Preparation method of graphene thermal conductive photovoltaic panel assembly and graphene thermal conductive photovoltaic panel assembly

Abstract

The invention discloses a method for preparing a graphene heat-conducting photovoltaic panel assembly, comprising the following steps: S1: forming a first heat-conducting micropore on a front plate glass and a back plate glass; S2: forming a three-dimensional heat-conducting graphene mesh film on the back plate glass; S3: preparing a packaging film; S4: printing a grid-shaped graphene aluminum paste pattern on the packaging film; S5: placing a plurality of groups of welded photovoltaic cells; S6: taking a packaging film on which a graphene aluminum paste pattern is not printed in step S2, covering it on the photovoltaic cell in step S4, and combining it with other components to form a photovoltaic assembly; S7: forming a second heat-conducting micropore, the invention arranges the heat-conducting fillers in the first heat-conducting micropores of the back plate glass and the front plate glass and in the pores of the second heat-conducting micropores in a directional manner, and forms a graphene film on the back plate glass and the front plate glass and cross-links with a longitudinal heat-conducting route to form a three-dimensional heat-conducting network, so as to improve the bonding force of the surface graphene film on the one hand; and on the other hand, the thermal conductivity of the product can be improved by more than 50%.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic panel assemblies, and in particular relates to a method for preparing a graphene thermal conductive photovoltaic panel assembly and a graphene thermal conductive photovoltaic panel assembly. Background Art

[0002] Double-glass photovoltaic modules mainly include photovoltaic cells in the middle, upper glass and lower glass. The upper glass and the lower glass are directly provided with packaging materials, and the photovoltaic cells are fixed between the upper glass and the lower glass through the packaging materials. Tempered glass material as the top material has the characteristics of low cost, firmness, stability, high transparency, waterproofness and gas resistance, and is widely used. However, tempered glass has low light transmittance, generally around 90% at the initial light transmittance. After a period of use, the light transmittance will drop significantly due to dust blocking. At the same time, it is a poor conductor of heat and has a large thermal resistance coefficient. When the temperature is high in summer, the module temperature can reach 70 to 80 degrees Celsius, reducing the power generation efficiency of the photovoltaic module. The above problems seriously reduce the power generation efficiency of the photovoltaic module and make it difficult to clean. Graphene is a high thermal conductivity material. At present, there are many studies on the combination of graphene and photovoltaic module heat dissipation, but only a layer of graphene is coated or deposited on the glass of the photovoltaic module.

[0003] CN104916711 B discloses that ordinary glass is immersed in a graphene dispersion for 30-60 seconds, the glass is taken out and air-dried, and then the glass is placed in a tempering furnace for heating, and then the glass is rapidly cooled to room temperature, and both sides of the glass are rapidly swept with dry cold air, which is divided into a rapid cooling period and a cooling period, and finally cooled to room temperature to produce graphene tempered glass. Through this technical process, the graphene coating is attached to the glass. The obtained product can increase diffusion, reduce reflection effect, and increase the light transmittance of the light-transmitting glass. The graphene film layer has high hydrophilicity, which makes the photovoltaic glass have a self-cleaning function. At the same time, graphene can reduce thermal resistance and photocatalytic effect, and improve light transmission to a certain extent. The power generation efficiency of photovoltaic modules is improved; however, there are the following defects: first, the graphene dispersion is attached to the glass by the impregnation method. Since the graphene and the glass surface are only combined by van der Waals force, the photovoltaic modules will inevitably rub against each other during transportation, so the film is easily rubbed off, causing film defects; in addition, since glass is a poor conductor, even if the graphene layer is attached to the upper and lower surfaces of the glass, there is a glass layer between the two graphene layers, resulting in heat not being able to smoothly dissipate from the inner surface of the glass to the outer surface of the glass, and heat is accumulated, that is, the longitudinal heat dissipation efficiency is not high, which in turn results in the heat of the photovoltaic cell being unable to be dissipated in time, and the heat dissipation efficiency is not significantly improved; Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a graphene thermal conductive photovoltaic panel assembly and a graphene thermal conductive photovoltaic panel assembly to solve the problems raised in the above background technology.

[0005] To solve this technical problem, the technical solution of the present invention is:

[0006] A method for preparing a graphene thermally conductive photovoltaic panel assembly comprises the following steps:

[0007] S1: using laser scanning to perform penetration drilling on the areas corresponding to the photovoltaic cells on the front glass and the back glass to form first heat-conducting micro-holes;

[0008] S2: Three-dimensional thermally conductive graphene mesh film formed on the back glass;

[0009] S3: Take the packaging film, spray the graphene dispersion on the upper and lower surfaces of the packaging film and air-dry it;

[0010] S4: printing a grid-shaped graphene aluminum paste pattern on the encapsulation film; forming a placement area for placing photovoltaic cells in the graphene aluminum paste pattern;

[0011] S5: Take a packaging film printed with a graphene aluminum paste pattern, and place a plurality of groups of welded photovoltaic cells in a regular arrangement on a placement area of ​​the packaging film;

[0012] S6: taking the encapsulation film prepared in step S4, covering the photovoltaic cell in step S5 with the encapsulation film, placing the photovoltaic cell covered with the encapsulation film on the back glass, placing the front glass on the photovoltaic cell covered with the encapsulation film, and then vacuuming and hot pressing to cure the upper and lower encapsulation films to obtain a photovoltaic module;

[0013] S7: laser drilling: along the gaps between the photovoltaic cells, the laser sequentially penetrates the front glass, the upper encapsulation film, the graphene aluminum paste pattern, the lower encapsulation film and the back glass to form a second heat-conducting micropore;

[0014] S8: In the second thermal conductive micropores and the first thermal conductive micropores of the front plate glass, carbon fiber bundle-graphene / photocurable transparent resin filler is scraped and coated for multiple times, and after each scraping, a magnetic arrangement device is used to directional arrange the magnetic graphene-wrapped carbon fiber bundle filler in the first thermal conductive micropores and the second thermal conductive micropores of the front plate glass and then solidify, when the carbon fiber bundle-graphene / photocurable transparent resin filler in the first thermal conductive micropores and the second thermal conductive micropores of the front plate glass is on the same plane as the top surface of the corresponding hole; graphene dispersion is sprayed on the front plate glass, air-dried and then solidified, and the graphene dispersion is cross-linked with the carbon fiber bundle-graphene / photocurable transparent resin filler to form a uniform front three-dimensional thermal conductive graphene membrane mesh.

