Separator, back contact battery assembly and photovoltaic system

Abstract

The utility model belongs to the field of photovoltaic technology, and discloses a separator, a back contact battery assembly and a photovoltaic system, the separator is used for insulating and isolating a bus bar and a solder strip on the back of a battery piece, the separator comprises an insulating substrate, at least one side of the insulating substrate is provided with a pressure-sensitive adhesive structure, and the pressure-sensitive adhesive structure is used for bonding the back of the battery piece or the bus bar. When a laminated assembly formed by a battery piece, a separator and a bus bar is covered with a flexible film to form a closed space, and the closed space is vacuumized to perform vacuum welding, the flexible film can apply pressure to the bus bar under the action of negative pressure, so that the pressure-sensitive adhesive structure realizes bonding under the action of pressure, and the welding efficiency is improved. Therefore, the separator is bonded and fixed with at least one of the bus bar and the battery piece through the pressure-sensitive adhesive structure, and the problems of pseudo soldering, missing soldering, short circuit and the like can be avoided to a certain extent. Since the bus bar, the separator and the battery piece are fixed by means of the existing vacuumizing process, the original fixing process is simplified, and the mass production efficiency can be improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to an isolation component, a back contact battery module, and a photovoltaic system. Background Technology

[0002] In back-contact solar cell modules, since the positive and negative electrodes of the cells are on their back side (non-light-receiving surface), there is no need to weld grid lines to conduct current on the light-receiving surface. The light-receiving area is increased compared to ordinary solar cells, which helps to improve the photoelectric conversion efficiency of the photovoltaic system.

[0003] In back-contact battery modules, busbars are specifically welded to the grid lines of the battery cells via solder strips to collect current. Since both the positive and negative electrodes of the battery cells are on the back side, positive and negative solder strips are located on the back of the cell. Busbars can only be welded to solder strips of the same polarity, and cannot be connected to solder strips of opposite polarities simultaneously to prevent short circuits. To achieve the connection between the busbar and the solder strips of the same polarity, an insulating separator is typically placed between the positive and negative solder strips on the back of the battery cell and the busbar to insulate them. Then, a specific process is used to connect the busbar to the solder strip of the same polarity.

[0004] During the welding and lamination curing processes of battery modules, the positions of the busbars and spacers relative to the battery cells must be kept fixed to prevent problems such as spacer displacement obscuring solder joints or busbar movement relative to spacers causing short circuits. In existing technologies, spacers are placed on the back of the battery cells and pre-fixed using methods such as heat pressing or applying adhesive tape. Then, the busbars are placed on the spacers and pre-fixed using heat pressing or applying adhesive tape to prevent movement of the spacers and busbars during welding and lamination. This pre-fixation process for spacers and busbars results in a longer production cycle and lower mass production efficiency for battery modules.

[0005] Therefore, there is an urgent need for an isolation component, a back-contact battery module, and a photovoltaic system to solve the aforementioned problems in the existing technology. Utility Model Content

[0006] The purpose of this invention is to provide an isolation component, a back-contact battery module, and a photovoltaic system that can ensure the fixed positions of the isolation component, the busbar, and the battery cells while eliminating the pre-fixing process of the isolation component and the busbar, thereby accelerating the production cycle and improving production efficiency.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] Firstly, an isolation element is provided, comprising:

[0009] An insulating substrate is used to insulate and isolate the busbar and the solder strip on the back of the battery cell, the insulating element comprising:

[0010] Insulating substrate;

[0011] A pressure-sensitive adhesive structure is provided on at least one side of the insulating substrate, and the pressure-sensitive adhesive structure is used to bond the back of the battery cell or the busbar.

[0012] As an optional solution for the isolation component provided by this utility model, the outer contour of the pressure-sensitive adhesive structure does not exceed the outer contour of the insulating substrate.

[0013] As an optional solution for the isolation component provided by this utility model, the insulating substrate is strip-shaped;

[0014] Multiple pressure-sensitive adhesive structures are spaced apart along the length of both sides of the insulating substrate; or, the pressure-sensitive adhesive structure extends from one end of the insulating substrate to the other end.

[0015] As an optional solution for the isolation component provided by this utility model, the pressure-sensitive adhesive structure includes an acrylic pressure-sensitive adhesive layer or an organosilicon resin pressure-sensitive adhesive layer.

[0016] As an optional solution for the isolation component provided by this utility model, the pressure-sensitive adhesive structure is provided on both opposite sides of the insulating substrate.

[0017] As an optional solution for the isolation component provided by this utility model, the pressure-sensitive adhesive structure is embedded in the insulating substrate.

[0018] As an optional solution for the isolation component provided by this utility model, the isolation component further includes a photovoltaic encapsulant film layer;

[0019] The photovoltaic encapsulant layer is provided on at least one side of the insulating substrate.

[0020] As an optional solution for the isolation component provided by this utility model, the photovoltaic encapsulant film layer is provided with an embedding area, and the pressure-sensitive adhesive structure is disposed in the embedding area;

[0021] The embedded region extends through the photovoltaic adhesive film layer, and the pressure-sensitive adhesive structure is bonded to the insulating substrate; or, there is a gap between the pressure-sensitive adhesive structure and the insulating substrate.

[0022] As an optional solution for the isolation component provided by this utility model, the pressure-sensitive adhesive structure, the photovoltaic adhesive film layer, and the insulating substrate are stacked in sequence;

[0023] Alternatively, the insulating substrate is strip-shaped, and multiple pressure-sensitive adhesive structures and multiple photovoltaic adhesive film layers are alternately distributed along the length of the insulating substrate.

