CN106206823A - A kind of reflective membrane for improving cell piece generated output and preparation method thereof - Google Patents

Abstract

The invention discloses a reflective film for improving the power generation power of a battery sheet. The reflective film uses a PVC layer (1) as a base material, and a TPU layer (2) is bonded to the front and back of the PVC layer (1). The TPU layer (2) on the front side of the layer (1) is bonded with an ABS layer (3), hot-pressed on the surface of the ABS layer to form a reflective structure (4) that reflects sunlight, and plated on the surface of the reflective structure (4). There is a layer of metal reflective film (5), and a layer of transparent insulating protective layer (6) is evenly sprayed on the surface of the metal reflective film (5). The present invention changes the traditional base materials such as glass fiber and non-environmentally friendly processes such as glue compounding, and makes a reflective strip film with low production cost, environmental protection, anti-aging, corrosion resistance and good insulation performance. It is not only simple in process, easy to operate, The production efficiency of the assembly line is high, which also reduces the production cost, and after compounding without glue, it solves the environmental pollution and higher cost caused by solvent-based glue.

Description

A kind of reflective film for improving the power generation power of battery sheet and its preparation method

technical field

The invention relates to a light-reflecting film for improving the power generation of battery sheets and a preparation method thereof. It belongs to the field of solar photovoltaic.

Background technique

At present, the industrialization of crystalline silicon solar photovoltaic cells has formed a scale, the photovoltaic industry is developing rapidly, and the technology is relatively mature. According to the latest national report data, as of September 2015, my country's cumulative photovoltaic power generation capacity has reached 37.95GW. However, at this stage, because the initial cost of solar photovoltaic power generation is still relatively high, photovoltaic projects must rely on subsidies to achieve profitability. Therefore, improving the conversion efficiency of solar photovoltaic modules and reducing the initial investment cost of photovoltaic projects is a must to achieve "grid parity" for photovoltaic power. one of the ways.

To reduce the initial investment cost and improve the conversion efficiency of photovoltaic modules, in addition to the silicon wafer itself, many manufacturers at home and abroad also use their brains on the manufacturing process. Through the innovation of grid line printing design, innovation and improvement of module manufacturing process technology, innovation of raw material manufacturing and bold trials, cost reduction and efficiency improvement have been achieved. In recent years, the conversion efficiency of solar photovoltaic modules has increased from 14.1 % is increased to 16.2%, and the number of photovoltaic arrays in a 1MW power generation unit can be reduced by 12%. In reducing the cost, the grid design of crystalline silicon cells and the preparation and application of reflective strips are one of the key factors. The design of the grid lines on the light-receiving surface of solar cells is to collect photocurrent to the maximum extent, that is, the thicker and denser the grid lines, the better. However, this will inevitably reduce the light-receiving area of the cells and form a contradiction of high shading. Among the factors affecting the production cost of photovoltaic modules, the cost of silver or silver-aluminum paste for the positive electrode grid of crystalline silicon cells accounts for about 20% of the total cost, while the efficiency of solar photovoltaic power generation is mainly affected by the amount of solar radiation. conversion rate, maximum power tracking and other issues. The ribbons of conventional photovoltaic modules are directly welded on the cells and connect adjacent cells to each other. The ribbon itself has a certain width, which will cover part of the light-receiving area of the cells and affect the light. However, it is impossible to reflect the light on the surface of the soldering strip to improve the utilization rate of light and increase the efficiency of components. The popularization and application of reflective strips also involves the performance, cost performance, preparation process, and production efficiency of the materials selected, so that the reflective strips can be used. Indirectly reduce the unit power generation cost to the greatest extent, and improve the performance comparison of solar photovoltaic power generation. Therefore, it is particularly important to seek a low shading rate, low cost, and high conversion efficiency cell dot busbar interconnected reflective cell assembly and a preparation method thereof.

Contents of the invention

The technical problem to be solved by the present invention is to provide a reflective film and its preparation method for increasing the power generation power of the cell in view of the above-mentioned prior art, which is not only simple in process, easy to operate, high in assembly line production efficiency, but also reduces production cost and environmental protection. pollute.

The technical solution adopted by the present invention to solve the above problems is: a reflective film used to increase the power generation power of the battery sheet. The reflective film uses a PVC layer as the base material, and a thermoplastic polyurethane material is bonded on the front and back of the PVC layer. The formed TPU layer is bonded with an ABS layer on the TPU layer on the front of the PVC layer, and the surface of the ABS layer is hot-pressed to form a reflective structure that reflects sunlight, and a layer of metal reflective film is coated on the surface of the reflective structure. The surface of the reflective film is evenly sprayed with a layer of transparent insulating protective layer.

