Photovoltaic cell string

Abstract

The utility model provides a photovoltaic cell string, relates to the field of photovoltaic technology, and aims to solve the technical problem that the fragmentation risk of a cell connection area is difficult to effectively reduce in the photovoltaic cell string. The photovoltaic battery string comprises at least two battery pieces and at least one packaging adhesive film, a connecting space is formed in the area where every two adjacent battery pieces of the at least two battery pieces are close to each other, and the connecting space at least comprises a gap between every two adjacent battery pieces; at least one groove is formed in the at least one packaging adhesive film, and the groove is communicated with the corresponding connecting space; buffer structures are arranged in the grooves and the corresponding connecting spaces, and two adjacent battery pieces are connected through the buffer structures; and the hardness of the buffer structure is smaller than that of the cured packaging adhesive film. The photovoltaic cell string provided by the utility model is accurately positioned through the buffer structure with lower hardness, so that the breaking risk of a connecting area between two adjacent cell sheets can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a photovoltaic cell string. Background Art

[0002] The statements in this section merely provide background technology related to the present invention and do not necessarily constitute prior art.

[0003] In the photovoltaic field, with the development of heterojunction (HJT) cell technology, silicon wafer thinning technology and busbar-free cell technology, the photovoltaic string assembly process at the module end, that is, the traditional welding process, is no longer applicable. For high-density packaging technology of photovoltaic modules, such as negative spacing stacking technology, hidden cracks are easily generated in the cell stacking area.

[0004] In the related art, when laying battery strings, it is necessary to add a process to apply adhesive film or glue to the overlapping areas of battery cells or the gaps between cells. The lamination process is combined with a low-fluidity packaging adhesive film, and the components are laminated. On the one hand, the cured adhesive film or glue is solid and has a high hardness, which increases the risk of cracking in the overlapping areas of battery cells; on the other hand, it is difficult to ensure the accuracy of the application position of the adhesive film or glue, which increases the risk of cracking in the overlapping areas of battery cells. Utility Model Content

[0005] The utility model aims to provide a photovoltaic cell string to solve the technical problem that it is difficult to effectively reduce the risk of cell sheet fragmentation in the overlapping area in the photovoltaic cell string.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] In a first aspect, the utility model provides a photovoltaic cell string, comprising at least two cells and at least one encapsulation film, wherein a connection space is provided in a region where two adjacent cells of the at least two cells are close to each other, and the connection space at least comprises a gap between the two adjacent cells;

[0008] At least one of the packaging films is formed with at least one groove, and the groove is communicated with the corresponding connection space;

[0009] A buffer structure is provided in the groove and the corresponding connection space, and two adjacent battery cells are connected via the buffer structure;

[0010] The hardness of the buffer structure is less than the hardness of the encapsulation film after curing.

[0011] According to at least one embodiment of the present utility model, the buffer structure is a structure made of liquid silicone or silicone resin.

[0012] According to at least one embodiment of the present invention, two adjacent battery cells have a zero spacing or a negative spacing in a preset direction, and the preset direction refers to a distribution direction from one battery cell to another of the two adjacent battery cells.

[0013] According to at least one embodiment of the present utility model, when two adjacent battery cells have a negative spacing in a preset direction, the ratio of the width of the buffer structure to the width of the overlapping area of ​​the two adjacent battery cells is (1-5):1;

[0014] The width direction of the buffer structure and the width direction of the overlapping regions of two adjacent battery cells are both preset directions.

[0015] According to at least one embodiment of the present utility model, when two adjacent battery cells have zero spacing in a preset direction, the width of the buffer structure is 2 mm to 10 mm;

[0016] The width direction of the buffer structure is a preset direction.

[0017] According to at least one embodiment of the present utility model, the buffer structure further includes a portion located in at least one subspace of the connection space;

[0018] The subspace refers to: the area between the parts where two adjacent battery cells are close to each other and the corresponding packaging films in the connection space.