[0024] As an optional solution for the isolation component provided by this utility model, the outer contour of the photovoltaic encapsulant layer is flush with the outer contour of the insulating substrate.

[0025] In a second aspect, a back contact battery assembly is provided, including the separator described above.

[0026] As an optional embodiment of the back contact battery assembly provided by this utility model, the back contact battery assembly further includes:

[0027] The back of the battery cell is bonded to a pressure-sensitive adhesive structure on one side of the insulating substrate;

[0028] A solder strip is disposed between the back side and the insulating substrate. The solder strip includes a positive electrode solder strip and a negative electrode solder strip, both of which are electrically connected to the battery cell.

[0029] A busbar is disposed on the side of the insulating substrate facing away from the battery cell and is bonded to the pressure-sensitive adhesive structure; the busbar is connected to the positive electrode solder strip or the negative electrode solder strip.

[0030] As an optional solution for the back contact battery assembly provided by this utility model, the orthographic projection of the pressure-sensitive adhesive structure onto the plane where the busbar is located falls within the area where the busbar is located.

[0031] As an optional solution for the back contact battery assembly provided by this utility model, the maximum dimension of the pressure-sensitive adhesive structure along the width direction of the busbar is 0.4 to 0.7 times the width dimension of the busbar.

[0032] As an optional solution for the back contact battery assembly provided by this utility model, the insulating substrate and the busbar have the same length direction, the length dimension of the insulating substrate is greater than or equal to the length dimension of the busbar, and the width dimension of the insulating substrate is greater than or equal to the width dimension of the busbar.

[0033] Thirdly, a photovoltaic system is provided, including the back-contact battery assembly as described above.

[0034] The beneficial effects of this utility model are:

[0035] This invention provides a separator and a back-contact battery assembly including the separator. The separator is applied between the battery cells and the busbars of the battery assembly. The insulating substrate of the separator can insulate and isolate the solder strips on the back of the busbars and battery cells, preventing the busbars from being connected to two solder strips of opposite polarities simultaneously, thus avoiding short circuits. By providing a pressure-sensitive adhesive structure on at least one side of the insulating substrate, after the separator and busbars are stacked sequentially on the battery cells, applying pressure to the busbars will cause the pressure-sensitive adhesive structure on one side of the insulating substrate to bond with the battery cells or busbars. This ensures a stable connection between the separator and at least one of the battery cells and busbars, helping to reduce relative displacement among the three components during subsequent welding and curing processes, and to a certain extent avoiding problems such as cold solder joints, open solder joints, and short circuits. When pressure-sensitive adhesive structures are provided on both sides of the insulating substrate, the busbars, separators, and battery cells can be fixed together, preventing relative displacement among the three components during subsequent welding and curing processes, avoiding problems such as cold solder joints, open solder joints, and short circuits, and helping to improve the yield rate of the battery assembly. After placing the separator on the back of the battery cell and after placing the busbar on the separator, no pre-fixing process is required, which can speed up the production cycle and improve mass production efficiency.

[0036] When welding battery modules in a vacuum environment, a flexible membrane is typically used to enclose the stacked assembly consisting of battery cells, separators, and busbars within a sealed space. When this sealed space is evacuated, the flexible membrane applies pressure to the busbars under negative pressure, achieving a fixed connection between the separator and at least one of the busbars and battery cells. In other words, the separator's structural design allows for the fixation of the busbars, separators, and battery cells using existing vacuuming processes, without requiring any additional steps, effectively shortening the production cycle.

[0037] This utility model also provides a photovoltaic system that, due to including the aforementioned high-yield and high-production-efficiency back-contact battery module, can improve power generation reliability, has a short construction cycle, and can be put into use quickly. Attached Figure Description

[0038] 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.

[0039] Figure 1 This is a schematic diagram of the battery assembly being vacuumed before laser welding, according to a specific embodiment of this utility model.

[0040] Figure 2 yes Figure 1A magnified view of a section at point C;

[0041] Figure 3 This is a schematic diagram of the first connection between the isolation component, the busbar, and the battery cell provided in a specific embodiment of this utility model;

[0042] Figure 4 This is a top view of the isolation member provided in the first embodiment of this utility model;

[0043] Figure 5 yes Figure 4 Cross-sectional view at point AA;

[0044] Figure 6 yes Figure 4 Cross-sectional view at point BB;

[0045] Figure 7 This is a partial cross-sectional view of the isolation member provided in the second embodiment of this utility model;

[0046] Figure 8 This is a schematic diagram of the structure of the isolation component provided in the third embodiment of this utility model;

[0047] Figure 9 This is a schematic diagram of the structure of the isolation component provided in the fourth embodiment of this utility model;

[0048] Figure 10 This is a schematic diagram of the structure of the isolation component provided in the fifth embodiment of this utility model;

[0049] Figure 11 This is a schematic diagram of the structure of the isolation component provided in the sixth embodiment of this utility model;

[0050] Figure 12 This is a schematic diagram of the second connection between the isolation component, the busbar, and the battery cell provided in a specific embodiment of this utility model.

[0051] In the picture:

[0052] 1. Insulator; 2. Battery cell; 3. Busbar; 4. Front panel; 5. Adhesive film;

[0053] 11. Insulating substrate; 12. Pressure-sensitive adhesive structure; 13. Photovoltaic adhesive film layer;

[0054] 131. Embedded area;

[0055] 100. Flexible membrane; 200. Enclosed space; 300. Welding platform;

[0056] 301. Bottom support; 302. Side support. Detailed Implementation

[0057] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0058] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0059] 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.

