Main-grid-free battery, photovoltaic module and photovoltaic system
By setting up adhesive layers with different adhesion forces on the battery cell, the problem of poor adhesion between the film layer and the metal during coating is solved, and the problem of shadowing of the head and tail and edges of the battery after thermal cycle test is avoided, and the reliability of photovoltaic modules and systems is improved.
Patent Information
- Application Number
- CN202421957776.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-13
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-08-13
AI Technical Summary
In the prior art, the film lamination welding technology has poor adhesion between the film layer and the metal during coating, resulting in the problem of head and tail of the battery and edge shadowing after thermal cycle test.
By setting adhesive layers with different bonding forces in different areas of the battery cell, and especially a second adhesive layer with greater bonding forces is arranged at part edges of the battery cell, the ends of the welding tape and the edges of the battery cell are well fixed, ensuring the adhesion between the adhesive layer and the battery cell and the metal welding tape during the coating process.
It enhances the fixing effect of specific positions of the battery cell, such as edge positions, avoids the problems of head and tail of the battery and edge shadows after thermal cycle testing, and improves the yield and reliability of photovoltaic modules and systems.
Smart Images
Figure CN222928745U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of photovoltaics, and particularly relates to a main-grid-free battery, a photovoltaic module and a photovoltaic system. Background Art
[0002] With the development of technologies such as heterojunction (HJT) battery technology and main-grid-free (0BB) battery technology, the combination of HJT battery and main-grid-free technology has become the research focus of the photovoltaic industry. In the process of manufacturing HJT main-grid-free batteries, how to effectively realize the effective connection between the solder ribbon and the battery chip has become one of the main factors hindering the development of HJT main-grid-free batteries.
[0003] The 0BB film laminating welding technology cancels the main grid line at the battery end, only retains the fine grid line, and realizes the connection between the solder ribbon and the battery chip through an adhesive method, and then realizes the welding through lamination. Because this process adopts a low-temperature and long-time lamination welding process, it has advantages for the thinning of HJT battery chips and the low silver content of the paste. In the implementation process of this process, the fixation of the solder ribbon mainly depends on the carrier film. Currently, the most widely used carrier film is the pre-crosslinked EVA film. This film has a poor adhesion to HJT batteries and there is a risk of delamination. In addition, the EVA film itself has a low strength when heated and a poor adhesion to metals. When performing film lamination, if the temperature is too high, the coating effect on the solder ribbon is poor, resulting in a poor pressing effect on the solder ribbon locally, and it is easy to have problems such as battery head and tail and edge shadow after thermal cycle testing.
[0004] Correspondingly, a new technical solution is needed in this field to solve the above problems. Summary of the Utility Model
[0005] In order to solve at least one of the above problems in the prior art, that is, to solve the problems that the adhesion between the film layer and the metal is poor during film lamination and the battery head, tail and edge shadow are easy to appear after thermal cycle testing, the present application provides a main-grid-free battery, including a battery chip, a solder ribbon, a first adhesive layer and a second adhesive layer. The solder ribbon is located on one side of the battery chip. Both the first adhesive layer and the second adhesive layer are used to fix the solder ribbon. The second adhesive layer is at least arranged at a partial edge position of the battery chip, and the first adhesive layer is arranged in the area of the battery chip except the second adhesive layer.
[0006] Wherein, the adhesion between the second adhesive layer and the battery chip is greater than the adhesion between the first adhesive layer and the battery chip; and / or the adhesion between the second adhesive layer and the solder ribbon is greater than the adhesion between the first adhesive layer and the solder ribbon.
[0007] For the ownerless grid battery of the present application, by setting adhesive layers with different adhesive forces in different areas of the battery cell, the fixing effect at specific positions of the battery cell, such as the edge position, can be enhanced, the adhesive forces between the adhesive layer, the battery cell and the metal solder strip during the film laminating process can be ensured, and the problems of battery head and tail and edge shadow after the thermal cycle test can be avoided. Specifically, the applicant has found through research that since the expansion coefficient of the solder strip is different from that of the battery cell, the deformation amounts of the solder strip and the battery cell are different after heating, and the deformation amount reaches the maximum at the end position of the solder strip. Therefore, after the solder strip is fixed to the side of the battery cell through the adhesive layer, the residual stress at the end of the solder strip is the largest, which easily leads to poor pressing effect of the film layer on the solder strip and the problems of battery head and tail and edge shadow after the thermal cycle test. In the present application, by arranging a second adhesive layer with a greater adhesive force at least at part of the edge positions of the battery cell, the ends of the solder strip and the edge of the battery cell can be well fixed, the adhesive forces between the adhesive layer, the battery cell and the metal solder strip during the film laminating process can be ensured, and the problems of battery head and tail and edge shadow after the thermal cycle test can be avoided.
