Battery string of three-terminal laminated battery, photovoltaic module and photovoltaic assembly
The perovskite-silicon tandem solar cell, with its three-terminal structure and specific interleaved connection method, solves the current matching and stability problems of existing connection structures, thereby improving the system's flexibility and power generation efficiency.
Patent Information
- Application Number
- CN202423027735.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2034-12-09
AI Technical Summary
Existing perovskite-silicon tandem solar cell connection structures suffer from strict current matching requirements, large voltage losses, and stability issues due to the instability of perovskite materials, resulting in low overall efficiency and susceptibility to environmental factors.
A three-terminal connection method is adopted to connect the perovskite cell and the crystalline silicon cell independently. Each cell has an independent output terminal, and the outputs are combined through an external circuit. A specific interleaved connection method is used to connect the top cell and the bottom cell with a maximum operating point voltage matching ratio of 2:1.
It improves system flexibility, optimizes overall performance, reduces current mismatch, prevents hot spot effect, and ensures power generation efficiency.
Smart Images
Figure CN223626247U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of photovoltaic cell technology, and relates to a three-terminal stacked battery string, photovoltaic module and photovoltaic component. Background Technology
[0002] With the continuous growth of global energy demand and the increasing severity of environmental pollution, the development and utilization of clean energy has become an international consensus. Solar energy, as a clean and renewable energy source, has enormous potential for development and utilization. Solar cells, as devices that directly convert sunlight into electricity, have been widely researched and applied in recent years.
[0003] Crystalline silicon solar cells are currently the most mature type of solar cell, mainly including monocrystalline silicon cells and polycrystalline silicon cells. Although they have reached commercial scale, their manufacturing process remains relatively complex, often requiring high temperatures and high-purity raw materials, resulting in high costs. Most importantly, their actual highest photoelectric conversion efficiency has reached 26.8%, close to their theoretical limit of 29.4%, making it difficult to achieve higher levels of light energy utilization.
[0004] Perovskite solar cells are an emerging type of solar cell with unique physical and chemical properties. Their fabrication process is relatively simple, and they have low cost and energy consumption. However, their large-area requirements and long-term stability issues, such as easy degradation under environmental factors like humidity, temperature, and light, limit their further application and development.
[0005] To overcome the limitations of single-type solar cells, researchers have proposed perovskite-silicon tandem solar cells. By combining perovskite and crystalline silicon cells in series or parallel, and utilizing their complementary spectral responses, perovskite-silicon tandem solar cells can fully utilize different bands of the solar spectrum, thereby significantly improving the overall photoelectric conversion efficiency to over 33%.
[0006] The connection structure of perovskite and crystalline silicon tandem solar cells has a significant impact on the performance of the cells. The two-terminal structure is the simplest connection method, where a perovskite cell and a crystalline silicon cell are connected in series to form a single voltage output. The two-terminal structure has only one input and one output terminal, i.e., two electrodes. Although the circuit design of the two-terminal structure is simple and easy to implement, it requires strict current matching; otherwise, it will affect the overall performance, leading to current waste and reduced overall efficiency. Furthermore, it is prone to voltage drop, especially in series connections, where poor resistance and contact can cause voltage drops. More importantly, the stability of the two-terminal structure is greatly affected by the stability of the perovskite material; environmental degradation of the perovskite material can affect the overall performance of the cell.
[0007] To address this, a three-terminal structure was further proposed. This structure connects the perovskite and crystalline silicon cells independently, each with an independent output terminal. An external circuit then combines the outputs of the two cells. The three-terminal structure has three electrodes: two input terminals and one common output terminal. This structure allows the perovskite and crystalline silicon cells to operate independently without requiring perfect matching, improving system flexibility. The voltage output of the two cells can be adjusted via an external circuit, optimizing overall performance. Furthermore, it facilitates fault isolation; even if one cell fails, the other can continue operating.
