Encapsulating solar cells
By employing a multi-layer structure combining a water-blocking layer and an encapsulant layer in perovskite solar cells, the problem of water-blocking failure during encapsulation is solved, achieving more efficient sealing and longer module lifespan, and reducing the risk of cell string displacement and circuit failure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TRINA SOLAR CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-06-23
AI Technical Summary
In existing technologies, perovskite solar cells are prone to water blockage failure during the encapsulation process, leading to water vapor penetration and affecting cell performance and lifespan.
The system employs a multi-layer structure combining a water-blocking layer and an adhesive film layer. The water-blocking layer covers the front of the battery cell, the adhesive film layer wraps around the battery cell, and the cover plate serves as the outer layer of protection, forming an all-around sealing system. After curing, the adhesive film layer forms a three-dimensional network structure to fix the battery string skeleton, and organic and inorganic water-blocking layers are combined to enhance the sealing effect.
It significantly improves the water-blocking performance of the solar cell encapsulation structure, reduces the risk of cell string displacement and circuit failure, extends module life, reduces maintenance costs, and avoids the risk of reaction between encapsulation materials and perovskite film layers.
Smart Images
Figure CN224402035U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of solar cell technology, and in particular to encapsulated solar cells. Background Technology
[0002] After years of development, perovskite solar cells have achieved a laboratory single-cell efficiency of 25.7%, and tandem cells combining crystalline silicon technology have reached 32%, demonstrating a very broad application prospect. Moreover, compared to crystalline silicon modules, perovskite solar cells have advantages such as solution processing, abundant raw materials, and low manufacturing costs, making them a promising next-generation commercial photovoltaic cell technology.
[0003] In related technologies, butyl rubber is typically used to seal the perimeter of the solar cell to achieve water resistance, and then an adhesive film is used to connect the front and back of the solar cell to a glass plate. However, after the solar cell is encapsulated in this way, the resulting battery is prone to water resistance failure. Utility Model Content
[0004] Therefore, it is necessary to provide a way to encapsulate solar cells to address the problem of water blockage failure that easily occurs when sealing solar cells with butyl rubber.
[0005] A solar cell, the encapsulated solar cell comprising:
[0006] A battery string, comprising multiple battery cells interconnected by interconnecting strips;
[0007] A water-blocking layer is provided on the front side of at least each of the battery cells;
[0008] An adhesive film layer is provided around each of the battery cells and around each of the water-blocking layers; and
[0009] The cover plate is provided on the front and back of the battery string, and the cover plate is located on the side of the water-blocking layer away from the battery cell.
[0010] In one embodiment, the water-blocking layer is provided on the back side of each of the battery cells, the water-blocking layer provided on the front side of the battery cells is a first water-blocking layer, and the water-blocking layer provided on the back side of the battery cells is a second water-blocking layer.
[0011] The cover plate is provided on the side of the first water-blocking layer away from the battery cell and the side of the second water-blocking layer away from the battery cell, respectively.
[0012] In one embodiment, the size of each water-blocking layer is less than or equal to the size of the corresponding battery cell.
[0013] In one embodiment, the encapsulated solar cell further includes a sealing layer disposed around the battery string, with one end of the sealing layer along a first direction bonded to a cover plate on the front of the battery string and the other end along the first direction bonded to a cover plate on the back of the battery string.
[0014] In one embodiment, the adhesive film layer includes a first adhesive film layer located inside the battery string and a second adhesive film layer located at the outer periphery of the battery string. The dimension of the second adhesive film layer along a second direction is larger than the dimension of the first adhesive film layer along a first direction. The second direction is the extension direction of the front side of the battery cell.
[0015] In one embodiment, the sealing layer is located on the side of the second adhesive film layer away from the battery string along a second direction.
[0016] In one embodiment, the water-blocking layer includes an organic water-blocking layer and an inorganic water-blocking layer, which are stacked sequentially along a first direction.
[0017] In one embodiment, the inorganic water-blocking layer is located on the side of the organic water-blocking layer adjacent to the corresponding battery cell.
[0018] In one embodiment, the thickness of the inorganic water-blocking layer is 10nm-200nm, and the thickness of the organic water-blocking layer is 0.4mm-0.6mm.
