Battery string and photovoltaic module

Abstract

The utility model relates to photovoltaic technology field especially, and more particularly to a kind of battery string and photovoltaic module.The battery string includes multiple battery piece, electrically conductive protruding part, electrically conductive receiving part and carrier film. Among them, two adjacent battery piece partially overlapping arrangement and form overlapping area.The front main grid line of battery piece is provided with at least one electrically conductive protruding part, and the back main grid line of battery piece is provided with electrically conductive receiving part corresponding and adapting with electrically conductive protruding part;At least part electrically conductive protruding part and at least part electrically conductive receiving part are located in overlapping area, and at least part carrier film is arranged in overlapping area.In two adjacent battery piece, the electrically conductive protruding part of one battery piece penetrates carrier film and forms metal direct connection with the electrically conductive receiving part of another battery piece.The battery string can reduce the obstruction to the surface of battery piece, improve power generation efficiency;Reduce the risk of battery piece hidden crack, improve reliability, save cost.

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] With the development of science and technology and the progress of the economy, photovoltaic modules are playing an increasingly prominent role in new energy technologies. As the core component of a photovoltaic power generation system, the interconnection technology of photovoltaic modules directly affects the overall power generation efficiency, as well as the reliability and manufacturing cost of the solar cells.

[0003] In existing technologies, photovoltaic (PV) modules typically use solder ribbon interconnects for the cells. This involves physically connecting the front and back electrodes of adjacent cells with metal solder ribbons to create a current conduction path. However, this solder ribbon interconnection method has several drawbacks. First, the solder ribbon can obscure the cell surface, leading to optical loss and reduced power generation efficiency. Second, the solder ribbon introduces thermal stress during the welding process, increasing the risk of microcracks in the cells and reducing the reliability of both the cells and the PV module. Furthermore, the solder ribbon in existing technologies accounts for a relatively high proportion of the PV module's resistance, increasing power loss and cost.

[0004] Therefore, there is an urgent need to design a battery string and photovoltaic module to solve the above technical problems. Utility Model Content

[0005] The purpose of this invention is to propose a battery string and photovoltaic module that reduces shading on the surface of the battery cells, improves power generation efficiency, reduces the risk of microcracks in the battery cells, improves reliability, and saves costs.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On the one hand, this utility model provides a battery string, comprising:

[0008] Multiple battery cells, with adjacent battery cells partially overlapping to form an overlapping area;

[0009] At least one conductive protrusion is provided on the front main grid line of the battery cell, and a conductive receiving portion is provided on the back main grid line of the battery cell that corresponds to and is adapted to the conductive protrusion; at least a portion of the conductive protrusion and at least a portion of the conductive receiving portion are located in the overlapping area.

[0010] The carrier membrane, at least a portion of which is disposed within the overlapping region;

[0011] In two adjacent battery cells, the conductive protrusion of one battery cell penetrates the carrier film and forms a direct metal connection with the conductive receiving portion of the other battery cell.

[0012] As an optional technical solution for battery strings, the conductive protrusion includes a base and a protrusion. One end of the base is connected to the front main grid line of the battery cell, and the other end of the base is connected to the protrusion.

[0013] As an optional technical solution for battery strings, the base is cylindrical and the protrusions are hemispherical.

[0014] As an optional technical solution for battery strings, the conductive protrusions are made of silver paste.

[0015] As an optional technical solution for battery strings, the conductive receiving part includes a groove filled with conductive silver paste, and the conductive silver paste is directly connected to the protruding metal.

[0016] As an alternative technical solution for battery strings, the height of the conductive protrusion is greater than the thickness of the carrier film, so that the protrusion can penetrate the carrier film and connect with the conductive receiving part.

[0017] As an optional technical solution for battery strings, along the extension direction of the main grid line on the front side of the battery cell, the conductive protrusion is at a first preset distance from the edge of the battery cell, and the first preset distance is set to 3mm-5mm.