[0008] Therefore, developing and researching new three-terminal perovskite-silicon tandem solar cells is of great practical significance for promoting their large-scale commercial application. Utility Model Content
[0009] In view of the problems existing in the prior art, the purpose of this utility model is to provide a battery string, photovoltaic module and photovoltaic module of a three-terminal stacked battery, wherein the battery string adopts a new and specific connection form to realize the circuit connection of the stacked battery, thereby forming a three-terminal stacked battery string.
[0010] To achieve this objective, the present invention adopts the following technical solution:
[0011] In a first aspect, this utility model provides a battery string of a three-terminal stacked battery, the battery string comprising N stacked batteries, N≥3; the stacked battery comprising a bottom battery, an intermediate layer and a top battery stacked sequentially; the stacked battery further comprising a top contact terminal T led out from the top battery, a bottom contact terminal B led out from the bottom battery, and a common contact terminal C jointly led out from the top battery and the bottom battery.
[0012] The N stacked batteries are connected by interconnecting strips, wherein the top contact terminal T of the Xth stacked battery is connected to the common contact terminal C of the (X+2)th stacked battery, the common contact terminal C of the Xth stacked battery is connected to the bottom contact terminal B of the (X+1)th stacked battery, 1≤X≤N-2; and the common contact terminal C of the (N-1)th stacked battery is connected to the bottom contact terminal B of the Nth stacked battery.
[0013] The common contact terminal C of the first, second, and Nth stacked batteries is also respectively set as the first external connection terminal for the battery string to form an external connection; the bottom contact terminal B of the first stacked battery, the top contact terminal T of the (N-1)th stacked battery, and the top contact terminal T of the Nth stacked battery are also respectively set as the first external connection terminal.
[0014] In the battery string described in this invention, the top and bottom batteries are connected in a specific staggered manner to form a series battery string, with the top and bottom batteries connected at a maximum operating point voltage matching ratio of 2:1. When drastic changes in outdoor weather or other operating conditions cause spectral variations, this reduces current mismatch between the top and bottom batteries, prevents hot spot effects, and ensures power generation efficiency.
[0015] The following are preferred technical solutions of this utility model, but are not intended to limit the technical solutions provided by this utility model. Through the following technical solutions, the technical objectives and beneficial effects of this utility model can be better achieved and realized.
[0016] As a preferred embodiment of the present invention, the bottom cell includes a crystalline silicon cell, the intermediate layer includes a transparent conductive metal oxide film and / or a polycrystalline silicon film layer, and the top cell includes a perovskite cell.
[0017] As a preferred technical solution of this utility model, the stacked batteries are arranged in a straight line with intervals of 2 to 4 mm, such as 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.5 mm, 3.8 mm or 4 mm, etc., but are not limited to the listed values. Other unlisted values within the above range are also applicable.
[0018] As a preferred technical solution of this utility model, in the stacked battery, the top contact end T, the bottom contact end B and the common contact end C are all disposed on the surface of the bottom battery away from the top battery, and the top contact end T is disposed along a short side edge, while the bottom contact end B and the common contact end C are disposed along opposite long side edges.
[0019] Secondly, this utility model provides a photovoltaic module, which contains a battery string of three-terminal stacked batteries as described in the first aspect.
[0020] As a preferred technical solution of this utility model, the photovoltaic module includes a front panel, a front encapsulation film, N stacked cells, an intermediate encapsulation film, an insulating layer, the interconnecting strip, a rear encapsulation film, a back panel, and a junction box, which are stacked in sequence; the interconnecting strip passes through the insulating layer and the intermediate encapsulation film to connect the N stacked cells to form the cell string.
[0021] As a preferred technical solution of this utility model, the interconnecting strip further includes a first external connecting strip, which connects the first external connection end of the battery string to the corresponding junction box; the junction box serves as a second external connection end for the photovoltaic module to form an external connection.
[0022] As a preferred embodiment of this invention, both the front panel and the back panel are glass plates.