[0019] In one embodiment, the water-blocking layer comprises an organic water-blocking material and an inorganic water-blocking material, wherein the inorganic water-blocking material diffuses into the organic water-blocking material.
[0020] In the aforementioned encapsulated solar cell, a water-blocking layer is disposed at least on the front side of each cell, effectively preventing moisture from entering from the top of the cell. Simultaneously, an adhesive film layer is disposed around the periphery of each cell and around the periphery of each water-blocking layer, wrapping the cell's periphery to prevent moisture from entering from the periphery. That is, this application employs a multi-layered structure combining a water-blocking layer and an adhesive film layer. The water-blocking layer covers at least the front of the cell, blocking moisture from contacting the cell at the source; the adhesive film layer wraps around the cell and the water-blocking layer, further enhancing the sealing effect; and finally, the cover plate serves as an outer protective layer, resisting external environmental erosion, forming a comprehensive protective system that blocks moisture from the front and seals it from all sides, thereby further enhancing the water-blocking effect of the encapsulation structure on the solar cell. Furthermore, after curing, the adhesive film layer forms a three-dimensional network structure, significantly increasing its tensile strength, which effectively fixes the cell string frame, greatly reducing the risk of cell string displacement and circuit failure caused by external forces, significantly extending the module's lifespan and reducing maintenance costs. Furthermore, the adhesive film layer does not come into direct contact with the battery cell, thus avoiding the risk of reaction between traditional encapsulation materials and perovskite film layers. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of a solar cell encapsulated in one embodiment.
[0022] Figure 2 This is a schematic diagram of the battery string structure in one embodiment.
[0023] Figure 3 This is a schematic diagram of a structure in one embodiment where a water-blocking layer is provided on the battery string.
[0024] Figure 4 This is a schematic diagram of a structure in one embodiment where an adhesive film layer is disposed on a battery string.
[0025] Reference numerals: 100, battery string; 110, battery cell;
[0026] 200. Water-blocking layer; 210. First water-blocking layer; 220. Second water-blocking layer;
[0027] 300, Adhesive film layer; 310, First adhesive film layer; 320, Second adhesive film layer;
[0028] 400. Cover plate; 410. Front cover plate; 420. Back cover plate;
[0029] 500. Sealing layer. Detailed Implementation
[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0032] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0036] In related technologies, butyl rubber is generally used to seal the perimeter of the solar cell. However, if tiny gaps appear at the bonding interface between the butyl rubber and the solar cell and glass plate, or if aging and cracking occur due to long-term use, moisture will seep into the solar cell area along the gaps, leading to water-blocking failure.
[0037] See Figure 1One embodiment of this application provides an encapsulated solar cell, which includes a cell string 100, a water-blocking layer 200, an encapsulating film layer 300, and a cover plate 400. The cell string 100 includes a plurality of cell sheets 110 interconnected by interconnecting strips; at least one water-blocking layer 200 is provided on the front side of each cell sheet 110; an encapsulating film layer 300 is provided around the periphery of each cell sheet 110 and around the periphery of each water-blocking layer 200; a cover plate 400 is provided on the front and back sides of the cell string 100, and the cover plate 400 is located on the side of the water-blocking layer 200 away from the cell sheets 110.
[0038] In this embodiment, the solar cells are generally placed face up, allowing moisture to easily enter the cell from the front of the cell 110. A water-blocking layer 200 is provided at least on the front of each cell 110, effectively preventing moisture from entering from above. Simultaneously, an adhesive film layer 300 is provided around each cell 110 and around each water-blocking layer 200, wrapping the periphery of the cell 110 to prevent moisture from entering from the periphery. In other words, the water-blocking layer 200 covers at least the front of the cell 110, blocking moisture from contacting the cell 110 at the source; the adhesive film layer 300 wraps around the cell 110 and the water-blocking layer 200, further enhancing the sealing effect; and finally, the cover plate 400 serves as an outer protective layer, resisting external environmental erosion, forming a comprehensive protective system that blocks moisture from the front and seals it from all sides, thereby further enhancing the water-blocking effect of the encapsulation structure on the solar cell. Furthermore, the adhesive film layer 300 forms a three-dimensional network structure after curing, which significantly improves its tensile strength. This effectively fixes the battery string 100 frame, greatly reducing the risk of battery string 100 displacement and circuit failure caused by external forces, significantly extending the module's lifespan and reducing maintenance costs. Moreover, the adhesive film layer 300 does not directly contact the battery cell 110, thus avoiding the risk of reaction between traditional encapsulation materials and perovskite films.