[0060] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0061] In this embodiment, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0062] In the embodiments of this utility model, the same reference numerals denote the same parts, and for the sake of brevity, detailed descriptions of the same parts are omitted in different embodiments.

[0063] like Figure 1 , Figure 2 as well as Figure 3 As shown, this embodiment provides a back contact battery assembly, including an separator 1, a battery cell 2, a solder strip (not shown in the figure), and a busbar 3.

[0064] In this configuration, the battery cell 2 is a back-contact battery cell 2, with the grid lines arranged on the back side (non-illuminated surface) and no grid lines on the front side (illuminated surface). Both the positive and negative electrodes are located on the back side of the battery cell 2. A back-contact battery assembly typically includes at least one battery string, which comprises at least two battery cells 2 connected in series. The specific number of battery cells 2 in the battery string is determined according to actual usage requirements.

[0065] The solder strips are disposed on the back of the battery cell 2, specifically including a positive solder strip and a negative solder strip. At least one positive solder strip and at least one negative solder strip are disposed on the back of the battery cell 2, and both the positive solder strip and the negative solder strip are electrically connected to the battery cell 2.

[0066] Busbar 3 is used to collect the current on the cell 2 and transmit it to the output end of the battery module. It is located on the back of the cell 2 and is used to collect the current on the same polarity solder strip, such as connecting only to the positive solder strip or only to the negative solder strip. Connecting solder strips of opposite polarity is prohibited.

[0067] See Figure 1 The separator 1 is disposed between the back of the busbar 3 and the back of the battery cell 2, and covers a portion of the solder ribbon, so that the solder ribbon and the busbar 3 are insulated from each other at the location of the separator 1. Figure 2 and Figure 3 Specifically, the separator 1 includes an insulating substrate 11. The insulating substrate 11 insulates and isolates the busbar 3 from the solder strips on the back of the battery cell 2. For example, the insulating substrate 11 covers multiple positive and multiple negative solder strips on the back of the battery cell 2, preventing the busbar 3 from directly contacting the positive and negative solder strips and causing a short circuit. For example, for a busbar 3 that is only connected to the positive solder strip, it can be subsequently connected to the positive solder strip using an auxiliary solder rod. When the insulating substrate 11 is in place, the busbar 3 remains insulated from the negative solder strip. That is, the insulating substrate 11 of the separator 1 can prevent the busbar 3 from being connected to two solder strips of different polarities simultaneously, thus preventing a short circuit.

[0068] For example, the insulating substrate 11 can be a PET (polyethylene terephthalate) layer. The PET layer has high insulation performance and high voltage resistance, ensuring reliable insulation isolation between the busbar 3 and the solder ribbon. Of course, the insulating substrate 11 can also be a PI (polyimide) layer, or a composite material layer containing at least two of the following materials: ethylene vinyl acetate copolymer, resin material, polyimide, polypropylene, polyethylene, etc. The specific material of the insulating substrate 11 is not limited here, as long as it can effectively insulate and isolate the busbar 3 and the solder ribbon.

[0069] See Figure 2 and Figure 3 The separator 1 provided in this embodiment of the present invention also includes a pressure-sensitive adhesive structure 12. The pressure-sensitive adhesive structure 12 is provided on at least one side of the insulating substrate 11, and the pressure-sensitive adhesive structure 12 is used to bond the back of the battery cell 2 or the busbar 3.

[0070] In some embodiments, pressure-sensitive adhesive structures 12 are provided on both opposite sides of the insulating substrate 11. The number and distribution of the pressure-sensitive adhesive structures 12 are not limited. The pressure-sensitive adhesive structures 12 on both sides of the insulating substrate 11 are used to bond the back of the battery cell 2 and the busbar 3, respectively, so that the busbar 3, the separator 1, and the battery cell 2 are fixed together. The pressure-sensitive adhesive has the characteristic of being sensitive to pressure during the bonding process; when it is pressed, it can firmly bond the objects to be bonded, and the greater the pressure, the stronger the bond.

[0071] By providing pressure-sensitive adhesive structures 12 on both sides of the insulating substrate 11, after the separator 1 and busbar 3 are sequentially stacked on the battery cell 2, applying pressure to the busbar 3 will cause the pressure-sensitive adhesive on both sides to bond to the battery cell 2 and the busbar 3 respectively. This fixes the busbar 3, separator 1, and battery cell 2 together, preventing relative displacement between them during subsequent welding and curing processes. This avoids problems such as poor soldering, open soldering, and short circuits, and helps improve the yield of the battery module. For example, if the insulating substrate 11 of the separator 1 shifts relative to the battery cell 2, it may cover the metal contact points on the battery cell 2 used for connecting with the solder ribbon, resulting in poor soldering or open soldering, poor current collection effect, and reduced photoelectric conversion efficiency. Furthermore, if the busbar 3 shifts relative to the separator 1, the outer contour of the busbar 3 may exceed the outer contour of the insulating substrate 11, causing the busbar 3 to make conductive contact with the solder ribbon of opposite polarity, resulting in an internal short circuit in the battery. The above problems can be effectively solved by fixing the busbar 3, the separator 1, and the battery cell 2.

