A photovoltaic module and a method for manufacturing the same

Abstract

The present application relates to a photovoltaic module and a method for manufacturing the photovoltaic module. The photovoltaic cell includes a cell group, a first encapsulant, a second encapsulant, a first cover plate, and a second cover plate. Along the thickness direction of the photovoltaic module, the first encapsulant and the second encapsulant are respectively located on both sides of the cell group, the first cover plate is located on the side of the first encapsulant away from the cell group, and the second cover plate is located on the side of the second encapsulant away from the cell group. The first encapsulant includes a filling member and a sealing member, and the sealing member is disposed around the filling member. The filling member includes silica gel, and the silica gel has a relatively high light transmittance, facilitating sunlight to pass through the first encapsulant and enter the cell group, so as to improve the light absorption efficiency of the cell group, and further contribute to improving the power generation efficiency of the photovoltaic module. The sealing member is disposed around the filling member, which can limit the position of the filling member, making the filling member located between the first cover plate and the cell group, and reducing the possibility of leakage of the filling member.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic power generation, and particularly relates to a photovoltaic module and a method for manufacturing the photovoltaic module. Background Art

[0002] With the increasing shortage of conventional energy supply and the increasingly prominent environmental pollution problems in the world, humans have realized the energy and environmental crises and begun to seek renewable clean energy to replace conventional energy. Photovoltaic power generation has become an emerging industry that has attracted widespread attention and key development in various countries around the world due to its characteristics such as cleanness, safety, convenience, and high efficiency. The photovoltaic module for photovoltaic power generation includes a first cover plate, a first encapsulant, a battery cell group, a second encapsulant, and a second cover plate. Currently, both the first encapsulant and the second encapsulant are EVA films, and their light transmittance is poor, 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 manufacturing 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, and the photovoltaic module includes:

[0005] A battery cell group;

[0006] A first encapsulant and a second encapsulant, along the thickness direction of the photovoltaic module, the first encapsulant and the second encapsulant are respectively located on both sides of the battery cell group;

[0007] A first cover plate and a second cover plate, the first cover plate is located on the side of the first encapsulant away from the battery cell group, and the second cover plate is located on the side of the second encapsulant away from the battery cell group;

[0008] Wherein, the first encapsulant includes a filling member and a sealing member, the sealing member is arranged around the filling member, and the filling member includes silica gel.

[0009] In a possible embodiment, the grammage of the filling member is 420 g / m 2 to 450 g / m 2 .

[0010] In a possible embodiment, the first encapsulant further includes a film layer, and the film layer is located on the side of the filling member and the sealing member close to the battery cell group.

[0011] In a possible embodiment, the filling member further includes a tackifier, and the ratio of the silica gel to the tackifier is 10:1.

[0012] In a possible embodiment, the tackifier includes: tetraethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol, and toluene.

[0013] In a possible embodiment, the grammage of the filler is 300 g / m 2 to 350 g / m 2 .

[0014] In a second aspect, the present application also relates to a method for manufacturing a photovoltaic module, the manufacturing method including:

[0015] Fixing the sealant to the first cover plate by spot welding, aligning the sealant with the edge of the first cover plate, the width of the sealant being 1 cm to 4 cm, and enclosing a receiving space on the surface of the first cover plate;

[0016] Injecting a liquid filler into the receiving space and filling the receiving space with the filler;

[0017] Placing the second encapsulant and the battery cell group on the second cover plate in sequence;

[0018] Placing the side of the first cover plate provided with the sealant and the filler on the side of the battery cell group away from the second encapsulant to form a stacked member;

[0019] Putting the stacked member into a lamination device for curing.

[0020] In a possible embodiment, when the first encapsulant includes the filler, the sealant, and the adhesive film layer, the filler includes silica gel and a tackifier. Before injecting the liquid filler into the receiving space, the manufacturing method includes:

[0021] Putting the silica gel and the tackifier into a mixing device at a ratio of 10:1;

[0022] Heating the mixing device to 50°C to 70°C and stirring for mixing.

[0023] In a possible embodiment, after placing the second encapsulant and the battery cell group on the second cover plate in sequence, the manufacturing method includes:

[0024] Laying an adhesive film layer on the battery cell group.

[0025] In a possible embodiment, when putting the stacked member into the lamination device for curing, the manufacturing method includes:

[0026] Raising the temperature of one cavity of the lamination device to 90°C to 110°C, evacuating for 450 s to 490 s, and laminating for 170 s to 200 s;

[0027] Heat the second chamber of the lamination device to 145°C to 148°C, evacuate for 10 s to 20 s, and laminate for 600 s to 650 s.

