Photovoltaic module and packaging method thereof

Abstract

The invention discloses a photovoltaic module and a packaging method thereof in the field of photovoltaic solar cells, and the packaging method comprises the steps: enabling the top electrodes of two adjacent cells to be oppositely arranged, enabling the positive electrode of each cell to be located at a first side, and enabling the negative electrode of each cell to be located at a second side; plating an isolating layer between the sub-battery areas of adjacent battery pieces; coating conductive slurry on the electrodes of the adjacent battery pieces; and combining two adjacent battery pieces, laminating the combined battery pieces, curing the conductive slurry, and forming a conductive slurry layer between the electrodes of the adjacent battery pieces, so that the two adjacent battery pieces are connected in parallel in the vertical direction. According to the invention, the two battery pieces of the photovoltaic module are connected in parallel through a vertical piece combining packaging method, so that the two surfaces of the photovoltaic module are respectively provided with a perovskite light absorption layer, and the generating capacity of the photovoltaic module is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic solar cells, and particularly to a photovoltaic module and a packaging method thereof. Background Art

[0002] The photovoltaic industry is an important part of new energy technologies. Novel hybrid perovskite materials, with their unique optoelectronic properties and high theoretical efficiency ceilings, have opened up new directions for the research and development of solar cells. In particular, perovskite solar cells not only have relatively low production costs but also can maintain good power generation performance under low-light conditions, making such cells show broad application prospects in fields such as building-integrated photovoltaics.

[0003] However, current packaging technologies for photovoltaic modules mainly focus on single-cell packaging and multi-cell horizontal parallel connection packaging. This packaging method not only consumes a large amount of float glass, increasing production costs, but also results in relatively low battery power generation due to the action of only one perovskite light-absorbing layer, making it difficult to meet the growing energy demand.

[0004] Although photovoltaic modules made of novel hybrid perovskite materials have many advantages, there are still many challenges in packaging technologies. On the one hand, how to effectively increase the current and power of the battery cells, reduce resistance, and thereby improve the efficiency and stability of the photovoltaic module is an urgent problem to be solved. On the other hand, how to optimize the packaging process, reduce material consumption, and lower production costs is also the key to promoting the large-scale application of perovskite solar cells.

[0005] Therefore, the present invention proposes a photovoltaic module and a packaging method thereof. Summary of the Invention

[0006] The purpose of the present invention is to provide a photovoltaic module and a packaging method thereof. Through the vertical parallel connection packaging method, two battery cells of the photovoltaic module are connected in parallel, and thus each side of the photovoltaic module has a perovskite light-absorbing layer, which can significantly increase the power generation of the photovoltaic module.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] In a first aspect, the present invention provides a packaging method for a photovoltaic module, including the following steps:

[0009] Set the top electrodes of two adjacent battery cells opposite to each other, and make the positive electrode of each battery cell located on the first side and the negative electrode of each battery cell located on the second side;

[0010] Deposit an isolation layer between the sub-cell regions of adjacent battery cells;

[0011] Coat a conductive paste on the electrodes of adjacent battery cells;

[0012] Laminating adjacent two pieces of solar cells together, laminating the laminated solar cells, and curing the conductive paste to form a conductive paste layer between the electrodes of adjacent solar cells, so that the adjacent two pieces of solar cells are connected in parallel in the vertical direction.

[0013] The beneficial effects of the above solution are as follows: Through the packaging method of vertical parallel connection of solar cells in the present invention, two pieces of solar cells in the photovoltaic module are connected in parallel. Furthermore, there is a perovskite light absorption layer on each side of the photovoltaic module, which can significantly improve the power generation of the photovoltaic module.

[0014] Through the combined process of the isolation layer, the conductive paste layer and the lamination treatment in the present invention, the packaging process is simplified and the production efficiency is improved. In addition, the conductive paste is cured by ultraviolet irradiation to ensure the stability and conductivity of the conductive paste layer, and improve the power generation efficiency and long-term stability of the photovoltaic module.

[0015] Furthermore, the packaging method further includes the following steps:

[0016] Wrapping the fixing layer around the sides of adjacent two pieces of solar cells;

[0017] Coating the protective layer on the FTO substrates of adjacent two pieces of solar cells;

[0018] Wherein, the fixing layer includes butyl tape.

[0019] The beneficial effects of the above solution are as follows: By using the fixing layer (such as butyl tape) in the present invention, the edge sealing performance of the photovoltaic module is enhanced, preventing moisture and dust from entering, and prolonging the service life of the photovoltaic module. At the same time, the bonding process of the fixing layer is simple and easy to implement, reducing the packaging difficulty.

[0020] Furthermore, depositing the isolation layer between the sub-cell regions of adjacent solar cells includes:

[0021] Depositing a first insulating film layer on the sub-cell region of one of the adjacent two pieces of solar cells;

[0022] Depositing a second insulating film layer on the sub-cell region of the other of the adjacent two pieces of solar cells;

[0023] Attaching one side of the adhesive film layer to the first insulating film layer, and attaching the other side of the adhesive film layer to the second insulating film layer.

[0024] The beneficial effects of the above solution are as follows: By setting the first insulating film layer, the second insulating film layer and the adhesive film layer in the present invention, the insulation performance of the sub-cell region is further enhanced to prevent short circuit. At the same time, the use of the adhesive film layer enhances the adhesion between the solar cells, ensuring the stability of the photovoltaic module during long-term use.

[0025] Further, the temperature of the lamination process is 80°C - 120°C, the pressure is 0.5 MPa - 1.0 MPa, and the lamination time is 10 - 20 minutes;

[0026] When curing the conductive paste, the wavelength of the ultraviolet irradiation is 320 nm - 400 nm, the power is 400 W, and the curing time is 15 minutes.

[0027] The beneficial effects of the above solution are as follows: By controlling the temperature, pressure, and time of the lamination process, the present invention ensures the tight bonding between the solar cells, avoiding problems such as bubbles and delamination. In addition, by curing the conductive paste through ultraviolet irradiation, the stability and conductivity of the conductive paste layer are ensured, improving the power generation efficiency and long-term stability of the photovoltaic module.