[0072] Moreover, after placing the separator 1 on the back of the battery cell 2 and after placing the busbar 3 on the separator 1, no pre-fixing process is required. Simply apply pressure to fix the busbar 3, separator 1 and battery cell 2 together, which can speed up the production cycle and improve mass production efficiency.

[0073] Furthermore, in the laser welding process of battery modules, the welding environment is a vacuum environment. To achieve this vacuum welding process, such as... Figure 1 and Figure 2As shown, a flexible membrane 100 is typically covered on the welding platform 300 to enclose the stacked assembly formed by the battery cell 2, the separator 1, and the busbar 3 within a closed space 200. This closed space 200 is then evacuated using a vacuum pump. During evacuation, the flexible membrane 100 applies pressure to the busbar 3 under negative pressure, thus securing the busbar 3, separator 1, and battery cell 2 together. In other words, the structure of the separator 1 can be used to fix the busbar 3, separator 1, and battery cell 2 using the existing vacuuming process, without requiring any additional steps, effectively shortening the production cycle.

[0074] like Figure 1 As shown, the back-contact battery assembly also includes a front panel 4 and an adhesive film 5. The battery cell 2 can be bonded and fixed to the front panel 4 through the adhesive film 5. Before laser welding, the front panel 4, adhesive film 5, battery cell 2, welding ribbon, separator 1, and busbar 3 are stacked sequentially to form a combined structure, which is then fixed on the welding platform 300. The welding platform 300 includes a bottom support 301 and side supports 302 located on both sides of the bottom support 301. The combined structure is placed on the bottom support 301. The dimensions of the front panel 4 and adhesive film 5 are both larger than the dimensions of the stacked assembly formed by the battery cell 2, separator 1, and busbar 3. When the flexible film 100 is covered on the stacked assembly, the combination... Figure 2 The two ends of the flexible membrane 100 are respectively placed on the edge area of ​​the adhesive film 5 and the side support 302, so that the flexible membrane 100 and the adhesive film 5 form a closed space 200. When the closed space 200 is evacuated, the flexible membrane 100 can apply a certain pressure to the stacked components under negative pressure, so as to fix the battery cell 2, the separator 1 and the busbar 3 before welding.

[0075] After the vacuum is evacuated to the preset vacuum level, the welding strip is scanned by a laser welding device to complete the welding process. Then the flexible film 100 can be removed and the welded semi-finished battery module can be transferred to the next process.

[0076] Furthermore, the back-contact battery module also includes a backplate. An adhesive film 5 and a backplate are sequentially stacked on the back side of the battery cells 2 of the pre-welded semi-finished battery module to form a laminate. This laminate is then subjected to a curing and lamination process to obtain the finished battery module. During the curing and lamination process, the adhesive film 5 melts at a high temperature and cures after cooling, firmly bonding the battery cells 2, the front plate 4, and the backplate together.

[0077] For example, the front panel 4 is a transparent glass plate with high light transmittance, which ensures that the solar cell 2 has a high photoelectric conversion efficiency. The back panel can be a glass plate, an aluminum alloy plate, a TPT (polyvinyl fluoride) composite film, etc.

[0078] For example, the film 5 can be a thermosetting or thermoplastic film such as EVA (ethylene-vinyl acetate copolymer), POE (polyolefin elastomer), or PVB (polyvinyl butyral) film. There is no limitation here. Of course, the types of film 5 are not limited to those listed above.

[0079] like Figure 3 As shown, in some embodiments of this utility model, the separator 1 further includes a photovoltaic encapsulant layer 13. A photovoltaic encapsulant layer 13 is provided on at least one side of the insulating substrate 11. The photovoltaic encapsulant layer 13 has the properties of melting at high temperature and curing after cooling, possessing the same properties as the adhesive film 5 used to bond the front panel 4, the battery cell 2, and the back panel. By providing photovoltaic encapsulant layers 13 on both sides of the insulating substrate 11, during the lamination process of the battery module (high temperature and vacuum environment), the photovoltaic encapsulant layer 13 can melt and cure after cooling. This melting and curing process can bond the busbar 3 and the insulating substrate 11 together, as well as the battery cell 2 and the insulating substrate 11 together, further improving the bonding strength of the busbar 3, the separator 1, and the battery cell 2 after the lamination process.

[0080] Furthermore, the surface of the pressure-sensitive adhesive structure 12 facing away from the insulating substrate 11 is not lower than the surface of the photovoltaic film layer 13 facing away from the insulating substrate 11. Therefore, the photovoltaic film layer 13 will not hinder the adhesion of the pressure-sensitive adhesive structure 12 to the solar cell 2 and the busbar 3.

[0081] It is understood that in some other embodiments, the photovoltaic encapsulant layer 13 may not be provided on the insulating substrate 11, and only the insulating substrate 11 and the pressure-sensitive adhesive structure 12 are included. During the vacuuming process before the welding process, the busbar 3, the separator 1 and the battery cell 2 can be initially fixed by means of vacuum pressure and the pressure-sensitive adhesive structure 12. In the lamination process, the adhesive film 5 between the back of the battery cell 2 and the backsheet can also ensure the stability of the three components.

[0082] For example, the photovoltaic encapsulant layer 13 can be an EVA (ethylene-vinyl acetate copolymer) encapsulant layer, a POE (polyolefin elastomer) encapsulant layer, a PVB (polyvinyl butyral) encapsulant layer, etc., but is not limited to the encapsulant layer types listed, as long as it can play an adhesive role in the lamination process.