[0028] This application relates to a photovoltaic module and a method for manufacturing the same. The photovoltaic cell includes a battery cell group, a first encapsulant, a second encapsulant, a first cover plate, and a second cover plate. Along the thickness direction of the photovoltaic module, the first encapsulant and the second encapsulant are respectively located on both sides of the battery cell group, the first cover plate is located on the side of the first encapsulant away from the battery cell group, and the second cover plate is located on the side of the second encapsulant away from the battery cell group. The first encapsulant includes a filling member and a sealing member, and the sealing member is disposed around the filling member. The filling member includes silica gel, which has a relatively high light transmittance, facilitating sunlight to pass through the first encapsulant and enter the battery cell group, thereby improving the light absorption efficiency of the battery cell group and further enhancing the power generation efficiency of the photovoltaic module. The sealing member disposed around the filling member can limit the position of the filling member, enabling the filling member to be located between the first cover plate and the battery cell group and reducing the possibility of leakage of the filling member. Description of the Drawings

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 Structural schematic diagram of an embodiment of the photovoltaic module provided by an embodiment of this application;

[0031] Figure 2 Structural schematic diagram of another embodiment of the photovoltaic module provided by an embodiment of this application;

[0032] Figure 3 Top view of the first cover plate, filling member, and sealing member provided by an embodiment of this application;

[0033] Figure 4 Side view of the first cover plate and the sealing member provided by an embodiment of this application;

[0034] Figure 5 Side view of the first cover plate, filling member, and sealing member provided by an embodiment of this application;

[0035] Figure 6 Structural schematic diagram of the battery cell group, second encapsulant, and second cover plate provided by an embodiment of this application;

[0036] Figure 7 Structural schematic diagram of the battery cell group, second encapsulant, second cover plate, and adhesive film layer provided by an embodiment of this application;

[0037] Figure 8 Flow chart of a preparation method of an embodiment of a photovoltaic module provided by an embodiment of the present application;

[0038] Figure 9 Flow chart of a preparation method of another embodiment of a photovoltaic module provided by an embodiment of the present application.

[0039] Reference numerals:

[0040] 1 - Battery cell group;

[0041] 2 - First encapsulation member;

[0042] 21 - Filling member;

[0043] 22 - Sealing member;

[0044] 23 - Glue film layer;

[0045] 25 - Accommodating space;

[0046] 3 - Second encapsulation member;

[0047] 4 - First cover plate;

[0048] 5 - Second cover plate. Detailed implementation manners

[0049] For a better understanding of the technical solutions of the present application, the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0050] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0051] 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", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0052] It should be understood that the term " / and" used herein is only a description of the associated relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0053] Such as Figures 1 to 5As shown in the figure, an embodiment of the present application provides a photovoltaic module, which includes a battery cell group 1, a first encapsulant 2, a second encapsulant 3, a first cover plate 4, and a second cover plate 5. Along the thickness direction of the photovoltaic module, the first encapsulant 2 and the second encapsulant 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 encapsulant 2 away from the battery cell group 1, and the second cover plate 5 is located on the side of the second encapsulant 3 away from the battery cell group 1. The first encapsulant 2 is used to connect the battery cell group 1 and the first cover plate 4, and the second encapsulant 3 is used to connect the battery cell group 1 and the second cover plate 5. The first encapsulant 2 includes a filling member 21 and a sealing member 22. The sealing member 22 is disposed around the filling member 21, and the filling member 21 includes a material with a relatively high light transmittance such as silica gel.

[0054] The battery cell group 1 includes a light-receiving surface and a backlight surface, where the light-receiving surface faces the sun to absorb sunlight. The first encapsulant 2 is located on the light-receiving surface, and the second encapsulant 3 is located on the backlight surface. The first cover plate 4 is photovoltaic glass with a good light transmittance. The filling member 21 in the first encapsulant 2 between the first cover plate 4 and the battery cell group 1 includes a material with a relatively high light transmittance such as silica gel, which facilitates sunlight to pass through the first cover plate 4 and the filling member 21 and irradiate the light-receiving surface of the battery cell group 1, so as to improve the light absorption efficiency of the battery cell group 1, and further contribute to improving the power generation efficiency of the photovoltaic module. The sealing member 22 in the first encapsulant 2 can be an EVA film, a POE film, etc. The sealing member 22 is located between the first cover plate 4 and the battery cell group 1. After lamination, the EVA film can bond the first cover plate 4 and the battery cell group 1 to improve the reliability of the photovoltaic module. The sealing member 22 is disposed around the filling member 21, which can limit the position of the filling member 21, make the filling member 21 located between the first cover plate 4 and the battery cell group 1, and reduce the possibility of leakage of the filling member 21. The sealing member 22 is located at the edge position of the first cover plate 4 to connect the first cover plate 4 and the battery cell group 1. Therefore, the sealing member 22 will block part of the battery cell group 1. The sealing member 22 is an EVA film or a POE film, so that the part of the battery cell group 1 blocked by the sealing member 22 can also absorb sunlight, improving the light absorption efficiency of the photovoltaic module. The second cover plate 5 can be an aluminum alloy backplane, a fiberglass backplane, a composite material backplane, etc., and the second encapsulant 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.

