reducing the risk of performance instability or structural damage due to local differences.
[0043] Continue to refer to Figure 4 Optionally, each of the battery cells 10 has a first edge and a second edge disposed opposite to each other in the second direction X; the second edge of the i-th battery cell is adjacent to the first edge of the (i+1)-th battery cell; the first pad 110 is disposed on the side closer to the first edge, and the second pad 120 is disposed on the side closer to the second edge. This arrangement can reduce the path when the first interconnection structure 20 connects adjacent battery cells 10, thereby reducing the amount of the first interconnection structure 20 used.
[0044] Continue to refer to Figure 5Optionally, the first pads 110 are arranged in rows to form at least two rows of first pads, and the second pads 120 are arranged in rows to form at least two rows of second pads. The first and second pad rows are staggered along the first direction Y, and the polarities of the pad rows of adjacent solar cells 10 on the same straight line are opposite. This row arrangement makes the pads 11 present a more regular layout on the solar cells 10, which facilitates subsequent connection operations with the interconnect structure. From a process perspective, it is more conducive to achieving standardized and large-scale production. For example, in automated welding processes, the rows of pads allow the welding equipment to more accurately and efficiently position and complete the welding task, improving production efficiency and connection quality.
[0045] Continue to refer to Figure 5 Optionally, the battery cell 10 is provided with a plurality of first electrodes and a plurality of second electrodes with opposite polarities; the first electrodes are arranged in rows to form at least two rows of first electrodes, and the second electrodes are arranged in rows to form at least two rows of second electrodes, with the first electrode rows and the second electrode rows being staggered; the electrode rows of two adjacent battery cells 10 on the same straight line have opposite polarities; the first pad 110 is provided in a one-to-one correspondence with the first electrode, and the second pad 120 is provided in a one-to-one correspondence with the second electrode.
[0046] Specifically, during the operation of the solar cell 10, the first electrode is used to collect the current generated inside the cell. For example, in a solar cell, when photons excite and generate electron-hole pairs, the electrons move towards the n-type semiconductor region of the cell. The first electrode (assuming it is connected to the n-type semiconductor) can effectively collect these electrons. The first electrode is configured in a one-to-one correspondence with the first pad 110. Through the corresponding first pad 110 and the first interconnect structure 20, it conducts the collected current to an external circuit or an adjacent solar cell 10. For example, in a battery string, the current collected by the first electrode is transmitted to the second electrode of the next solar cell through the first pad 110 and the first interconnect structure 20, thereby realizing the series connection between the solar cells, constructing a complete current path, enabling the entire battery string to work normally and output electrical energy.
[0047] The second electrode has the opposite polarity to the first electrode. It is used to collect current from external circuits or adjacent cells and guide it into the cell. In the case of cells connected in series, it receives current transmitted from the first electrode of the adjacent cell through the first interconnect structure 20.
[0048] Continue to refer to Figures 1 to 5Optionally, the battery string further includes multiple second interconnect structures 40 and multiple third interconnect structures 50. The second interconnect structures 40 are disposed on at least one pad in the odd-numbered rows of the first battery cell 10 connected in series; the third interconnect structures 50 are disposed on at least one pad in the even-numbered rows of the last battery cell 10 connected in series; the carrier film 30 corresponding to the first battery cell 10 connected in series also covers at least a portion of the area of the pads 11 on which the second interconnect structures 40 are disposed, and the carrier film 30 corresponding to the last battery cell 10 connected in series also covers at least a portion of the area of the pads 11 on which the third interconnect structures 50 are disposed.