[0008] In a preferred technical solution of the above-mentioned ownerless grid battery, the second adhesive layer is an adhesive film or a dotting layer.
[0009] In a preferred technical solution of the above-mentioned ownerless grid battery, the second adhesive layer is arranged on two opposite first edges of the battery cell, and the length direction of the second adhesive layer is perpendicular to the length direction of the solder strip.
[0010] By arranging the second adhesive layer on the first edge of the battery cell in the above setting method, the two ends of the solder strip can be fixed by using the second adhesive layer, and the fixing effect at the end of the solder strip can be improved.
[0011] In a preferred technical solution of the above-mentioned ownerless grid battery, the second adhesive layer is further arranged on two opposite second edges of the battery cell, and the length direction of the second adhesive layer is parallel to the length direction of the solder strip.
[0012] By arranging the second adhesive layer on the second edge of the battery cell in the above setting method, the two ends of the grid lines of the battery cell can be fixed by using the second adhesive layer, and the fixing effect at the end of the grid lines of the battery cell can be improved.
[0013] In a preferred technical solution of the above-mentioned ownerless grid battery, the width of the second adhesive layer arranged on the first edge or the second edge is any value between 11 mm and 20 mm; and / or
[0014] The width of the second adhesive layer arranged on the second edge is greater than the width of the second adhesive layer arranged on the first edge.
[0015] If the width of the second adhesive layer on the second edge is greater than the width of the second adhesive layer on the first edge, the too thin adhesive film after lamination at the battery edge can be avoided, and the product stability can be improved.
[0016] In the preferred technical solution of the above-mentioned main-gridless battery, the second adhesive layer is also disposed between the two first edges, and the length direction of the second adhesive layer disposed between the two first edges is perpendicular to the length direction of the solder strip.
[0017] By adding the second adhesive layer between the two first edges in the above setting method, the second adhesive layer can be used to fix other positions of the solder strip, improving the reliability of the welding rod, so that the main-gridless battery is less likely to have problems such as solder joint detachment and solder strip offset during the reliability test.
[0018] In the preferred technical solution of the above-mentioned main-gridless battery, the width of the second adhesive layer disposed between the two first edges is any value in the range of 0.5 mm to 20 mm.
[0019] In the preferred technical solution of the above-mentioned main-gridless battery, the tensile strength of the second adhesive layer is greater than 20 Mpa; and / or
[0020] the elongation at break of the second adhesive layer is any value in the range of 200% to 500%; and / or
[0021] the adhesion between the second adhesive layer and the battery cell is greater than 50 N / cm; and / or
[0022] the adhesion between the second adhesive layer and the solder strip is greater than 30 N / cm.
[0023] In the preferred technical solution of the above-mentioned main-gridless battery, the first adhesive layer is an EVA film; and / or
[0024] the second adhesive layer is one of a PVB film, a TPO film, an epoxy resin film, a polyurethane film, and an acrylate film; and / or
[0025] the second adhesive layer is an epoxy resin adhesive or a curing adhesive; and / or
[0026] The main-gridless battery is a heterojunction battery.
[0027] The present application also provides a photovoltaic module, which includes the main-gridless battery according to any one of the above technical solutions.
[0028] By providing adhesive layers with different adhesive forces in different regions of the battery cell in the photovoltaic module of the present application, the fixing effect of specific positions of the battery cell, such as the edge position, can be enhanced, the adhesive forces between the adhesive layer and the battery cell and the metal solder strip during the film covering process can be ensured, problems such as battery head and tail and edge shadow after the thermal cycle test can be avoided, and the yield and reliability of the photovoltaic module can be improved.
[0029] The present application also provides a photovoltaic system, which includes the above-mentioned photovoltaic module.