[0023] As a preferred embodiment of this invention, the photovoltaic module further includes an edge sealant disposed between the front panel and the back panel, and surrounding the perimeter of the other layers; the edge sealant comprises butyl rubber; the thickness of the edge sealant is 0.8–1.2 mm, for example, 0.8 mm, 0.83 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.92 mm, 0.95 mm, 0.98 mm, 1 mm, 1.03 mm, 1.05 mm, 1.08 mm, 1.1 mm. The values are m, 1.15mm, 1.18mm or 1.2mm, etc., and the width is 10 to 15mm, such as 10mm, 10.3mm, 10.5mm, 10.8mm, 11mm, 11.4mm, 11.8mm, 12mm, 12.3mm, 12.6mm, 12.9mm, 13.3mm, 13.7mm, 14mm, 14.3mm, 14.5mm, 14.8mm or 15mm, etc., but are not limited to the listed values. Other unlisted values within the above range also apply.
[0024] As a preferred embodiment of this invention, the pre-encapsulation film, the intermediate encapsulation film, and the post-encapsulation film are independently selected from POE film or TOP film; the thickness of the pre-encapsulation film is 0.4–0.6 mm, for example, 0.4 mm, 0.43 mm, 0.45 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.55 mm, 0.58 mm, or 0.6 mm, etc.; the thickness of the intermediate encapsulation film is 0.1–0.2 mm, for example, 0.1 mm, 0.12 mm, etc. The thickness of the encapsulating film is 0.14mm, 0.16mm, 0.18mm, or 0.2mm, etc.; the thickness of the post-encapsulation film is 0.4 to 0.6mm, for example, 0.4mm, 0.43mm, 0.45mm, 0.48mm, 0.5mm, 0.52mm, 0.55mm, 0.58mm, or 0.6mm, etc.; the length and width dimensions of the pre-encapsulation film, the intermediate encapsulation film, and the post-encapsulation film are the same; however, it is not limited to the listed values, and other unlisted values within the above range are also applicable.
[0025] As a preferred embodiment of this utility model, the insulating layer comprises a PET film layer; the thickness of the insulating layer is 0.05 to 0.15 mm, such as 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, or 0.15 mm, but is not limited to the listed values. Other unlisted values within the above range are also applicable.
[0026] As a preferred embodiment of this invention, the junction box is further connected to cables and connectors; the end near the first stacked battery cell is the head of the battery string and the photovoltaic module, and the end near the Nth stacked battery cell is the tail of the battery string and the photovoltaic module; the connector in the junction box at the head and the junction box at the tail are used to connect with each other.
[0027] Thirdly, this utility model provides a photovoltaic module containing n photovoltaic modules as described in the second aspect, where n≥2; in the photovoltaic module, the end near the first tandem cell and the end near the Nth tandem cell are mutually head-to-tail, and the connector in the junction box at the head and the connector in the junction box at the tail are mutually male and female; the photovoltaic module is formed by connecting the junction box at the head of one photovoltaic module to the junction box at the tail of another photovoltaic module respectively.
[0028] As a preferred technical solution of this utility model, in the photovoltaic module, the junction box connected to the common contact terminal C of the first stacked cell is JF1C, the junction box connected to the bottom contact terminal B of the first stacked cell is JF1B, the junction box connected to the common contact terminal C of the second stacked cell is JF2C, the junction box connected to the top contact terminal T of the Nth stacked cell is JL1T, the junction box connected to the common contact terminal C of the Nth stacked cell is JL1C, and the junction box connected to the top common contact terminal T of the (N-1)th stacked cell is JL2T.
[0029] The photovoltaic module also includes a second external connection strip, which connects the second external connection terminals of the n photovoltaic modules respectively. The junction boxes JL1T, JL2T and JL1C of the Yth photovoltaic module are connected to the junction boxes JF2C, JF1C and JF1B of the (Y+1)th photovoltaic module respectively, where 1≤Y≤n-1.