[0039] The solar cell 110 can be a perovskite-crystalline silicon tandem solar cell, in which the bottom cell can be a Topcon cell or an HJT cell.
[0040] It should be noted that each battery cell 110 includes a front side, a back side, and a side side located between the front side and the back side. Each battery cell 110 is provided with an adhesive film layer 300 around its perimeter, that is, each battery cell 110 is provided with an adhesive film layer 300 on its side. Similarly, each water-blocking layer 200 is provided with an adhesive film layer 300 around its perimeter, which can also be considered as each water-blocking layer 200 being provided with an adhesive film layer 300 on its side.
[0041] Specifically, the encapsulant layer 300 is a non-uniform encapsulant film, which can be at least one of EVA (ethylene-vinyl acetate copolymer), POE (polyolefin elastomer), TPO (thermoplastic polyolefin), or TPU (thermoplastic polyurethane). The non-uniform encapsulant film is a pre-crosslinked or micro-crosslinked film, encapsulated using a low-temperature encapsulation process (low-temperature encapsulation <120℃), which avoids the problem of peroxide decomposition residues on the solar cell 110 in traditional high-temperature processes. Simultaneously, the crosslinked film itself exhibits significantly increased strength, effectively fixing the solar cell string 100 frame, enhancing the overall mechanical strength of the module, and reducing the risk of water blockage failure.
[0042] In some embodiments, a water-blocking layer 200 is provided on the back side of each battery cell 110, the water-blocking layer 200 provided on the front side of each battery cell 110 is a first water-blocking layer 210, and the water-blocking layer 200 provided on the back side of each battery cell 110 is a second water-blocking layer 220. A cover plate 400 is respectively provided on the side of the first water-blocking layer 210 away from the battery cell 110 and the side of the second water-blocking layer 220 away from the battery cell 110.
[0043] In this embodiment, a first water-blocking layer 210 and a second water-blocking layer 220 are respectively provided on the front and back of the battery cell 110, forming a double-sided waterproof barrier. This effectively blocks both rain impacts from the front and moisture intrusion from the back due to environmental humidity. Simultaneously, an adhesive film layer 300 is provided around the first water-blocking layer 210 on the front of the battery cell 110, around the battery cell 110 itself, and around the second water-blocking layer 220 on the back of the battery cell 110. The adhesive film layer 300, together with the first water-blocking layer 210 and the second water-blocking layer 220, completely encapsulates the battery cell 110, greatly improving its waterproof reliability in harsh environments such as high humidity and heavy rainfall.
[0044] In addition, the water-blocking layer 200, by closely adhering to the upper and lower surfaces of the solar cell 110, disperses external impact forces and reduces the risk of microcracks in the solar cell 110 due to uneven stress. At the same time, the surrounding adhesive film layer 300 firmly bonds the solar cell 110, the water-blocking layer 200 and the cover plate 400 together, effectively restricting the displacement of the solar cell 110, significantly enhancing the module's resistance to external forces during transportation, installation and use, and greatly reducing the probability of solar cell 110 damage and circuit failure caused by vibration and collision.
[0045] In some embodiments, the size of each water-blocking layer 200 is less than or equal to the size of the corresponding battery cell 110.
[0046] In this embodiment, the size of each water-blocking layer 200 is smaller than the size of the corresponding battery cell 110, or the size of each water-blocking layer 200 is equal to the size of the corresponding battery cell 110, so as to ensure that there is a sufficient gap between two adjacent water-blocking layers 200 for setting the adhesive film layer 300, so that the adhesive film layer 300 forms a three-dimensional network structure after curing, thereby effectively fixing the battery string 100 skeleton.
[0047] In some embodiments, the encapsulated solar cell further includes a sealing layer 500, which is disposed around the battery string 100. One end of the sealing layer 500 along a first direction is bonded to the cover plate 400 on the front side of the battery string 100, and the other end along the first direction is bonded to the cover plate 400 on the back side of the battery string 100.
[0048] The sealing layer 500 can be butyl rubber.
