Photovoltaic module and preparation method thereof

Abstract

The invention relates to a photovoltaic module and a preparation method of the photovoltaic module, a photovoltaic cell comprises a cell piece group, a first packaging piece, a second packaging piece, a first cover plate and a second cover plate, and the first packaging piece and the second packaging piece are located on the two sides of the cell piece group respectively in the thickness direction of the photovoltaic module. The first cover plate is located on the side, away from the battery piece set, of the first packaging piece, and the second packaging piece is located on the side, away from the battery piece set, of the second packaging piece. The first package includes a filler and a seal disposed around the filler. The filling piece comprises silica gel, and the light transmittance of the silica gel is high, so that sunlight can conveniently penetrate through the first packaging piece to enter the battery piece group, the light absorption efficiency of the battery piece group is improved, and the power generation efficiency of the photovoltaic module is improved. The sealing member is arranged around the filling member, can limit the position of the filling member, enables the filling member to be located between the first cover plate and the cell group, and reduces the leakage possibility of the filling member.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a photovoltaic module and a method for preparing the photovoltaic module. Background Art

[0002] As the world's conventional energy supply is increasingly in short supply and environmental pollution problems are becoming increasingly prominent, humans have realized the crisis of energy and environment and have begun to seek renewable clean energy to replace conventional energy. Solar photovoltaic power generation has become an emerging industry that is widely concerned and focused on by countries around the world due to its cleanliness, safety, convenience, and efficiency. The photovoltaic module used for photovoltaic power generation includes a first cover plate, a first packaging member, a battery cell group, a second packaging member, and a second cover plate. At present, the first packaging member and the second packaging member are both EVA films, which have poor light transmittance, resulting in a certain loss of light reaching the surface of the battery cell group, thereby affecting the photoelectric conversion efficiency of the photovoltaic module. Summary of the invention

[0003] In view of this, the embodiments of the present application provide a photovoltaic module and a method for preparing the photovoltaic module to solve the problem of low photoelectric conversion efficiency of the photovoltaic module.

[0004] In a first aspect, the present application relates to a photovoltaic module, the photovoltaic module comprising: Battery cell group; A first packaging member and a second packaging member, along the thickness direction of the photovoltaic module, the first packaging member and the second packaging member are respectively located on two sides of the battery cell group; a first cover plate and a second cover plate, wherein the first cover plate is located at a side of the first package away from the battery cell group, and the second cover plate is located at a side of the second package away from the battery cell group; The first packaging component includes a filling component and a sealing component, the sealing component is arranged around the filling component, and the filling component includes silica gel.

[0005] In a possible embodiment, the weight of the filler is 420 g / m 2 Up to 450g / m 2 .

[0006] In a possible embodiment, the first packaging component further includes an adhesive film layer, and the adhesive film layer is located on a side of the filling component and the sealing component close to the battery cell group.

[0007] In a possible embodiment, the filling member further includes a viscosity enhancer, and the ratio of the silica gel to the viscosity enhancer is 10:1.

[0008] In a possible embodiment, the adhesion promoter includes: tetraethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol and toluene.

[0009] In a possible embodiment, the weight of the filler is 300 g / m 2 Up to 350g / m 2 .

[0010] In a second aspect, the present application also relates to a method for preparing a photovoltaic module, the method comprising: Fixing the sealing member to the first cover plate by spot ironing, the sealing member is aligned with the edge of the first cover plate, the width of the sealing member is 1 cm to 4 cm, and a receiving space is enclosed on the surface of the first cover plate; Injecting a liquid filling member into the accommodation space, and allowing the filling member to fill the accommodation space; Placing the second packaging component and the battery cell group on the second cover plate in sequence; Placing the side of the first cover plate provided with the sealing member and the filling member on the side of the battery cell group away from the second packaging member to form a stacked member; The stack is placed in a laminating apparatus for curing.

[0011] In a possible embodiment, when the first packaging component includes the filling component, the sealing component and the adhesive film layer, the filling component includes silica gel and a tackifier, and before the liquid filling component is injected into the accommodating space, the preparation method includes: Put the silica gel and the tackifier into a mixing device at a ratio of 10:1; The mixing device was heated to 50°C to 70°C and stirred to mix.

[0012] In a possible embodiment, after placing the second packaging component and the battery cell group on the second cover plate in sequence, the preparation method includes: A glue film layer is laid on the battery cell group.

[0013] In a possible embodiment, when the laminate is placed in a laminating device for curing, the preparation method includes: Raising the temperature of a chamber of the laminating device to 90° C. to 110° C., evacuating for 450 seconds to 490 seconds, and laminating for 170 seconds to 200 seconds; The temperature of the second chamber of the laminating device is raised to 145° C. to 148° C., vacuumed for 10 to 20 seconds, and laminated for 600 to 650 seconds.