[0055] This application does not limit the structure of the solar cell. The types of solar 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.

[0056] For a PERC cell, along its thickness direction, the PERC cell sequentially includes a front surface metal silver electrode, a front surface silicon nitride passivation layer, a phosphorus layer emitter, a P-type substrate silicon layer, a local aluminum back surface field, a metal aluminum back electrode, and a back passivation layer (Al2O3 / SiNx). The PERC cell uses a passivation film to passivate the back surface, replacing the full aluminum back surface field, enhancing the internal back reflection of light in the silicon substrate, reducing the back surface recombination rate, and increasing the efficiency of the cell by 0.5% - 1%.

[0057] For a TOPCon cell, along its thickness direction, the TOPCon cell sequentially includes a metal silver electrode, a front surface silicon nitride passivation layer, a boron-doped emitter, an N-type substrate silicon layer, a diffusion doping layer, an ultra-thin silicon oxide, a doped polysilicon, silicon nitride, and a metal silver electrode. The back surface of the cell is composed of an ultra-thin silicon oxide layer (1nm - 2nm) and a phosphorus-doped microcrystalline amorphous hybrid Si thin film, and the two together form a passivated contact structure. This structure can block the recombination of minority carriers (holes), improving the open-circuit voltage and short-circuit current of the cell. The ultra-thin oxide layer allows majority carriers (electrons) to tunnel into the polysilicon layer while blocking the recombination of minority carriers (holes). The good passivation effect of the ultra-thin silicon oxide and the heavily doped silicon thin film causes the energy band on the silicon wafer surface to bend, thus forming a field passivation effect, greatly increasing the probability of electron tunneling, reducing the contact resistance, improving the open-circuit voltage and short-circuit current of the cell, and thus improving the conversion efficiency of the cell.

[0058] For an HJT cell, along its thickness direction, the HJT cell sequentially includes a front surface low-temperature silver electrode, a front surface conductive thin film, an N-type amorphous silicon thin film, an intrinsic amorphous silicon thin film, an N-type substrate silicon layer, an intrinsic amorphous silicon thin film, a P-type amorphous silicon thin film, a back surface conductive thin film, and a back surface low-temperature silver electrode.

[0059] For an IBC cell, along its thickness direction, the IBC cell sequentially includes a silicon nitride back layer, an N+ front surface field, an N-type substrate silicon layer, a P+ emitter, an N+ back field, an aluminum oxide passivation layer, a silicon nitride antireflection layer, and a metal silver electrode. The IBC cell uses ion implantation technology to obtain P and N regions with good uniformity and precisely controllable junction depth. There are no grid lines blocking on the front side of the cell, which can eliminate the shading current loss of the metal electrode, maximize the utilization of incident photons, and increase the short-circuit current by about 7% compared with conventional solar cells. Due to the back contact structure, there is no need to consider the problem of grid line occlusion, 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, resulting in a lower front surface recombination rate and surface reflection.

[0060] For a perovskite cell, along its thickness direction, the perovskite cell sequentially includes a substrate material, a conductive thin film, an electron transport layer (titanium dioxide), a perovskite absorption layer (hole transport layer), and a metal cathode. The perovskite material has 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 less loss. Therefore, it can generate a high photovoltage and current, making the perovskite exhibit a high photoelectric conversion efficiency.

[0061] In a possible embodiment, the grammage of the filling member 21 is 420 g / m 2 to 450 g / m 2 , and the thickness of the first encapsulation member 2 is 250 μm to 500 μm.

[0062] The grammage of the filling member 21 is 420 g / m 2 to 450 g / m 2 , making the thickness of the first encapsulation member 2 be 300 μm to 360 μm. The first encapsulation member 2 and the second encapsulation member 3 are respectively located on both sides of the battery cell group 1 in the thickness direction, 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 encapsulation member 2 is located on the light-receiving surface of the battery cell group 1, and sunlight needs to pass through the first cover plate 4 and the first encapsulation member 2 and enter the battery cell group 1. The first encapsulation member 2 and the second encapsulation member 3 can enhance the mechanical strength and the ability to resist external force damage of the component, enabling the photovoltaic module to be applicable to extreme weather such as hail, snow, and wind. The battery cell group 1 includes a plurality of battery cells, and the plurality of battery cells are connected by solder strips. The first encapsulation member 2 and the second encapsulation member 3 can provide buffering for the battery cell group 1 to reduce the possibility of stress concentration between the solder strip and the battery cell and reduce the risk of battery cell cracking. If the grammage of the filling member 21 is greater than 450 g / m 2, the thickness of the first encapsulant 2 is greater than 500 μm, which leads to an increase in the light transmittance of the first encapsulant 2, reduces the intensity of sunlight received by the battery cell group 1, reduces the power generation efficiency of the photovoltaic module, and also increases the weight and production cost of the photovoltaic module. If the grammage of the filling member 21 is less than 420 g / m 2 , the thickness of the first encapsulant 2 is less than 250 μm, resulting in poor mechanical properties of the photovoltaic module. When the photovoltaic module is impacted in extreme weather such as hail, snow, and wind, it is easily damaged. In addition, the buffering effect of the first encapsulant 2 on the battery cell group 1 is small, increasing the possibility of battery cell cracking. At the same time, it will also increase the aging speed of the first encapsulant 2, reduce the stability and sealing performance of the first encapsulant 2. Therefore, the grammage of the filling member 21 can be 420 g / m 2 , 435 g / m 2 , 450 g / m 2 etc., so that the thickness of the first encapsulant 2 can be 250 μm, 380 μm, 500 μm, etc., facilitating sunlight to pass through the first encapsulant 2 and irradiate into the battery cell group 1. At the same time, it can also improve the protection effect on 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.

