Disclosure of Invention
In view of the above, the present invention provides a solar cell package structure and a solar cell package method, which can reduce the influence of water vapor erosion on a solar cell chip, improve the service life of a solar cell, and reduce the power attenuation of a solar cell module during use.
Based on the above purpose, the solar cell packaging structure provided by the invention comprises a photovoltaic back plate, a solar cell chip, a photovoltaic front plate and a first PVA (polyvinyl alcohol) film arranged between the solar cell chip and the photovoltaic front plate, wherein the photovoltaic back plate, the solar cell chip and the photovoltaic front plate are sequentially stacked from bottom to top.
In some embodiments of the invention, the packaging structure further comprises a second PVA film disposed between the solar chip and the photovoltaic backsheet.
In some embodiments of the present invention, the package structure further includes a sealing rubber strip, an upper end surface of the sealing rubber strip is disposed around the edge of the photovoltaic front panel, and a lower end surface of the sealing rubber strip is disposed around the edge of the photovoltaic back panel.
In some embodiments of the invention, the photovoltaic front sheet is ultra-white float glass;
and/or the photovoltaic back plate is toughened glass.
In some embodiments of the invention, the photovoltaic front sheet has a thickness of 4-5 mm;
and/or the thickness of the first PVA film is 200-500 mu m;
and/or the thickness of the photovoltaic back plate is 3.2-4 mm.
In some embodiments of the invention, the second PVA film has a thickness of 200-500. mu.m.
The invention also provides a packaging method of the solar cell, the solar cell is stacked according to the packaging structure to form a solar component to be laminated, and the solar component to be laminated is placed into a laminating machine, and the packaging method comprises the following steps:
in the temperature rise stage, heating the part of the laminating machine is started, and the temperature rise range is controlled to be 120-160 ℃;
in the vacuumizing stage, after the solar module to be laminated after the lamination and lamination are finished enters an inner cavity of a laminating machine, vacuumizing is carried out for 400-800S, and the vacuum degree is 5-25 Pa;
a first pressurizing stage, pressurizing the solar module, wherein the pressure is-75 to-65 kPa, and the pressurizing time is 120 to 240S;
a second pressurizing stage, continuously pressurizing the solar assembly, wherein the pressure is-45 to-55 kPa, and the pressurizing time is 120 to 240S;
in the third pressurizing stage, the solar module is continuously pressurized, the pressure is-45 to-35 kPa, and the pressurizing time is 720 to 960S;
and in the cooling stage, the laminated solar module is conveyed to a cooling area through a conveyor belt, the cooling time is 300-600S, and the solar module is cooled to room temperature.
From the above, it can be seen that the present invention has the following advantages compared with the prior art:
the packaging structure and the packaging method of the solar cell provided by the invention can reduce the influence of water vapor erosion on the solar cell chip, prolong the service life of the solar cell and reduce the power attenuation of the solar cell module during the use.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings.
The solar cell packaging structure provided by the embodiment comprises a photovoltaic back plate 6, a solar cell chip 4, a photovoltaic front plate 1 and a first PVA film 2, wherein the photovoltaic back plate, the solar cell chip 4 and the photovoltaic front plate 1 are sequentially stacked from bottom to top, and the first PVA film 2 is arranged between the solar cell chip 4 and the photovoltaic front plate 1.
In this embodiment, optionally, when the first PVA film 2 is disposed between the solar cell chip 4 and the photovoltaic front panel 1, the encapsulation adhesive film disposed between the solar cell chip 4 and the photovoltaic back panel 6 may be selected from one of an EVA (polyethylene-polyvinyl acetate copolymer) adhesive film, a POE (ethylene- α -olefin copolymer) adhesive film, or a PVB (polyvinyl butyral) adhesive film, at this time, the first PVA film 2 disposed between the solar cell chip 4 and the photovoltaic front panel 1 may effectively absorb water vapor penetrating from the photovoltaic front panel 1 into the inside of the solar cell, so as to effectively solve the problem of performance degradation of the solar cell module caused by water vapor penetrating into the solar cell module to erode the solar cell chip 4, and prolong the service life of the solar cell chip 4.
As shown in fig. 2, in this embodiment, preferably, the packaging structure further includes a second PVA film 5 disposed between the solar chip 4 and the photovoltaic back sheet 6, that is, the first PVA film 2 is disposed between the solar chip 4 and the photovoltaic front sheet 1, and the second PVA film 5 is disposed between the solar chip 4 and the photovoltaic back sheet 6, the first PVA film 2 disposed between the solar chip 4 and the photovoltaic front sheet 1 can effectively absorb moisture permeating from the photovoltaic front sheet 1 into the solar cell, and the second PVA film 5 disposed between the solar chip 4 and the photovoltaic back sheet 6 can effectively absorb moisture permeating from the photovoltaic back sheet 6 into the solar cell. First PVA film 2 and second PVA film 5 are high water absorption resin film, and upper and lower two-layer high water absorption resin film can the effective absorption permeate the inside steam of solar module from one side of photovoltaic front bezel 6 and one side of photovoltaic backplate 1, and separation steam, humidity get into solar cell chip 4, and the while still separation oxygen prolongs the life of solar cell chip 4.
In this embodiment, preferably, the lengths of the first PVA film 2 and the second PVA film 5 are longer than the length of the solar cell chip 4, and when the sealing rubber strip 3 is used to encapsulate the two sides of the solar cell chip 4, the overflowing first PVA film 2 and the second PVA film 5 can absorb water vapor entering from the two sides, so that the water vapor cannot corrode the solar cell chip 4.