[0014] The present application relates to a photovoltaic module and a method for preparing the photovoltaic module. The photovoltaic cell includes a battery cell group, a first package, a second package, a first cover plate and a second cover plate. Along the thickness direction of the photovoltaic module, the first package and the second package are respectively located on both sides of the battery cell group, the first cover plate is located on the side of the first package away from the battery cell group, and the second package is located on the side of the second package away from the battery cell group. The first package includes a filling member and a sealing member, and the sealing member is arranged around the filling member. The filling member includes silica gel, and the silica gel has a high light transmittance, which facilitates sunlight to pass through the first package and enter the battery cell group, so as to improve the light absorption efficiency of the battery cell group, thereby facilitating the improvement of the power generation efficiency of the photovoltaic module. The sealing member is arranged around the filling member, which can limit the position of the filling member, so that the filling member is located between the first cover plate and the battery cell group, and the possibility of leakage of the filling member is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 A schematic diagram of the structure of an embodiment of a photovoltaic assembly provided in an embodiment of the present application; Figure 2 A schematic structural diagram of another embodiment of a photovoltaic assembly provided in an embodiment of the present application; Figure 3 A top view of a first cover plate, a filling member, and a sealing member provided in an embodiment of the present application; Figure 4 A side view of a first cover plate and a sealing member provided in an embodiment of the present application; Figure 5 A side view of a first cover plate, a filling member and a sealing member provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of a battery cell group, a second packaging component and a second cover plate provided in an embodiment of the present application; Figure 7 A schematic diagram of the structure of a battery cell group, a second packaging component, a second cover plate and an adhesive film layer provided in an embodiment of the present application; Figure 8 A flowchart of a method for preparing a photovoltaic module according to an embodiment of the present application; Fig. 9 A flow chart of a method for preparing another embodiment of a photovoltaic module provided in an embodiment of the present application.

[0017] Reference numerals: 1-Battery cell group; 2-first package; 21- Filling piece; 22-seal; 23-adhesive film layer; 25- Accommodation space; 3- second packaging; 4- first cover plate; 5- Second cover plate. DETAILED DESCRIPTION

[0018] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0019] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0020] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0021] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0022] like Figures 1 to 5 As shown, the embodiment of the present application provides a photovoltaic module, including a battery cell group 1, a first package 2, a second package 3, a first cover plate 4 and a second cover plate 5. Along the thickness direction of the photovoltaic module, the first package 2 and the second package 3 are respectively located on both sides of the battery cell group 1, the first cover plate 4 is located on the side of the first package 2 away from the battery cell group 1, and the second cover plate 5 is located on the side of the second package 3 away from the battery cell group 1. The first package 2 is used to connect the battery cell group 1 and the first cover plate 4, and the second package 3 is used to connect the battery cell group 1 and the second cover plate 5. The first package 2 includes a filling member 21 and a sealing member 22, and the sealing member 22 is arranged around the filling member 21, and the filling member 21 includes a material with high light transmittance such as silica gel.

[0023] The cell group 1 includes a light-receiving surface and a backlight surface, wherein the light-receiving surface faces the sun to absorb sunlight, the first package 2 is located on the light-receiving surface, the second package 3 is located on the backlight surface, the first cover plate 4 is photovoltaic glass, and has good light transmittance, and the filler 21 in the first package 2 located between the first cover plate 4 and the cell group 1 includes a material with high light transmittance such as silica gel, which facilitates sunlight to pass through the first cover plate 4 and the filler 21 to irradiate the light-receiving surface of the cell group 1, so as to improve the light absorption efficiency of the cell group 1, thereby facilitating the improvement of the power generation efficiency of the photovoltaic module. The sealing member 22 in the first package 2 can be an EVA film, a POE film, etc. The sealing member 22 is located between the first cover plate 4 and the cell group 1. After lamination, the EVA film can bond the first cover plate 4 and the cell group 1 to improve the reliability of the photovoltaic module. The sealing member 22 is arranged around the filler 21, which can limit the position of the filler 21, so that the filler 21 is located between the first cover plate 4 and the cell group 1, and the possibility of leakage of the filler 21 is reduced. The seal 22 is located at the edge of the first cover plate 4 to connect the first cover plate 4 and the battery cell group 1, so the seal 22 will block part of the battery cell group 1. The seal 22 is an EVA film or a POE film, so that the part of the battery cell group 1 blocked by the seal 22 can also absorb sunlight, thereby improving the light absorption efficiency of the photovoltaic module. The second cover plate 5 can be an aluminum alloy back plate, a glass fiber back plate, a composite material back plate, etc., and the second packaging member 3 can be an EVA film, a POE film, an EPE film (a three-layer co-extruded film composed of EVA, POE, and EVA), etc., to bond the battery cell group 1 and the second cover plate 5.

[0024] The present application does not limit the structure of the battery cell. The types of battery cells include but are not limited to Passivated Emitter Rear Cell (PERC), Tunnel Oxide Passivated Contact (TOPCon), Heterojunction with Intrinsic Thin-film (HJT), Interdigitated Back Contact (IBC), perovskite cells, etc.