[0018] As an optional technical solution for battery strings, along the extension direction of the main grid line on the back of the battery cell, the conductive receiving part is at a second preset distance from the edge of the battery cell, and the second preset distance is set to 3mm-5mm.

[0019] On the other hand, this utility model provides a photovoltaic module, which includes a plurality of the above-described battery strings and a busbar, wherein the busbar is electrically connected to the battery cells at the end of the battery strings so as to discharge the current generated by the battery strings.

[0020] As an optional technical solution for photovoltaic modules, the busbar is electrically connected to the conductive protrusions or conductive receiving portions of the cells at the end of the cell string; or, the busbar is electrically connected to the front main grid line or the back main grid line of the cells at the end of the cell string.

[0021] The beneficial effects of this utility model include at least the following:

[0022] This invention provides a battery string comprising multiple battery cells, conductive protrusions, conductive receivers, and a carrier film. Adjacent battery cells partially overlap to form an overlapping area. At least one conductive protrusion is provided on the front main grid line of each battery cell, and a corresponding conductive receiver is provided on the back main grid line of the battery cell. At least a portion of the conductive protrusions and at least a portion of the conductive receivers are located within the overlapping area, and at least a portion of the carrier film is disposed within the overlapping area. In two adjacent battery cells, the conductive protrusion of one battery cell penetrates the carrier film to form a direct metal connection with the conductive receiver of the other battery cell.

[0023] Traditional technologies require solder ribbons to cover the surface of the solar cell to create current paths, inevitably causing light shading and optical loss. This invention replaces the solder ribbons with conductive protrusions on the front main grid lines and conductive receivers on the back main grid lines, significantly reducing surface shading, lowering optical loss, and improving photovoltaic module power generation efficiency. Traditional solder ribbons require high-temperature welding to connect to the solar cell, generating thermal stress that can easily lead to microcracks. In this invention, the conductive protrusions are printed, requiring only mechanical pressure during lamination to penetrate the carrier film and form a direct metal connection with the conductive receivers. This eliminates the need for high-temperature processes, fundamentally eliminating the damage caused by thermal stress from high-temperature welding, reducing the probability of microcracks, and improving the reliability of the photovoltaic module. Furthermore, the direct metal connection between the conductive protrusions and the conductive receivers eliminates the interface contact loss between the solder ribbon and the insulating layer in traditional technologies, reducing the overall resistance of the cell string, decreasing power loss, and saving costs.

[0024] This utility model also provides a photovoltaic module, which has high power generation efficiency and high reliability, and can achieve the purpose of saving costs. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model 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 the content of the embodiments of this utility model and these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the battery string structure provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the conductive protrusion on the front side of the battery cell provided in this embodiment of the utility model;

[0028] Figure 3 This is a schematic diagram of the structure of the conductive receiving part on the back of the battery cell provided in this embodiment of the utility model;

[0029] Figure 4 This is a top view of the photovoltaic module provided in this embodiment of the utility model.

[0030] Figure Labels

[0031] 10. Solar cell; 11. Overlapping area; 12. Front main grid line; 20. Conductive protrusion; 21. Base; 22. Protrusion; 30. Conductive receiving part; 31. Groove; 40. Carrier film; 50. Battery string; 60. Busbar. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0039] This embodiment provides a battery string that can reduce shading on the surface of the battery cells, improve power generation efficiency, reduce the risk of microcracks in the battery cells, improve reliability, and save costs.

[0040] like Figures 1-3 As shown, the battery string 50 mainly includes multiple battery cells 10, conductive protrusions 20, conductive receivers 30, and a carrier film 40. Adjacent battery cells 10 partially overlap to form an overlapping region 11. At least one conductive protrusion 20 is provided on the front main grid line 12 of the battery cell 10, and a conductive receiver 30 corresponding to and adapted to the conductive protrusion 20 is provided on the back main grid line of the battery cell 10. At least a portion of the conductive protrusions 20 and at least a portion of the conductive receivers 30 are located within the overlapping region 11, and at least a portion of the carrier film 40 is disposed within the overlapping region 11. In two adjacent battery cells 10, the conductive protrusion 20 of one battery cell 10 penetrates the carrier film 40 to form a direct metal connection with the conductive receiver 30 of the other battery cell 10.