[0028] Further, the components of the conductive paste include:

[0029] Lithium bis(trifluoromethanesulfonyl)imide;

[0030] Butyl acrylate;

[0031] Polyethylene glycol diacrylate;

[0032] 1-Hydroxycyclohexyl phenyl ketone;

[0033] Among them, the molar percentage of polyethylene glycol diacrylate to butyl acrylate is 0.1%, the molar percentages of 1-hydroxycyclohexyl phenyl ketone to butyl acrylate are 1% respectively, and the molar concentration of lithium bis(trifluoromethanesulfonyl)imide is 0.5 mol / L

[0034] The beneficial effects of the above solution are as follows: The combination of lithium bis(trifluoromethanesulfonyl)imide, butyl acrylate, polyethylene glycol diacrylate, and 1-hydroxycyclohexyl phenyl ketone in the conductive paste of the present invention ensures the conductivity, transparency, and adhesiveness of the paste. In addition, the component ratio of the conductive paste is clear, and the preparation process is simple, suitable for large-scale production.

[0035] In a second aspect, the present invention provides a photovoltaic module, which includes:

[0036] At least two oppositely arranged solar cells, each solar cell includes a sub-cell region and electrodes located at the edge of the sub-cell region, the electrodes include a positive electrode and a negative electrode, the positive electrode of each solar cell is located on the first side, and the negative electrode of each solar cell is located on the second side;

[0037] An isolation layer, the isolation layer connects the sub-cell regions of adjacent solar cells;

[0038] A conductive paste layer, the conductive paste layer connects the electrodes of adjacent solar cells, making the adjacent two solar cells connected in parallel in the vertical direction.

[0039] The beneficial effects of the above solution are as follows: In the photovoltaic module of the present invention, adjacent solar cells are connected in parallel through a conductive paste layer in the vertical direction, which not only optimizes the current transmission path, reduces energy loss, but also improves the performance and adaptability of the photovoltaic module in multiple dimensions:

[0040] (1) Optimization of current transmission path and reduction of energy loss: Adjacent solar cells are connected in parallel through a conductive paste layer in the vertical direction, shortening the current transmission path and reducing the energy loss caused by series resistance. Compared with the traditional horizontal arrangement, the vertical structure reduces the length of the lateral current path and improves the carrier collection efficiency.

[0041] (2) Simplification of internal wiring of photovoltaic module and reduction of process complexity: The positive and negative electrodes of all solar cells are uniformly distributed on the first side and the second side, simplifying the internal wiring design of the photovoltaic module, reducing the process complexity, and improving the assembly efficiency of the production line. Due to the unified electrode positions, the production line does not need to frequently adjust the electrode positioning, accelerating the production speed and reducing the production cost.

[0042] (3) Improvement of space utilization and increase of power density: The vertical arrangement of solar cells maximizes the use of three-dimensional space, significantly increasing the power density per unit projected area, which is suitable for scenarios with limited roof area or BIPV (Building Integrated Photovoltaics). It not only improves the power generation efficiency of the photovoltaic module, but also reduces the floor area, making the application of photovoltaic energy more extensive and flexible.

[0043] (4) Improvement of heat dissipation and optimization of temperature management: The vertical layout promotes the lateral diffusion of heat along the plane of the solar cells, avoiding the problem of heat accumulation at the bottom in the traditional horizontal array. It helps to reduce the operating temperature of the solar cells, improve the photoelectric conversion efficiency and the service life of the photovoltaic module.

[0044] (5) Flexible adjustment of power output of photovoltaic module and customized production:

[0045] The power output of the photovoltaic module can be flexibly adjusted by increasing or decreasing the number of vertically stacked layers, facilitating customized production and meeting the diverse power requirements of different application scenarios. During maintenance, a faulty solar cell can be replaced individually without replacing the entire photovoltaic module, reducing the operation and maintenance costs.

[0046] (6) Double-sided perovskite light-absorbing layer improves power generation: Through vertical parallel-chip encapsulation, two solar cells are connected in parallel, and each side has a layer of perovskite light-absorbing layer, significantly improving the power generation of the photovoltaic module. The high light absorption and conversion efficiency of perovskite materials enable the photovoltaic module to generate more electric energy under light conditions.

[0047] (7) Parallel design reduces efficiency loss and improves system stability: The parallel design superimposes the total output current (while keeping the voltage unchanged), which is especially suitable for application scenarios sensitive to high current demand (such as energy storage systems or DC microgrids). At the same time, it reduces the overall efficiency loss caused by partial shading or cell performance differences. In a complex lighting environment, the vertical parallel design can maintain the stability of the system's power generation, improving the adaptability and reliability of the photovoltaic system.

[0048] (8) The isolation layer prevents micro-short circuits and extends the life of photovoltaic modules: The isolation layer, as a physical barrier, effectively separates the sub-cell area from the conductive paste, preventing micro-short circuit problems caused by paste diffusion. At the same time, in harsh environments such as high humidity and salt spray, the isolation layer can inhibit the migration of metal ions and electrochemical corrosion, reducing the potential leakage current, thereby extending the service life of photovoltaic modules.

[0049] Furthermore, the photovoltaic module further includes:

[0050] A fixing layer that covers the sides of two adjacent cells;

[0051] A protective layer that covers the FTO substrates of two adjacent cells.

[0052] The beneficial effects of the above solution are: By setting the fixing layer and the protective layer, the mechanical strength of the photovoltaic module is enhanced, preventing the cells from being damaged during transportation and use. The covering settings of the fixing layer (such as butyl tape) and the protective layer effectively prevent moisture and dust from entering the interior of the photovoltaic module, extending the service life of the photovoltaic module.