[0049] Optionally, the second interconnect structure 40 is used to bring out the first electrode of the first cell 10 connected in series. The first electrode of the first cell 10 needs to be connected to an external circuit or other components to transmit current. The third interconnect structure 50 is used to bring out the second electrode of the last cell 10 connected in series. In the current loop of the cell string, the second electrode of the last cell 10 also needs to interact with an external circuit. Assume there is a photovoltaic module composed of several cell strings. The second interconnect structure 40 on the first cell of each cell string connects the first electrode of the cell to the positive DC bus of the photovoltaic module. When sunlight shines on the cell and generates electricity, the current flows from the first electrode of the first cell through the second interconnect structure 40 to the positive DC bus, and then flows within the photovoltaic module according to the designed circuit path. The third interconnect structure 50 on the last cell of each cell string connects its second electrode to the negative DC bus, thus completing the current loop construction of each cell string in the entire photovoltaic module, so that the electrical energy generated by each cell string can be transmitted and collected in an orderly manner within the photovoltaic module, and finally converted into alternating current for user use.
[0050] Figure 6 This is a schematic diagram of another battery string structure provided in an embodiment of this utility model. (See diagram below.) Figure 6 As shown, optionally, the carrier film 30 includes a plurality of carrier film blocks 310 arranged along the first direction Y; the carrier film blocks 310 are configured in a one-to-one correspondence with at least one pad 11 on which the first interconnect structure 20 is provided. This correspondence configuration allows the carrier film blocks 310 to act precisely on specific pad positions, thereby better assisting the connection operation between the first interconnect structure 20 and the pad 11, and further saving the amount of carrier film used.
[0051] Optionally, when the odd-numbered rows of the first battery cell 10 connected in series are provided with the second interconnection structure 40, the carrier film block 310 corresponding to the first sub-cell is also provided with a one-to-one correspondence with the pad 11 provided with the second interconnection structure 40.
[0052] Optionally, when the even-numbered rows of the last battery cell 10 in series are provided with a third interconnection structure 50, the carrier film block 310 corresponding to the last sub-cell is also provided with a one-to-one correspondence with the pad 11 provided with the third interconnection structure 50.
[0053] Optionally, the carrier film covers at least 80% of the area of the pad 11. This arrangement allows for more effective fixation of the first interconnect structure 20 to the pad 11. During the assembly, transportation, and use of the battery string, a larger coverage area means more contact points and greater adhesion, preventing the first interconnect structure 20 from shifting or loosening due to external forces, vibrations, or other factors, thus ensuring the stability of the connection between the first interconnect structure 20 and the third pad.
[0054] Figure 7 This is a cross-sectional structural diagram of a battery cell provided in an embodiment of this utility model. For example... Figure 7 As shown, the pad 11 is disposed on one side of the battery cell 10; the first interconnect structure 20 is disposed on the side of the pad 11 away from the battery cell 10; and the carrier film 30 is disposed on the side of the first interconnect structure 20 away from the battery cell 10.
[0055] Based on the same inventive concept, this utility model also provides a photovoltaic module. Figure 8 This is a cross-sectional structural diagram of a photovoltaic module provided in an embodiment of this utility model. Figure 8 As shown, the photovoltaic module includes multiple battery strings 100 provided in any embodiment of the present invention, and has the beneficial effects of any embodiment of the present invention.
[0056] Optionally, the photovoltaic module also includes an outer encapsulation film 100, a front cover plate 200, and a back cover plate 300; multiple battery strings are interconnected, and the outer encapsulation film connects the front cover plate 200, the interconnected battery strings, and the back cover plate 300 to each other.
[0057] Specifically, multiple battery strings are interconnected to form a battery string layer 400. The outer encapsulation film 100 includes a front encapsulation film 1001 and a back encapsulation film 1002. The front encapsulation film 1001 and the front cover plate 200 are sequentially covered in the direction away from the front of the battery string layer 400, and the back encapsulation film 1002 and the back cover plate 300 are sequentially covered in the direction away from the back of the battery string layer 400.