[0063] As Figure 2 shown, in a possible embodiment, the first encapsulant 2 further includes an adhesive film layer 23. The adhesive film layer 23 is located on the side of the filling member 21 and the sealing member 22 close to the battery cell group 1. One side of the adhesive film layer 23 covers the battery cell group 1, and the other side can be bonded to the sealing member 22.

[0064] The adhesive film layer 23 can be a POE adhesive film. The molecular structure of the POE adhesive film is stable, without the precipitation of acetate ions, and has excellent anti-PID performance, resulting in a relatively high power generation efficiency of the photovoltaic module. The POE adhesive film also has high elasticity and strength, can withstand external impacts and pressures, is not easily deformed or broken, and can improve the reliability of the photovoltaic module. The POE adhesive film also has good heat resistance, anti-aging property and waterproof property, enabling the photovoltaic module to be used outdoors for a long time, blocking the penetration of water vapor and other harmful substances into the battery cell group 1, so as to improve the service life of the photovoltaic module.

[0065] In a possible embodiment, the filling member 21 further includes a tackifier, and the ratio of silicone to the tackifier in the filling member 21 is 10:1.

[0066] A tackifier is added to the silicone of the filling member 21, enabling the filling member 21 and the adhesive film layer 23 to better fuse together. After the adhesive film layer 23 cures, it can reduce the possibility of delamination between the adhesive film layer 23 and the filling member 21, facilitating sunlight to pass through the adhesive film layer 23 and the filling member 21 and be absorbed by the battery cell group 1. Adding a tackifier to the silicone can also improve the bonding strength between the adhesive film layer 23 and the filling member 21 to enhance the strength of the photovoltaic module. The liquid silicone can be addition-cured liquid silicone. If the ratio of silicone to tackifier in the filling member 21 is greater than 10:1, the content of the tackifier in the filling member 21 is relatively low, resulting in a decrease in the bonding strength between the filling member 21, the adhesive film layer 23, and the first cover plate 4, failing to achieve an ideal bonding effect. At the same time, it will also lead to poor physical properties such as the tensile strength and tear strength of the filling member 21. If the ratio of silicone to tackifier in the filling member 21 is less than 10:1, the content of the tackifier in the filling member 21 is relatively high, breaking the balance of the cross-linking reaction, thereby affecting the normal cross-linking process of the filling member 21 and resulting in cross-linking failure. At the same time, the excessive tackifier may also cause a decrease in the cross-linking density of the silicone molecular structure, instead reducing the bonding strength.

[0067] In a possible embodiment, the liquid silicone can be condensation-cured liquid silicone. At this time, the ratio of the liquid silicone to the tackifier can be from 100:1 to 20:1. If the ratio of the liquid silicone to the tackifier is less than 100:1, the content of the tackifier in the filling member 21 is relatively low, resulting in a decrease in the bonding strength between the filling member 21, the adhesive film layer 23, and the first cover plate 4, failing to achieve an ideal bonding effect. At the same time, it will also lead to poor physical properties such as the tensile strength and tear strength of the filling member 21. If the ratio of the liquid silicone to the tackifier is greater than 20:1, the content of the tackifier in the filling member 21 is relatively high, breaking the balance of the cross-linking reaction, thereby affecting the normal cross-linking process of the filling member 21 and resulting in cross-linking failure. At the same time, the excessive tackifier may also cause a decrease in the cross-linking density of the silicone molecular structure, instead reducing the bonding strength.

[0068] In a possible embodiment, the tackifier includes tetraethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol, and toluene.