[0083] like Figure 4 , Figure 5 as well as Figure 6 The diagram shown is a structural schematic of the isolation member 1 provided in some embodiments of this utility model. Wherein, Figure 4 This is a top view of the isolation component 1. Figure 5 for Figure 4 A cross-sectional view along the AA direction, the cross-section does not pass through pressure-sensitive adhesive structure 12. Figure 6 for Figure 4 The cross-sectional view along the BB direction shows the section passing through the pressure-sensitive adhesive structure 12. Pressure-sensitive adhesive structures 12 and photovoltaic film layers 13 are provided on both sides of the insulating substrate 11, with the photovoltaic film layer 13 directly covering the insulating substrate 11. The photovoltaic film layer 13 has an embedding area 131, within which the pressure-sensitive adhesive structure 12 is positioned. This ensures the stability of the pressure-sensitive adhesive structure 12 relative to the photovoltaic film layer 13, and allows the surface of the pressure-sensitive adhesive structure 12 to be flush with the photovoltaic film layer 13 during processing. This avoids affecting the initial fixation of the pressure-sensitive adhesive to the solar cell 2 and busbar 3 under vacuum pressure, and also avoids affecting the curing and bonding of the photovoltaic film layer 13 to the solar cell 2 and busbar 3 during the lamination process, while ensuring a good appearance for the separator 1. Furthermore, embedding the pressure-sensitive adhesive structure 12 within the photovoltaic film layer 13 helps reduce the overall thickness of the separator 1, preventing the finished battery module from exceeding thickness limits.

[0084] Of course, the pressure-sensitive adhesive structure 12 can also be slightly higher than the photovoltaic adhesive film layer 13, for example, within 30μm of the photovoltaic adhesive film layer, and further limited to within 15μm. It is understandable that even if the pressure-sensitive adhesive structure 12 is slightly higher than the photovoltaic adhesive film layer 13, the photovoltaic adhesive film layer 13 can still be smoothly cured and connected to the solar cell 2 and the busbar 3 under the pressure of the lamination process.

[0085] Specifically Figure 6 In this design, the embedded region 131 penetrates the photovoltaic encapsulant film layer 13, allowing the bottom surface of the pressure-sensitive adhesive structure 12 to be directly bonded to the insulating substrate 11. This ensures that the insulating substrate 11, busbar 3, and solar cell 2 do not shift relative to each other during both laser welding and lamination processes, preventing short circuits caused by contact between the busbar 3 and solder strips of opposite polarity. Furthermore, the process of creating the embedded region 131 through the photovoltaic encapsulant film layer 13 is simpler, allowing for direct cutting or molding in a special mold.

[0086] like Figure 7 As shown, the isolation member 1 provided in other embodiments of this utility model is different from... Figures 4 to 6 In the shown separator 1, the embedded area 131 on the photovoltaic encapsulant layer 13 does not penetrate the photovoltaic encapsulant layer 13. The bottom of the pressure-sensitive adhesive structure 12 is bonded to the bottom wall of the embedded area 131, but there is a gap between it and the insulating substrate 11. In this case, the bonding area between the photovoltaic encapsulant layer 13 and the insulating substrate 11 is large, which can improve the bonding strength between the insulating substrate 11 and the busbar 3 and the solar cell 2 after lamination.

[0087] For example, a pressure-sensitive adhesive structure 12 in a molten state can be filled into the embedded region 131, and then formed after cooling and curing. The method of forming the pressure-sensitive adhesive structure 12 on the photovoltaic film layer 13 is not limited here.

[0088] like Figures 4 to 7 In the shown separator 1, the insulating substrate 11 is strip-shaped to match the shape of the busbar 3, providing insulation and isolation from the solder strip along the entire length of the busbar 3. The photovoltaic encapsulant layer 13 is also strip-shaped, extending in the same direction as the insulating substrate 11. Multiple embedding areas 131 are spaced along the length of the photovoltaic encapsulant layer 13, and each embedding area 131 contains a pressure-sensitive adhesive structure 12. This ensures that multiple pressure-sensitive adhesive structures 12 are distributed along the length of both sides of the insulating substrate 11, effectively improving the fixation strength between the busbar 3, the separator 1, and the solar cell 2 during vacuuming. Furthermore, the multiple pressure-sensitive adhesive structures 12 are evenly spaced to ensure uniform connection strength along the length of the separator 1.

[0089] In some embodiments, such as Figure 8 As shown, the pressure-sensitive adhesive structure 12, the photovoltaic film layer 13, and the insulating substrate 11 are sequentially stacked. The process is simple; the photovoltaic film layer 13 and the pressure-sensitive adhesive structure 12 are simply stacked sequentially on the insulating substrate 11. At this point, the pressure-sensitive adhesive structure 12 is slightly higher than the photovoltaic film layer 13. The photovoltaic film layer 13 will melt under high temperature during the lamination process of the battery module. Under the pressure of the lamination process, the photovoltaic film layer 13 can also be smoothly cured and bonded to the battery cell 2 and the busbar 3. The thickness of the pressure-sensitive adhesive structure 12 is, for example, less than 30 μm, and further less than 10 μm, to avoid the problem of the photovoltaic film layer 13 failing to fully bond with the busbar 3 and the battery cell 2 during the lamination process.

[0090] Furthermore, Figure 8 In the isolation component 1 shown, both the insulating substrate 11 and the photovoltaic film layer 13 are strip-shaped, and multiple pressure-sensitive adhesive structures 12 are distributed along the length direction of the photovoltaic film layer 13.