[0025] For PERC cells, along the thickness direction, PERC cells include the front surface metal silver electrode, the front surface silicon nitride passivation layer, the phosphorus layer emitter, the P-type base silicon layer, the local aluminum back field, the metal aluminum back electrode, and the back passivation layer (Al2O3 / SiNx). PERC cells use a passivation film to passivate the back, replacing the full aluminum back field, enhancing the internal back reflection of light in the silicon base, reducing the recombination rate on the back, and increasing the efficiency of the cell by 0.5%-1%.

[0026] For TOPCon cells, along the thickness direction, TOPCon cells include metal silver electrodes, front surface silicon nitride passivation layers, boron-doped emitters, N-type base silicon layers, diffused doping layers, ultra-thin silicon oxide, doped polysilicon, silicon nitride, and metal silver electrodes. The back of the cell is composed of an ultra-thin silicon oxide layer (1nm~2nm) and a phosphorus-doped microcrystalline amorphous mixed Si film, which together form a passivation contact structure. This structure can block the recombination of minority carrier holes and increase the open circuit voltage and short circuit current of the cell. The ultra-thin oxide layer allows majority electrons to tunnel into the polysilicon layer while blocking the recombination of minority carrier holes. The good passivation effect of ultra-thin silicon oxide and heavily doped silicon film causes the energy band on the silicon wafer surface to bend, thereby forming a field passivation effect, greatly increasing the probability of electron tunneling, and reducing the contact resistance, which increases the open circuit voltage and short circuit current of the cell, thereby improving the cell conversion efficiency.

[0027] For HJT cells, along the thickness direction, the HJT cells include a front low-temperature silver electrode, a front conductive film, an N-type amorphous silicon film, an intrinsic amorphous silicon film, an N-type base silicon layer, an intrinsic amorphous silicon film, a P-type amorphous silicon film, a back conductive film, and a back low-temperature silver electrode.

[0028] For IBC cells, along the thickness direction, IBC cells include silicon nitride anti-layer, N+ front surface field, N-type base silicon layer, P+ emitter, N+ back field, aluminum oxide passivation layer, silicon nitride anti-reflection layer, and metal silver electrode. IBC cells use ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth. There is no grid line blocking on the front of the cell, which can eliminate the shading current loss of the metal electrode and achieve the maximum utilization of incident photons. The short-circuit current can be increased by about 7% compared with conventional solar cells; due to the back contact structure, there is no need to consider the grid line blocking problem, and the grid line ratio can be appropriately widened, thereby reducing the series resistance and having a high fill factor; the surface passivation and surface light trapping structure can be optimized to obtain a lower front surface recombination rate and surface reflection.

[0029] For perovskite cells, along the thickness direction, the perovskite cell includes substrate material, conductive film, electron transport layer (titanium dioxide), perovskite absorption layer (hole transport layer), and metal cathode. Perovskite materials have a high light absorption coefficient and a long carrier diffusion distance. After the photons absorbed by the perovskite material are converted into electrons, they are easily collected by the electrode with low loss, so they can generate higher photoelectric voltage and current, making perovskite show higher photoelectric conversion efficiency.

[0030] In a possible embodiment, the weight of the filling member 21 is 420 g / m 2 Up to 450g / m 2 , the thickness of the first package 2 is 250 μm to 500 μm.

[0031] The weight of the filler 21 is 420 g / m 2 Up to 450g / m 2 , so that the thickness of the first package 2 is 300μm to 360μm. The first package 2 and the second package 3 are respectively located on both sides of the thickness direction of the battery cell group 1, and are used to connect the battery cell group 1, the first cover plate 4 and the second cover plate 5, and encapsulate the battery cell group 1. The first package 2 is located on the light-receiving surface of the battery cell group 1, and the sunlight needs to pass through the first cover plate 4 and the first package 2 to enter the battery cell group 1. The first package 2 and the second package 3 can enhance the mechanical strength and resistance to external force damage of the component, so that the photovoltaic component can be suitable for extreme weather such as hail, wind and snow. The battery cell group 1 includes multiple battery cells, and the multiple battery cells are connected by welding strips. The first package 2 and the second package 3 can provide a buffer for the battery cell group 1 to reduce the possibility of stress concentration between the welding strip and the battery cell, and reduce the risk of hidden cracks in the battery cell. If the weight of the filler 21 is greater than 450g / m 2 The thickness of the first package 2 is greater than 500 μm, which increases the light transmittance of the first package 2, reduces the intensity of sunlight received by the cell group 1, reduces the power generation efficiency of the photovoltaic module, and increases the weight and production cost of the photovoltaic module. 2 The thickness of the first package 2 is less than 250 μm, which results in poor mechanical properties of the photovoltaic module. When the photovoltaic module is impacted in extreme weather such as hail, snow, etc., it is easy to be damaged. The buffering effect of the first package 2 on the battery cell group 1 is small, which increases the possibility of hidden cracks in the battery cell. At the same time, it also increases the aging speed of the first package 2, reduces the stability of the first package 2 and the sealing performance of the first package 2. Therefore, the weight of the filler 21 can be 420 g / m 2 , 435g / m 2 , 450g / m 2 Etc., so that the thickness of the first package 2 can be 250μm, 380μm, 500μm, etc., which is convenient for sunlight to pass through the first package 2 and enter the battery cell group 1. At the same time, it can also improve the protection effect of the battery cell group 1 and the service life of the photovoltaic module, which is beneficial to improving the power generation efficiency and reliability of the photovoltaic module.