[0069] Tetraethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol, and toluene can improve the bonding strength between the filling member 21 and the adhesive film layer 23 to enhance the strength of the photovoltaic module. The materials in the tackifier are all transparent materials, reducing the impact of the tackifier on the light transmittance of the silicone and improving the light transmittance of the filling member 21, thereby enhancing the light absorption efficiency of the photovoltaic module.

[0070] In a possible embodiment, the grammage of the filling member 21 is 300 g / m 2 to 350 g / m2 .

[0071] The thickness of the first encapsulation member 2 is 250 μm to 500 μm. The first encapsulation member 2 includes a filling member 21 and a film layer 23. Therefore, the sum of the thicknesses of the film layer 23 and the filling member 21 is 250 μm to 500 μm. The grammage of the film layer 23 is 100 g / m 2 , if the grammage of the filling member 21 is less than 300 g / m 2 , it will cause the thickness of the first encapsulation member 2 to be less than 250 μm, resulting in poor mechanical properties of the photovoltaic module. When the photovoltaic module is impacted in extreme weather such as hail, snow, and wind, it is easily damaged. It will also cause a small buffering effect of the first encapsulation member 2 on the battery cell group 1, increasing the possibility of hidden cracks in the battery cells. At the same time, it will also increase the aging speed of the first encapsulation member 2, reduce the stability of the first encapsulation member 2, and the sealing performance of the first encapsulation member 2. If the thickness of the filling member 21 is greater than 350 g / m 2 , it will cause the thickness of the first encapsulation member 2 to be greater than 500 μm, resulting in a reduction in the light transmittance of the first encapsulation member 2, affecting the power generation efficiency of the photovoltaic module, and also increasing the weight and production cost of the photovoltaic module. Therefore, the grammage of the filling member 21 can be 300 g / m 2 , 325 g / m 2 , 350 g / m 2 , so that the first encapsulation member 2 can improve the protection effect on the battery cell group 1 and the service life of the photovoltaic module. At the same time, it can also have good light transmittance, making the photovoltaic module have good reliability and high power generation efficiency.

[0072] In a possible embodiment, the grammage of the second encapsulation member 3 is 350 g / m 2 to 420 g / m 2 .

[0073] If the grammage of the second encapsulation member 3 is less than 350 g / m 2 , the thickness of the second encapsulation member 3 is small, and the buffering effect on the battery cell group 1 is poor, resulting in easy occurrence of hidden cracks in the battery cells. In extreme weather such as hail, snow, and wind, the photovoltaic module is easily damaged, and the service life of the photovoltaic module is also shortened. If the grammage of the second encapsulation member 3 is greater than 420 g / m 2 , the thickness of the second encapsulation member 3 is large, resulting in a high production cost of the photovoltaic module. If the photovoltaic module is a double-glass module and the second cover plate 5 is photovoltaic glass, sunlight can pass through the second cover plate 5 and the second encapsulation member 3 and irradiate onto the battery cell group 1 to improve the power generation efficiency of the photovoltaic module. However, the large thickness of the second encapsulation member 3 will affect the light transmittance of the second encapsulation member 3 and reduce the power generation efficiency of the photovoltaic module. Therefore, the grammage of the second encapsulation member 3 can be 350 g / m 2 , 390 g / m 2 , 420 g / m2 , which can reduce the production cost of photovoltaic modules and also enable the photovoltaic cells to have good reliability and high power generation efficiency.

[0074] Such as Figures 4 to 9 As shown, the embodiment of the present application also provides a method for manufacturing a photovoltaic module, and the manufacturing steps include:

[0075] S1. Fix the seal 22 to the first cover plate 4, align the seal 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;

[0076] S2. Inject a liquid filling member 21 into the receiving space 25 so that the filling member 21 fills the receiving space 25;

[0077] S3. Place the second encapsulation member 3 and the battery cell group 1 on the second cover plate 5 in sequence;

[0078] S4. Place the side of the first cover plate 4 provided with the seal 22 and the filling member 21 on the side of the battery cell group 1 away from the second encapsulation member 3 to form a stacked member;

[0079] S5. Place the stacked member into a lamination device for curing.

[0080] First, fix the seal 22 to the first cover plate 4, and then inject the filling member 21 into the receiving space 25 enclosed by the seal 22, which can limit the position of the filling member 21 on the first cover plate 4 and reduce the possibility of the filling member 21 flowing out. The battery cell group 1 includes a plurality of series-connected and / or parallel-connected battery cells, and the battery cells are connected by welding tapes. The filling member 21 at the middle position of the first encapsulation member 2 is liquid silicone, and the liquid silicone has viscosity. After placing the battery cell group 1 on the first encapsulation member 2, the position of the battery cell group 1 will be restricted, and it is not convenient to adjust the position of the battery cell group 1. The supporting force of the liquid silicone on the battery cell group 1 is poor, and the battery cells are prone to deformation when placed on the first encapsulation member 2. First, place the second encapsulation member 3 and the battery cell group 1 on the second cover plate 5 in sequence. The second encapsulation member 3 and the second cover plate 5 can provide a supporting force for the battery cell group 1 and reduce the possibility of the battery cell group 1 deforming. Place the battery cell group 1 on the second encapsulation member 3, and then place the first encapsulation member 2 and the first cover plate 4 on the battery cell group 1 so that the first encapsulation member 2 is bonded to the battery cell group 1, further restricting the position of the filling member 21 in the stacked member. The stacked member is placed into a lamination device for curing to cure the seal 22 and the second encapsulation member 3, and to fixedly connect the first cover plate 4, the first encapsulation member 2, the battery cell group 1, the second encapsulation member 3, and the second cover plate 5 in the stacked member, improving the strength of the photovoltaic module.