[0041] Based on the above design, in traditional technology, the solder ribbon needs to cover the surface of the solar cell 10 to construct the current path, inevitably causing light shading and optical loss. This embodiment replaces the solder ribbon with conductive protrusions 20 on the front main grid line 12 of the solar cell 10 and conductive receiving parts 30 on the back of the solar cell 10, significantly reducing shading of the solar cell 10 surface, lowering optical loss, and improving the power generation efficiency of the photovoltaic module. Traditional solder ribbons need to be connected to the solar cell 10 through high-temperature welding, which generates thermal stress on the solar cell 10, easily leading to microcracks. In this embodiment, the conductive protrusions 20 are printed, requiring only mechanical pressure during lamination to penetrate the carrier film 40 and form a direct metal connection with the conductive receiving parts 30. There are no high-temperature processes throughout, eliminating the damage to the solar cell 10 caused by high-temperature welding thermal stress at the source, reducing the probability of microcracks in the solar cell 10, and improving the reliability of the photovoltaic module. Furthermore, in this embodiment, the conductive protrusion 20 and the conductive receiving part 30 form a direct metal connection, which eliminates the interface contact loss between the solder strip and the insulating layer in the conventional technology, reduces the overall resistance of the battery string 50, reduces power loss, and saves costs.

[0042] Optionally, in this embodiment, the conductive protrusion 20 and the conductive receiving portion 30 may be provided only in the overlapping region 11, or they may be provided in both the overlapping region 11 and the non-overlapping region. Preferably, a conductive protrusion 20 is provided on each front main grid line 12 in the overlapping region 11, and a conductive receiving portion 30 is provided at each back main grid line in the overlapping region 11.

[0043] like Figures 1-2 As shown, the conductive protrusion 20 includes a base 21 and a protrusion 22. One end of the base 21 is connected to the front main grid line 12 of the solar cell 10, and the other end of the base 21 is connected to the protrusion 22. The design of the base 21 makes the connection between the conductive protrusion 20 and the front main grid line 12 of the solar cell 10 more stable, avoiding poor contact or detachment problems caused by directly connecting the protrusion 22. The protrusion 22 is designed to facilitate penetration of the carrier film 40, and its shape and size can be independently optimized to ensure penetration force and contact reliability.

[0044] For example, the base 21 can be cylindrical, with a diameter matching the width of the front main grid line 12. The protrusion 22 can be hemispherical.

[0045] The tip of the hemispherical protrusion 22 is curved, which allows for more uniform force distribution when penetrating the carrier film 40, avoiding localized stress concentration caused by sharp edges and thus preventing tearing of the carrier film 40. Simultaneously, when the hemispherical protrusion 22 contacts the conductive receiver 30, the curved surface can adapt to minor deviations in the conductive receiver 30 (such as uneven surfaces), ensuring a stable contact area.

[0046] Optionally, in this embodiment, the height of the base 21 can be set between 30μm and 50μm, and the height of the protrusion 22 can be set between 30μm and 50μm.

[0047] The conductive protrusion 20 is made of silver paste. The base 21 and the protrusion 22 can be printed using an integrated silver paste printing process to ensure structural strength and conductivity. Alternatively, they can be formed using a two-stage printing process. For example, the base 21 is printed in the first stage with a height of 30μm-50μm; the protrusion 22 is printed in the second stage with a height of 30μm-50μm.

[0048] In some alternative embodiments, the conductive protrusion 20 is made of nano-silver paste material with a certain amount of carbon nanotubes added. The carbon nanotubes are dispersed by ultrasonication to ensure uniform distribution, thereby improving the conductivity and mechanical strength of the conductive protrusion 20.