[0019] According to at least one embodiment of the present invention, a welding strip is provided on at least one surface of the battery cell, the portion of the buffer structure located in the subspace is a protruding structure protruding from the corresponding surface of the battery cell, and the ratio of the height of the protruding structure to the diameter of the welding strip is (2 to 5):1.

[0020] According to at least one embodiment of the present utility model, the photovoltaic cell string further includes at least one adhesive film, and the adhesive film is used to fix the welding ribbon to the surface of the corresponding cell sheet.

[0021] According to at least one embodiment of the present invention, each of the battery cells is arranged in parallel with the packaging film; or,

[0022] Each of the battery cells is arranged at a preset angle to the packaging film.

[0023] In a second aspect, the utility model provides a photovoltaic cell assembly, including a photovoltaic cell string and two packaging boards that package the photovoltaic cell string, wherein the photovoltaic cell string includes a buffer structure and at least two cell sheets;

[0024] The buffer structure has two opposite surfaces, each of which is connected to the corresponding packaging board, and each of the battery cells is embedded in the buffer structure;

[0025] The buffer structure is a structure made of liquid silicone or silicone resin.

[0026] According to at least one embodiment of the present invention, a barrier layer is further provided between the peripheral edge portions of the two packaging plates, and the barrier layer is used to form a closed space between the two packaging plates.

[0027] Among the one or more technical solutions provided in the exemplary embodiments of the present utility model, at least one of the following beneficial effects can be achieved.

[0028] The photovoltaic cell string of the exemplary embodiment of the utility model includes at least two cells and at least one packaging film, and the area where two adjacent cells are close to each other has a connection space, wherein the connection space at least includes the gap between two adjacent cells. A groove corresponding to the connection space is provided on at least one packaging film, and a buffer structure is provided in the groove and the corresponding connection space, that is, the buffer structure is provided in the groove and the gap between the corresponding two adjacent cells. By providing a groove on the packaging film, the buffer structure can be precisely positioned so that at least a part of the buffer structure is located in the gap between two adjacent cells, and the connection between the two cells close to each other is achieved through the buffer structure, and the hardness of the buffer structure is less than the hardness of the packaging film after curing. Based on this, the risk of breakage in the connection area between two adjacent cells can be reduced.

[0029] Furthermore, compared with the prior art which uses film gaskets or thermosetting glue in the connection area between two adjacent battery cells, the hardness of the buffer structure of the exemplary embodiment of the utility model is less than the hardness of the encapsulation film after curing, and is also less than the hardness of the film gasket or glue in the solid state, thereby reducing the risk of breakage in the connection area between two adjacent battery cells, especially reducing the risk of breakage of the battery string during lamination. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present invention and are used to explain the principles of the present invention together with the description thereof, wherein these drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification;

[0031] Figure 1 It is a schematic diagram of the axonometric structure of a photovoltaic cell string according to an embodiment of the utility model;

[0032] Figure 2is a schematic diagram of a cross-sectional structure of a photovoltaic cell string according to an embodiment of the present utility model;

[0033] Figure 3 It is a partial front view structural diagram of a photovoltaic cell string according to an embodiment of the utility model;

[0034] Figure 4 It is a schematic diagram of a partial axonometric structure of a photovoltaic cell assembly according to an embodiment of the utility model;

[0035] Figure 5 is a schematic diagram of a photovoltaic cell string structure according to another embodiment of the present utility model;

[0036] Figure 6 It is a schematic diagram of the structure of a photovoltaic cell string (without packaging film) according to an embodiment of the utility model.

[0037] Figure numerals: 10, battery cell; 20, welding strip; 30, connection space; 31, buffer structure; 40, packaging film; 50, adhesive film; 60, packaging board. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] Due to the high temperature resistance of HJT cells and the development of silicon wafer thinning (50-130 microns), the traditional photovoltaic string assembly process at the module end, that is, the traditional welding process, is no longer applicable. In order to reduce the levelized cost of energy (LCOE) of photovoltaic modules in terminal application scenarios, the industry needs high-density packaging technology for photovoltaic modules. The problem of cell fragmentation inside the module is becoming more and more serious in the production process of photovoltaic modules and actual use scenarios, especially in the battery string assembly process. The gap position of the cell, and even the overlapping area of ​​the cell in the negative spacing module, is very easy to break due to the increasing number of welding strips, for example, the number of welding strips increases from 11 (BusBar, BB) to 20BB.