[0081] Such as Figure 5As shown, in a possible embodiment, the thickness of the seal 22 can be from 0.6 mm to 2 mm, and the thickness of the liquid filling member 21 can be from 0.3 mm to 1 mm. Making the thickness of the liquid filling member 21 less than that of the seal 22 can reduce the possibility of bubbles being generated inside the filling member 21.

[0082] The material of the first cover plate 4 is photovoltaic glass. During the lamination process, the edge of the first cover plate 4 will warp, resulting in the edge of the first encapsulation member 2 shifting inward, reducing the amount of the first encapsulation member 2 in its original position, or a part of the edge of the first encapsulation member 2 will overflow, resulting in a shortage at the original position. Both will cause bubbles to be generated at the edge position of the first encapsulation member 2. The thickness of the encapsulation member is greater than that of the filling member 21, which can increase the amount of the encapsulation member at the edge position, reserve the possibility of edge offset or overflow during lamination, and thus can reduce the possibility of bubbles being generated at the first encapsulation member 2. The bubbles are located at the edge position of the seal 22 in the first encapsulation member 2. If a small amount of bubbles are generated after lamination and the bubbles are located at the edge position of the photovoltaic module, after installing the frame of the photovoltaic module, the position with bubbles can be blocked by the frame to reduce the influence of the bubbles on the light absorption efficiency of the photovoltaic module.

[0083] The width of the seal 22 is from 1 cm to 4 cm. When the seal 22 is aligned with the edge of the first cover plate 4, it can enclose an accommodation space 25 on the first cover plate 4 to limit the position of the filling member 21. After lamination and curing, the seal 22 is used to compensate for the edge offset or overflowed 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 for the edge offset or overflow of the first encapsulation member 2 is small, resulting in an increased possibility of bubbles being generated at the edge of the photovoltaic module. The light transmittance of the filling member 21 is greater than that of the seal 22, and the light absorption efficiency at the position where the battery cell contacts the filling member 21 is greater than that at the position where the battery cell contacts the seal 22. If the width of the seal 22 is greater than 4 cm, the contact area between the seal 22 and the battery cell increases, the accommodation space 25 enclosed by the seal 22 decreases, and the contact area between the filling member 21 and the battery cell decreases, resulting in a decrease in the light transmittance of the first encapsulation member 2 and a reduction in the light absorption efficiency of the battery cell, and thus a decrease in the power generation efficiency of the photovoltaic module.

[0084] In a possible embodiment, butyl rubber has good sealing and waterproof properties. Therefore, the material of the seal 22 can also be butyl rubber. Due to the relatively high cost of butyl rubber, the width of butyl rubber as the seal 22 can be from 0.6 mm to 1.5 mm, and the thickness can be from 0.6 mm to 2 mm, so that the butyl rubber can limit the position of the filling member 21 on the first cover plate 4 and can compensate for the vacancies generated by edge offset or overflow of glue, just reducing the possibility of bubbles being generated inside the photovoltaic module.

[0085] Such as Figure 4As shown, when fixing the seal 22 to the first cover plate 4, the preparation method includes:

[0086] S11. Align the edge of the seal 22 with the edge of the first cover plate 4;

[0087] S12. Fix the seal 22 to the first cover plate 4 by spot ironing.

[0088] Aligning the edge of the seal 22 with the edge of the first cover plate 4 enables the seal 22 to encapsulate the edges of the first cover plate 4 and the battery cell, reducing the possibility of external impurities entering the photovoltaic module. The seal 22 can be fixed to the first cover plate 4 by spot ironing with a welding head, so that the seal 22 encloses an accommodation space 25. After injecting the filling member 21 into the accommodation space 25, the position of the filling member 21 on the first cover plate 4 can be restricted. When forming the laminate, it is necessary to flip the first cover plate 4 so that the side of the first cover plate 4 provided with the seal 22 and the filling member 21 contacts the battery cell. Fixing the seal 22 to the first cover plate 4 by spot ironing can reduce the possibility of the seal 22 falling off during flipping.