[0015] Preferably, the method of performing the first thermal conductive micro-hole drilling on the front plate glass and the back plate glass in step S1 comprises the following sub-steps:

[0016] S11: Draw a longitudinal spacing line on the front glass and the back glass, wherein the width of the longitudinal spacing line is slightly larger than the lateral spacing between two adjacent photovoltaic cells;

[0017] The distance between two adjacent longitudinal spacing lines is slightly larger than the width of the photovoltaic cell;

[0018] S12: Draw a horizontal spacing line on the front glass and the back glass, wherein the width of the horizontal spacing line is slightly larger than the vertical spacing between two adjacent photovoltaic cells;

[0019] The distance between two adjacent transverse spacing lines is slightly greater than the height of the photovoltaic cell;

[0020] S13: Punching holes in a grid area surrounded by the longitudinal spacing lines and the transverse spacing lines by using a laser punching machine.

[0021] Preferably, the method for forming a three-dimensional thermally conductive graphene mesh film on the back glass in step S2 comprises the following steps:

[0022] S21: preparing carbon fiber bundle-graphene / light-cured transparent resin filler;

[0023] S22: applying the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back glass for multiple times, aligning them in a directional manner using a magnetic alignment device, and curing them to form a longitudinal heat conductive layer;

[0024] S23: Before the filler on the top of the longitudinal heat conductive layer is cured, a graphene dispersion is sprayed on the surface of the back glass, air-dried and cured, and the graphene layer on the surface of the back glass is cross-linked with the longitudinal heat conductive layer to form a three-dimensional heat conductive graphene mesh film.

[0025] Preferably, the method for preparing carbon fiber bundle-graphene / photocurable transparent resin filler comprises the following sub-steps:

[0026] S211: Magnetic loading of carbon fibers;

[0027] S212: preparing a graphene dispersion: adding graphene oxide prepared by the Hummers method to DMF, performing ultrasonic dispersion and exfoliation to obtain a uniformly dispersed graphene oxide / DMF solution, adding hydrazine to the solution for reduction to obtain a graphene / DMF solution;

[0028] S213: heating the graphene / DMF in an oil bath, adding a magnetically loaded carbon fiber bundle, and ultrasonically vibrating for 12-24 hours to obtain a carbon fiber bundle-graphene suspension;

[0029] S214: dissolving the transparent oligomer in the solvent in a mass ratio of the transparent oligomer to the solvent of 1:1, and performing ultrasonic treatment for 24 hours using an ultrasonic cleaning apparatus with a frequency of 35-45 kHz;

[0030] S215: mixing the carbon fiber bundle-graphene suspension obtained in step S213 with the transparent oligomer / solvent mixture obtained in step S214, and ultrasonicating them for 15-36 hours using an ultrasonic cleaner with a frequency of 35-45 kHz;

[0031] S216: magnetically stirring the mixed solution prepared in step S215 at 20-40° C., adding a photoinitiator / solvent solution, wherein the mass ratio of the photoinitiator to the photocurable resin is 0.01-0.1, and stirring until the solvent is completely evaporated to obtain a carbon fiber bundle-graphene / photocurable transparent resin filler;

[0032] In step S211, the magnetic loading of the carbon fiber is performed using ferric chloride solution and ferrous chloride solution. This is a prior art and will not be described in detail here.

[0033] Preferably, it includes a conveying platform, the conveying platform includes conveying chains on both sides, the conveying chains on both sides are provided with glass clamping devices, the glass clamping device includes a glass placing platform, blocking parts are provided above the two sides of the glass placing platform, a clamping cavity is formed between the blocking parts and the two sides of the glass placing platform, a scraping device, a magnetic arrangement device and a curing box are sequentially arranged along the glass conveying direction, the magnetic arrangement device includes an upper magnetic arrangement device and a lower magnetic arrangement device arranged in the up and down directions of the glass placing platform, the upper magnetic arrangement device and the lower magnetic arrangement device can be away from or close to the glass placing platform, the upper magnetic arrangement device includes a mounting top frame arranged above the conveying platform, a first cylinder is fixed on the mounting top frame, a first electromagnet is provided on the piston rod of the first cylinder, the lower magnetic arrangement device includes a mounting bottom frame arranged below the conveying platform, a second cylinder is fixed on the mounting bottom frame, a second electromagnet is provided on the piston rod of the second cylinder The scraping device includes a third cylinder connected to the mounting top frame through a slider, a scraper is fixed on the piston rod of the third cylinder, and also includes a fourth cylinder fixed on the mounting top frame, the piston rod of the fourth cylinder is fixedly connected to the third cylinder, and the third cylinder is pushed by the fourth cylinder to move laterally along the mounting top frame.