[0058] In the fabrication of photovoltaic modules, the front cover plate 200, front encapsulating film 1001, cell string layer 400, back encapsulating film 1002, and back cover plate 300 are first arranged sequentially to complete the preparatory work before lamination. Then, the five-layer structure, including the front cover plate 200, front encapsulating film 1001, cell string layer 400, back encapsulating film 1002, and back cover plate 300, is vacuum-sealed and heated for lamination. This causes the front encapsulating film 1001 and back encapsulating film 1002 to cross-link and cure, protecting the cell string layer 400. This ultimately achieves a secure bond between the five layers (front cover plate 200, front encapsulating film 1001, cell string layer 400, back encapsulating film 1002, and back cover plate 300). Optionally, the front cover plate 200 and back cover plate 300 can be made of glass.
[0059] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A battery string, characterized in that, include: N series-connected solar cells, M first interconnect structures, and P carrier films; N is an integer greater than or equal to 2, M is an integer greater than or equal to 1, and P is equal to N or an integer multiple of N; Each of the solar cells is provided with multiple pads, the pads including a first pad and a second pad, the first pad and the second pad being arranged alternately along a first direction; At least one first interconnection structure is provided between each pair of adjacent battery cells. The first interconnection structure is used to connect at least one second pad of the i-th battery cell connected in series with at least one first pad of the (i+1)-th battery cell connected in series; where i is an integer greater than or equal to 1 and less than N. P carrier films are spaced apart along a second direction, and the carrier films cover at least a portion of the area of the pads; The first direction intersects with the second direction.
2. The battery string according to claim 1, characterized in that, The carrier film is configured in a one-to-one correspondence with the battery cell. The battery cell has a first edge and a second edge that are configured opposite to each other in the second direction. The first distance and the second distance may be equal or unequal. The first distance is the distance between the carrier film and the first edge, and the second distance is the distance between the carrier film and the second edge.
3. The battery string according to claim 1, characterized in that, The battery cells each have a first edge and a second edge that are disposed opposite to each other in the second direction; the second edge of the i-th battery cell is adjacent to the first edge of the (i+1)-th battery cell; The first pad is located on the side near the first edge, and the second pad is located on the side near the second edge.
4. The battery string according to claim 1, characterized in that, The first pads are arranged in rows to form at least two rows of first pads, and the second pads are arranged in rows to form at least two rows of second pads. The first pad rows and the second pad rows are staggered along a first direction, and the polarities of the pad rows of two adjacent solar cells that are on the same straight line are opposite.
5. The battery string according to claim 1, characterized in that, It also includes multiple second interconnect structures and multiple third interconnect structures; The second interconnect structure is disposed on at least one of the pads in the odd-numbered rows of the first battery cell connected in series; The third interconnect structure is disposed on at least one of the pads in the even-numbered row of the last of the series-connected solar cells; The carrier film corresponding to the first battery cell in series also covers at least a portion of the area of the pads on which the second interconnect structure is provided, and the carrier film corresponding to the last battery cell in series also covers at least a portion of the area of the pads on which the third interconnect structure is provided.
6. The battery string according to claim 1, characterized in that, The carrier membrane includes a plurality of carrier membrane blocks arranged along the first direction; The carrier membrane block is configured to correspond one-to-one with the pads on which the first interconnect structure is provided.
7. The battery string according to claim 1, characterized in that, The carrier film covers at least 80% of the area of the pad.
8. The battery string according to claim 1, characterized in that, The solder pad is disposed on one side of the battery cell; The first interconnect structure is disposed on the side of the pad away from the battery cell; The carrier film is disposed on the side of the first interconnect structure away from the battery cell.
9. The battery string according to claim 1, characterized in that, The carrier film is in the shape of a block or a strip; and / or, the area of each pad is not less than 20um*0.1mm.
10. A photovoltaic module, characterized in that, It includes multiple battery strings as described in any one of claims 1-9, and also includes an outer encapsulation film, a front cover plate, and a back cover plate; Multiple battery strings are interconnected, and the outer encapsulation film connects the front cover, the interconnected battery strings, and the back cover.