[0032] like Figure 2 As shown, in a possible embodiment, the first packaging component 2 further includes a film layer 23, which is located on a side of the filling component 21 and the sealing component 22 close to the battery cell group 1, one side of the film layer 23 covers the battery cell group 1, and the other side can be bonded to the sealing component 22.

[0033] The film layer 23 can be a POE film. The molecular structure of the POE film is stable, no acetate ions are precipitated, and it has excellent anti-PID performance, which makes the photovoltaic module have a higher power generation efficiency. The POE film also has high elasticity and strength, can withstand external impact and pressure, is not easy to deform or break, and can improve the reliability of the photovoltaic module. The POE film also has good heat resistance, aging resistance and waterproofness, so that the photovoltaic module can be used outdoors for a long time, blocking water vapor and other harmful substances from penetrating into the battery cell group 1, so as to increase the service life of the photovoltaic module.

[0034] In a possible embodiment, the filling member 21 further includes a tackifier, and the ratio of silica gel to the tackifier in the filling member 21 is 10:1.

[0035] Adding a tackifier to the silicone of the filler 21 allows the filler 21 and the film layer 23 to be better integrated together. After the film layer 23 is cured, the possibility of stratification between the film layer 23 and the filler 21 can be reduced, making it easier for sunlight to pass through the film layer 23 and the filler 21 and be absorbed by the battery cell group 1. Adding a tackifier to the silicone can also increase the bonding strength between the film layer 23 and the filler 21 to increase the strength of the photovoltaic module. The liquid silicone can be an addition-type liquid silicone. If the ratio of silicone to tackifier in the filler 21 is greater than 10:1, the content of tackifier in the filler 21 is low, resulting in a decrease in the bonding strength between the filler 21 and the film layer 23 and the first cover plate 4, and the ideal bonding effect cannot be achieved. At the same time, it also causes the filler 21 to have poor physical properties such as tensile strength and tear strength. If the ratio of silicone to thickener in the filler 21 is less than 10:1, the content of thickener in the filler 21 is relatively high, which breaks the balance of the cross-linking reaction, thereby affecting the normal cross-linking process of the filler 21 and causing cross-linking failure. At the same time, excessive thickener may also cause the cross-linking density of the silicone molecular structure to decrease, thereby reducing the bonding strength.

[0036] In a possible embodiment, the liquid silicone can be a condensation type liquid silicone. In this case, the ratio of liquid silicone to thickener can be 100:1 to 20:1. If the ratio of liquid silicone to thickener is less than 100:1, the content of thickener in the filler 21 is too low, resulting in a decrease in the bonding strength between the filler 21 and the film layer 23 and the first cover plate 4, and failure to achieve an ideal bonding effect. At the same time, it will also cause the filler 21 to have poor physical properties such as tensile strength and tear strength; if the ratio of liquid silicone to thickener is greater than 20:1, the content of thickener in the filler 21 is high, which breaks the balance of the cross-linking reaction, thereby affecting the normal cross-linking process of the filler 21 and causing cross-linking failure. At the same time, excessive thickener may also cause the cross-linking density of the silicone molecular structure to decrease, thereby reducing the bonding strength.

[0037] In one possible embodiment, the adhesion promoter includes tetraethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol and toluene.

[0038] TEOS, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol and toluene can improve the bonding strength between the filler 21 and the adhesive film layer 23, so as to improve the strength of the photovoltaic module. The materials in the tackifier are all transparent materials, which reduces the effect of the tackifier on the transmittance of the silica gel, improves the transmittance of the filler 21, and further improves the light absorption efficiency of the photovoltaic module.

[0039] In a possible embodiment, the weight of the filling member 21 is 300 g / m 2 Up to 350g / m 2 .