The PVA film has the following advantages:
the PVA film is a functional polymer material with high water absorption capacity and high water retention capacity, can absorb water which is dozens of times or thousands of times of the self weight, can not separate the water even under external pressure, and can be applied to the packaging of the solar cell to effectively prevent water vapor from corroding the solar cell chip 4.
The PVA film has no heat absorption and heat release phenomena in the water absorption process, so that the PVA film is applied to battery packaging without considering the influence on the battery in the working process.
The PVA film has good light transmission and extremely low fogging degree, and is used on a packaging structure without worrying about the influence on light absorption of a battery.
The PVA film has good heat sealability, compactness and strong bonding force, has good flexibility, high compressive strength, high tearing strength and long service life, and can be applied to solar cell packaging in a hot pressing mode.
Therefore, the PVA film is selected, has high light transmittance and low degree of atomization, can effectively reduce the influence on the solar cell chip 4 to absorb sunlight, and effectively increases the photoelectric conversion efficiency; the PVA film has super-strong water absorption and retention capacity, effectively absorbs water entering the solar cell module, protects the solar cell chip 4 from water vapor erosion and oxidation, prolongs the service life of the solar cell and reduces the power attenuation of the solar cell in the using process.
The environment of the solar component after being packaged requires that the water vapor content is lower than 0.5g/m2The PVA film can effectively absorb water vapor and prevent the water vapor from invading the solar cell chip 4 as a water absorption film, and simultaneously, the water vapor content is lower than 0.5g/m2Under the environment of (2), the viscosity attenuation value of PVA is very small, and the peeling strength of PVA/glass is more than 30N/cm, so that the requirements of packaging cohesiveness and cohesiveness can be met.
In this embodiment, the package structure further includes a sealing rubber strip 3, an upper end surface of the sealing rubber strip 3 is disposed around the edge of the photovoltaic front panel 1, and a lower end surface of the sealing rubber strip 3 is disposed around the edge of the photovoltaic back panel 6. From this, constitute a confined space between photovoltaic front bezel 1, photovoltaic backplate 6 and joint strip 3, make first PVA film 2, second PVA film 5 and solar cell chip 4 encapsulation in this space to solar cell chip 4's protection has been improved, wherein, joint strip 3 can with the fixed adhesion in edge of photovoltaic front bezel 1 and photovoltaic backplate 6, has also strengthened the reliability of solar cell chip 4 encapsulation from this.
In order to enhance the waterproof performance of the solar cell module, the sealing rubber strip 3 is preferably butyl rubber, which has good chemical stability and thermal stability, most notably air tightness and water tightness, good heat resistance, ozone resistance, aging resistance, chemical resistance, shock absorption, electrical insulation performance, good resistance to sunlight and ozone, and can effectively increase the stability of the overall structure of the cell.
In this embodiment, the photovoltaic front panel 1 may be a rigid material having a certain light transmittance, weather resistance, insulation property, and water resistance, and preferably, the photovoltaic front panel 1 is ultra-white float glass.
In order to prolong the service life of the solar cell module and reduce the problem of power attenuation in the long-term use process, the photovoltaic back plate 6 is required to play a role in protecting and supporting the cell piece and has reliable insulation, water resistance and aging resistance, and preferably, the photovoltaic back plate 6 is toughened glass.
In this embodiment, the thickness of the photovoltaic front panel 1 is 4-5mm, the thickness of the first PVA film 2 is 200-500 μm, the thickness of the sealing strip 3 is 400-1000 μm, the thickness of the second PVA film 5 is 200-500 μm, and the thickness of the photovoltaic back panel 6 is 3.2-4 mm. Wherein, if the thickness of the first PVA film 2 is too large, the permeability of the solar cell module is influenced, and if the thickness of the first PVA film 2 is too small, the bonding performance is reduced; if the thickness of the photovoltaic front plate 1 is too large, the light transmittance of the solar cell module is affected, and if the thickness of the photovoltaic front plate 1 is too small, the water blocking performance is reduced; if the thickness of the photovoltaic back sheet 6 is too large, the light reflection rate of the solar cell module is affected, and if the thickness of the photovoltaic back sheet 6 is too small, the water blocking performance is reduced.
As shown in fig. 3, this embodiment further provides a method for encapsulating a solar cell, the solar cell is stacked according to the above-mentioned encapsulation structure, for example, the photovoltaic back sheet 6, the second PVA film 5, the solar cell chip 4, the sealant 3, the first PVA film 2, and the photovoltaic front sheet 1 are sequentially stacked from bottom to top to form a solar module to be laminated, and the solar module to be laminated is placed in a laminator, including the following steps:
in the temperature rise stage, heating the part of the laminating machine is started, and the temperature rise range is controlled to be 120-160 ℃;
in the vacuumizing stage, after the solar module to be laminated after the lamination and lamination are finished enters an inner cavity of a laminating machine, vacuumizing is carried out for 400-800S, and the vacuum degree is 5-25 Pa;
a first pressurizing stage, pressurizing the solar module, wherein the pressure is-75 to-65 kPa, and the pressurizing time is 120 to 240S;
a second pressurizing stage, continuously pressurizing the solar assembly, wherein the pressure is-45 to-55 kPa, and the pressurizing time is 120 to 240S;
in the third pressurizing stage, the solar module is continuously pressurized, the pressure is-45 to-35 kPa, and the pressurizing time is 720 to 960S;
and in the cooling stage, the laminated solar module is conveyed to a cooling area through a conveyor belt, the cooling time is 300-600S, and the solar module is cooled to room temperature.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.
The embodiments of the invention are intended to embrace all such alternatives, modifications and variances that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements and the like that may be made without departing from the spirit and principles of the invention are intended to be included within the scope of the invention.