[0049] In this embodiment, the water-blocking layer 200 and the adhesive film layer 300 form internal protection for the individual solar cell 110; the sealing layer 500 surrounds the solar cell string 100 and is tightly bonded to the front and back cover plates 420 of the solar cell string 100, thus forming a highly sealed external protection for the entire solar cell string 100. The combination of internal and external protection effectively blocks the intrusion of external impurities such as rainwater and dust, preventing moisture from penetrating into the solar cell string 100 and causing a short circuit, and preventing dust from covering the cell surface and affecting light absorption efficiency, thereby ensuring the normal operation of the solar cell.
[0050] Furthermore, the adhesive layer 300 includes a first adhesive layer 310 located inside the battery string 100 and a second adhesive layer 320 located on the outer periphery of the battery string 100. The dimension of the second adhesive layer 320 along the second direction is larger than the dimension of the first adhesive layer 310 along the first direction. The second direction is the extension direction of the front side of the battery cell 110, that is, the second direction can be considered as the thickness direction of the adhesive layer 300.
[0051] In this embodiment, the first adhesive film layer 310 is located inside the battery string 100, ensuring a tight fit between the battery cells 110 and achieving good electrical connection and optical transmission. The second adhesive film layer 320 is thickened at the outer periphery of the battery string 100, which can better fill the gap between the battery string 100 and the front cover plate 410 and the back cover plate 420, enhance the adhesion strength between the battery string 100 and the cover plate 400, and make the entire encapsulation structure more stable, less prone to delamination or detachment in complex environments. At the same time, the thickness of the second adhesive film layer 320 is greater than that of the first adhesive film layer 310, which can form a more complete wrapping and coverage of the outer periphery of the battery string 100, thus providing better protection for the edges of the battery string 100, which are susceptible to environmental corrosion.
[0052] Specifically, the sealing layer 500 is located on the side of the second adhesive film layer 320 away from the battery string 100 along the second direction.
[0053] In this embodiment, the sealing layer 500 is butyl rubber. Butyl rubber has extremely low air permeability and moisture permeability. When used as the sealing layer 500 on the side of the second adhesive film layer 320 away from the battery string 100, it forms a highly efficient barrier against moisture and gas. This effectively prevents moisture and oxygen in the air from penetrating into the battery string 100, improving water resistance. Furthermore, the butyl rubber has good adhesion to the glass cover plate 400 and the second adhesive film layer 320, firmly bonding to the second adhesive film layer 320, the front cover plate 410, and the back cover plate 420, enhancing the integrity and stability of the solar cell encapsulation structure.
[0054] In some embodiments, the water-blocking layer 200 includes an organic water-blocking layer and an inorganic water-blocking layer, which are stacked sequentially along a first direction.
[0055] In this embodiment, the organic water-blocking layer and the inorganic water-blocking layer are sequentially stacked along a first direction. The inorganic water-blocking layer can be at least one of aluminum oxide, titanium dioxide, silicon dioxide, and silicon nitride. The inorganic water-blocking layer is PDMS. By utilizing the multilayered organic water-blocking layer 200 and the inorganic water-blocking layer, the water-oxygen pathway can be extended while maintaining the overall flexibility and transparency of the film.
[0056] As an inorganic water-blocking layer, PDMS (polydimethylsiloxane) has several advantages. First, its light transmittance is close to that of optical glass, meaning it has almost no impact on the light absorption efficiency of perovskite solar cells. Second, PDMS employs a two-component non-peroxide crosslinking system (such as platinum-catalyzed addition reaction), fundamentally avoiding the erosion of perovskite grain boundaries by free radicals generated from the decomposition of traditional peroxide crosslinking agents. Furthermore, PDMS itself has low stress, preventing the cell film from being affected during high and low temperature stress release.
[0057] Furthermore, the inorganic water-blocking layer is located on the side of the organic water-blocking layer that is close to the corresponding solar cell 110.
[0058] In this embodiment, the inorganic water-blocking layer is directly attached to the surface of the solar cell 110. The inorganic water-blocking layer (such as silicon dioxide) has a natural chemical bond (Si-O bond) with the surface of the silicon-based solar cell, and its adhesion strength is above 10 N / cm, which can prevent water-blocking failure caused by interface peeling. In the perovskite solar cell, the coordination effect between the titanium dioxide inorganic water-blocking layer and the surface of methylamine lead iodide can inhibit ion migration and at the same time block water vapor from eroding the perovskite layer.