[0040] The thickness of the first package 2 is 250 μm to 500 μm. The first package 2 includes a filler 21 and a film layer 23. Therefore, the sum of the thickness of the film layer 23 and the filler 21 is 250 μm to 500 μm. The weight of the film layer 23 is 100 g / m 2 If the weight of the filler 21 is less than 300 g / m 2 , which will cause the thickness of the first package 2 to be less than 250μm, resulting in poor mechanical properties of the photovoltaic module. When the photovoltaic module is impacted in extreme weather such as hail, wind and snow, it is easy to be damaged. It will also cause the first package 2 to have a smaller buffering effect on the battery cell group 1, increasing the possibility of hidden cracks in the battery cell. At the same time, it will also increase the aging speed of the first package 2, reduce the stability of the first package 2 and the sealing performance of the first package 2. If the thickness of the filling member 21 is greater than 350g / m 2 , which will cause the thickness of the first package 2 to be greater than 500 μm, resulting in a decrease in the light transmittance of the first package 2, affecting the power generation efficiency of the photovoltaic module, and increasing the weight and production cost of the photovoltaic module. Therefore, the weight of the filler 21 can be 300 g / m 2 , 325g / m 2 , 350g / m 2 , so that the first packaging component 2 can improve the protection effect of the battery cell group 1 and the service life of the photovoltaic module, and at the same time can have good light transmittance, so that the photovoltaic module has good reliability and high power generation efficiency.

[0041] In a possible embodiment, the weight of the second packaging member 3 is 350 g / m 2 Up to 420g / m 2 .

[0042] If the weight of the second packaging member 3 is less than 350 g / m 2The second packaging member 3 has a small thickness, which has a poor buffering effect on the cell group 1, causing the cell to be prone to cracking. The photovoltaic module is easily damaged in extreme weather such as hail, snow, etc., and the service life of the photovoltaic module is shortened. If the weight of the second packaging member 3 is greater than 420g / m 2 The second package 3 has a large thickness, which results in a high production cost of the photovoltaic module. If the photovoltaic module is a double-glass module, the second cover plate 5 is photovoltaic glass, and sunlight can pass through the second cover plate 5 and the second package 3 to enter the battery cell group 1 to improve the power generation efficiency of the photovoltaic module. The second package 3 has a large thickness, which will affect the light transmittance of the second package 3 and reduce the power generation efficiency of the photovoltaic module. Therefore, the gram weight of the second package 3 can be 350g / m 2 , 390g / m 2 , 420g / m 2 , which can reduce the production cost of photovoltaic modules and enable photovoltaic cells to have better reliability and higher power generation efficiency.

[0043] like Figures 4 to 9 As shown, the embodiment of the present application also provides a method for preparing a photovoltaic module, and the preparation steps include: S1, fix the sealing member 22 to the first cover plate 4, align the sealing member 22 with the edge of the first cover plate 4, and enclose a receiving space 25 on the surface of the first cover plate 4; S2, injecting a liquid filling member 21 into the accommodation space 25, so that the filling member 21 fills the accommodation space 25; S3, placing the second packaging component 3 and the battery cell group 1 on the second cover plate 5 in sequence; S4, placing the side of the first cover plate 4 provided with the sealing member 22 and the filling member 21 on the side of the battery cell group 1 away from the second packaging member 3 to form a stacked member; S5. Place the laminated parts into a laminating device for curing.

[0044] First, the seal 22 is fixed to the first cover plate 4, and then the filler 21 is injected into the accommodating space 25 enclosed by the seal 22, which can limit the position of the filler 21 on the first cover plate 4 and reduce the possibility of the filler 21 flowing out. The battery cell group 1 includes a plurality of battery cells connected in series and / or in parallel, and the battery cells are connected by welding strips. The filler 21 in the middle position of the first package 2 is liquid silicone, which is viscous. After the battery cell group 1 is placed on the first package 2, the position of the battery cell group 1 will be limited, and it is not convenient to adjust the position of the battery cell group 1. Liquid silicone has poor support for the battery cell group 1, and the battery cell is easily deformed when placed on the first package 2. First, the second package 3 and the battery cell group 1 are placed on the second cover plate 5 in sequence. The second package 3 and the second cover plate 5 can provide support for the battery cell group 1 and reduce the possibility of deformation of the battery cell group 1. The cell group 1 is placed on the second package 3, and the first package 2 and the first cover plate 4 are placed on the cell group 1 to bond the first package 2 to the cell group 1, further limiting the position of the filler 21 in the stack. The stack is placed in a laminating device for curing, so that the sealant 22 and the second package 3 are cured, and the first cover plate 4, the first package 2, the cell group 1, the second package 3 and the second cover plate 5 in the stack are fixedly connected to improve the strength of the photovoltaic module.

[0045] like Figure 5 As shown, in a possible embodiment, the thickness of the sealing member 22 may be 0.6 mm to 2 mm, and the thickness of the liquid filling member 21 may be 0.3 mm to 1 mm. The thickness of the liquid filling member 21 is smaller than the thickness of the sealing member 22, which can reduce the possibility of bubbles generated inside the filling member 21.