[0040] In the related art, an additional step is added during the battery cell stringing process, that is, a film pad or a heat-cured glue is set at the battery cell connection to reduce the risk of battery cell breakage in this area. However, since the pad or heat-cured glue cannot be accurately positioned and has high hardness after being stringed, the risk of battery cell breakage in this area during lamination will increase.

[0041] In response to the above-mentioned problems, the photovoltaic cell string provided by the exemplary embodiment of the utility model uses a buffer structure with a hardness less than that of the packaging film to fill the grooves of the packaging film and the connecting space between adjacent cell sheets corresponding to the grooves. The buffer structure can be accurately set in the connecting space through the precise positioning of the grooves, thereby reducing the risk of cell breakage in this area.

[0042] Figure 1 Schematic diagram of the isometric structure of a photovoltaic cell string according to the embodiment of the present utility model. Figure 1 As shown, the photovoltaic cell string provided by the exemplary embodiment of the utility model includes at least two cells 10. The two cells 10 have zero spacing or negative spacing in the area close to each other, and multiple welding strips are required to connect the two cells. For example, the welding strip 20 below the cell 10 on the left is connected to the welding strip 20 above the cell 10 on the right. Therefore, the two cells 10 are staggered in the vertical direction, and there is a certain gap between the two cells 10 in the vertical direction, so that the welding strips 20 of the two cells 10 can be connected to each other or share the same set of welding strips. It should be noted that the left side, right side, and vertical direction mentioned above all refer to Figure 1 Directions on paper as shown.

[0043] Figure 2 Schematic diagram of the cross-sectional structure of a photovoltaic cell string according to an embodiment of the present utility model. Figure 2 As shown, the photovoltaic cell string provided by the exemplary embodiment of the utility model also includes two encapsulation films 40, which are respectively located on both sides of the battery cell 10, and the area where two adjacent battery cells 10 in at least two battery cells 10 are close to each other has a connection space 30, and the connection space 30 at least includes the gap between the two adjacent battery cells 10; at least one groove is formed on at least one encapsulation film 40, and the groove is connected to the corresponding connection space 30; a buffer structure 31 is arranged in the groove and the corresponding connection space 30, and the two adjacent battery cells 10 are connected through the buffer structure 31; the hardness of the buffer structure 31 is less than the hardness of the encapsulation film 40 after curing.

[0044] In practical applications, a specific pattern is designed on a packaging film 40. For example, during the lamination process, a groove, that is, an elongated through hole, is opened on the packaging film 40 on the side close to the photovoltaic front panel. The opening shape, size and position of the groove correspond to the connection space 30 in the area where two adjacent battery cells 10 are close to each other, and the groove is connected to the corresponding connection space 30. A buffer structure 31 is arranged in the groove and the corresponding connection space 30, and the connection space 30 at least includes the gap between the two adjacent battery cells 10, that is, the buffer structure 31 extends from the position of the groove to at least the gap between the two adjacent battery cells 10. Since the groove is formed on the packaging film 40, the number, shape and size of the groove can be accurately controlled during the preparation of the packaging film 40, so that the buffer structure 31 can be accurately controlled in the connection space 30 in the area where two adjacent battery cells 10 are close to each other, and the shape and size of the buffer structure 31 can also be controlled. Based on this, compared with the prior art, by precisely controlling the relative position relationship between the buffer structure 31 and the connection space 30, the buffer structure 31 can buffer the area where two adjacent battery cells 10 are close to each other, thereby reducing the risk of the battery cell 10 breaking in this area.