[0034] Preferably, in step S22, the method of scraping the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back glass for multiple times, aligning them in a directional manner using a magnetic alignment device, and curing them to form a longitudinal heat conductive layer comprises the following steps:

[0035] S221: placing the back plate glass on the glass placement platform and clamping and fixing it with a glass clamping device;

[0036] S222: The back plate glass is scraped with the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 by a scraping device, and the microporous glass skeleton after scraping is left to stand for 10-15S. After standing, the height of the filler in the first heat-conducting micropore is lower than the height of the first heat-conducting micropore of the back plate glass; and it is transported to the magnetic arrangement device. At this time, the first magnet and the second magnet are both approached until the first magnet is attached to the top surface of the microporous glass skeleton, and the second magnet is attached to the bottom surface of the glass placement platform, and the graphene-wrapped carbon fiber bundles in the pores of the back plate glass are magnetically arranged, and the magnetic arrangement time is 4S-15S;

[0037] S223: transporting the back plate glass after step S222 to a curing box for curing;

[0038] S224: repeating steps S221 and S222 to continue to stack and form a plurality of second directional heat conducting layers on the first directional heat conducting layer, wherein the sum of the height of the second directional heat conducting layer and the height of the first directional heat conducting layer is lower than the height of the first heat conducting micro-holes of the back plate glass;

[0039] S224: Scrape carbon fiber-graphene photocuring filler on the back panel glass until it is on the same plane as the top surface of the first thermal conductive micropore of the back panel glass, and then transport the back panel back to the magnetic arrangement device. At this time, the first magnet and the second magnet are both close to the back panel glass until the distance between the first magnet and the top surface of the back panel glass is 1-15nm. The second magnet is attached to the bottom surface of the glass placement platform to magnetically arrange the graphene-wrapped carbon fiber bundles in the pores of the back panel glass. The magnetic arrangement time is 4S-10S; the directional arrangement of the filler is completed.

[0040] The present invention adopts a multiple coating method, so that after a single coating, the carbon fibers wrapped by graphene in the back panel glass are not easy to aggregate due to their small number, and are then easily shaped and arranged. In addition, after solidification, a matrix is ​​formed and coated again, so that the graphene-wrapped carbon fiber bundle coating is directionally arranged above the solidified matrix, thereby allowing the graphene-wrapped carbon fibers to achieve longitudinal extension, thereby improving their continuity in the pores of the back panel glass.

[0041] Preferably, the packaging film is an EVA packaging film.

[0042] Preferably, the grid-shaped graphene aluminum paste printing pattern includes horizontal printed lines, the width of the horizontal printed lines is slightly larger than the longitudinal spacing between two adjacent photovoltaic cells; the distance between two adjacent horizontal printed lines is slightly larger than the height of the photovoltaic cell; and also includes longitudinal printed lines, the longitudinal printed lines and the horizontal printed lines are arranged in a cross to form a number of placement areas for placing photovoltaic cells, the width of the longitudinal printed lines is slightly larger than the lateral spacing between two adjacent photovoltaic cells; the distance between two adjacent longitudinal printed lines is slightly larger than the width of the photovoltaic cell.

[0043] Preferably, the height of the graphene aluminum paste pattern lines is the same as the height of the photovoltaic cell sheet.

[0044] Preferably, the graphene aluminum paste is prepared by the following method, comprising the following steps:

[0045] S41: mechanically dispersing the graphene powder and the ball milling medium, placing them in a ball mill, and then filtering, washing, and drying to obtain graphene powder;

[0046] S42: mixing the slurry components, placing the organic carrier in a high-speed disperser, dispersing the graphene powder in the organic carrier while stirring, adding aluminum powder in batches, stirring evenly, and obtaining a mixed slurry;

[0047] S43: grinding the mixed slurry and adjusting the viscosity of the slurry to obtain a finished product.

[0048] The present invention also provides a technical solution, a graphene thermal conductive photovoltaic panel assembly, comprising a plurality of groups of welded photovoltaic cells, a graphene aluminum paste layer formed between each cell, an encapsulation film layer is arranged in the upper and lower directions of the cell and the graphene aluminum paste layer, a graphene layer is sprayed on the outer surface of the encapsulation film layer to form a core, and also comprises a front plate glass and a back plate glass, the front plate glass and the back plate glass are respectively compounded on the upper and lower surfaces of the core; a plurality of first longitudinal thermal conductive layers are formed in the front plate glass and the back plate glass, a second longitudinal thermal conductive layer is formed between adjacent photovoltaic cells, and the second longitudinal thermal conductive layer penetrates the front plate glass, the upper encapsulation film, the graphene aluminum paste pattern, the lower encapsulation film and the back plate glass.

[0049] The above technical solution has the following beneficial effects:

[0050] The present invention arranges the thermal conductive fillers in the first thermal conductive micropores and the second thermal conductive micropores of the back plate glass and the front plate glass in a directional manner, so that a continuous thermal conductive route is formed in the pore from the bottom to the top, and a graphene film is formed on the back plate glass and the front plate glass and cross-linked with the longitudinal thermal conductive route to form a three-dimensional thermal conductive network, on the one hand, the bonding force of the surface graphene film is improved; on the other hand, the thermal conductivity of the product can be increased by more than 50%; and the multiple curing magnetic absorption arrangement method makes the thermal conductive filler more stable and more uniform compared with the existing directional arrangement technology; in addition, a grid-shaped graphene aluminum paste pattern is printed on the packaging film, and the heat of the photovoltaic cell is conducted to the second thermal conductive micropore through the graphene aluminum paste pattern, and a graphene layer is formed on the packaging film, so that the internal heat is easier to be discharged and the thermal conductivity is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic structural diagram of the front glass in the present invention;

[0052] Figure 2 It is a schematic diagram of the partial structure of the graphene thermal conductive photovoltaic panel assembly in the present invention;

[0053] Figure 3 It is a schematic diagram of the structure of the magnetic attraction device in the present invention;

[0054] Figure 4 It is a structural schematic diagram of the glass clamping device in the present invention;

[0055] Figure 5 is a Raman spectrum of the photovoltaic module glass of Example 1 of the present invention before and after the eraser wiping experiment;

[0056] Figure 6 It is a Raman spectrum diagram of the photovoltaic module glass of comparative example 2 in the present invention before and after the eraser wiping experiment. DETAILED DESCRIPTION

[0057] like Figure 1-6 As shown, in order to further explain the technical solution of the present invention, the present invention is described in detail through specific embodiments below.