[0046] The material of the first cover plate 4 is photovoltaic glass. During the lamination process, the edge of the first cover plate 4 will bend, causing the edge of the first package 2 to shift inward, reducing the amount of the first package 2 at the original position, or the edge of the first package 2 will overflow partially, resulting in a missing portion at the original position, both of which will cause bubbles to be generated at the edge of the first package 2. The thickness of the package is greater than the thickness of the filler 21, which can increase the amount of the package at the edge position, reserve the possibility of edge shift or overflow during lamination, and thus reduce the possibility of bubbles at the first package 2. The bubbles are located at the edge of the seal 22 in the first package 2. If a small amount of bubbles are generated after lamination, the bubbles are located at the edge of the photovoltaic module. After the frame of the photovoltaic module is installed, the position with bubbles can be blocked by the frame to reduce the influence of bubbles on the light absorption efficiency of the photovoltaic module.

[0047] The width of the seal 22 is 1 cm to 4 cm. When the seal 22 is aligned with the edge of the first cover plate 4, it can enclose a receiving space 25 on the first cover plate 4 to limit the position of the filler 21. After lamination and curing, the seal 22 is used to compensate for edge offset or overflow of glue. If the width of the seal 22 is less than 1 cm, the volume of the seal 22 is small, and the compensation effect on the edge offset or overflow of the first package 2 is small, resulting in an increased possibility of bubbles on the edge of the photovoltaic module. The light transmittance of the filler 21 is greater than the light transmittance of the seal 22, and the light absorption efficiency of the position where the cell and the filler 21 contact is greater than the light absorption efficiency of the position where the cell and the seal 22 contact. If the width of the seal 22 is greater than 4 cm, the area where the seal 22 contacts the cell increases, the receiving space 25 enclosed by the seal 22 decreases, and the area where the filler 21 contacts the cell decreases, resulting in a decrease in the light transmittance of the first package 2 and a decrease in the light absorption efficiency of the cell, thereby causing a decrease in the power generation efficiency of the photovoltaic module.

[0048] In a possible embodiment, butyl rubber has good sealing and waterproof properties, so the material of the seal 22 can also be butyl rubber. Due to the high cost of butyl rubber, the width of butyl rubber used as the seal 22 can be 0.6mm to 1.5mm, and the thickness can be 0.6mm to 2mm. The butyl rubber can limit the position of the filler 21 on the first cover plate 4 and compensate for the vacancies caused by edge offset or overflow, thereby reducing the possibility of bubbles in the photovoltaic module.

[0049] like Figure 4 As shown, when the sealing member 22 is fixed to the first cover plate 4, the preparation method includes: S11, aligning the sealing member 22 with the edge of the first cover plate 4; S12, fixing the sealing member 22 to the first cover plate 4 by spot hot stamping.

[0050] The seal 22 is aligned with the edge of the first cover plate 4, so that the seal 22 can encapsulate the edge of the first cover plate 4 and the battery cell, reducing the possibility of foreign impurities entering the photovoltaic module. The seal 22 can be fixed to the first cover plate 4 by spot-heating through a welding head, so that the seal 22 encloses the accommodation space 25, and the position of the filler 21 on the first cover plate 4 can be limited after the filler 21 is injected into the accommodation space 25. When forming a laminate, the first cover plate 4 needs to be turned over so that the side of the first cover plate 4 provided with the seal 22 and the filler 21 is in contact with the battery cell. Fixing the seal 22 to the first cover plate 4 by spot-heating can reduce the possibility of the seal 22 falling off when turning over.

[0051] like Figure 3 and Figure 5 As shown, when a liquid filling member 21 is injected into the accommodation space 25 and the filling member 21 fills the accommodation space 25, the preparation method includes: S21, injecting 800 g to 1100 g of the liquid filler 21 into the accommodation space 25; S22, evenly spread the liquid filler 21 in the receiving space 25 by using a scraper, and let it stand until the surface is flat.

[0052] The weight of the filling piece 21 in the receiving space 25 is 420 g / m 2 Up to 450g / m 2 The weight of the filling member 21 injected into the accommodating space 25 can be adjusted according to the size of the accommodating space 25. For example, if the length of the first cover plate 4 is 2272 mm and the width is 1128 mm, if the liquid filling member 21 injected into the accommodating space 25 is less than 800 g, the gram weight of the filling member 21 in the accommodating space 25 is less than 420 g / m 2 , resulting in a smaller thickness of the filler 21 and poorer stability of the photovoltaic module. If the liquid filler 21 injected into the accommodation space 25 is greater than 1100g, the weight of the filler 21 in the accommodation space 25 is greater than 450g / m 2 , resulting in a larger thickness of the filler 21 and a lower transmittance, so the weight of the filler 21 can be 800g, 900g, 1000g, 1100g, etc., so that the first package 2 has a higher transmittance, so as to improve the power generation efficiency of the photovoltaic module, and at the same time improve the stability of the photovoltaic module, so as to improve the reliability of the photovoltaic module. The liquid filler 21 has a certain viscosity, and the filler 21 is evenly applied in the receiving space 25 by a scraper, which can reduce the time required for the liquid filler 21 to cover the receiving space 25, which is beneficial to improving the production efficiency of the photovoltaic module. After the scraper applies the liquid filler 21 to the receiving space 25, the filler 21 is left to stand until the surface is flat, which can make the surface of the filler 21 smoother.