[0045] Furthermore, since the hardness of the buffer structure 31 is smaller than the hardness of the encapsulation film 40 after curing, compared with the prior art in which a film pad is provided in the connection space 30, or a thermosetting glue is provided, the battery cells are all in a solid state with relatively high hardness after being strung together. The hardness of the buffer structure 31 provided by the exemplary embodiment of the utility model is smaller than the hardness of the encapsulation film 40, and is even smaller than the hardness of the above-mentioned glue or film pad after curing. Therefore, the risk of the battery cell 10 breaking in this area can be reduced.

[0046] Considering that the buffer structure 31 needs to be at least arranged in the gap between two adjacent battery cells 10, so that the two battery cells 10 form a buffer connection. Exemplarily, the buffer structure 31 is made of silicone resin, and can also be made of liquid silicone. By using a material in a liquid state, it can be embedded in the gap between two adjacent battery cells 10. For the convenience of description, the following description takes liquid silicone as an example. It should be understood that the material of the buffer structure 31 should not be limited to liquid silicone. On the one hand, liquid silicone is a thick liquid with high viscosity. It can enter the connecting space 30 connected to it through the groove structure of the packaging film 40, thereby filling at least the gap between two adjacent battery cells 10 to form a part of the buffer structure 31; since the size, shape and position of the groove can be precisely opened, the liquid silicone can also be filled in the connecting space 30 with the corresponding size, shape and position to form a more precise buffer structure 31, thereby reducing the risk of the battery cell 10 breaking in this area; on the other hand, after the string is completed, the liquid silicone can be cured to form an elastomer in the lamination stage of the component. The hardness of the elastomer is smaller than that of the packaging film 40, and is also smaller than the solid glue or solid film gasket in the prior art, thereby further reducing the risk of battery cell breakage.

[0047] In some embodiments, Figure 2 As shown, the packaging film 40 with a groove is pre-bonded on the packaging board 60, for example, pre-bonded on the front plate glass. Before laying the battery string, liquid silicone is coated in the corresponding groove. After laying the battery string, since the front plate glass is located at the top and the other packaging board 60, that is, the back plate glass or back plate, is placed at the bottom, the liquid silicone coated in the groove will naturally fill the gap between two adjacent battery cells 10 under the action of gravity, and then after the subsequent lamination process, the liquid silicone filled in the area of ​​the battery cell has a supporting effect after thermal curing, forming a part of the buffer structure 31, which can not only reduce the risk of battery cell fragmentation, but also effectively inhibit the lateral displacement of the battery cell in the battery string, maintain the straightness of the battery string, and improve the production yield of the assembly. Furthermore, compared with the use of glue or adhesive strips in the prior art, an additional process and corresponding facilities are required, and the battery layout in the connection space between two adjacent battery cells needs to be redesigned, resulting in reduced production efficiency. The liquid silicone process of the photovoltaic battery string provided by the exemplary embodiment of the utility model does not need to change the existing string laying, string assembly and lamination process, and the production process is more convenient.

[0048] Figure 3 It is a partial front view structural diagram of a photovoltaic cell string according to an embodiment of the utility model; Figure 4 Schematic diagram of the partial isometric structure of a photovoltaic cell assembly according to the embodiment of the present utility model. Figure 3 and Figure 4As shown, the relative position relationship between any two adjacent cells 10 in the photovoltaic cell string provided by the exemplary embodiment of the utility model is a negative spacing in a preset direction, wherein the preset direction refers to the distribution direction from one cell 10 to another cell 10 in the two adjacent cells 10, that is, Figure 3 The horizontal direction of the paper. There is an overlapping area between two adjacent battery cells 10, and due to the presence of the welding strip 20 in the overlapping area, the overlapping area of ​​the two battery cells 10 has a certain height in the vertical direction, that is, there is a certain gap between the two battery cells 10 in the vertical direction. A part of the above-mentioned liquid silicone can be filled in the gap by fluidity, and solidified after the lamination process to form a part of the buffer structure 31.