[0053] Furthermore, the isolation layer includes:

[0054] A first insulating film layer that connects to the sub-cell area of one of the two adjacent cells;

[0055] A second insulating film layer that connects to the sub-cell area of the other of the two adjacent cells;

[0056] An adhesive film layer, one side of which connects to the first insulating film layer and the other side of which connects to the second insulating film layer.

[0057] The beneficial effects of the above solution are: By setting the first insulating film layer, the second insulating film layer and the adhesive film layer, the insulation performance of the sub-cell area is further enhanced, preventing short circuits. At the same time, the use of the adhesive film layer enhances the adhesion between the cells, ensuring the stability of the photovoltaic module during long-term use.

[0058] Furthermore, the conductive paste layer includes:

[0059] The first conductive layer, and the first conductive layer is connected to the positive electrodes of adjacent solar cells;

[0060] The second conductive layer, and the second conductive layer is connected to the negative electrodes of adjacent solar cells.

[0061] The beneficial effects of the above solution are: the first conductive layer and the second conductive layer of the present invention are respectively connected to the positive and negative electrodes of adjacent solar cells, ensuring efficient current transmission and reducing resistance loss.

[0062] Further, the solar cell is an inverted perovskite solar cell;

[0063] Two adjacent solar cells are arranged in a mirror image.

[0064] The beneficial effects of the above solution are: the inverted perovskite solar cell of the present invention has a high photoelectric conversion efficiency and is suitable for vertical parallel-chip packaging, further improving the power generation performance of the photovoltaic module. In addition, the adjacent solar cells are arranged in a mirror image, which facilitates the alignment and connection of the positive and negative electrodes and simplifies the packaging process.

[0065] Compared with the prior art, the beneficial effects of the present invention at least include:

[0066] By the vertical parallel-chip packaging method of the present invention, two solar cells of the photovoltaic module are connected in parallel, and then there is a perovskite light-absorbing layer on each side of the photovoltaic module, significantly increasing the power generation of the photovoltaic module. By forming an isolation layer, the conductive paste is effectively prevented from spreading to the sub-cell area, avoiding short-circuit problems and improving the stability and safety of the photovoltaic module. By forming a conductive paste layer to directly connect the electrodes of adjacent solar cells, complex welding processes are not required, simplifying the packaging process and reducing production costs. Description of the Drawings

[0067] Figure 1 is a schematic flow chart of the packaging method of the photovoltaic module according to an embodiment of the present invention.

[0068] Figure 2 is a schematic structural diagram of the photovoltaic module according to an embodiment of the present invention.

[0069] In the figure: 1, solar cell; 11, FTO substrate; 12, NiOx film layer; 13, perovskite film layer; 14, C 60 film layer; 15, SnO 2 film layer; 16, ITO film layer; 2, isolation layer; 21, first insulating film layer; 22, second insulating film layer; 23, adhesive film layer; 31, first conductive layer; 32, second conductive layer; 4, fixing layer; 5, protective layer. Detailed Embodiments

[0070] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. Like reference numerals in the figures denote like or similar structures and thus their repetitive description will be omitted.

[0071] The words expressing positions and directions described in the present invention are all illustrated by taking the accompanying drawings as examples, but can be changed according to needs, and all the changes made are included in the protection scope of the present invention.

[0072] To promote the large-scale application of perovskite solar cells, the present invention proposes a photovoltaic module and its encapsulation method, aiming to vertically parallel-connect and encapsulate two cell sheets 1 into an efficient and stable photovoltaic module through vertical parallel-connection encapsulation technology, so as to show significant beneficial effects in multiple aspects such as current transmission, wiring design, space utilization, heat management, power adjustment, operation and maintenance cost, power generation improvement, system stability, and protection of the isolation layer 2, and synergistically improve the performance and adaptability of the photovoltaic module.

[0073] Reference Figure 1 , in order to optimize the encapsulation process, reduce material consumption, and lower production costs, the encapsulation method of the present invention includes steps S1 - S4. Further, in order to reduce the encapsulation difficulty, the encapsulation method of the present invention further includes steps S5 - S6.

[0074] Step S1: Oppositely arrange the top electrodes of two adjacent cell sheets 1, and make the positive electrode of each cell sheet 1 located on the first side and the negative electrode of each cell sheet 1 located on the second side.

[0075] Reference Figure 2 , the cell sheet 1 includes, arranged in sequence: an FTO substrate 11, a NiOx film layer 12, a perovskite film layer 13, a C 60 film layer 14, a SnO 2 film layer 15, and a top electrode. Among them, the FTO substrate 11 is a fluorine-doped tin oxide (FTO) glass substrate, mainly composed of a certain proportion of fluorine elements doped into a tin oxide (SnO 2 ) matrix. It has good electrical conductivity and transparency, and usually has a visible light transmittance of more than 85%. The NiOx film layer 12, namely a nickel oxide film layer, is a semiconductor material with a wide bandgap and good electrical conductivity. It serves as a hole transport layer in the inverted perovskite cell sheet 1, responsible for transporting photo-generated holes from the photoactive layer to the electrode, thereby improving the photoelectric conversion efficiency. The perovskite film layer 13 is the light absorption layer in the inverted perovskite cell sheet 1, composed of a perovskite thin film, and has excellent photoelectric conversion performance. The C 60 film layer 14 is composed of C60 A thin film composed of molecules, C 60 The molecule is a spherical structure molecule composed of 20 six-membered rings and 12 five-membered rings, with a strong delocalized π bond and unique physical and chemical properties. SnO 2 The film layer 15 is a tin dioxide thin film, which is an n-type semiconductor material with a wide direct bandgap, having a wide bandgap, high exciton binding energy, low resistivity, and high visible light transmittance (reaching 97%). The top electrode can be the ITO film layer 16. The ITO film layer 16, namely indium tin oxide semiconductor transparent conductive film, is an N-type oxide semiconductor with good conductivity and transparency.

[0076] Step S2: Deposit an isolation layer 2 between the sub-cell regions of adjacent cell sheets 1.