[0089] As Figure 3 and Figure 5 shown, when injecting the liquid filling member 21 into the accommodation space 25 and filling the accommodation space 25 with the filling member 21, the preparation method includes:

[0090] S21. Inject 800 g to 1100 g of the liquid filling member 21 into the accommodation space 25;

[0091] S22. Evenly coat the liquid filling member 21 in the accommodation space 25 with a scraper and let it stand until the surface is flat.

[0092] The weight per square meter of the filling member 21 in the accommodation space 25 is 420 g / m 2 to 450 g / m 2 , and the weight of the filling member 21 injected into the accommodation space 25 can be adjusted according to the size of the accommodation space 25. Taking the length of the first cover plate 4 as 2272 mm and the width as 1128 mm as an example, if the liquid filling member 21 injected into the accommodation space 25 is less than 800 g, the weight per square meter of the filling member 21 in the accommodation space 25 is less than 420 g / m 2 , resulting in a smaller thickness of the filling member 21 and poorer stability of the photovoltaic module. If the liquid filling member 21 injected into the accommodation space 25 is greater than 1100 g, the weight per square meter of the filling member 21 in the accommodation space 25 is greater than 450 g / m 2, which results in a relatively large thickness of the filling member 21 and a relatively low light transmittance. Therefore, the weight of the filling member 21 can be 800 g, 900 g, 1000 g, 1100 g, etc., so that the first encapsulation member 2 has a relatively high light transmittance to improve the power generation efficiency of the photovoltaic module, and at the same time improve the stability of the photovoltaic module to improve the reliability of the photovoltaic module. The liquid filling member 21 has a certain viscosity. By using a squeegee to evenly coat the filling member 21 in the accommodating space 25, the time required for the liquid filling member 21 to cover the accommodating space 25 can be reduced, which is beneficial to improving the production efficiency of the photovoltaic module. After the squeegee coats the liquid filling member 21 in the accommodating space 25, the filling member 21 is left standing until the surface is flat, which can make the surface of the filling member 21 smoother.

[0093] In a possible embodiment, a plurality of liquid outlets are provided at intervals on the squeegee, and the liquid filling member 21 can be injected into the accommodating space 25 through the liquid outlets. When injecting the liquid filling member 21 into the accommodating space 25:

[0094] S23. Along the length direction or width direction of the photovoltaic module, the squeegee moves from one side of the accommodating space 25 to the other side, and the liquid filling member 21 is injected into the accommodating space 25 through the liquid outlets during the movement of the squeegee.

[0095] By providing liquid outlets on the squeegee, during the process of the squeegee moving from one side to the other side, the liquid filling member 21 can be injected into the accommodating space 25, and at the same time, the liquid filling member 21 can be made more uniform in the accommodating space 25, which is beneficial to improving the production efficiency of the photovoltaic module.

[0096] In a possible embodiment, the first encapsulation member 2 includes a filling member 21, a sealing member 22, and an adhesive film layer 23. The sealing member 22 is located at the edge position of the first cover plate 4. The filling member 21 is located in the accommodating space 25 surrounded by the sealing member 22 and has the same height as the sealing member 22. The adhesive film layer 23 is located on the side of the filling member 21 and the sealing member 22 away from the first cover plate 4. One side of the adhesive film layer 23 is bonded to the battery cell, and the other side is bonded to the sealing member 22 to seal the filling member 21 in the accommodating space 25 to improve the anti-PID performance of the photovoltaic module and the service life of the photovoltaic module. The filling member 21 includes silica gel and a tackifier to improve the fusion of the filling member 21 and the adhesive film layer 23 and reduce the possibility of delamination or peeling between the filling member 21 and the adhesive film layer 23 after the laminate is cured. Before injecting the liquid filling member 21 into the accommodating space 25, the preparation method includes:

[0097] S201. Put silica gel and a tackifier into a mixing device in a ratio of 10:1;

[0098] S202. Heat the mixing device to 50°C to 70°C and stir and mix.

[0099] Mix silica gel and tackifier in a ratio of 10:1, so that the filler 21 and the adhesive film layer 23 can be better fused, reducing the possibility of delamination or detachment between the filler 21 and the adhesive film layer 23 after lamination of the stacked components, 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 mixture, facilitating the fusion of the mixture. The mixing device stirs and mixes the mixture, which can improve the uniformity of the mixing of silica gel and tackifier.

[0100] As Figure 7 shown, after sequentially placing the second encapsulation 3 and the battery cell group 1 on the second cover plate 5, the preparation method includes:

[0101] S31. Lay the adhesive film layer 23 on the battery cell group 1.

[0102] The filler 21 and the sealant 22 in the first encapsulation 2 are fixed to the first cover plate 4. First, place the adhesive film layer 23 on the battery cell group 1, and then place the first cover plate 4, the filler 21 and the sealant 22 on the adhesive film layer 23. After lamination, the adhesive film layer 23 is fused with the filler 21 and the sealant 22, facilitating the processing of the photovoltaic module and being beneficial to improving the production efficiency of the photovoltaic module.