[0049] In other embodiments, the relative position relationship between any two adjacent cells 10 in the photovoltaic cell string provided by the exemplary embodiment of the utility model is zero spacing in a preset direction. When the two adjacent ends of the two cells 10 are at the same horizontal position, the welding strip 20 between the two cells cannot be arranged due to its certain diameter. Therefore, the two adjacent cells 10 are also similar Figure 3 The two cells 10 are arranged in a staggered manner, that is, there is a certain gap between the two cells 10 in the vertical direction. When a part of the liquid silicone is filled by fluidity, it is also filled in the gap at least. It should be understood that at this time, the silicone has a certain width in the preset direction, and through the gap, it can at least adhere to the adjacent ends of the two cells 10 to form a connection with a buffering effect.

[0050] When two adjacent battery cells 10 have a negative spacing in a preset direction, the ratio of the width of the buffer structure 31 to the width of the overlapping region of the two adjacent battery cells 10 is (1-5):1; the width direction of the buffer structure 31 and the width direction of the overlapping region of the two adjacent battery cells 10 are both in the preset direction. Figure 2 As shown, the width W1 of the buffer structure 31 is consistent with the width of the groove of the packaging film 40 and the width of the connection space 30, and the width of the overlapping area of ​​two adjacent battery cells 10 is W2, that is, the ratio of W2:W1 is 1:(1-5). When W2:W1 is 1:1, that is, the buffer structure 31 is formed in the gap of the overlapping area of ​​the two battery cells 10, when W2:W1 is 1:5, in addition to forming a part of the buffer structure 31 in the gap of the overlapping area of ​​the two battery cells 10, the battery cells 10 at a certain distance from the two ends close to each other are also filled with silica gel to form another part of the buffer structure 31. Within this width ratio range, the buffer structure 31 can minimize the risk of battery cell breakage.

[0051] It should be understood that a portion of the buffer structure 31 formed by liquid silicone is disposed in the entire overlapping region of the two battery cells 10 .

[0052] When two adjacent battery cells 10 have zero spacing in a preset direction, the width W1 of the buffer structure 31 is 2 mm to 10 mm. Within this width range, the buffer structure 31 can minimize the risk of battery cell breakage.

[0053] Figure 5 FIG. 1 is a schematic diagram of a photovoltaic cell string structure according to another embodiment of the present invention. Figure 5 As shown, the buffer structure 31 in the photovoltaic cell string provided by the exemplary embodiment of the utility model, in addition to having a portion in the gap between two adjacent battery cells 10, also includes a portion located in at least one subspace of the connecting space 30, wherein the subspace refers to the area between the parts where two adjacent battery cells 10 are close to each other in the connecting space 30 and the corresponding packaging film 40.

[0054] Since two adjacent battery cells 10 are staggered in the vertical direction, that is, perpendicular to the preset direction, they are prone to breakage in this area after packaging. Therefore, the buffer structure 31 should also be formed in the subspace, such as Figure 5 As shown, there are two areas between the parts where two adjacent battery cells 10 are close to each other and the corresponding packaging films 40, that is, there are two sub-spaces, and a buffer structure 31 is formed in both sub-spaces. From another perspective, the packaging film 40 with grooves is pre-bonded to the front glass, and liquid silicone is applied to the corresponding grooves before laying the battery string. After laying the battery string, the liquid silicone will first fill one sub-space under the action of gravity, and then naturally fill the gap between the two adjacent battery cells 10, and then continue to fill the other sub-space between the battery cell 10 and the back plate or back plate glass, thereby forming a buffer structure 31 from one packaging film 40 to another packaging film 40.

[0055] Exemplarily, a soldering strip 20 is disposed on at least one surface of the battery cell 10, and the portion of the buffer structure 31 located in the subspace is a protruding structure protruding from the corresponding surface of the battery cell 10, and the ratio of the height of the protruding structure to the diameter of the soldering strip 20 is (2-5):1, and optionally (3-4):1. Figure 2 As shown, the height of the convex structure of the buffer structure 31 located in the subspace is consistent with the height H from the corresponding surface of the battery cell 10 to the encapsulation film 40. The height of the convex structure is within this ratio, and the liquid silicone can completely cover the welding strip 20 and form a buffer structure 31, which can play a reliable buffering role. Exemplarily, the above-mentioned welding strip 20 can adopt a low-temperature welding strip, such as a photovoltaic welding strip with a low melting point, which includes a conductive copper core and a welding material coated on the outside of the conductive copper core, wherein the welding material is one or more of metal tin, lead, bismuth, and silver, and the melting point of the welding material is between 140-170°C.