[0077] In application, the photovoltaic module includes at least two relatively arranged cell sheets 1. Each cell sheet 1 includes a sub-cell region and electrodes located at the edge of the sub-cell region, where the electrodes include a positive electrode and a negative electrode. Preferably, the cell sheet 1 is an inverted perovskite cell sheet 1. In actual application, step S2 includes: steps S2.1 - S2.3.

[0078] Step S2.1: Deposit a first insulating film layer 21 on the sub-cell region of one of the adjacent two cell sheets 1.

[0079] Among them, the first insulating film layer 21 is a first SiO 2 film layer.

[0080] Step S2.2: Deposit a second insulating film layer 22 on the sub-cell region of the other of the adjacent two cell sheets 1.

[0081] Among them, the second insulating film layer 22 is a second SiO2 film layer.

[0082] In application, the SiO 2 film layer is deposited on the sub-cell region of the cell sheet by chemical vapor deposition (CVD) process, and the deposition temperature: 300 °C, deposition pressure: 100 Pa, deposition time: 30 minutes, SiO 2 film layer thickness: 1500 mm.

[0083] Step S2.3: Attach one side of the adhesive film layer 23 to the first insulating film layer 21, and attach the other side of the adhesive film layer 23 to the second insulating film layer 22.

[0084] Among them, the adhesive film layer 23 is a POE film layer.

[0085] During application, the POE film layer 23 is cut into the same size as the insulating film layer, and the film layer 23 is attached to the first insulating film layer 21 and the second insulating film layer 22 using a hot pressing process. The thickness of the POE film layer is 0.7 mm.

[0086] Step S3: Coat a conductive paste on the electrodes of adjacent solar cells 1.

[0087] The conductive paste is an ion-conductive elastomer that does not contain solvents, does not corrode metal electrodes, is resistant to high temperatures, high pressures, oxidation, and has good stretchability, transparency, adhesiveness, and ionic conductivity. Using lithium bis(trifluoromethanesulfonyl)imide as the electrolyte salt, butyl acrylate as the monomer, polyethylene glycol diacrylate as the crosslinking agent, and 1-hydroxycyclohexyl phenyl ketone as the photoinitiator, the lithium bis(trifluoromethanesulfonyl)imide powder, polyethylene glycol diacrylate, and photoinitiator are dissolved in the butyl acrylate liquid to form a transparent conductive paste.

[0088] During application, the components of the conductive paste of the present invention include: lithium bis(trifluoromethanesulfonyl)imide, butyl acrylate, polyethylene glycol diacrylate, and 1-hydroxycyclohexyl phenyl ketone. Among them, the molar percentage of polyethylene glycol diacrylate to butyl acrylate is 0.1%, the molar percentage of 1-hydroxycyclohexyl phenyl ketone to butyl acrylate is 1%, and the molar concentration of lithium bis(trifluoromethanesulfonyl)imide is 0.5 mol / L.

[0089] Step S4: Combine two adjacent solar cells 1 with the positive electrodes facing each other and the negative electrodes facing each other, perform lamination on the combined solar cells 1, and cure the conductive paste to form a conductive paste layer between the electrodes of adjacent solar cells 1, so that two adjacent solar cells 1 are connected in parallel in the vertical direction.

[0090] During application, the temperature of the lamination process is 80°C - 120°C, the pressure is 0.5 MPa - 1.0 MPa, and the lamination time is 10 - 20 minutes; when curing the conductive paste, the wavelength of the ultraviolet irradiation is 320 nm - 400 nm, the power is 400 W, and the curing time is 15 minutes.

[0091] During actual application, two solar cells 1 are combined with the positive electrodes facing each other and the negative electrodes facing each other, so that the conductive paste contacts the electrodes; pressure is applied to the combined solar cells 1 for lamination, so that part of the conductive paste overflows and is discharged through a specifically set small opening, avoiding an excess of conductive paste in the photovoltaic module.

[0092] Step S5: Wind the fixing layer 4 around the sides of two adjacent solar cells 1.

[0093] During application, the fixing layer 4 includes a butyl tape. The butyl tape is used to wind around the side surface of the first battery, the side surface of the isolation layer, and the side surface of the second battery in sequence, so as to relatively fix the positions of the first battery and the second battery, and prevent the battery chips from shifting or loosening during installation or use.

[0094] Step S6: Cover the protective layer 5 on the FTO substrates 11 of two adjacent battery chips 1.

[0095] During application, the protective layer includes: a first baffle and a second baffle. Among them, the first baffle is covered on the FTO substrate of the first battery; the second baffle is covered on the FTO substrate of the second battery to form a complete photovoltaic module.

[0096] The vertical parallel-chip packaging method of the present invention does not require the use of float glass as the backplane glass. It can not only reduce the use of float glass, lower the production cost, but also reduce the product weight. The power generation of the photovoltaic module is significantly improved through the double-sided light-absorbing layer, that is, the photovoltaic module of the same weight has a larger power generation. In addition, vertical parallel-chip packaging can also avoid the welding difficulty and unappealing appearance problems brought by traditional metal busbars.

[0097] Reference Figure 2 , in order to increase the current and power of the battery chip 1, reduce the resistance, and further improve the efficiency and stability of the photovoltaic module, the photovoltaic module of the present invention includes: at least two oppositely arranged battery chips 1, an isolation layer 2, and a conductive paste layer. Further, in order to improve the mechanical strength and sealing performance of the photovoltaic module, the photovoltaic module of the present invention may also include: a fixing layer 4 and a protective layer 5.

[0098] Each battery chip 1 of the present invention includes a sub-battery region and electrodes located at the edge of the sub-battery region. Among them, the electrodes include a positive electrode and a negative electrode. Among them, the battery chip 1 is an inverted perovskite battery chip 1.