[0058] Example 1

[0059] A method for preparing a graphene thermally conductive photovoltaic panel assembly comprises the following steps:

[0060] S1: Use laser scanning to penetrate and punch holes in the area corresponding to the photovoltaic cells on the front glass and the back glass to form the first heat-conducting micropores; This link of the present embodiment includes the following sub-steps: S11: Draw longitudinal spacing lines 100 on the front glass and the back glass, the width of the longitudinal spacing lines is slightly larger than the horizontal spacing between two adjacent photovoltaic cells, and in this embodiment, the width of the longitudinal spacing lines is 1.5CM; the distance between two adjacent longitudinal spacing lines is slightly larger than the width of the photovoltaic cells, and in this embodiment, the distance between two adjacent longitudinal spacing lines is 18.5CM; S12 : Draw horizontal spacing lines 101 on the front glass and the back glass, the width of the horizontal spacing lines is slightly larger than the longitudinal spacing between two adjacent photovoltaic cells. In this embodiment, the width of the horizontal spacing lines is 1.5CM; the distance between two adjacent horizontal spacing lines is slightly larger than the height of the photovoltaic cell. In this embodiment, the distance between two adjacent horizontal spacing lines is 18.5CM; S13: Use a laser puncher to punch holes in the grid area surrounded by the longitudinal spacing lines and the horizontal spacing lines. The holes are arranged in a horizontal and longitudinal array, the hole spacing is 3cm, and the hole diameter is 2mm.

[0061] S2: forming a three-dimensional thermally conductive graphene mesh film on the back glass; comprising the following steps:

[0062] S21: Prepare carbon fiber bundle-graphene / photocurable transparent resin filler; it includes the following sub-steps: S211: Magnetic loading of carbon fiber, the magnetic loading of carbon fiber adopts ferric chloride solution and ferrous chloride solution to carry out magnetic loading of carbon fiber. This is the prior art and will not be described in detail here; S212: Prepare graphene dispersion: add graphene oxide prepared by Hummers method into DMF, ultrasonically disperse and peel, and obtain a uniformly dispersed graphene oxide / DMF solution, the mass ratio of graphene oxide / DMF solution is 1:25, hydrazine is added to the solution for reduction, the mass ratio of hydrazine to graphene oxide is 1:1.5, and graphene / DMF solution is obtained; S213: heat graphene / DMF in an oil bath, add magnetically loaded carbon fiber bundle, the mass ratio of carbon fiber bundle to graphene is 1:5; ultrasonically vibrate for 12-24h to obtain carbon Fiber bundle-graphene suspension; S214: according to the mass ratio of high-transparency epoxy resin to tetrahydrofuran solution of 1:1, the high-transparency epoxy resin is dissolved in the tetrahydrofuran solution, and ultrasonic treatment is performed for 24 hours using an ultrasonic cleaner with a frequency of 35-45kHz; S215: the carbon fiber bundle-graphene suspension obtained in step S213 and the high-transparency epoxy resin / tetrahydrofuran solution mixture obtained in step S214 are mixed with each other, and ultrasonic treatment is performed for 15-36 hours using an ultrasonic cleaner with a frequency of 35-45kHz; S216: the mixed solution prepared in step S215 is magnetically stirred at 20-40°C, and a photoinitiator / solvent solution is added, wherein the mass ratio of the photoinitiator to the photocurable resin is 0.01-0.1, and stirring is continued until the solvent is completely volatilized to obtain a carbon fiber bundle-graphene / photocurable transparent resin filler.

[0063] S22: coating the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back glass three times, and aligning them using a magnetic alignment device, and curing them to form a longitudinal heat conductive layer;

[0064] Specifically, the equipment involved includes a conveying platform 200, the conveying platform includes conveying chains 201 on both sides, the conveying chains on both sides are provided with glass clamping devices, the glass clamping device includes a glass placement platform 202, blocking parts 203 are provided above the two sides of the glass placement platform, and a clamping cavity 204 is formed between the blocking parts and the two sides of the glass placement platform. A scraping device 205, a magnetic arrangement device 206 and a curing box 207 are sequentially arranged along the glass conveying direction, and the magnetic arrangement device includes an upper magnetic attraction arranged in the upper and lower directions of the glass placement platform. Arrangement device, and lower magnetic arrangement device, the upper magnetic arrangement device and the lower magnetic arrangement device can be away from or close to the glass placement platform, the upper magnetic arrangement device includes a mounting top frame 210 arranged above the conveying platform, a first cylinder 211 is fixed on the mounting top frame, and a first electromagnet 212 is arranged on the piston rod of the first cylinder, and the lower magnetic arrangement device includes a mounting bottom frame 213 arranged below the conveying platform, a second cylinder 214 is fixed on the mounting bottom frame, and a second electromagnet 215 is arranged on the piston rod of the second cylinder. The scraping device includes a third cylinder 216 connected to the mounting top frame through a slider, a scraper 217 is fixed on the piston rod of the third cylinder, and also includes a fourth cylinder 218 fixed on the mounting top frame, the piston rod of the fourth cylinder is fixedly connected to the third cylinder, and the third cylinder is pushed by the fourth cylinder to move laterally along the mounting top frame.