[0056] In the photovoltaic stringing process, each cell 10 has welding strips 20 on both surfaces, and the welding strips 20 of two adjacent cells 10 need to be connected in series or share a set of welding strips, and the cells 10 need to be staggered. Therefore, the welding strips 20 need to be pre-fixed. For example, Figure 2-Figure 4 As shown, the photovoltaic cell string also includes a plurality of adhesive films 50, which are used to fix the soldering tape 20 to the surface of the corresponding cell 10. The adhesive film will melt under hot pressing conditions, and the cell 10 and the soldering tape 20 will be bonded and fixed into a whole. Exemplarily, the adhesive film material may include a pre-cross-linked EVA film, a POE film, and a pre-cross-linking degree of 30%-70%. Optionally, the film material may also include a thermoplastic PVB film, a POE film, and a TPO film. It should be understood that the adhesive film 50 provided here is not the encapsulation film 40 of the photovoltaic module.

[0057] In the photovoltaic cell string of the exemplary embodiment of the present utility model, the arrangement of the cells 10 can be various, and the cells 10 can be cells without a main grid or cells with a main grid.

[0058] For example, if Figure 2 As shown, each battery cell 10 is arranged in parallel with the packaging film 40, that is, relative to the packaging board 60, each battery cell 10 is staggered along the vertical direction and parallel to the packaging board 60 along a preset direction.

[0059] In another optional embodiment, in order to perform high-density component packaging, such as Figure 5 As shown, each battery cell 10 is arranged at a preset angle with the packaging film 40, that is, relative to the packaging board 60, each battery cell 10 is staggered along the vertical direction, and each battery cell 10 forms a preset angle with the packaging board 60 along the preset direction, thereby reducing the distance between the two packaging boards 60, saving space and improving power.

[0060] Figure 6 Schematic diagram of the structure of a photovoltaic cell string (without encapsulation film) according to an embodiment of the present utility model. Figure 6 As shown, an exemplary embodiment of the utility model also provides a photovoltaic cell assembly, including a photovoltaic cell string and two packaging boards 60 for packaging the photovoltaic cell string, the photovoltaic cell string including a buffer structure 31 and at least two battery cells 10; the buffer structure 31 has two opposite surfaces, each surface is connected to a corresponding packaging board 60, and each battery cell 10 is embedded in the buffer structure 31; the buffer structure 31 is a structure made of liquid silicone or silicone resin.

[0061] Exemplarily, a barrier layer is further provided between the peripheral edge portions of the two packaging plates 60 , and the barrier layer is used to form a closed space between the two packaging plates 60 .

[0062] In practical applications, the battery cells 10 and the welding strips 20 are grouped in series, and the welding strips 20 are pre-fixed on the surface of the corresponding battery cells 10 by the adhesive film 50. For example, the laid battery cells 10 pass through the hot pressing mechanism, and the adhesive film 50 melts to bond the welding strips 20 and the battery cells 10 to form a whole, thus completing the battery string grouping; in the battery string lamination process, one or more glue coating nozzles are used to apply liquid silicone on the inner side of a package board 60 of the component until the area away from the edge of the package board 60. Since the liquid silicone is a thick liquid with a high viscosity, it will not naturally flow to the side edge of the package board 60, and then the battery string is laid and the convergence welding is performed. After the circuit connection is completed, the liquid silicone coating action is repeated on the other surface of the battery string, and finally another package board 60 is closed, and then a barrier layer is set between the peripheral edge parts of the two package boards 60 to prevent the liquid silicone from overflowing out of the component. Exemplarily, the barrier layer is formed using a non-porous edge sealing tape or a cured butyl hot melt adhesive to seal the edge of the component. Finally, the stacked components enter the lamination equipment. During the lamination process, they first undergo low-temperature vacuum exhaust, and the components can be ultrasonically treated simultaneously to accelerate the exhaust of air inside the components and exhaust the air wrapped inside the liquid silicone. Then, after high-temperature lamination, the liquid silicone is solidified to form a buffer structure 31. Based on this, each battery cell 10 is embedded in the buffer structure 31, and the surface of the buffer structure 31 formed by the liquid silicone is respectively connected to the corresponding packaging board 60, and a part of the buffer structure 31 is also formed in the gap between two adjacent battery cells 10.