[0030] In the photovoltaic system of the present application, by providing adhesive layers with different adhesive forces in different regions of the cell, the fixing effect at specific positions of the cell, such as the edge position, can be enhanced, the adhesive forces between the adhesive layer and the cell and the metal solder ribbon during the film covering process can be ensured, the problems of cell head and tail and edge shadows after the thermal cycle test can be avoided, and the reliability of the photovoltaic system can be improved. Description of the Drawings
[0031] The present application will be described below with reference to the accompanying drawings. In the drawings:
[0032] Figure 1 is the layout diagram of the cell and the solder ribbon of the main-gridless cell of the present application;
[0033] Figure 2 is the structural diagram of the first layout mode of the first adhesive layer and the second adhesive layer in the main-gridless cell of the present application;
[0034] Figure 3 is the structural diagram of the second layout mode of the first adhesive layer and the second adhesive layer in the main-gridless cell of the present application;
[0035] Figure 4 is the structural diagram of the third layout mode of the first adhesive layer and the second adhesive layer in the main-gridless cell of the present application.
[0036] Reference numerals list
[0037] 1. Cell; 11. First edge; 12. Second edge; 2. Solder ribbon; 3. First adhesive layer; 4. Second adhesive layer. Detailed Embodiments
[0038] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application.
[0039] It should be noted that in the description of the present application, the terms indicating directions or positional relationships such as "up", "down", "vertical", "horizontal", "inside", "outside", etc. are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, "a plurality of" means at least two.
[0040] In addition, it should be noted that in the description of this application, unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0041] First, refer to Figure 1 and Figure 2 , and a brief introduction to the main-gridless battery of this application will be given.
[0042] As Figure 1 and Figure 2 shown, in order to solve the problems of poor adhesion between the film layer and the metal during film lamination in the film laminating welding technology, and easy appearance of battery head and tail and edge shadows after thermal cycle testing, this application provides a main-gridless battery, including a battery cell 1, a welding strip 2, a first adhesive layer 3, and a second adhesive layer 4. The welding strip 2 is located on one side of the battery cell 1. Both the first adhesive layer 3 and the second adhesive layer 4 are used to fix the welding strip 2. The second adhesive layer 4 ( Figure 2 the diagonal area in Figure 2 ) is arranged at least at part of the edge position of the battery cell 1, and the first adhesive layer 3 ( Figure 2 the dotted line area at the midpoint) is arranged in the area of the battery cell 1 except for the second adhesive layer 4. Among them, the adhesion between the second adhesive layer 4 and the battery cell 1 is greater than the adhesion between the first adhesive layer 3 and the battery cell 1, and / or the adhesion between the second adhesive layer 4 and the welding strip 2 is greater than the adhesion between the first adhesive layer 3 and the welding strip 2.
[0043] For the main-gridless battery of this application, by setting adhesive layers with different adhesion in different areas of the battery cell 1, the fixing effect of specific positions of the battery cell 1 such as the edge position can be enhanced, the adhesion between the adhesive layer and the battery cell 1 and the metal welding strip 2 during the film lamination process can be ensured, and the problems of battery head and tail and edge shadows after thermal cycle testing can be avoided. Specifically, the applicant has found through research that since the expansion coefficient of the welding strip 2 is different from that of the battery cell 1, the deformation amounts of the welding strip 2 and the battery cell 1 are different after heating, and this deformation amount reaches the maximum at the end position of the welding strip 2. Therefore, after the welding strip 2 is fixed to the side of the battery cell 1 through the adhesive layer, the residual stress at the end of the welding strip 2 is the largest, which easily leads to poor pressing effect of the film layer on the welding strip 2 and easy appearance of battery head and tail and edge shadows after thermal cycle testing. And in this application, by arranging the second adhesive layer 4 with greater adhesion at least at part of the edge position of the battery cell 1, the end of the welding strip 2 and the edge of the battery cell 1 can be well fixed, the adhesion between the adhesive layer and the battery cell 1 and the metal welding strip 2 during the film lamination process can be ensured, and the problems of battery head and tail and edge shadows after thermal cycle testing can be avoided.
[0044] Next, in combination with Figure 1And Figure 2 , the first implementation manner of the main-gridless battery of the present application is introduced. Figure 2 In order to show the positional relationship between the display glue layer and the solder ribbon 2, the solder ribbon 2 is shown as a dotted line.