[0065] The method for forming a longitudinal heat-conducting layer in this embodiment includes the following steps: S221: placing the back panel glass on a glass placing platform and clamping and fixing it with a glass clamping device; S222: scraping the carbon fiber bundle-graphene / photocuring transparent resin filler obtained in step S21 on the back panel glass through a scraping device, and letting the microporous glass skeleton after scraping stand for 10-15S. After standing, the filler height in the first heat-conducting micropore is one-third of the height of the first heat-conducting micropore of the back panel glass; and transporting it to the magnetic arrangement device. At this time, the first magnet and the second magnet are both approached until the first magnet is attached to the top surface of the microporous glass skeleton, and the second magnet is attached to the bottom surface of the glass placing platform, and the graphene-wrapped carbon fiber bundles in the pores of the back panel glass are magnetically arranged, and the magnetic arrangement time is 4S-15S; S223: the back panel glass that has completed step S222 is placed The plate glass is transported to a curing box for curing; S224: repeat steps S221-S222 to continue to stack and form a second directional heat conducting layer on the first directional heat conducting layer, wherein the sum of the height of the second directional heat conducting layer and the height of the first directional heat conducting layer is two-thirds of the height of the first heat conducting micropores of the back plate glass; S224: scrape carbon fiber-graphene photocuring filler on the back plate glass until it is on the same plane as the top surface of the first heat conducting micropores of the back plate glass, and re-transport the back plate to the magnetic arrangement device. At this time, the first magnet and the second magnet are both close to the back plate glass until the distance between the first magnet and the top surface of the back plate glass is 1-15nm, and the second magnet is attached to the bottom surface of the glass placement platform to magnetically arrange the graphene-wrapped carbon fiber bundles in the pores of the back plate glass, and the magnetic arrangement time is 4S-10S; the directional arrangement of the filler is completed.

[0066] S23: Before the filler on the top of the longitudinal heat conductive layer is cured, a graphene dispersion is sprayed on the surface of the back glass, air-dried and cured, and the graphene layer on the surface of the back glass is cross-linked with the longitudinal heat conductive layer to form a three-dimensional heat conductive graphene mesh film.

[0067] S3: Take a packaging film, which is an EVA packaging film, spray a graphene dispersion on the upper and lower surfaces of the packaging film and air-dry it; the graphene dispersion is a graphene / DMF solution prepared in S212;

[0068] S4: Printing a grid-shaped graphene aluminum paste pattern on the encapsulation film; the grid-shaped graphene aluminum paste printing pattern includes horizontal printing lines, the width of the horizontal printing lines is slightly larger than the longitudinal spacing between two adjacent photovoltaic cells; the distance between two adjacent horizontal printing lines is slightly larger than the height of the photovoltaic cell; and also includes longitudinal printing lines, the longitudinal printing lines and the horizontal printing lines are arranged in a cross to form a plurality of placement areas for placing photovoltaic cells, the width of the longitudinal printing lines is slightly larger than the lateral spacing between two adjacent photovoltaic cells; the distance between two adjacent longitudinal printing lines is slightly larger than the height of the photovoltaic cell. The width of the battery cell, the height of the graphene aluminum paste pattern lines is the same as the height of the photovoltaic battery cell, and the graphene aluminum paste is prepared by the following method, including the following steps: S41: mechanically dispersing the graphene powder and the ball milling medium and placing them in a ball mill for ball milling, and then filtering, washing, and drying to obtain the graphene powder; S42: mixing the slurry components, placing the organic carrier in a high-speed disperser, dispersing the graphene powder in the organic carrier while stirring, adding aluminum powder in batches, stirring evenly, to obtain a mixed slurry; S43: grinding the mixed slurry, and adjusting the slurry viscosity to obtain a finished product.

[0069] S5: Take a packaging film printed with a graphene aluminum paste pattern, and place a plurality of groups of welded photovoltaic cells in a regular arrangement on a placement area of ​​the packaging film;

[0070] S6: Take the encapsulation film prepared in step S4, cover the photovoltaic cell in step S5 with the encapsulation film, place the photovoltaic cell covered with the encapsulation film on the back glass, place the front glass on the photovoltaic cell covered with the encapsulation film, and then vacuum and hot press to solidify the upper and lower encapsulation films to obtain a photovoltaic module;

[0071] S7: laser drilling: along the gaps between the photovoltaic cells, the laser sequentially penetrates the front glass, the upper encapsulation film, the graphene aluminum paste pattern, the lower encapsulation film and the back glass to form a second heat-conducting micropore;

[0072] S8: In the second thermal conductive micropore and the first thermal conductive micropore of the front plate glass, carbon fiber bundle-graphene / photocurable transparent resin filler is scraped three times, and after each scraping, a magnetic arrangement device is used to directional arrange the magnetic graphene-wrapped carbon fiber bundle filler in the first thermal conductive micropore of the front plate glass and the second thermal conductive micropore, and then solidify it, when the carbon fiber bundle-graphene / photocurable transparent resin filler in the first thermal conductive micropore of the front plate glass and the second thermal conductive micropore is on the same plane as the top surface of the corresponding hole; spray graphene dispersion on the front plate glass, air-dry and then solidify, the graphene dispersion and carbon fiber bundle-graphene / photocurable transparent resin filler are cross-linked to form a uniform front three-dimensional thermal conductive graphene film mesh. The specific method in this embodiment is the same as the rear three-dimensional thermal conductive graphene film mesh of the back plate glass, which will not be repeated here.