[0030] Among them, junction boxes JF2C, JF1C and JF1B of the first photovoltaic module, and junction boxes JL1T, JL2T and JL1C of the nth photovoltaic module, respectively serve as the third external connection terminals for forming external connections of the photovoltaic modules.
[0031] Compared with existing technical solutions, this utility model has at least the following beneficial effects:
[0032] In the battery string described in this invention, the top and bottom batteries are connected in a specific staggered manner to form a series battery string, with the top and bottom batteries connected at a maximum operating point voltage matching ratio of 2:1. When drastic changes in outdoor weather or other operating conditions cause spectral variations, this reduces current mismatch between the top and bottom batteries, prevents hot spot effects, and ensures power generation efficiency. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the electrical connection of the battery strings of the three-terminal stacked battery in Example 1;
[0034] Figure 2 This is a schematic diagram of the stacked battery structure in Example 1;
[0035] Figure 3 This is a schematic diagram showing the arrangement of the contact ends of the stacked battery in Example 1;
[0036] Figure 4 This is a top view of the battery string in Example 1 after it has been electrically connected;
[0037] Figure 5 This is a schematic diagram of the photovoltaic module in Example 2;
[0038] Figure 6 This is a schematic diagram of the electrical connection of the photovoltaic module in Example 3;
[0039] In the diagram: 10-Layered cell, 11-Bottom cell, 12-Middle layer, 13-Top cell, 20-Interconnecting strip, 30-Cell string, 40-Photovoltaic module, 41-Front panel, 42-Edge sealant, 43-Front encapsulation film, 44-Middle encapsulation film, 45-Insulating layer, 46-Rear encapsulation film, 47-Back panel, 48-Gateway box. Detailed Implementation
[0040] The technical solution of this utility model will be further illustrated below through specific embodiments.
[0041] Those skilled in the art should understand that the embodiments described are merely to help understand the present invention and should not be regarded as specific limitations on the present invention.
[0042] Example 1
[0043] This embodiment provides a battery string of a three-terminal stacked battery, such as Figure 4 As shown, the battery string 30 includes:
[0044] N-cell stacked battery 10 ( Figure 4 (Only a portion is shown), half-cell size solar cells can be used; such as Figure 2As shown, the stacked battery 10 includes a bottom battery 11, an intermediate layer 12, and a top battery 13 stacked sequentially; the bottom battery 11 is a crystalline silicon battery, the intermediate layer 12 is a transparent conductive oxide thin film, and the top battery 13 is a perovskite battery; as shown... Figure 3 As shown, the stacked battery 10 further includes a top contact terminal T led out from the top battery 13, a bottom contact terminal B led out from the bottom battery, and a common contact terminal C jointly led out from the top battery 13 and the bottom battery 11; in the stacked battery 10, the top contact terminal T, the bottom contact terminal B, and the common contact terminal C are all disposed on the surface of the bottom battery 11 on the side away from the top battery 13, and the top contact terminal T is disposed along a short edge, while the bottom contact terminal B and the common contact terminal C are disposed along opposite long edges; Figure 4 As shown, the N stacked batteries 10 are arranged in a straight line with their long sides facing each other and their short sides spaced apart. The spacing between the two adjacent stacked batteries 10 is the same and is uniformly selected from 2 to 4 mm.
[0045] like Figure 1 and Figure 4 As shown, Figure 4 In the diagram, the top battery 13 is represented by a thin cube, and the bottom battery 11 is represented by a thick cube. The top battery 13 has a top contact terminal T (with a top electrode T) leading out, and the bottom battery 11 has a bottom contact terminal B (with a bottom electrode B) leading out. The top battery 13 and the bottom battery 11 have a common contact terminal C (with a common electrode C) leading out. Note that, as shown above, in the actual stacked battery 10, both the top contact terminal T and the common contact terminal C are located on the bottom surface of the bottom battery 11. N stacked batteries 10 are connected by interconnecting strips 20. The top contact terminal T of the Xth stacked battery 10 is connected to the common contact terminal C of the (X+2)th stacked battery 10, and the common contact terminal C of the Xth stacked battery 10 is connected to the bottom contact terminal B of the (X+1)th stacked battery 10, where 1 ≤ X ≤ N-2; the common contact terminal C of the (N-1)th stacked battery 10 is connected to the bottom contact terminal B of the Nth stacked battery 10.