[0091] In some embodiments, such as Figure 9 As shown, the insulating substrate 11 in the separator 1 is strip-shaped. Multiple pressure-sensitive adhesive structures 12 and multiple photovoltaic film layers 13 are provided on each side of the insulating substrate 11, with the multiple pressure-sensitive adhesive structures 12 and multiple photovoltaic film layers 13 alternately distributed along the length of the insulating substrate 11. The multiple pressure-sensitive adhesive structures 12 ensure that the busbar 3, the separator 1, and the solar cell 2 are firmly fixed during vacuuming. The multiple photovoltaic film layers 13 ensure that the insulating substrate 11 is firmly bonded to the busbar 3 and the solar cell 2 during lamination. Therefore, the separator 1 also ensures that the busbar 3, the separator 1, and the solar cell 2 will not shift relative to each other during laser welding and lamination, and that the three are firmly connected in the finished laminated solar module, which helps to improve the service life of the solar module.

[0092] Figure 9In the isolation component 1 shown, the pressure-sensitive adhesive structure 12 and the photovoltaic film layer 13 are both directly coated on the surface of the insulating substrate 11. Optionally, the pressure-sensitive adhesive structure 12 and the photovoltaic film layer 13 are flush with the surfaces of the insulating substrate 11 facing away from each other.

[0093] exist Figures 4 to 9 In the illustrated embodiment, multiple pressure-sensitive adhesive structures 12 are spaced apart along the length of the insulating substrate 11. The multiple pressure-sensitive adhesive structures 12 on both sides of the insulating substrate 11 can be arranged facing each other or staggered; no limitation is made here.

[0094] In some other embodiments, such as Figure 10 As shown, only one pressure-sensitive adhesive structure 12 can be provided on each side of the insulating substrate 11. The pressure-sensitive adhesive structure 12 extends from one end of the insulating substrate 11 to the other end, which can ensure that the separator 1 can stably connect the busbar 3 and the battery cell 2 during the vacuuming process, and that the connection is firm and uniform in the length direction of the busbar 3.

[0095] Figure 10 In the shown separator 1, both the insulating substrate 11 and the pressure-sensitive adhesive structure 12 are elongated strips. The length and width of the pressure-sensitive adhesive structure 12 can be smaller than the length and width of the insulating substrate 11, respectively. In this case, a photovoltaic film layer 13 can be placed on the area of ​​the insulating substrate 11 where the pressure-sensitive adhesive structure 12 is not arranged, or the photovoltaic film layer 13 can be omitted. The pressure-sensitive adhesive structure 12 can also be completely aligned with the insulating substrate 11, with the two having the same dimensions. In this case, there is no need to arrange the photovoltaic film layer 13. Optionally, the strip-shaped pressure-sensitive adhesive structure 12 is stacked on the surface of the insulating substrate 11, which simplifies the manufacturing process.

[0096] like Figure 11 As shown, as an example of the separator 1 provided in this embodiment, a pressure-sensitive adhesive structure 12 can also be embedded in the insulating substrate 11. Specifically, multiple grooves are spaced along the length of the insulating substrate 11, and a pressure-sensitive adhesive structure 12 is disposed in each groove, which can fix the position of the pressure-sensitive adhesive structure 12 relative to the insulating substrate 11. Further, the surface of the pressure-sensitive adhesive structure 12 is flush with the surface of the insulating substrate 11. At this time, the total thickness of the separator 1 is the same as the total thickness of the insulating substrate 11, which can make the overall thickness of the separator 1 smaller, and thus make the thickness of the finished battery module thinner. It can be understood that in Figure 11 The isolation element 1 shown may consist only of an insulating substrate 11 and a pressure-sensitive adhesive structure 12 flush with the surface of the insulating substrate 11. Of course, if the pressure-sensitive adhesive structure 12 is configured to protrude above the surface of the insulating substrate 11, a photovoltaic adhesive film layer 13 can be coated on the insulating substrate 11, so that the upper part of the pressure-sensitive adhesive structure 12 is embedded in the photovoltaic adhesive film layer 13, and the pressure-sensitive adhesive structure 12 is flush with the surface of the photovoltaic adhesive film layer 13.

[0097] In some embodiments, the outer contour of the pressure-sensitive adhesive structure 12 does not exceed the outer contour of the insulating substrate 11. On the one hand, for the pressure-sensitive adhesive structure 12 between the insulating substrate 11 and the battery cell 2, the portion exceeding the outer contour of the insulating substrate 11 can easily cover the structure on the back of the battery cell 2, such as grid lines and metal contact points, causing poor soldering and resulting in low photoelectric conversion efficiency. For the pressure-sensitive adhesive structure 12 between the insulating substrate 11 and the busbar 3, the portion exceeding the outer contour of the insulating substrate 11 bends towards the battery cell 2 under the pressure applied during the vacuuming process, which can also lead to the problem of covering the structure on the back of the battery cell 2. On the other hand, if the pressure-sensitive adhesive structure 12 exceeds the outer contour of the insulating substrate 11, not only will the appearance quality of the separator 1 be poor, but it will also cause waste of pressure-sensitive adhesive material. At the same time, the portion of the pressure-sensitive adhesive that exceeds the outer contour of the insulating substrate 11 is very likely to adhere to the flexible film 100 covered during the vacuuming process, making it difficult to remove the flexible film 100 intact after the vacuum is broken.