[0103] In a possible embodiment, when the laminated component is placed in the lamination device for curing, the preparation method includes:

[0104] Raise the temperature of one cavity of the lamination device to 90°C to 110°C, evacuate the vacuum for 450 s to 490 s, and laminate for 170 s to 200 s.

[0105] Raise the temperature of the second cavity of the lamination device to 145°C to 148°C, evacuate the vacuum for 10 s to 20 s, and laminate for 600 s to 650 s.

[0106] The stacked component is pre-pressed in one cavity. One cavity heats the stacked component to 90°C to 110°C through heat transfer oil or steam, softening the first encapsulation 2 and the second encapsulation 3 to reach the molten state, providing a fluidity basis for subsequent pressing. At a temperature of 90°C to 110°C, evacuating the vacuum in one cavity can discharge the air and moisture in each layer of the stacked component, reducing the possibility of residual bubbles in the photovoltaic module after lamination, and further reducing the possibility of delamination or debonding in the photovoltaic module. One cavity applies an initial pressure to the stacked component through a segmented pressurization function and lasts for 600 s to 650 s, enabling the layers of the stacked component to be initially adhered, reducing the possibility of damage to the photovoltaic module caused by stress concentration in the subsequent pressing stage.

[0107] The two-chamber serves as the main pressure chamber, and precise pressure is applied through a hydraulic or pneumatic system to completely fill the gap between the molten first encapsulant 2 and the second encapsulant 3 into the cell stack 1, the first cover plate 4, and the second cover plate 5, forming a dense encapsulation structure to improve the reliability of the photovoltaic module. The temperature of the two-chamber is maintained at 145°C to 148°C for 600 s to 650 s by controlling the heating plate through the PID algorithm, enabling the cross-linking and curing reaction of the first encapsulant 2 and the second encapsulant 3 to be fully completed, making the laminated photovoltaic module more reliable. A cooling system is inherited at the end of the two-chamber, and the laminated photovoltaic module is rapidly cooled through the circulation of heat-conducting oil or forced cold air, reducing the possibility of the photovoltaic module being cracked due to thermal stress, which is beneficial to improving the yield of the photovoltaic module.

[0108] This application relates to a photovoltaic module and a preparation method thereof. The photovoltaic cell includes a cell stack 1, a first encapsulant 2, a second encapsulant 3, a first cover plate 4, and a second cover plate 5. Along the thickness direction of the photovoltaic module, the first encapsulant 2 and the second encapsulant 3 are respectively located on both sides of the cell stack 1, the first cover plate 4 is located on the side of the first encapsulant 2 away from the cell stack 1, and the second cover plate 5 is located on the side of the second encapsulant 3 away from the cell stack 1. The first encapsulant 2 includes a filling member 21 and a sealing member 22, and the sealing member 22 is disposed around the filling member 21. The filling member 21 includes silica gel, and the silica gel has a relatively high light transmittance, facilitating sunlight to pass through the first encapsulant 2 and enter the cell stack 1 to improve the light absorption efficiency of the cell stack 1, thereby being beneficial to improving the power generation efficiency of the photovoltaic module. The sealing member 22 is disposed around the filling member 21, which can limit the position of the filling member 21, making the filling member 21 located between the first cover plate 4 and the cell stack 1 and reducing the possibility of leakage of the filling member 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); Wherein, 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; The width of the sealing member (22) is 1 cm to 4 cm; 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); The cell group (1) comprises a light-receiving surface and a backlight surface, the first packaging component (2) is located on the light-receiving surface, the second packaging component (3) is located on the backlight surface, and the first cover plate (4) is photovoltaic glass.

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 filling member (21) further comprises a tackifier, and the ratio of the silica gel to the tackifier is 10:

1.

4. The photovoltaic module according to claim 3, characterized in that: The tackifier comprises: ethyl orthosilicate, dimethyldimethoxysilane, phenyltrimethoxysilane, hexamethyldisiloxane, acidic ion exchange resin, methanol and toluene.

5. The photovoltaic module according to claim 3, characterized in that: The filling piece (21) has a gram weight of 300 g / m 2 Up to 350g / m 2 .

6. 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 spot hot stamping, the first cover plate (4) being photovoltaic glass, 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, with the backlight surface of the battery cell group (1) facing the second packaging component (3); Laying an adhesive film layer (23) on the light-receiving surface of the battery cell group (1); 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 adhesive film layer (23) away from the battery cell group (1) to form a stacked member; The stack is placed in a laminating apparatus for curing.

7. The method for preparing a photovoltaic module according to claim 6, 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.

8. The method for preparing a photovoltaic module according to claim 6, 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.

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