[0045] Such as Figure 1 And Figure 2 As shown, in a possible implementation manner, the main-gridless battery is a heterojunction battery (abbreviated as HJT battery). The main-gridless battery includes a battery chip 1, a solder ribbon 2, a first glue layer 3, and a second glue layer 4. The battery chip 1 is generally rectangular, and a plurality of sub-grid electrodes are arranged thereon. A plurality of solder ribbons 2 are laid on the sub-grid electrodes. In the implementation manner shown in the present application Figure 1 As shown, on the upper side of the battery chip 1 ( Figure 1 The side shown in Figure 2 ), a plurality of sub-grid electrodes extending in the horizontal direction are arranged, and twenty-four solder ribbons 2 extending in the vertical direction are laid on the upper side of the sub-grid electrodes. The twenty-four solder ribbons 2 are laid basically evenly in the horizontal direction. Both the first glue layer 3 and the second glue layer 4 are laid on the upper side of the solder ribbon 2 for fixing the solder ribbon 2 to the upper side of the battery chip 1. In this implementation manner, the second glue layer 4 is arranged at two opposite first edges 11 of the battery chip 1, and the length direction of the second glue layer 4 is perpendicular to the length direction of the solder ribbon 2. The first glue layer 3 is arranged in the area between the two second glue layers 4. Taking
[0046] As an example of the shown orientation, the upper and lower edges of the battery chip 1 are provided with the second glue layer 4, and each second glue layer 4 extends in the horizontal direction. The first glue layer 3 is laid in the area between the upper and lower second glue layers 4.
[0047] Further, on the premise of meeting the above performance parameters, the second adhesive layer 4 can be a film or a dotting layer. When the second adhesive layer 4 is a film, the second adhesive layer 4 can be one of a PVB film (polyvinyl butyral), a TPO film (thermoplastic polyolefin), an epoxy resin film, a polyurethane film, and an acrylate film; or the second adhesive layer 4 can also be a multi-layer composite film, such as a PET and silicone composite. When the second adhesive layer 4 is a dotting layer, the second adhesive layer 4 can be an adhesive layer formed by epoxy resin glue, curing glue, etc.
[0048] In a possible implementation, the first adhesive layer 3 is an EVA film, where EVA is ethylene-vinyl acetate copolymer. The EVA film is a thermosetting film, which has high transparency, ultraviolet aging resistance and damp heat aging resistance, extremely low shrinkage rate, and relatively high volume resistivity. Compared with thermoplastic films, it will not cause problems such as hot spot delamination, bubbles, broken grids, and de-soldering due to later heat effects after heat setting.
[0049] In the above setting method, the upper side area of the battery cell 1 is divided according to the bonding force requirements. The two ends of the welding tape 2 are prone to de-soldering, and for the area with relatively high bonding performance requirements, the second adhesive layer 4 is used for fixation to improve the fixation effect of the end of the welding tape 2. For the remaining areas, compared with the bonding requirements, higher temperature resistance requirements are needed, and traditional thermosetting films are used for fixation, so as to achieve regional control of the film layer and improve the overall performance of the product.
[0050] Those skilled in the art can understand that although the above implementation is introduced by taking the HJT battery as an example, the application scenario of the present application is not limited to this. Those skilled in the art can apply the technical solution of the present application to other main-gridless batteries.
[0051] Those skilled in the art can also understand that the width of the second adhesive layer 4 and the performance parameters of the second adhesive layer 4 are only limited to this implementation. Those skilled in the art can adjust the above parameters based on specific application scenarios, as long as it is ensured that the bonding force of the second adhesive layer 4 is greater than that of the first adhesive layer 3.
[0052] In addition, although the above implementation is described by taking the battery cell 1 as being roughly rectangular and having twenty-four welding tapes 2 provided on the battery cell 1, this is only exemplary. In other implementations, those skilled in the art can adjust the shape of the battery cell 1, the number of welding tapes 2, etc. Such adjustments do not deviate from the principle of the present application. For example, the shape of the battery cell 1 can also be square, chamfered rectangle, chamfered square, etc.
[0053] Furthermore, the above-described embodiments are introduced by taking the example that the bonding force between the second adhesive layer 4 and the solar cell 1 and the bonding force between the second adhesive layer 4 and the solder ribbon 2 are both greater than those of the first adhesive layer 3. However, this is only a preferred embodiment. In other embodiments, as long as at least one of the bonding force between the second adhesive layer 4 and the solar cell 1 and the bonding force between the second adhesive layer 4 and the solder ribbon 2 is greater than that of the first adhesive layer 3, the object of improving the edge fixing effect of the main-gridless solar cell in the present application can be achieved.