[0099] The inverted perovskite battery chip 1 has a high photoelectric conversion efficiency. The theoretical limit conversion efficiency of a single-junction perovskite battery can reach 33%, which is much higher than that of traditional silicon-based solar cells. In addition, the perovskite material can still maintain a high power generation performance under low-light conditions, which makes it have broad prospects in indoor photovoltaic applications. The production cost of perovskite solar cells is relatively low, especially in the context of large-scale mass production, and its cost advantage is more obvious. However, at present, in the production cost of perovskite batteries, glass materials account for a large proportion, about half of the total cost.

[0100] Reference Figure 2 , the inverted perovskite battery chip 1 includes, arranged in sequence: an FTO substrate 11, a NiOx film layer 12, a perovskite film layer 13, a C 60 film layer 14, a SnO 2 film layer 15, and an ITO film layer 16.

[0101] In application, the thickness of the NiOx film layer 12 is 8 nm - 15 nm, preferably 10 nm; the thickness of the perovskite film layer 13 is 300 nm - 450 nm, preferably 400 nm; the C 60 film layer has a thickness of 20 nm - 25 nm, preferably the C 60 film layer has a thickness of 25 nm; the SnO 2 film layer has a thickness of 15 nm - 20 nm, preferably the SnO 2 film layer has a thickness of 15 nm; the ITO film layer 16 has a thickness of 100 nm - 200 nm, preferably 150 nm.

[0102] Reference Figure 2 , in actual application, two adjacent battery cells 1 are arranged in a mirror image. The ITO film layers 16 of two adjacent battery cells 1 are arranged opposite to each other.

[0103] The isolation layer 2 of the present invention is connected to the sub - battery regions of adjacent battery cells 1, and is used to prevent the conductive materials for parallel connection from diffusing into the sub - battery regions and causing a short - circuit.

[0104] Reference Figure 2 , in order to further enhance the insulation performance of the sub - battery regions and prevent short - circuits, the isolation layer 2 of the present invention includes: a first insulating film layer 21, a second insulating film layer 22, and an adhesive film layer 23. Among them, both the first insulating film layer 21 and the second insulating film layer 22 are SiO 2 film layers, and the adhesive film layer 23 is a POE film layer. The POE film layer is a thermoplastic elastomer copolymerized from polyethylene and polyolefin elastomer, and its main components are made from olefins (such as ethylene and propylene) through a polymerization reaction.

[0105] Reference Figure 2 , in application, the first insulating film layer 21 is connected to the sub - battery region of one of the two adjacent battery cells 1, the second insulating film layer 22 is connected to the sub - battery region of the other of the two adjacent battery cells 1, one side of the adhesive film layer 23 is connected to the first insulating film layer 21, and the other side of the adhesive film layer 23 is connected to the second insulating film layer 22 to enhance the adhesion between the battery cells 1 and ensure the stability of the photovoltaic module during long - term use.

[0106] In actual application, in order to further enhance the adhesion strength between the insulating film layers and provide better mechanical support and buffering for the parallel - connected battery cells 1, a concave structure (not shown) is provided on the insulating film layer, and protruding structures (not shown) matching the concave structure are provided on both sides of the adhesive film layer 23, and the protruding structures are embedded in the concave structures.

[0107] The conductive paste layer of the present invention connects the electrodes of adjacent solar cells 1. As a bus bar, the conductive paste layer connects the positive electrodes to positive electrodes and negative electrodes to negative electrodes of the upper and lower solar cells 1 to form a parallel circuit, which not only avoids the soldering process but also enables the parallel connection of adjacent two solar cells 1 in the vertical direction.

[0108] During application, referring to Figure 2 , the conductive paste layer includes a first conductive layer 31 and a second conductive layer 32. Among them, the first conductive layer 31 connects the positive electrodes to positive electrodes of adjacent solar cells 1, and the second conductive layer 32 connects the negative electrodes to negative electrodes of adjacent solar cells 1. In actual application, the positive electrode of each solar cell 1 of the present invention is located on the first side, and the negative electrode of each solar cell 1 is located on the second side, which can not only simplify the wiring design inside the photovoltaic module, reduce the process complexity, improve the assembly efficiency of the production line, but also reduce the frequency of electrode positioning adjustment of the production line, thereby accelerating the production speed and reducing the production cost.

[0109] The fixing layer 4 of the present invention is coated on the sides of adjacent two solar cells 1, and the protective layer 5 is coated on the FTO substrates 11 of adjacent two solar cells 1, which can not only prevent the solar cells 1 from being damaged during transportation and use, but also effectively prevent moisture and dust from entering the inside of the photovoltaic module, and prolong the service life of the photovoltaic module. During application, the fixing layer 4 can wind and fix adjacent two solar cells 1 and the isolation layer 2 therebetween to prevent them from moving or deforming inside the module; the protective layer 5 provides additional protection to prevent damage to the module caused by external factors. In actual application, the fixing layer 4 is a butyl tape.

[0110] The present invention realizes the parallel connection of solar cells 1 in the vertical direction by connecting the positive and negative electrodes of adjacent solar cells 1 through the first conductive layer 31 and the second conductive layer 32 respectively. The parallel structure can effectively reduce the series resistance between solar cells 1, reduce the energy loss during current transmission, and thus improve the overall current output efficiency of the photovoltaic module. During application, under the same illumination conditions, the photovoltaic module can output a higher current, improve the power generation, and is especially suitable for application scenarios with higher requirements for current output.

[0111] Furthermore, by connecting the solar cells 1 in parallel in the vertical direction, the present invention can effectively utilize the space structure of the module, reduce the gap between solar cells 1, and improve the space utilization rate of the photovoltaic module. More solar cells 1 can be arranged in a limited space, thereby improving the photoelectric conversion efficiency per unit area, and is especially suitable for application scenarios with limited space (such as rooftop photovoltaic systems or portable photovoltaic devices).

[0112] Furthermore, the parallel structure of the present invention can reduce the concentrated heat generation phenomenon of the current during transmission, reduce the heat loss of the battery chip 1 and the connection part, thereby reducing the operating temperature of the component. The lower operating temperature helps to improve the photoelectric conversion efficiency of the battery chip and reduce the problems of material aging or performance degradation caused by overheating.