[0098] In some embodiments, such as Figures 4 to 8 As shown, the outer contour of the photovoltaic encapsulant layer 13 is flush with the outer contour of the insulating substrate 11. Without wasting materials, the area occupied by the photovoltaic encapsulant layer 13 on the insulating substrate 11 can be maximized, thereby increasing the bonding area between the insulating substrate 11 and the busbar 3 and the solar cell 2 during the lamination process and improving the bonding strength.

[0099] In this embodiment of the invention, the heat distortion temperature of the pressure-sensitive adhesive structure 12 is greater than that of the photovoltaic adhesive film layer 13. For example... Figure 6 As shown, the pressure-sensitive adhesive structure 12 is bonded to the surface of the insulating substrate 11. During the lamination process of the battery module, when the photovoltaic film layer 13 melts in a high-temperature environment, the pressure-sensitive adhesive structure 12 has not yet reached the heat distortion temperature. It can still maintain its shape throughout the lamination process and is firmly bonded to the battery cell 2 or busbar 3. It will not be forced to move due to the flowability generated by the photovoltaic film layer 13, the front panel 4 and the film 5 on the back panel side when they melt. It always firmly bonds the insulating substrate 11, the busbar 3 and the battery cell 2, which can further ensure that the busbar 3, the separator 1 and the battery cell 2 do not shift relative to each other during the lamination process, and avoid the busbar 3 from contacting the solder strip of opposite polarity and causing a short circuit.

[0100] In some embodiments of this utility model, the pressure-sensitive adhesive structure 12 includes an acrylic pressure-sensitive adhesive layer. The acrylic pressure-sensitive adhesive layer has high transparency, excellent weather resistance and heat resistance, and can maintain its shape in the temperature range of -40℃ to 200℃. The lamination temperature of photovoltaic modules is usually between 100℃ and 200℃. In this temperature range, the photovoltaic film layer 13 is in a molten state, while the acrylic pressure-sensitive adhesive layer can still maintain its original shape and function normally in this temperature range. This avoids the relative movement of the solar cell 2, busbar 3 and separator 1 caused by the fluidity of the photovoltaic film layer 13, the front panel 4 and the film 5 on the back panel side in the molten state.

[0101] In other embodiments of this invention, the pressure-sensitive adhesive structure 12 can also be a silicone resin pressure-sensitive adhesive layer. The silicone resin pressure-sensitive adhesive layer can maintain its shape between -60℃ and 200℃. For some types of silicone resin pressure-sensitive adhesive layers, the heat distortion temperature can reach 300℃. Using a silicone resin pressure-sensitive adhesive layer can achieve the same effects.

[0102] Combination Figure 3 and Figure 12 The insulating substrate 11 and the busbar 3 have the same length direction, and both are elongated. The length of the insulating substrate 11 is greater than or equal to the length of the busbar 3, and the width W2 of the insulating substrate 11 is greater than or equal to the width W1 of the busbar 3. That is, the orthographic projection of the busbar 3 onto the plane of the insulating substrate 11 falls completely within the area of ​​the insulating substrate 11, so that the busbar 3 is completely shielded by the insulating substrate 11 and cannot contact the opposite polarity solder strip on the back of the battery cell 2, thereby avoiding short circuit problems.

[0103] In some embodiments, see Figure 12 The orthographic projection of the pressure-sensitive adhesive structure 12 onto the plane of the busbar 3 falls within the area where the busbar 3 is located, meaning the pressure-sensitive adhesive structure 12 will not exceed the outer contour of the busbar 3. If the pressure-sensitive adhesive structure 12 exceeds the outer contour of the busbar 3, the excess portion will adhere to the flexible membrane 100 covering the busbar 3 during the vacuuming process, making it difficult to remove the flexible membrane 100 after the vacuum is broken, and may also cause damage to the flexible membrane 100.

[0104] In some specific embodiments, the maximum dimension W3 of the pressure-sensitive adhesive structure 12 along the width direction of the busbar 3 is 0.4 to 0.7 times the width dimension W1 of the busbar 3. Within this size range, the pressure-sensitive adhesive structure 12 will not extend beyond the busbar 3 along the width direction of the busbar 3, thus preventing adhesion to the flexible membrane 100. At the same time, the size of the pressure-sensitive adhesive structure 12 is not too small, resulting in insufficient connection strength with the busbar 3 and the battery cell 2.

[0105] For example, the maximum dimension W3 of the pressure-sensitive adhesive structure 12 along the width direction of the busbar 3 is 0.4 times, 0.43 times, 0.5 times, 0.55 times, 0.58 times, 0.6 times, 0.65 times, 0.7 times, etc. of the width dimension W1 of the busbar 3, but is not limited to the listed multiples.

[0106] For example, the pressure-sensitive adhesive structure 12 is in the shape of a rectangular sheet, with its adjacent two sides being parallel to the adjacent two sides of the insulating substrate 11, and the size of the side of the pressure-sensitive adhesive structure 12 that is parallel to the width direction of the insulating substrate 11 is 0.4 to 0.7 times the width dimension W1 of the busbar 3.

[0107] Combination Figure 1 and Figure 2 The laser welding process for the back contact battery assembly with the separator 1 provided in this embodiment is roughly as follows:

[0108] S1. Loading: Place the combined structure formed by the front plate 4, adhesive film 5, battery cell 2, welding strip, separator 1 and busbar 3 arranged according to the pattern onto the welding platform 300.