[0046] The first, second, (N-1), and Nth stacked batteries 10 are designated as F1, F2, L2, and L1, respectively. Taking the first stacked battery 10 as an example, its top contact is designated as F1T, its bottom contact as F1B, and its common contact as F1C. The contact designations for the second, (N-1), and Nth stacked batteries 10 follow the same pattern.
[0047] Since F1, F2, L1 and L2 are located at the beginning and end of the battery string 30, and the connection is continuously interrupted, F1C, F1B, F2C, L1T, L1C and L2T are not connected to the contact ends of other stacked batteries 10 in the string, but are used as the first external connection ends to form an external connection for the battery string 30.
[0048] Example 2
[0049] This embodiment provides a photovoltaic module, such as Figure 5 As shown, the photovoltaic module 40 includes:
[0050] Front panel 41 is a glass front panel, made of ultra-clear tempered velvet glass;
[0051] Edge sealant 42 is made of a material with low water vapor permeability, preferably butyl rubber. Edge sealant 42 forms a closed ring around the four edges of the front panel 41, with a width of 10-15 mm and a height of 0.8-1.2 mm.
[0052] The front sealing film 43 is made of POE film or TOP film with low water vapor permeability. The front sealing film 43 is located in the area enclosed by the edge sealant 42. Its length and width are the same as the inner length and width of the edge sealant 42, and its thickness is 0.4 to 0.6 mm.
[0053] N stacked batteries 10 provided in Embodiment 1 are arranged according to the scheme of the battery string 30; the end closer to the first stacked battery 10 is the head of the battery string 30 and the photovoltaic module 40, and the end closer to the Nth stacked battery 10 is the tail of the battery string 30 and the photovoltaic module 40.
[0054] The intermediate encapsulation film 44 has the same length and width as the front encapsulation film 43. An opening is designed at the contact end of each stacked battery 10 on the intermediate encapsulation film 44 to facilitate electrical connection between the interconnecting strip 20 and the corresponding contact end. The thickness of the intermediate encapsulation film 44 is 0.1 to 0.2 mm.
[0055] The insulating layer 45 is made of a PET film layer with a thickness of 0.05 to 0.15 mm. The length, width, opening position and opening shape of the insulating layer 45 are consistent with the intermediate encapsulation film 44.
[0056] The interconnecting strip 20, made of tin-plated copper strip, passes through the insulating layer 45 and the intermediate encapsulation film 44 according to the battery string 30 provided in Embodiment 1, and is soldered to the contact ends of the corresponding N stacked batteries 10 to form a series electrical connection, constituting the battery string 30; the other parts of the interconnecting strip 20, except for the soldering points, are located on the intermediate encapsulation film 44 and the insulating film layer 45 to isolate them from other parts of the stacked batteries 10, thereby achieving a specific electrical connection; the interconnecting strip 20 also includes a first external connecting strip, one end of which is connected to the first external connecting end of the battery string 30;
[0057] The post-sealing film 46 is made of POE film or TOP film with low water vapor permeability. The post-sealing film 46 is located in the area enclosed by the edge sealant 42. Its length and width are consistent with the inner length and width of the edge sealant 42. Its thickness is 0.4 to 0.6 mm. The post-sealing film 46 has openings at the corresponding positions of the specific contact ends F1C, F1B, F2C, L1T, L1C and L2T for the lead-out of the first outer connecting strip.