[0063] It should be noted that the above-mentioned battery cells 10 are all embedded in the buffer structure 31, which means that the other parts except the peripheral side surfaces of the battery cell group formed by each battery cell 10 may be embedded in the buffer structure 31, or each battery cell 10 may be embedded in the buffer structure 31 regardless of the peripheral side surfaces or surfaces, that is, the buffer structure 31 completely wraps each battery cell 10.

[0064] Compared with the prior art, the photovoltaic cell assembly of the exemplary embodiment of the utility model uses a buffer structure 31 formed by liquid silicone, which can completely replace the packaging film in the traditional photovoltaic cell assembly. It only needs to apply liquid silicone between each cell 10 and the packaging board 60, without using the packaging film 40 to form the packaging and fixation of the assembly. The cured buffer structure 31 is an elastomer, which can also effectively prevent adjacent cells from breaking in the connection area.

[0065] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A photovoltaic cell string, characterized in that: It comprises at least two battery cells and at least one packaging film, wherein the regions where two adjacent battery cells of the at least two battery cells are close to each other have a connection space, and the connection space at least comprises a gap between the two adjacent battery cells; At least one of the packaging films is formed with at least one groove, and the groove is communicated with the corresponding connection space; A buffer structure is provided in the groove and the corresponding connection space, and two adjacent battery cells are connected via the buffer structure; The hardness of the buffer structure is less than the hardness of the encapsulation film after curing.

2. The photovoltaic cell string according to claim 1, characterized in that: The buffer structure is a structure made of liquid silicone or silicone resin.

3. The photovoltaic cell string according to claim 1, characterized in that: Two adjacent battery cells have a zero spacing or a negative spacing in a preset direction, and the preset direction refers to a distribution direction from one battery cell to another of the two adjacent battery cells.

4. The photovoltaic cell string according to claim 3, characterized in that: When two adjacent battery cells have a negative spacing in a preset direction, the ratio of the width of the buffer structure to the width of the overlapping area of ​​the two adjacent battery cells is (1-5):1; Alternatively, when two adjacent battery cells have zero spacing in a preset direction, the width of the buffer structure is 2 mm to 10 mm; The width direction of the buffer structure and the width direction of the overlapping regions of two adjacent battery cells are both preset directions.

5. The photovoltaic cell string according to claim 3, characterized in that: The buffer structure also includes a portion located in at least one subspace of the connection space; The subspace refers to: the area between the parts where two adjacent battery cells are close to each other and the corresponding packaging films in the connection space.

6. The photovoltaic cell string according to claim 5, characterized in that: A welding strip is arranged on at least one surface of the battery cell, and the portion of the buffer structure located in the subspace is a protruding structure protruding from the corresponding surface of the battery cell, and the ratio of the height of the protruding structure to the diameter of the welding strip is (2-5):

1.

7. The photovoltaic cell string according to claim 6, characterized in that: The photovoltaic cell string further comprises at least one adhesive film, and the adhesive film is used to fix the welding strip to the surface of the corresponding cell sheet.

8. The photovoltaic cell string according to any one of claims 1 to 7, characterized in that: Each of the battery cells is arranged in parallel with the packaging film; or, Each of the battery cells is arranged at a preset angle to the packaging film.

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