[0049] like Figure 1 and Figure 3 As shown, the conductive receiving part 30 in this embodiment includes a groove 31 filled with conductive silver paste, which is directly connected to the metal bump 22. The groove 31 provides precise alignment space for the bump 22, and the conductive silver paste filling the groove 31 further enhances the contact conductivity, ensuring the stability and reliability of the direct metal connection. During the lamination process, the conductive silver paste in the groove 31 can deform with the bump 22 to form an adaptive contact, avoiding contact failure caused by stress concentration.

[0050] Optionally, in this embodiment, the groove 31 is formed at the position corresponding to the main grid line on the back side of the battery cell 10 by laser grooving process.

[0051] Optionally, the groove 31 in this embodiment has a semi-circular structure.

[0052] In this embodiment, the height of the conductive protrusion 20 is greater than the thickness of the carrier film 40, so that the protrusion 22 can penetrate the carrier film 40 and connect with the conductive receiving part 30. This allows the conductive protrusion 20 to completely penetrate the carrier film 40 during lamination and directly contact the conductive receiving part 30, eliminating the film layer barrier of the carrier film 40 and achieving effective direct metal connection. Simultaneously, the redundant height design of the conductive protrusion 20 allows for slight deformation of the protrusion 22 under pressure during lamination (due to the good toughness of the silver paste), ensuring a tight fit between the conductive protrusion 20 and the conductive receiving part 30 and avoiding incomplete connections caused by uneven thickness of the carrier film 40.

[0053] Preferably, the height of the base 21 of the conductive protrusion 20 is greater than the thickness of the carrier film 40, so that the protrusion 22 of the conductive protrusion 20 can completely pass through the carrier film 40 and directly contact the conductive receiving part 30.

[0054] For example, in this embodiment, the height of the conductive protrusion 20 is set to 100 μm, and the thickness of the carrier film 40 is set to 80 μm.

[0055] For example, during lamination, the contact pressure between the conductive protrusion 20 and the conductive receiving portion 30 is not less than 3 MPa, so as to form an ohmic contact with an interface resistance of less than 0.5 mΩ.

[0056] In some optional embodiments, along the extending direction of the front main grid line 12 of the battery cell 10, the conductive protrusion 20 is spaced at a first preset distance from the edge of the battery cell 10, the first preset distance being 3mm-5mm. Along the extending direction of the back main grid line of the battery cell 10, the conductive receiving portion 30 is spaced at a second preset distance from the edge of the battery cell 10, the second preset distance being 3mm-5mm.

[0057] By positioning the conductive protrusion 20 and the conductive receiving part 30 at a distance of 3mm-5mm from the edge of the solar cell 10, the edge area of ​​the solar cell 10 can be effectively utilized, the ineffective space can be reduced, and the effective light-receiving area of ​​the solar cell 10 can be avoided, thus reducing optical loss and improving the power of the photovoltaic module.

[0058] like Figure 4 As shown, this embodiment also provides a photovoltaic module, which includes multiple battery strings 50 and busbars 60. The busbars 60 are electrically connected to the battery cells 10 at the ends of the battery strings 50 so that the current generated by the battery strings 50 can be discharged.

[0059] Specifically, the busbar 60 is made of highly conductive copper foil material, with a protective layer plated on its surface to enhance corrosion resistance. During the assembly of the photovoltaic module, the busbar 60 is connected to the solar cells 10 at the end of the cell string 50 by ultrasonic welding. For example, one end of the busbar 60 is connected to the conductive protrusion 20 of the solar cell 10 at the middle end of the cell string 50, while the other end extends out of the photovoltaic module and connects to an external circuit, thereby efficiently discharging the current generated by the cell string 50 and realizing the transmission and utilization of electrical energy.