[0054] The following will introduce the second embodiment of the main-gridless solar cell of the present application in conjunction with Figure 1 and Figure 3 .
[0055] As shown in Figure 1 and Figure 3 , on the basis of the first embodiment, the second adhesive layer 4 is further disposed between the two first edges 11, and the length direction of the second adhesive layer 4 disposed between the two first edges 11 is perpendicular to the length direction of the solder ribbon 2. Referring to Figure 3 , that is to say, on the basis of the second adhesive layer 4 being disposed on the two first edges 11, a plurality of second adhesive layers 4 are further disposed between the two second adhesive layers 4 laid on the first edges 11, and the second adhesive layer 4 extends and is laid in the horizontal direction. Figure 3 In the embodiment shown, three additional second adhesive layers 4 are further disposed between the two second adhesive layers 4 located on the first edges 11, and the widths of the three second adhesive layers 4 are smaller than the width of the second adhesive layer 4 laid on the first edges 11. In a possible embodiment, the width of the second adhesive layer 4 disposed between the two first edges 11 is any value in the range of 0.5 mm to 20 mm.
[0056] On the premise of the above setting method, the first adhesive layer 3 is laid between adjacent second adhesive layers 4. Figure 3 In the embodiment shown, there are four first adhesive layers 3, and each first adhesive layer 3 is laid between adjacent second adhesive layers 4.
[0057] In the above setting method, by adding the second adhesive layer 4 between the two first edges 11, the second adhesive layer 4 can be used to fix other positions of the solder ribbon 2, improving the reliability of the solder joint, so that the main-gridless solar cell is less likely to have problems such as solder joint detachment and solder ribbon 2 offset during the reliability test. The width of the second adhesive layer 4 located in the middle is smaller than the width of the second adhesive layer 4 laid on the first edges 11, which can ensure that the influence on other performances is minimized on the premise of fixing the solder ribbon 2.
[0058] Of course, the number of the second adhesive layers 4 and the number of the first adhesive layers 3 between the two first edges 11 are only exemplary, and those skilled in the art can adjust them based on the specific application scenario.
[0059] The following will introduce in conjunction with Figure 1 And Figure 4 , a third implementation manner of the main-gridless battery of the present application will be introduced.
[0060] As Figure 1 and Figure 4 shown, compared with the first implementation manner, in this implementation manner, the second adhesive layer 4 is further disposed on two opposite second edges 12 of the battery cell 1, and the length direction of the second adhesive layer 4 is parallel to the length direction of the welding tape 2. Referring to Figure 4 , that is to say, on the premise that the second adhesive layer 4 is respectively laid on the two first edges 11, the second adhesive layer 4 is also laid on the two second edges 12 of the battery cell 1, and the second adhesive layer 4 extends and is laid in the vertical direction. Among them, the width of the second adhesive layer 4 laid on the second edge 12 is any value in the range of 11 mm to 20 mm, and the width of the second adhesive layer 4 disposed on the first edge 11 is smaller than the width of the second adhesive layer 4 disposed on the second edge 12.
[0061] On the premise of the above setting manner, the first adhesive layer 3 is laid in the area enclosed by the second adhesive layer 4 laid on the first edge 11 and the second edge 12.
[0062] In the above setting manner, by disposing the second adhesive layer 4 on the second edge 12 of the battery cell 1, the two ends of the grid lines of the battery cell 1 can be fixed by the second adhesive layer 4, and the fixing effect of the grid line ends of the battery cell 1 can be improved. Since the width of the second adhesive layer 4 on the second edge 12 is greater than the width of the second adhesive layer 4 on the first edge 11, it is possible to avoid the adhesive film being too thin after the battery edge is laminated, and improve the product stability.
[0063] Those skilled in the art can understand that the width of the second adhesive layer 4 laid on the second edge 12 is not necessarily greater than the width of the second adhesive layer 4 laid on the first edge 11. Those skilled in the art can make adjustments based on specific application scenarios, and such adjustments do not deviate from the principle of the present application.
[0064] Those skilled in the art can also understand that although the layout manner of the second adhesive layer 4 and the first adhesive layer 3 of the present application is introduced in combination with three specific implementation manners above, the layout manner of the second adhesive layer 4 and the first adhesive layer 3 of the main-gridless battery of the present application is not limited to this. Those skilled in the art can improve the above implementation manners without departing from the principle of the present application so that the present application is applicable to more specific application scenarios. For example, the second adhesive layer 4 can also be laid only on the second edge 12; or multiple second adhesive layers 4 can be laid between the two first edges 11 on the basis of the third implementation manner, etc.