[0109] S2. Fixing: Fix the combined structure on the welding platform 300;

[0110] S3, Covering with flexible film 100: Covering the above-mentioned combined structure with flexible film 100 so that the battery cells 2, welding ribbons, separators 1, and busbars 3 laid on the front panel 4 are within the enclosed space 200;

[0111] S4. Vacuuming: Vacuuming is performed on the above-mentioned enclosed space 200 so that the separator 1, the busbar 3 and the battery cell 2 are initially fixed by the pressure-sensitive adhesive structure 12.

[0112] S5. Laser welding: Laser scans the welding strip to complete the welding process;

[0113] S6. Break the vacuum: Break the vacuum state of the aforementioned enclosed space 200;

[0114] S7. Remove the flexible membrane 100: Separate the flexible membrane 100 from the above-mentioned welded composite structure;

[0115] S8. Material preparation: The assembled structure after welding is transferred to the next packaging process to complete the packaging of the battery module.

[0116] This invention also provides a photovoltaic system, including at least one back-contact battery module as described above. Because this photovoltaic system incorporates the aforementioned high-yield and high-production-efficiency back-contact battery module, it improves power generation reliability and has a short construction cycle, enabling rapid deployment.

[0117] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios of photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter and is converted into AC power required by the mains grid before being connected to the mains grid to achieve solar power supply.

[0118] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A separator for insulatingly isolating the busbar (3) and the solder strip on the back of the battery cell (2), characterized in that, The isolation element includes: Insulating substrate (11); Pressure-sensitive adhesive structure (12), wherein the insulating substrate (11) is provided with the pressure-sensitive adhesive structure (12) on at least one side, and the pressure-sensitive adhesive structure (12) is used to bond the back of the battery cell (2) or the busbar (3).

2. The isolation component according to claim 1, characterized in that, The outer contour of the pressure-sensitive adhesive structure (12) does not exceed the outer contour of the insulating substrate (11).

3. The isolation component according to claim 1, characterized in that, The insulating substrate (11) is strip-shaped; The insulating substrate (11) has multiple pressure-sensitive adhesive structures (12) spaced apart along its length on both sides; or, the pressure-sensitive adhesive structure (12) extends from one end of the insulating substrate (11) to the other end.

4. The isolation member according to claim 1, characterized in that, The pressure-sensitive adhesive structure (12) includes an acrylic pressure-sensitive adhesive layer or an organosilicon pressure-sensitive adhesive layer.

5. The separator according to any one of claims 1-4, characterized in that, The pressure-sensitive adhesive structure (12) is provided on both sides of the insulating substrate (11).

6. The separator according to any one of claims 1-4, characterized in that, The pressure-sensitive adhesive structure (12) is embedded in the insulating substrate (11).

7. The separator according to any one of claims 1-4, characterized in that, The insulating component also includes a photovoltaic encapsulant layer (13); The photovoltaic encapsulant layer (13) is provided on at least one side of the insulating substrate (11).

8. The separator according to claim 7, characterized in that, The photovoltaic adhesive film layer (13) is provided with an embedding area (131), and the pressure-sensitive adhesive structure (12) is disposed in the embedding area (131); The embedded region (131) extends through the photovoltaic adhesive film layer (13), and the pressure-sensitive adhesive structure (12) is bonded to the insulating substrate (11); or, there is a gap between the pressure-sensitive adhesive structure (12) and the insulating substrate (11).

9. The isolation member according to claim 7, characterized in that, The pressure-sensitive adhesive structure (12), the photovoltaic adhesive film layer (13), and the insulating substrate (11) are stacked sequentially; Alternatively, the insulating substrate (11) is strip-shaped, and a plurality of pressure-sensitive adhesive structures (12) and a plurality of photovoltaic adhesive film layers (13) are alternately distributed along the length direction of the insulating substrate (11).

10. The separator according to claim 7, characterized in that, The outer contour of the photovoltaic film layer (13) is flush with the outer contour of the insulating substrate (11).

11. A back-contact battery assembly, characterized in that, Includes the isolation element as described in any one of claims 1-10.

12. The back contact battery assembly according to claim 11, characterized in that, The back contact battery assembly also includes: The back side of the battery cell (2) is bonded to the pressure-sensitive adhesive structure (12) on one side of the insulating substrate (11); A solder strip is disposed between the back side and the insulating substrate (11). The solder strip includes a positive electrode solder strip and a negative electrode solder strip. Both the positive electrode solder strip and the negative electrode solder strip are electrically connected to the battery cell (2). Busbar (3) is disposed on the side of the insulating substrate (11) facing away from the battery cell (2) and is bonded to the pressure-sensitive adhesive structure (12); the busbar (3) is connected to the positive electrode solder strip or the negative electrode solder strip.

13. The back contact battery assembly according to claim 12, characterized in that, The orthographic projection of the pressure-sensitive adhesive structure (12) onto the plane of the busbar (3) falls within the area of ​​the busbar (3).

14. The back contact battery assembly according to claim 13, characterized in that, The maximum dimension of the pressure-sensitive adhesive structure (12) along the width direction of the busbar (3) is 0.4 to 0.7 times the width dimension of the busbar (3).

15. The back contact battery assembly according to any one of claims 12-14, characterized in that, The insulating substrate (11) has the same length direction as the busbar (3), the length dimension of the insulating substrate (11) is greater than or equal to the length dimension of the busbar (3), and the width dimension of the insulating substrate (11) is greater than or equal to the width dimension of the busbar (3).

16. A photovoltaic system, characterized in that, Includes the back contact battery assembly as described in any one of claims 11-15.

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