[0058] Back plate 47 is a glass back plate made of ordinary tempered glass. Its size is the same as that of the front plate 41 and the same as that of the rear encapsulation film 46. Lead-out holes are opened at the corresponding positions of the openings in the rear encapsulation film 46 for the lead-out of the first external connecting strip.
[0059] Junction boxes 48 are independent junction boxes, each connecting a cable and a connector. Junction boxes 48 are installed at the lead-out holes of the back plate 47, leading out specific contact ends of the first and last stacked battery cells 10. Specifically, the other ends of the first external connecting strips connected to F1C, F1B, F2C, L1T, L1C, and L2T in the battery string 30 are led out and connected to the corresponding junction boxes 48. These junction boxes 48 are sequentially designated JF1C, JF1B, JF2C, JL1T, JL1C, and JL2T. Furthermore, the junction boxes 48 connect to the cable connectors to form a second external connection end, used for external connection of the photovoltaic module 40. Specifically, the junction boxes 48 installed at the beginning use male connectors, while those installed at the end use female connectors, and vice versa, to facilitate connection with more photovoltaic modules 40.
[0060] Example 3
[0061] This embodiment provides a photovoltaic module, such as Figure 6 As shown, the photovoltaic module includes:
[0062] Contains n photovoltaic modules 40 as described in Example 2 ( Figure 6 (Only a portion is shown), n≥2; The photovoltaic module also includes a second external connection strip, which connects the second external connection terminals of n photovoltaic modules 40 respectively, wherein the junction boxes JL1T, JL2T and JL1C of the Yth photovoltaic module 40 are connected to the junction boxes JF2C, JF1C and JF1B of the (Y+1)th photovoltaic module 40 respectively, 1≤Y≤n-1;
[0063] Among them, junction boxes JF2C, JF1C and JF1B of the first photovoltaic module 40, and junction boxes JL1T, JL2T and JL1C of the nth photovoltaic module, respectively serve as the third external connection terminals for forming external connections of the photovoltaic modules.
[0064] As can be seen from the above, the battery string of the three-terminal stacked battery described in this utility model, through a specific connection method, can reduce the degradation problem caused by current mismatch between perovskite and crystalline silicon cells due to outdoor spectral changes. Furthermore, connecting through a junction box serving as a second external connection terminal in the photovoltaic module is more suitable for forming a continuously connected photovoltaic string (module).
[0065] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
[0066] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.
[0067] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.
Claims
1. A battery string of a three-terminal stacked battery, characterized in that, The battery string includes N stacked batteries, where N≥3; the stacked batteries include a bottom battery, a middle layer and a top battery stacked in sequence; the stacked batteries also include a top contact terminal T led out from the top battery, a bottom contact terminal B led out from the bottom battery, and a common contact terminal C led out from the top battery and the bottom battery together; The N stacked batteries are connected by interconnecting strips, wherein the top contact terminal T of the Xth stacked battery is connected to the common contact terminal C of the (X+2)th stacked battery, the common contact terminal C of the Xth stacked battery is connected to the bottom contact terminal B of the (X+1)th stacked battery, 1≤X≤N-2; and the common contact terminal C of the (N-1)th stacked battery is connected to the bottom contact terminal B of the Nth stacked battery.
2. The battery string of the three-terminal stacked battery according to claim 1, characterized in that, In the battery string, the common contact terminal C of the first, second, and Nth stacked batteries is also respectively set as the first external connection terminal for the battery string to form an external connection; the bottom contact terminal B of the first stacked battery, the top contact terminal T of the (N-1)th stacked battery, and the top contact terminal T of the Nth stacked battery are also respectively set as the first external connection terminal.
3. The battery string of the three-terminal stacked battery according to claim 1, characterized in that, The bottom cell includes a crystalline silicon cell, the intermediate layer includes a transparent conductive metal oxide film and / or a polycrystalline silicon film layer, and the top cell includes a perovskite cell.
4. The battery string of the three-terminal stacked battery according to claim 1, characterized in that, The stacked batteries are arranged in a straight line with intervals of 2 to 4 mm between the two adjacent stacked batteries.