[0073] Example 2

[0074] The difference from Example 1 is that in step S1, the holes are arranged in a horizontal and vertical array, the hole spacing is 3 cm, and the hole diameter is 4 mm;

[0075] Example 3

[0076] The difference from Example 1 is that in step S1, the holes are arranged in a horizontal and vertical array, the hole spacing is 3 cm, and the hole diameter is 6 mm;

[0077] Example 4

[0078] The difference from Example 1 is that in step S1, the holes are arranged in a horizontal and vertical array, the hole spacing is 3 cm, and the hole diameter is 8 mm;

[0079] Example 5

[0080] The difference from Example 3 is that in step S1, the holes are arranged in a horizontal and vertical array, the hole spacing is 2 cm, and the hole diameter is 6 mm;

[0081] Example 6

[0082] The difference from Example 3 is that in step S1, the holes are arranged in a horizontal and vertical array, the hole spacing is 4 cm, and the hole diameter is 6 mm;

[0083] Example 7

[0084] The difference from Example 3 is that: the packaging film in step S3 is an EVA packaging film, and the graphene dispersion is not sprayed on the upper and lower surfaces of the packaging film;

[0085] Comparative Example 1

[0086] The remaining steps in this embodiment are the same as those in Embodiment 3, except that when forming the longitudinal heat conduction channel inside the back glass and the front glass, the heat conduction channel is formed by one-time coating and one-time curing.

[0087] Comparative Example 2

[0088] The remaining steps in this embodiment are the same as those in Embodiment 3, except that the graphene film is formed only on the surfaces of the back glass and the front glass by spraying, and no longitudinal heat conduction channel is formed inside the back glass and the front glass.

[0089] Comparative Example 3

[0090] In this embodiment, ordinary EVA packaging film is used as the bonding layer, and graphene dispersion is not sprayed on its surface to form a graphene film; and a grid-shaped graphene aluminum paste pattern is not printed on the packaging film. At the same time, the graphene film is only formed on the surface of the back glass and the front glass by spraying, and no longitudinal heat conduction channel is formed inside the back glass and the front glass.

[0091] Experimental results: The thermal conductivity of Examples 1-7 and Comparative Examples 1-2 was tested along the length arrangement direction of the graphene wrapped carbon fiber bundles; the thermal conductivity was tested using a C-THERM TCI instrument using the ASTM D7984 standard for the thermal conductivity of high thermal conductivity graphene heat dissipation materials.

[0092] The test results are shown in Table 1.

[0093] Table 1

[0094] Group Thermal conductivity (W / mK) Example 1 723 Example 2 745 Example 3 845 Example 4 923 Example 5 1033 Example 6 738 Example 7 665 Comparative Example 1 616 Comparative Example 2 477 Comparative Example 3 416

[0095] Transmittance measurement:

[0096] Table 2

[0097]

[0098]

[0099] As shown in Table 1, by directional arrangement of the graphene-wrapped carbon fiber bundles in the pores of the backplane glass, the graphene-wrapped carbon fiber bundles form a continuous heat conduction route from the bottom to the top in the pores of the backplane glass, and the thermal conductivity coefficient can be increased by more than 50%, which greatly improves the thermal conductivity of the photovoltaic module.

[0100] By comparing Example 1 to Example 4, it can be seen that as the aperture of the back glass and the front glass increases, the thermal conductivity of the photovoltaic module first increases and then tends to be flat, proving that when the aperture of the glass pore is 6 mm, the carbon fiber bundle-graphene / photocurable transparent resin filler is easier to level in the pore, and the graphene-wrapped carbon fiber bundle has better dispersion, which is easy to improve the arrangement effect of the overall product;

[0101] By comparing Example 3 with Examples 5 and 6, it can be seen that the smaller the hole spacing is, the higher the thermal conductivity of the product is. However, it can be seen from Table 2 that its light transmittance will be reduced; therefore, the best hole spacing is 3 cm.

[0102] By comparing Example 1 with Comparative Example 1, it can be seen that the multiple curing magnetic attraction arrangement makes the thermal conductivity path of the graphene-wrapped carbon fiber bundle more continuous than that of one-time molding, so as to improve its thermal conductivity; by comparing Example 1 with Comparative Example 2, it can be seen that the longitudinal thermal conduction channel formed inside the back glass and the front glass can significantly improve the thermal conductivity efficiency of the photovoltaic module; by comparing Comparative Example 2 with Comparative Example 3, it can be seen that the EVA encapsulation film is used as a bonding layer, and a graphene dispersion is sprayed on its surface to form a graphene film; and a grid-like graphene aluminum paste pattern is printed on the encapsulation film; the thermal conductivity efficiency of the photovoltaic module can be improved.

[0103] This test example is used to characterize the interfacial bonding strength between the graphene film of Example 1 and Comparative Example 2 and glass.

[0104] The front glass plates of the photovoltaic modules of Example 1 and Comparative Example 2 were subjected to an eraser wiping experiment. The test method was to use a 4B eraser to wipe the front glass plate samples of the photovoltaic modules of Example 1 and Comparative Example 2 back and forth 10 times with the same force; the surface resistance and Raman signal of the samples to be tested before and after wiping were measured;

[0105]

[0106]

[0107] According to the analysis, the Raman signal of the three-dimensional thermal conductive graphene film mesh glass formed in Example 1 has no significant change before and after wiping. Compared with before wiping, the sample only has a decrease in 2D value after wiping, and the surface resistance has a slight increase, indicating that the structure of the graphene layer on the glass surface has no significant change; while the Raman signal of the photovoltaic module front plate glass of Comparative Example 2 has a large change before and after wiping. Compared with before wiping, the signal intensity of the graphene relative to the substrate is significantly weakened after wiping, and the 2D peak almost disappears. The surface resistance shows no conductivity, indicating that the graphene layer on the glass surface is severely damaged during the wiping process. This qualitative experiment shows that the bonding strength between the formed three-dimensional thermal conductive graphene film mesh and the glass substrate is improved.