[0053] In a possible embodiment, the scraper is provided with a plurality of liquid outlets arranged at intervals, and the liquid filler 21 can be injected into the receiving space 25 through the liquid outlets. When the liquid filler 21 is injected into the receiving space 25: S23, the scraper moves from one side of the accommodating space 25 to the other side along the length direction or the width direction of the photovoltaic module, and the liquid filling member 21 is injected into the accommodating space 25 through the liquid outlet during the movement of the scraper.

[0054] A liquid outlet is provided on the scraper so that the liquid filler 21 can be injected into the receiving space 25 when the scraper moves from one side to the other. At the same time, the liquid filler 21 can be more evenly distributed in the receiving space 25, which is beneficial to improving the production efficiency of photovoltaic modules.

[0055] In a possible embodiment, the first packaging component 2 includes a filling component 21, a sealing component 22 and a film layer 23. The sealing component 22 is located at the edge of the first cover plate 4. The filling component 21 is located in the receiving space 25 enclosed by the sealing component 22 and has the same height as the sealing component 22. The film layer 23 is located on the side of the filling component 21 and the sealing component 22 away from the first cover plate 4. One side of the film layer 23 is bonded to the battery cell and the other side is bonded to the sealing component 22. The filling component 21 is sealed in the receiving space 25 to improve the anti-PID performance of the photovoltaic module and the service life of the photovoltaic module. The filling component 21 includes silica gel and a tackifier to improve the fusion of the filling component 21 and the film layer 23 and reduce the possibility of delamination or detachment of the filling component 21 and the film layer 23 after the laminate is cured. Before injecting the liquid filling component 21 into the receiving space 25, the preparation method includes: S201, putting silica gel and tackifier into a mixing device at a ratio of 10:1; S202, heating the mixing device to 50°C to 70°C, and stirring and mixing.

[0056] The silica gel and the tackifier are mixed in a ratio of 10:1, so that the filler 21 and the film layer 23 can be better integrated, and the possibility of the filler 21 and the film layer 23 being delaminated or falling off after the laminated parts are laminated is reduced, which is beneficial to improving the reliability of the photovoltaic module. Heating the mixing device to 50°C to 70°C can reduce the viscosity of the silica gel and tackifier mixed material, which is convenient for the integration of the mixed material. The mixing device stirs and mixes the mixed material, which can improve the uniformity of the silica gel and the tackifier.

[0057] like Figure 7 As shown, after the second packaging component 3 and the battery cell group 1 are placed on the second cover plate 5 in sequence, the preparation method includes: S31 , laying an adhesive film layer 23 on the battery cell group 1 .

[0058] The filler 21 and the sealant 22 in the first packaging component 2 are fixed to the first cover plate 4. The adhesive film layer 23 is first placed on the battery cell group 1, and then the first cover plate 4, the filler 21 and the sealant 22 are placed on the adhesive film layer 23. After lamination, the adhesive film layer 23 is fused with the filler 21 and the sealant 22, which is convenient for the processing of photovoltaic modules and is beneficial to improving the production efficiency of photovoltaic modules.

[0059] In a possible embodiment, when the laminate is placed in a laminating device for curing, the preparation method includes: The temperature of one chamber of the laminating device is raised to 90° C. to 110° C., vacuumed for 450 seconds to 490 seconds, and laminated for 170 seconds to 200 seconds.

[0060] The temperature of the second chamber of the laminating device is raised to 145° C. to 148° C., vacuumed for 10 to 20 seconds, and laminated for 600 to 650 seconds.

[0061] The stack is pre-pressed in a cavity, and the cavity heats the stack to 90°C to 110°C through heat-conducting oil or steam, so that the first package 2 and the second package 3 soften and reach a molten state, providing a fluidity basis for subsequent lamination. At a temperature of 90°C to 110°C, a cavity is evacuated to discharge the air and moisture in each layer of the stack, reducing the possibility of bubbles remaining in the photovoltaic module after lamination, and further reducing the possibility of stratification or delamination in the photovoltaic module. The initial pressure is applied to the stack in a cavity through the segmented pressurization function, and lasts for 600s to 650s, so that the layers of the stack are initially fitted, which can reduce the possibility of damage to the photovoltaic module caused by stress concentration in the subsequent lamination stage.

[0062] The second chamber is used as the main pressure chamber. Through the hydraulic or pneumatic system, precise pressure is applied to completely fill the gap between the first package 2 and the second package 3 in the molten state into the battery cell group 1, the first cover plate 4 and the second cover plate 5, forming a dense packaging structure to improve the reliability of the photovoltaic module. The temperature of the second chamber is maintained at 145°C to 148°C by controlling the heating plate through the PID algorithm, and it lasts for 600s to 650s, so that the cross-linking and curing reaction of the first package 2 and the second package 3 is fully completed, making the laminated photovoltaic module more reliable. The cooling system is inherited at the end of the second chamber, and the laminated photovoltaic module is quickly cooled down through the circulation of thermal oil or forced cold air, reducing the possibility of hidden cracks in the photovoltaic module caused by thermal stress, which is conducive to improving the yield rate of the photovoltaic module.