5. The battery string of the three-terminal stacked battery according to claim 1, characterized in that, In the stacked battery, the top contact end T, the bottom contact end B, and the common contact end C are all disposed on the surface of the bottom battery away from the top battery, and the top contact end T is disposed along a short edge, while the bottom contact end B and the common contact end C are disposed along opposite long edges.
6. A photovoltaic module, characterized in that, The photovoltaic module contains a battery string of a three-terminal stacked battery as described in any one of claims 1-5.
7. The photovoltaic module according to claim 6, characterized in that, The photovoltaic module includes a front panel, a front encapsulation film, N stacked cells, an intermediate encapsulation film, an insulating layer, interconnecting strips, a rear encapsulation film, a back panel, and a junction box, which are stacked in sequence. The interconnecting strips pass through the insulating layer and the intermediate encapsulation film to connect the N stacked cells to form the cell string.
8. The photovoltaic module according to claim 7, characterized in that, The interconnecting strip also includes a first external connecting strip, which connects the first external connection end of the battery string to the corresponding junction box; the junction box serves as a second external connection end for the photovoltaic module to form an external connection.
9. The photovoltaic module according to claim 7, characterized in that, Both the front panel and the back panel are glass panels; The photovoltaic module also includes an edge sealant, which is disposed between the front panel and the back panel and surrounds the perimeter of the other layers; the edge sealant includes butyl rubber; the thickness of the edge sealant is 0.8-1.2 mm and the width is 10-15 mm; The front encapsulation film, the intermediate encapsulation film, and the rear encapsulation film are independently selected from POE film or TOP film; the thickness of the front encapsulation film is 0.4-0.6 mm; the thickness of the intermediate encapsulation film is 0.1-0.2 mm; the thickness of the rear encapsulation film is 0.4-0.6 mm; the length and width dimensions of the front encapsulation film, the intermediate encapsulation film, and the rear encapsulation film are the same; The insulating layer includes a PET film layer; the thickness of the insulating layer is 0.05 to 0.15 mm.
10. The photovoltaic module according to claim 7, characterized in that, The junction box is also connected to cables and connectors; in the photovoltaic module, the end near the first tandem cell and the end near the Nth tandem cell are the beginning and end of each other, and the connector in the junction box at the beginning and the connector in the junction box at the end are used to connect with each other.
11. A photovoltaic module, characterized in that, A photovoltaic module comprising n photovoltaic modules as described in any one of claims 6-10, where n ≥ 2; wherein the photovoltaic module has an end near the first tandem cell and an end near the Nth tandem cell as the beginning and end of each other, and the photovoltaic module is formed by connecting the junction box located at the beginning of one photovoltaic module to the junction box located at the end of another photovoltaic module.
12. The photovoltaic module according to claim 11, characterized in that, In the photovoltaic module, the junction box connected to the common contact terminal C of the first stacked cell is JF1C, the junction box connected to the bottom contact terminal B of the first stacked cell is JF1B, the junction box connected to the common contact terminal C of the second stacked cell is JF2C, the junction box connected to the top contact terminal T of the Nth stacked cell is JL1T, the junction box connected to the common contact terminal C of the Nth stacked cell is JL1C, and the junction box connected to the top common contact terminal T of the (N-1)th stacked cell is JL2T. The photovoltaic module also includes a second external connection strip, which connects the second external connection terminals of the n photovoltaic modules respectively. The junction boxes JL1T, JL2T and JL1C of the Yth photovoltaic module are connected to the junction boxes JF2C, JF1C and JF1B of the (Y+1)th photovoltaic module respectively, where 1≤Y≤n-1. Among them, junction boxes JF2C, JF1C and JF1B of the first photovoltaic module, and junction boxes JL1T, JL2T and JL1C of the nth photovoltaic module, respectively serve as the third external connection terminals for forming external connections of the photovoltaic modules.