[0060] In some optional embodiments, when conductive protrusions 20 and conductive receivers 30 are also provided in the non-overlapping areas of the solar cells 10, the busbar 60 can be electrically connected to the conductive protrusions 20 or conductive receivers 30 of the solar cells 10 at the end of the solar string 50. When conductive protrusions 20 and conductive receivers 30 are not provided in the non-overlapping areas of the solar cells 10, the busbar 60 can be electrically connected to the front main grid line 12 or the back main grid line of the solar cells 10 at the end of the solar string 50. This makes the photovoltaic module more adaptable and compatible with different installation requirements and circuit designs, ensuring that the photovoltaic module can operate stably and efficiently in various application scenarios.

[0061] In some optional embodiments, the photovoltaic module further includes a short solder strip, one end of which is connected to the busbar 60; the other end of the short solder strip can be electrically connected to the conductive protrusion 20 or conductive receiving portion 30 of the cell 10 at the end of the cell string 50, and the other end of the short solder strip can also be electrically connected to the front main grid line 12 or the back main grid line of the cell 10 at the end of the cell string 50.

[0062] Because the photovoltaic module has the aforementioned battery string 50, it has high power generation efficiency and high reliability, thus achieving the goal of cost savings.

[0063] Obviously, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

[0064] Note that in the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A battery string, characterized in that, include: Multiple battery cells (10) are arranged in a partially overlapping manner to form an overlapping area (11) between two adjacent battery cells (10); At least one conductive protrusion (20) is provided on the front main grid line (12) of the battery cell (10), and a conductive receiving part (30) is provided on the back main grid line of the battery cell (10) corresponding to and adapted to the conductive protrusion (20); at least a portion of the conductive protrusion (20) and at least a portion of the conductive receiving part (30) are located in the overlapping area (11); A carrier membrane (40), at least a portion of which is disposed within the overlapping region (11); In two adjacent battery cells (10), the conductive protrusion (20) of one battery cell (10) penetrates the carrier film (40) and forms a direct metal connection with the conductive receiving portion (30) of the other battery cell (10).

2. The battery string according to claim 1, characterized in that, The conductive protrusion (20) includes a base (21) and a protrusion (22). One end of the base (21) is connected to the front main grid line (12) of the battery cell (10), and the other end of the base (21) is connected to the protrusion (22).

3. The battery string according to claim 2, characterized in that, The base (21) is cylindrical and the protrusion (22) is hemispherical.

4. The battery string according to claim 2, characterized in that, The conductive protrusion (20) is a silver paste component.

5. The battery string according to claim 2, characterized in that, The conductive receiving part (30) includes a groove (31) filled with conductive silver paste, and the conductive silver paste is directly connected to the metal of the protrusion (22).

6. The battery string according to claim 2, characterized in that, The height of the conductive protrusion (20) is greater than the thickness of the carrier film (40) so that the protrusion (22) can penetrate the carrier film (40) and connect with the conductive receiving part (30).

7. The battery string according to claim 1, characterized in that, Along the extension direction of the front main grid line (12) of the battery cell (10), the conductive protrusion (20) is at a first preset distance from the edge of the battery cell (10), and the first preset distance is set to 3mm-5mm.

8. The battery string according to claim 1, characterized in that, Along the extension direction of the back main grid line of the battery cell (10), the conductive receiving part (30) is at a second preset distance from the edge of the battery cell (10), and the second preset distance is set to 3mm-5mm.

9. A photovoltaic module, characterized in that, The photovoltaic module includes a battery string (50) and a busbar (60) as described in any one of claims 1-8, wherein the busbar (60) is electrically connected to the battery cells (10) at the end of the battery string (50) to facilitate the discharge of current generated by the battery string (50).

10. The photovoltaic module according to claim 9, characterized in that, The busbar (60) is electrically connected to the conductive protrusion (20) or conductive receiving part (30) of the battery cell (10) at the end of the battery string (50). Alternatively, the busbar (60) is electrically connected to the front main grid line (12) or the back main grid line of the battery cell (10) at the end of the battery string (50).

Images