[0108] The purpose of the present invention is also to provide a graphene thermal conductive photovoltaic panel assembly prepared by the above method, comprising a plurality of groups of welded photovoltaic cells 400, a graphene aluminum paste layer 401 formed between each cell, a packaging film layer 402 is arranged in the upper and lower directions of the cell and the graphene aluminum paste layer, a graphene layer is sprayed on the outer surface of the packaging film layer to form a core, and also comprises a front plate glass 404 and a back plate glass 405, the front plate glass and the back plate glass are respectively compounded on the upper and lower surfaces of the core; a plurality of first longitudinal thermal conductive layers 406 are formed in the front plate glass and the back plate glass, a second longitudinal thermal conductive layer 407 is formed between adjacent photovoltaic cells, and the second longitudinal thermal conductive layer penetrates the front plate glass, the upper packaging film, the graphene aluminum paste pattern, the lower packaging film and the back plate glass.

Claims

1. A method for preparing a graphene thermally conductive photovoltaic panel assembly, characterized in that: The steps include: S1: using laser scanning to perform penetration drilling on the areas corresponding to the photovoltaic cells on the front glass and the back glass to form first heat-conducting micro-holes; S2: Three-dimensional thermally conductive graphene mesh film formed on the back glass; S3: Take the packaging film, spray the graphene dispersion on the upper and lower surfaces of the packaging film and air-dry it; S4: printing a grid-shaped graphene aluminum paste pattern on the encapsulation film; forming a placement area for placing photovoltaic cells in the graphene aluminum paste pattern; S5: Take a packaging film printed with a graphene aluminum paste pattern, and place a plurality of groups of welded photovoltaic cells in a regular arrangement on a placement area of ​​the packaging film; S6: Take the encapsulation film prepared in step S4, cover the photovoltaic cell in step S5 with the encapsulation film, place the photovoltaic cell covered with the encapsulation film on the back glass, place the front glass on the photovoltaic cell covered with the encapsulation film, and then vacuum and hot press to solidify the upper and lower encapsulation films to obtain a photovoltaic module; S7: laser drilling: along the gaps between the photovoltaic cells, the laser sequentially penetrates the front glass, the upper encapsulation film, the graphene aluminum paste pattern, the lower encapsulation film and the back glass to form a second heat-conducting micropore; S8: In the second thermal conductive micropores and the first thermal conductive micropores of the front plate glass, carbon fiber bundle-graphene / photocurable transparent resin filler is scraped and coated for multiple times, and after each scraping, a magnetic arrangement device is used to directional arrange the magnetic graphene-wrapped carbon fiber bundle filler in the first thermal conductive micropores and the second thermal conductive micropores of the front plate glass and then solidify, when the carbon fiber bundle-graphene / photocurable transparent resin filler in the first thermal conductive micropores and the second thermal conductive micropores of the front plate glass is on the same plane as the top surface of the corresponding hole; graphene dispersion is sprayed on the front plate glass, air-dried and then solidified, and the graphene dispersion is cross-linked with the carbon fiber bundle-graphene / photocurable transparent resin filler to form a uniform front three-dimensional thermal conductive graphene membrane mesh.

2. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 1, characterized in that: The method of performing the first heat-conducting micro-hole drilling on the front plate glass and the back plate glass in step S1 includes the following sub-steps: S11: Draw a longitudinal spacing line on the front glass and the back glass, wherein the width of the longitudinal spacing line is slightly larger than the lateral spacing between two adjacent photovoltaic cells; The distance between two adjacent longitudinal spacing lines is slightly larger than the width of the photovoltaic cell; S12: Draw a horizontal spacing line on the front glass and the back glass, wherein the width of the horizontal spacing line is slightly larger than the vertical spacing between two adjacent photovoltaic cells; The distance between two adjacent transverse spacing lines is slightly greater than the height of the photovoltaic cell; S13: Punching holes in a grid area surrounded by the longitudinal spacing lines and the transverse spacing lines by using a laser punching machine.

3. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 1, characterized in that: The method for forming a three-dimensional thermally conductive graphene mesh film on the back plate glass in step S2 comprises the following steps: S21: preparing carbon fiber bundle-graphene / light-cured transparent resin filler; S22: applying the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back glass for multiple times, aligning them in a directional manner using a magnetic alignment device, and curing them to form a longitudinal heat conductive layer; S23: Before the filler on the top of the longitudinal heat conductive layer is cured, a graphene dispersion is sprayed on the surface of the back glass, air-dried and cured, and the graphene layer on the surface of the back glass is cross-linked with the longitudinal heat conductive layer to form a three-dimensional heat conductive graphene mesh film.

4. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 3, characterized in that: The method for preparing carbon fiber bundle-graphene / photocurable transparent resin filler comprises the following sub-steps: S211: Magnetic loading of carbon fibers; S212: preparing a graphene dispersion: adding graphene oxide prepared by the Hummers method to DMF, performing ultrasonic dispersion and exfoliation to obtain a uniformly dispersed graphene oxide / DMF solution, adding hydrazine to the solution for reduction to obtain a graphene / DMF solution; S213: heating the graphene / DMF in an oil bath, adding a magnetically loaded carbon fiber bundle, and ultrasonically vibrating for 12-24 hours to obtain a carbon fiber bundle-graphene suspension; S214: dissolving the transparent oligomer in the solvent in a mass ratio of the transparent oligomer to the solvent of 1:1, and performing ultrasonic treatment for 24 hours using an ultrasonic cleaning apparatus with a frequency of 35-45 kHz; S215: mixing the carbon fiber bundle-graphene suspension obtained in step S213 with the transparent oligomer / solvent mixture obtained in step S214, and ultrasonicating them for 15-36 hours using an ultrasonic cleaner with a frequency of 35-45 kHz; S216: The mixed solution prepared in step S215 is magnetically stirred at 20-40° C., and a photoinitiator / solvent solution is added, wherein the mass ratio of the photoinitiator to the photocurable resin is 0.01-0.1, and the mixture is stirred until the solvent is completely evaporated to obtain a carbon fiber bundle-graphene / photocurable transparent resin filler.

5. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 1, characterized in that: The invention comprises a conveying platform, wherein the conveying platform comprises conveying chains on both sides, and glass clamping devices are arranged on the conveying chains on both sides, and the glass clamping device comprises a glass placing platform, and blocking parts are arranged above the two sides of the glass placing platform, and a clamping cavity is formed between the blocking parts and the two sides of the glass placing platform, and a scraping device, a magnetic arrangement device and a curing box are arranged in sequence along the glass conveying direction, and the magnetic arrangement device comprises an upper magnetic arrangement device and a lower magnetic arrangement device arranged in the upper and lower directions of the glass placing platform, and the upper magnetic arrangement device and the lower magnetic arrangement device can be away from or close to the glass placing platform, and the upper magnetic arrangement device comprises a A mounting frame above the conveying platform, a first cylinder is fixed on the mounting frame, a first electromagnet is arranged on the piston rod of the first cylinder, the lower magnetic arrangement device includes a mounting base frame arranged below the conveying platform, a second cylinder is fixed on the mounting base frame, a second electromagnet is arranged on the piston rod of the second cylinder, the scraping device includes a third cylinder connected to the mounting frame through a slider, a scraper is fixed on the piston rod of the third cylinder, and also includes a fourth cylinder fixed on the mounting frame, the piston rod of the fourth cylinder is fixedly connected to the third cylinder, and the third cylinder is pushed by the fourth cylinder to move laterally along the mounting frame.

6. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 5, characterized in that: In step S22, the method of scraping the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back glass for multiple times, aligning them in a directional manner using a magnetic alignment device, and curing them to form a longitudinal heat conductive layer includes the following steps: S221: placing the back plate glass on the glass placement platform and clamping and fixing it with a glass clamping device; S222: scraping the carbon fiber bundle-graphene / photocurable transparent resin filler obtained in step S21 on the back plate glass by a scraping device, and letting the microporous glass skeleton after scraping stand for 10-15 seconds. After standing, the height of the filler in the first heat-conducting micropore is lower than the height of the first heat-conducting micropore of the back plate glass; And transported to the magnetic alignment device, at this time, the first magnet and the second magnet are close to each other until the first magnet is attached to the top surface of the microporous glass skeleton, and the second magnet is attached to the bottom surface of the glass placement platform, and the graphene-wrapped carbon fiber bundles in the pores of the back plate glass are magnetically aligned, and the magnetic alignment time is 4S-15S; S223: transporting the back plate glass after step S222 to a curing box for curing; S224: repeating steps S221 and S222 to continue to stack and form a plurality of second directional heat conducting layers on the first directional heat conducting layer, wherein the sum of the height of the second directional heat conducting layer and the height of the first directional heat conducting layer is lower than the height of the first heat conducting micro-holes of the back plate glass; S224: Scrape carbon fiber-graphene photocuring filler on the back panel glass until it is on the same plane as the top surface of the first thermal conductive micropore of the back panel glass, and then transport the back panel back to the magnetic arrangement device. At this time, the first magnet and the second magnet are both close to the back panel glass until the distance between the first magnet and the top surface of the back panel glass is 1-15nm. The second magnet is attached to the bottom surface of the glass placement platform to magnetically arrange the graphene-wrapped carbon fiber bundles in the pores of the back panel glass. The magnetic arrangement time is 4S-10S; the directional arrangement of the filler is completed.

7. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 1, characterized in that: The grid-shaped graphene aluminum paste printing pattern includes horizontal printing lines, the width of the horizontal printing lines is slightly larger than the longitudinal spacing between two adjacent photovoltaic cells; the distance between two adjacent horizontal printing lines is slightly larger than the height of the photovoltaic cell; it also includes longitudinal printing lines, the longitudinal printing lines and the horizontal printing lines are arranged in a cross to form a number of placement areas for placing photovoltaic cells, the width of the longitudinal printing lines is slightly larger than the lateral spacing between two adjacent photovoltaic cells; the distance between two adjacent longitudinal printing lines is slightly larger than the width of the photovoltaic cell.

8. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 7, characterized in that: The height of the graphene aluminum paste pattern lines is the same as the height of the photovoltaic cell.

9. The method for preparing a graphene thermally conductive photovoltaic panel assembly according to claim 1, characterized in that: The graphene aluminum paste is prepared by the following method, comprising the following steps: S41: mechanically dispersing the graphene powder and the ball milling medium, placing them in a ball mill, and then filtering, washing, and drying to obtain graphene powder; S42: mixing the slurry components, placing the organic carrier in a high-speed disperser, dispersing the graphene powder in the organic carrier while stirring, adding aluminum powder in batches, stirring evenly, and obtaining a mixed slurry; S43: grinding the mixed slurry and adjusting the viscosity of the slurry to obtain a finished product.

10. A graphene thermally conductive photovoltaic panel assembly, characterized in that: The invention comprises a plurality of groups of welded photovoltaic cells, wherein a graphene aluminum paste layer is formed between each cell, and an encapsulation film layer is arranged on the upper and lower directions of the cell and the graphene aluminum paste layer, and a graphene layer is sprayed on the outer surface of the encapsulation film layer to form a core body, and also comprises a front plate glass and a back plate glass, wherein the front plate glass and the back plate glass are respectively compounded on the upper and lower surfaces of the core body; a plurality of first longitudinal heat conductive layers are formed in the front plate glass and the back plate glass, and a second longitudinal heat conductive layer is formed between adjacent photovoltaic cells, and the second longitudinal heat conductive layer penetrates the front plate glass, the upper encapsulation film, the graphene aluminum paste pattern, the lower encapsulation film and the back plate glass.

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