[0059] Specifically, the inorganic water-blocking layer has a thickness of 10nm-200nm, while the organic water-blocking layer has a thickness of 0.4mm-0.6mm. The 10nm-200nm thickness of the inorganic water-blocking layer avoids the light scattering loss of traditional thick films (film thickness > 200nm). The inorganic water-blocking layer can be achieved using precision coating technologies such as ALD and magnetron sputtering. The 0.4mm-0.6mm thickness of the organic water-blocking layer is problematic. A thickness less than 0.4mm results in insufficient molecular chain network density, shortening the water and oxygen permeation path; a thickness greater than 0.6mm reduces thermal conductivity, hindering heat dissipation within the solar cell 110.
[0060] In some other embodiments, the water-blocking layer 200 includes organic water-blocking materials and inorganic water-blocking materials, with the inorganic water-blocking materials diffusing into the organic water-blocking materials.
[0061] In this embodiment, the inorganic water-blocking material diffuses into the organic water-blocking material, forming a continuous, interwoven nanoscale barrier. Water molecules and oxygen must bypass the complex paths formed by the inorganic particles to penetrate, effectively extending the diffusion distance and significantly improving the water-blocking effect.
[0062] Combination Figures 2-4 In actual production, firstly, adhesive film layers 300 are made on the front and back of each battery cell 110 in the battery string 100; then, adhesive film layers 300 are made between two adjacent battery cells 110 and around the entire battery string 100; next, a front cover plate 410 is covered on the front of the battery string 100 and a back cover plate 420 is covered on the back of the battery string 100; finally, the outer periphery of the front cover plate 410 and the back cover plate 420 is sealed by a sealing layer 500.
[0063] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0064] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A type of encapsulated solar cell, characterized in that, The encapsulated solar cell includes: A battery string, comprising multiple battery cells interconnected by interconnecting strips; A water-blocking layer is provided on the front side of at least each of the battery cells; An adhesive film layer is provided around each of the battery cells and around each of the water-blocking layers; and The cover plate is provided on the front and back of the battery string, and the cover plate is located on the side of the water-blocking layer away from the battery cell.
2. The encapsulated solar cell according to claim 1, characterized in that, Each of the battery cells has a water-blocking layer on its back side. The water-blocking layer on the front side of the battery cell is a first water-blocking layer, and the water-blocking layer on the back side of the battery cell is a second water-blocking layer. The cover plate is provided on the side of the first water-blocking layer away from the battery cell and the side of the second water-blocking layer away from the battery cell, respectively.
3. The encapsulated solar cell according to claim 1, characterized in that, The size of each of the water-blocking layers is less than or equal to the size of the corresponding battery cell.
4. The encapsulated solar cell according to claim 1, characterized in that, The encapsulated solar cell further includes a sealing layer disposed around the battery string, with one end of the sealing layer along a first direction bonded to a cover plate on the front of the battery string and the other end along the first direction bonded to a cover plate on the back of the battery string.
5. The encapsulated solar cell according to claim 1, characterized in that, The adhesive film layer includes a first adhesive film layer located inside the battery string and a second adhesive film layer located on the outer periphery of the battery string. The dimension of the second adhesive film layer along a second direction is larger than the dimension of the first adhesive film layer along a first direction. The second direction is the extension direction of the front side of the battery cell.
6. The encapsulated solar cell according to claim 5, characterized in that, The sealing layer is located on the side of the second adhesive film layer away from the battery string along the second direction.
7. The encapsulated solar cell according to claim 1, characterized in that, The water-blocking layer includes an organic water-blocking layer and an inorganic water-blocking layer, which are stacked sequentially along a first direction.
8. The encapsulated solar cell according to claim 7, characterized in that, The inorganic water-blocking layer is located on the side of the organic water-blocking layer that is close to the corresponding battery cell.
9. The encapsulated solar cell according to claim 7, characterized in that, The thickness of the inorganic water-blocking layer is 10nm-200nm, and the thickness of the organic water-blocking layer is 0.4mm-0.6mm.
10. The encapsulated solar cell according to claim 1, characterized in that, The water-blocking layer comprises organic water-blocking materials and inorganic water-blocking materials, wherein the inorganic water-blocking materials diffuse into the organic water-blocking materials.