[0065] The present application also provides a photovoltaic module, and the photovoltaic module includes the main-gridless battery in any of the above implementation manners.
[0066] For the photovoltaic module of the present application, by providing adhesive layers with different adhesive forces in different regions of the cell 1, the fixing effect of specific positions of the cell 1, such as the edge position, can be enhanced, the adhesive forces between the adhesive layer and the cell 1 and the metal solder strip 2 during the film covering process can be ensured, the problems of cell head and tail and edge shadow after the thermal cycle test can be avoided, and the yield and reliability of the photovoltaic module can be improved.
[0067] The present application also provides a photovoltaic system, which includes the above-mentioned photovoltaic module.
[0068] For the photovoltaic system of the present application, by providing adhesive layers with different adhesive forces in different regions of the cell 1, the fixing effect of specific positions of the cell 1, such as the edge position, can be enhanced, the adhesive forces between the adhesive layer and the cell 1 and the metal solder strip 2 during the film covering process can be ensured, the problems of cell head and tail and edge shadow after the thermal cycle test can be avoided, and the reliability of the photovoltaic system can be improved.
[0069] Those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims of the present application, any one of the claimed embodiments can be used in any combination.
[0070] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.
Claims
1. A busbar-less battery, characterized in that: The invention comprises a battery cell, a welding strip, a first adhesive layer and a second adhesive layer, wherein the welding strip is located on one side of the battery cell, the first adhesive layer and the second adhesive layer are both used to fix the welding strip, the second adhesive layer is arranged at least at a part of the edge position of the battery cell, and the first adhesive layer is arranged in the area of the battery cell except the second adhesive layer. The bonding force between the second adhesive layer and the battery cell is greater than the bonding force between the first adhesive layer and the battery cell; and / or the bonding force between the second adhesive layer and the soldering tape is greater than the bonding force between the first adhesive layer and the soldering tape.
2. The busbar-free battery according to claim 1, characterized in that: The second adhesive layer is an adhesive film or an adhesive dot layer.
3. The busbar-free battery according to claim 1, characterized in that: The second adhesive layer is disposed on two first edges of the battery cell that are opposite to each other, and a length direction of the second adhesive layer is perpendicular to a length direction of the welding strip.
4. The busbar-free battery according to claim 3, characterized in that: The second adhesive layer is also arranged on two second edges of the battery cell that are opposite to each other, and the length direction of the second adhesive layer is parallel to the length direction of the welding strip.
5. The busbar-free battery according to claim 4, characterized in that: The width of the second adhesive layer disposed on the first edge or the second edge is any value between 11 mm and 20 mm; and / or The width of the second adhesive layer disposed on the second edge is greater than the width of the second adhesive layer disposed on the first edge.
6. The busbar-free battery according to any one of claims 3 to 5, characterized in that: The second adhesive layer is further disposed between the two first edges, and a length direction of the second adhesive layer disposed between the two first edges is perpendicular to a length direction of the welding strip.
7. The busbar-free battery according to claim 6, characterized in that: The width of the second adhesive layer disposed between the two first edges is any value between 0.5 mm and 20 mm.
8. The busbar-free battery according to claim 1, characterized in that: The tensile strength of the second adhesive layer is greater than 20Mpa; and / or The elongation at break of the second adhesive layer is any value between 200% and 500%; and / or The bonding force between the second adhesive layer and the battery cell is greater than 50 N / cm; and / or The bonding force between the second adhesive layer and the welding strip is greater than 30N / cm.
9. The busbar-free battery according to claim 1, characterized in that: The first adhesive layer is an EVA adhesive film; and / or The second adhesive layer is one of a PVB film, a TPO film, an epoxy resin film, a polyurethane film, and an acrylate film; and / or The second adhesive layer is epoxy resin adhesive or curing adhesive; and / or The busbar-free battery is a heterojunction battery.
10. A photovoltaic module, characterized in that: The photovoltaic module comprises the busbar-less cell according to any one of claims 1 to 9.
11. A photovoltaic system, characterized in that: The photovoltaic system comprises the photovoltaic module according to claim 10.