[0063] The present application relates to a photovoltaic module and a method for preparing the photovoltaic module. The photovoltaic cell comprises a cell group 1, a first package 2, a second package 3, a first cover plate 4 and a second cover plate 5. Along the thickness direction of the photovoltaic module, the first package 2 and the second package 3 are respectively located on both sides of the cell group 1, the first cover plate 4 is located on the side of the first package 2 away from the cell group 1, and the second package 3 is located on the side of the second package 3 away from the cell group 1. The first package 2 comprises a filler 21 and a seal 22, and the seal 22 is arranged around the filler 21. The filler 21 comprises silica gel, and the silica gel has a high light transmittance, which facilitates sunlight to pass through the first package 2 and enter the cell group 1, so as to improve the light absorption efficiency of the cell group 1, thereby facilitating the improvement of the power generation efficiency of the photovoltaic module. The seal 22 is arranged around the filler 21, which can limit the position of the filler 21, so that the filler 21 is located between the first cover plate 4 and the cell group 1, and reduce the possibility of leakage of the filler 21.

Claims

1. A photovoltaic module, characterized in that: The photovoltaic module comprises: Battery cell group (1); A first encapsulation component (2) and a second encapsulation component (3), wherein along the thickness direction of the photovoltaic module, the first encapsulation component (2) and the second encapsulation component (3) are respectively located on two sides of the cell group (1); a first cover plate (4) and a second cover plate (5), wherein the first cover plate (4) is located on a side of the first packaging member (2) away from the battery cell group (1), and the second cover plate (5) is located on a side of the second packaging member (3) away from the battery cell group (1); The first packaging component (2) comprises a filling component (21) and a sealing component (22); the sealing component (22) is arranged around the filling component (21); and the filling component (21) comprises silica gel.

2. The photovoltaic module according to claim 1, characterized in that: The filling piece (21) has a gram weight of 420 g / m 2 Up to 450g / m 2 .

3. The photovoltaic module according to claim 1, characterized in that: The first packaging component (2) further comprises an adhesive film layer (23), wherein the adhesive film layer (23) is located on a side of the filling component (21) and the sealing component (22) close to the battery cell group (1).

4. The photovoltaic module according to claim 3, characterized in that: The filling member (21) further comprises a tackifier, and the ratio of the silica gel to the tackifier is 10:

1.

5. The photovoltaic module according to claim 4, characterized in that: The tackifier comprises: ethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol and toluene.

6. The photovoltaic module according to claim 4, characterized in that: The filling piece (21) has a gram weight of 300 g / m 2 Up to 350g / m 2 .

7. A method for preparing a photovoltaic module, characterized in that: The preparation method comprises: The sealing member (22) is fixed to the first cover plate (4) by hot stamping, the sealing member (22) being aligned with the edge of the first cover plate (4), the width of the sealing member (22) being 1 cm to 4 cm, and forming a receiving space (25) on the surface of the first cover plate (4); Injecting a liquid filling member (21) into the accommodating space (25), and allowing the filling member (21) to fill the accommodating space (25); Placing the second packaging component (3) and the battery cell group (1) on the second cover plate (5) in sequence; Placing the side of the first cover plate (4) provided with the sealing member (22) and the filling member (21) on the side of the battery cell group (1) away from the second packaging member (3) to form a stacked member; The stack is placed in a laminating apparatus for curing.

8. The method for preparing a photovoltaic module according to claim 7, characterized in that: When the first packaging component (2) comprises the filling component (21), the sealing component (22) and the adhesive film layer (23), the filling component (21) comprises silica gel and a tackifier, and before the liquid filling component (21) is injected into the accommodating space (25), the preparation method comprises: Put the silica gel and the tackifier into a mixing device at a ratio of 10:1; The mixing device was heated to 50°C to 70°C and stirred to mix.

9. The method for preparing a photovoltaic module according to claim 8, characterized in that: After the second packaging component (3) and the battery cell group (1) are placed on the second cover plate (5) in sequence, the preparation method comprises: A glue film layer (23) is laid on the battery cell group (1).

10. The method for preparing a photovoltaic module according to claim 7, characterized in that: When the laminate is placed in a laminating device for curing, the preparation method comprises: Raising the temperature of a chamber of the laminating device to 90° C. to 110° C., evacuating for 450 seconds to 490 seconds, and laminating for 170 seconds to 200 seconds; The temperature of the second chamber of the laminating device is raised to 145° C. to 148° C., vacuumed for 10 to 20 seconds, and laminated for 600 to 650 seconds.

Images