[0113] The traditional connection method of the battery chip 1 usually adopts series connection or complex welding process, while the present invention directly connects the electrodes of adjacent battery chips 1 in parallel through the conductive paste layer (the first conductive layer 31 and the second conductive layer 32), simplifying the electrical connection method between the battery chips 1. In application, simplifying the connection process can reduce the production difficulty, reduce the failure rate during the production process, while reducing the manufacturing cost and improving the production efficiency.

[0114] In addition, since the battery chips of the present invention are connected by a conductive paste layer instead of the traditional welding method, the replacement or maintenance of a single battery chip 1 is more convenient. It reduces the maintenance cost of the photovoltaic module and improves the maintainability and repairability of the module. Furthermore, through the unified connection method of the conductive paste layer, the electrical connection consistency between adjacent battery chips 1 is ensured, reducing the performance fluctuations caused by the connection process differences. It improves the overall performance consistency of the photovoltaic module and ensures the stable output of the module during long-term use.

[0115] In order to make the purpose, technical solution and advantages of the present invention clearer, Example 1 and Comparative Example 1 are used to further elaborate on the present invention in detail. 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.

[0116] Example 1

[0117] Since the existing single battery chip 1 packaging or multi-battery horizontal parallel chip packaging consumes a large amount of float glass, increasing the production cost, and there is only one layer of perovskite light-absorbing layer, the power generation is low. In addition, the traditional metal bus bar welding is difficult and the appearance is not beautiful. In this embodiment, through the vertical parallel chip packaging method, two battery chips 1 are packaged in parallel into one component, and a transparent bus bar is used to replace the traditional metal bus bar, which can not only reduce the production cost but also increase the power generation.

[0118] 1. Prepare two battery chips 1

[0119] The preparation method of each battery chip 1 is the same.

[0120] 1.1 Preparation of the FTO substrate 11:

[0121] Use fluorine-doped tin oxide glass of 300mm×30mm as the FTO substrate 11.

[0122] By laser etching P1, patterning etching is performed on the FTO substrate 11, marked as P1, and the FTO substrate 11 is divided into 36 sub-cell regions, ensuring uniform deposition of subsequent film layers and electrical isolation between battery cells.

[0123] After etching, the substrate is thoroughly cleaned to ensure no impurities on the surface.

[0124] 1.2 Film layer deposition:

[0125] Nickel oxide (NiOx) film layer: Using physical vapor deposition (PVD) technology, a NiOx film layer 12 with a thickness of about 10 nm is deposited on the FTO substrate 11. As a hole transport layer, the thickness of NiOx has an important impact on battery performance and needs to be precisely controlled to ensure good hole transport efficiency.

[0126] Perovskite film layer 13: Using slot-die coating technology, a perovskite film layer 13 with a thickness of about 400 nm is coated on the above NiOx film layer 12. As a light absorption layer, the thickness of the perovskite film layer 13 directly affects the light absorption efficiency and charge separation efficiency of the battery. After coating, flash annealing treatment is carried out to make the film layer crystallize well and standby after returning to room temperature.

[0127] C 60 Film layer: Deposit 25 nm of C on the perovskite film layer 13 through an evaporation device. 60 Film layer. C 60 As an electron transport layer, it helps the effective transport of electrons.

[0128] SnO 2 Film layer: Use atomic layer deposition (ALD) technology to deposit 15 nm of SnO on the C 60 Film layer. SnO 2 Film layer. SnO 2 Then serves as a protective layer to improve the stability of the battery.

[0129] ITO film layer 16: Deposit 150 nm of ITO film layer 16, namely the top electrode, on the SnO 2 Film layer through PVD technology. The transparent conductive property of the ITO film layer 16 ensures the photoelectric conversion efficiency of the battery.

[0130] During application, before depositing the ITO film layer 16, after the substrate returns to room temperature, use a laser to scribe the P2 line to form the battery structure, and remove all film layers in the edge cleaning area to the glass layer, namely the FTO substrate 11, to ensure the cleanliness of the top electrode.

[0131] 1.3 Deposition of isolation layer 2:

[0132] Cover the top electrode in the edge cleaning area with a mask plate and deposit 1500 nm of SiO on the battery chip 1 using PVD technology.2 The insulating film layer prevents short - circuit of the sub - battery and wear of the top electrode.

[0133] 1.4 Battery performance test:

[0134] Clamp the positive and negative electrodes of the test equipment to the positive and negative electrodes of the perovskite photovoltaic cell 1 respectively to test the current - voltage curve.

[0135] Test results of one battery cell 1:

[0136] Open - circuit voltage (Voc) of the battery: 36.54 V; short - circuit photocurrent (Jsc): 18.01 mA / cm 2 ; Fill factor (FF): 54.02; Energy conversion efficiency: 9.56%; Area of a single - cell: 19.6 cm 2 .

[0137] Test results of another battery cell 1:

[0138] Open - circuit voltage (Voc) of the battery: 36.47 V; short - circuit photocurrent (Jsc): 17.76 mA / cm 2 ; Fill factor (FF): 55.79; Energy conversion efficiency: 9.72%; Area of a single - cell: 19.6 cm 2 .

[0139] 2. Preparation of photovoltaic modules

[0140] 2.1 Preparation of conductive paste:

[0141] Dissolve lithium bis(trifluoromethanesulfonyl)imide powder, polyethylene glycol diacrylate and photoinitiator in butyl acrylate liquid to form a transparent conductive paste. Among them, the molar percentages of polyethylene glycol diacrylate and 1 - hydroxycyclohexyl phenyl ketone in butyl acrylate are 0.1% and 1% respectively, and the molar concentration of lithium bis(trifluoromethanesulfonyl)imide is fixed at 0.5 M.

[0142] 2.2 Coating of conductive paste:

[0143] Drop - coat the transparent conductive paste onto the surfaces of the positive and negative top electrodes in the clear - edge area of the battery cell 1 for pre - shaping.

[0144] 2.3 Encapsulation of modules:

[0145] (1) Stick butyl tape on the four edges of two adjacent battery cells 1 to ensure the sealing of the edge of the photovoltaic module.

[0146] (2) Uniformly cover a layer of POE film layer 23 with a thickness of 0.7 mm outside the conductive paste area, that is, in the sub - battery area.

[0147] (3) Close another piece of cell 1 in a way that the positive and negative electrodes correspond, that is, close the upper and lower pieces of cell 1 in the way that the positive electrode is connected to the positive electrode and the negative electrode is connected to the negative electrode, ensuring that the conductive paste contacts the metal electrodes of the upper and lower cells 1.

[0148] 2.4 Lamination and curing:

[0149] Carry out lamination treatment to ensure that all layers of the photovoltaic module are tightly combined.

[0150] After lamination, cure the transparent bus bar, that is, the conductive paste layer, within 15 minutes by ultraviolet irradiation (320nm - 400nm, 400W power).

[0151] 2.5 Component performance test

[0152] Clamp the positive and negative electrodes of the test equipment to the positive and negative electrodes of the transparent bus bar led out from two small holes of the perovskite photovoltaic module respectively to test the current - voltage curve.

[0153] Test results:

[0154] Open - circuit voltage (Voc) of the cell: 36.44V; short - circuit photocurrent (Jsc): 35.69mA / cm 2 ; Fill factor (FF): 56.62; Energy conversion efficiency: 10.23%; Area of a single cell: 19.6cm 2 .

[0155] Comparative example 1

[0156] The photovoltaic module of Comparative example 1 is a single - glass photovoltaic module, including: protective layer 5, tempered glass, encapsulant film, cell 1, backsheet and junction box. Among them, the protective layer 5 is used to fix and protect the internal structure; the tempered glass provides necessary physical strength and protection; the encapsulant film serves as an adhesive to ensure the tight combination between all layers of the module; the cell 1 is the core component for photoelectric conversion; the backsheet further protects the internal structure of the module from the external environment; the junction box is responsible for the collection and output of electric energy. In addition, the 60 small cells 1 in the single - glass photovoltaic module of Comparative example 1 are on the same horizontal plane, and the series and parallel connections of the circuit are realized through a precise metal welding process to construct a complete photovoltaic power generation unit.

[0157] The difference between Comparative example 1 and Example 1 lies in:

[0158] (1) Encapsulation method:

[0159] Comparative example 1: Adopt the traditional single - glass module encapsulation method, and the cells 1 are connected by metal welding on the same horizontal plane.

[0160] Example 1: Adopt the vertical parallel - sheet encapsulation method, and two cells 1 are connected in parallel in the vertical direction without welding.

[0161] (2) Bus bar material:

[0162] Comparative Example 1: Using traditional metal bus bars (such as copper strips or silver strips), there are problems such as difficult welding, unattractive appearance, and easy corrosion.

[0163] Example 1: Using a transparent conductive paste as the bus bar, which has the advantages of being transparent, corrosion-resistant, high-temperature resistant, etc., and welding is not required.

[0164] (3) Insulation treatment:

[0165] Comparative Example 1: Without special insulation treatment, the electrical isolation between the solar cells 1 depends on the encapsulant film and the backsheet.

[0166] Example 1: Deposit a 1500nm SiO 2 insulating film layer on the sub-cell areas of the upper and lower solar cells 1 to prevent the transparent conductive paste from spreading to the sub-cell areas and causing short circuits.

[0167] (4) Encapsulation process:

[0168] Comparative Example 1: The encapsulation process is complex, involving multiple processes such as metal welding and lamination, and the welding process is likely to damage the solar cells 1.

[0169] Example 1: The encapsulation process is simplified. The upper and lower solar cells 1 are connected by a transparent paste, and after lamination, it is cured by ultraviolet irradiation. The process is simple and does not damage the solar cells 1.

[0170] It can be seen that the single-glass photovoltaic module of Comparative Example 1 has problems such as low power generation, high production cost, unattractive appearance, and poor long-term stability. Specifically: The single-glass photovoltaic module has only one perovskite light-absorbing layer, and the power generation is limited; Metal welding to connect the circuit has resistance loss, further reducing the power generation efficiency. Traditional single-glass modules need to use a large amount of float glass as the backsheet, increasing the production cost; The metal welding process is complex, increasing the production difficulty and cost. The metal bus bar is opaque, affecting the appearance of the module, especially in the building integrated photovoltaic (BIPV) application, the aesthetics is poor. Metal welding is likely to generate thermal stress, and long-term use may cause the solar cells 1 to crack or become de-soldered, affecting the life of the module; The metal bus bar is easily corroded, especially in a humid environment, which may cause the performance of the module to decline.

[0171] Compared with Comparative Example 1, in Example 1, by depositing SiO on the sub-cell areas of the lower solar cells 1 2 isolation layer 2, using a POE encapsulant film with a specific shape and a transparent conductive paste to achieve non-contact parallel connection, not only avoids many problems brought by welding, but also significantly improves the power generation efficiency of the module (the power generation gain can reach 100% when the illumination on both sides is the same), reduces the water permeability (the water permeability is 0), and effectively reduces the cost.

[0172] As can be seen from the above embodiments, the photovoltaic module of the present invention realizes the vertical parallel connection of the cells 1 by connecting the electrodes of adjacent cells 1 through the conductive paste layer, which can effectively increase the current output in the photovoltaic module. Since the parallel connection allows the currents generated by each cell 1 to be added together, the overall electrical energy output is improved. At the same time, since the cells 1 in the parallel connection can share the voltage, each cell 1 operates at its optimal working voltage, thereby improving the conversion efficiency of the entire photovoltaic module.

[0173] In traditional photovoltaic modules, the cells 1 are often connected by wires or solder tapes. These connection methods introduce additional resistance, resulting in power loss. In the present invention, the conductive paste layer directly connects the electrodes of the cells 1, reducing the resistance of the connection part and thus reducing the power loss.

[0174] At the same time, the encapsulation process of traditional photovoltaic modules often involves complex wire connection and welding processes, which not only increases the production cost but also may lead to unstable encapsulation quality. In the photovoltaic module of the present invention, the parallel connection of the cells 1 is realized through the conductive paste layer, simplifying the encapsulation process and reducing the production cost.

[0175] The coating and curing process of the conductive paste layer of the present invention is relatively simple and easy to realize automated production, improving the production efficiency. Since the photovoltaic module of the present invention has the advantages of compact structure, high electrical energy output, and stable efficiency, it can be widely applied to various occasions requiring high-efficiency and stable electrical energy output. Especially in the field of building integrated photovoltaics, this photovoltaic module can be embedded into the building structure as a transparent or semi-transparent material, meeting the requirements of building aesthetics and realizing efficient photovoltaic power generation.

[0176] In addition, in the photovoltaic module of the present invention, the isolation layer 2 not only connects the sub-cell regions of adjacent cells 1 but also prevents the diffusion of conductive materials into the sub-cell regions to cause short circuits, enhancing the structural stability of the photovoltaic module and ensuring the safe connection between the cells 1. In addition, the presence of the isolation layer 2 can also prevent the cells 1 from deforming or being damaged due to external forces during the encapsulation process, further improving the reliability of the photovoltaic module.

[0177] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention. All such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A method for packaging a photovoltaic module, characterized in that: The following steps are involved: The top electrodes of two adjacent battery cells (1) are arranged opposite to each other, and the positive electrode of each battery cell (1) is located on the first side, and the negative electrode of each battery cell (1) is located on the second side; Plating an isolation layer (2) between sub-cell regions of adjacent cell sheets (1); Coating a conductive paste on electrodes of adjacent battery cells (1); Two adjacent battery cells (1) are joined together, the joined battery cells (1) are laminated, and the conductive paste is cured to form a conductive paste layer between electrodes of the adjacent battery cells (1), so that the two adjacent battery cells (1) are connected in parallel in a vertical direction.

2. The method for packaging a photovoltaic module according to claim 1, characterized in that: The packaging method further comprises the following steps: Winding the fixing layer (4) on the side surfaces of two adjacent battery sheets (1); The protective layer (5) is coated on the FTO substrate (11) of two adjacent battery cells (1); Wherein, the fixing layer (4) comprises butyl tape.

3. The method for packaging a photovoltaic module according to claim 1, characterized in that: The step of plating an isolation layer (2) between sub-cell regions of adjacent cell sheets (1) comprises: Plating a first insulating film layer (21) on the sub-cell region of one of two adjacent cell sheets (1); Plating a second insulating film layer (22) on the sub-cell region of the other cell (1) of the two adjacent cell slices (1); One side of the adhesive film layer (23) is attached to the first insulating film layer (21), and the other side of the adhesive film layer (23) is attached to the second insulating film layer (22).

4. The method for packaging a photovoltaic module according to claim 1, characterized in that: The lamination process has a temperature of 80°C-120°C, a pressure of 0.5MPa-1.0MPa, and a lamination time of 10-20 minutes; When curing the conductive paste, the wavelength of ultraviolet irradiation is 320nm-400nm, the power is 400W, and the curing time is 15 minutes.

5. The method for packaging a photovoltaic module according to claim 1, characterized in that: The components of the conductive paste include: Lithium bis(trifluoromethanesulfonyl imide); Butyl acrylate; Polyethylene glycol diacrylate; 1-Hydroxycyclohexylphenylketone; The molar percentage of polyethylene glycol diacrylate to butyl acrylate is 0.1%, the molar percentage of 1-hydroxycyclohexyl phenyl ketone to butyl acrylate is 1%, and the molar concentration of lithium bis(trifluoromethanesulfonyl imide) is 0.5 mol / L.

6. A photovoltaic module, characterized in that: The photovoltaic module comprises: At least two battery cells (1) arranged opposite to each other, each battery cell (1) comprising a sub-battery region and an electrode located at an edge of the sub-battery region, the electrode comprising a positive electrode and a negative electrode, the positive electrode of each battery cell (1) being located on a first side, and the negative electrode of each battery cell (1) being located on a second side; An isolation layer (2), the isolation layer (2) connecting sub-cell regions of adjacent cell sheets (1); A conductive paste layer connects electrodes of adjacent battery cells (1) so that two adjacent battery cells (1) are connected in parallel in a vertical direction.

7. The photovoltaic module according to claim 6, characterized in that: The photovoltaic module further comprises: A fixing layer (4), the fixing layer (4) being coated on the side surfaces of two adjacent battery cells (1); A protective layer (5), the protective layer (5) being coated on the FTO substrate (11) of two adjacent battery cells (1).

8. The photovoltaic module according to claim 6, characterized in that: The isolation layer (2) comprises: A first insulating film layer (21), the first insulating film layer (21) connecting the sub-cell region of one of the two adjacent cell sheets (1); A second insulating film layer (22), the second insulating film layer (22) connecting the sub-cell region of the other cell (1) of the two adjacent cell slices (1); An adhesive film layer (23), wherein one side of the adhesive film layer (23) is connected to the first insulating film layer (21), and the other side of the adhesive film layer (23) is connected to the second insulating film layer (22).

9. The photovoltaic module according to claim 6, characterized in that: The conductive paste layer comprises: A first conductive layer (31), the first conductive layer (31) connecting the positive electrodes of adjacent battery cells (1); A second conductive layer (32), wherein the second conductive layer (32) is connected to the negative electrode of an adjacent battery cell (1).

10. The photovoltaic module according to claim 6, characterized in that: The cell (1) is an inverted perovskite cell (1); Two adjacent battery cells (1) are arranged in a mirror image.

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