Preferably, insulating grooves are provided downward from the upper surface of the metal reflective film at positions equidistant from both sides of the reflective film.

The present invention also provides a method for preparing the above-mentioned reflective film, the method comprising the following steps:

Step 1. Melt and compound ABS plastic, thermoplastic polyurethane TPU, PVC and thermoplastic polyurethane TPU into a layered base body in a top-down manner. During melting, the temperature of the heating roller is controlled at 145°C-150°C, and the line speed is 280-300 meters per minute, after cooling, harvest large rolls;

Step 2. Prepare a mirror-surface molded roller. Use the mirror-surface molded roller to heat-press the ABS surface into a reflective structure that reflects solar energy. The temperature of the molded roller is 145-150°C, and the line speed is 280-300 m/min;

Step 3, using an electroplating process to coat a layer of metal reflective film on the surface of the reflective structure in step 2;

Step 4: Spray evenly a layer of transparent polyurethane film on the surface of the electroplated metal reflective film in step 3, the temperature of the polyurethane liquid is 165-170°C, and the nozzle pressure is 2-2.4kg;

Step 5. Cut the laminated, hot-pressed and electroplated reflective film into long strips of a certain size, with a cutting tension of 0.15-0.40kg and a line speed of 380-400 m/min;

Step 6. Etch an insulating groove from the upper surface of the metal reflective film at positions equidistant from both sides of the long reflective film in step 5, and complete the preparation of the reflective strip.

Preferably, the reflective structure in step 2 is an isosceles triangle structure with a base angle of 30-45°, and its density is 10-12 isosceles triangle structures within the range of 1-2.8 mm ² .

Compared with the prior art, the present invention has the advantages of:

1. Adopt novel and unique manufacturing technology of reflective strip film, change the traditional glass fiber and other substrates and use glue compounding and other non-environmental protection technology, and make it low production cost, environmental protection and anti-aging, corrosion resistance and good insulation performance Reflective strip film is not only simple in process, easy to operate, high in assembly line production efficiency, but also reduces production costs, and after compounding without glue, it solves the environmental pollution and higher costs caused by solvent-based glue.

2. Insulation grooves are set at both ends of the reflective strip to avoid possible short circuits between the battery sheets and ensure the safety performance of the battery components.

3. The surface of the metal layer of the reflective strip is sprayed with a transparent insulating layer, which not only ensures that the reflective strip has good insulation performance, but also protects the metal layer of the reflective strip well, improves the anti-aging and corrosion resistance of the metal layer of the reflective strip, and its service life Up to 30 years or more.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

detailed description

Below in conjunction with embodiment the present invention is described in further detail.

Referring to Fig. 1, the present invention relates to a reflective film for increasing the power generation of a battery sheet. The reflective film uses a PVC layer 1 as the base material, and TPU made of thermoplastic polyurethane material is bonded to the front and back of the PVC layer 1. Layer 2, an ABS layer 3 is bonded to the TPU layer 2 on the front side of the PVC layer 1, the overall thickness of the four-layer structure is 120 microns, and the surface of the ABS layer is hot-pressed to form a reflective structure 4 that reflects sunlight, and the reflective structure It is a micro-shaped isosceles triangle structure, or other microstructures, and a layer of metal reflective film 5 is coated on the surface of the reflective structure 4. The thickness of the metal reflective film is 0.35 microns. The insulating protection layer 6 of polyurethane material is provided with insulating groove 7 along the ABS layer from the upper surface of metal reflective film 5 on both sides of reflective film, and the width of described insulating groove 7 is 0.1mm, and depth is 0.2mm, and the insulating groove The main function is to prevent the adjacent cells from being connected through the reflective film, resulting in a short circuit. The TPU layer of the reflective film is to replace the role of glue to heat-fuse the upper and lower layers, and has good transparent insulation performance and strong bonding force. The metal surface layer with micro-shaped isosceles triangle-like concave-convex structure plays a role in projecting its surface. The light is reflected to the front glass and then to the cell, thereby increasing the light utilization rate by 5% and the module power by more than 2.5%. The middle layer is made of ABS and PVC material, which plays the role of strong base and barrier, and forms a firm reflective strip, and through the bonding of the reflective strip and the welding strip, the toughness and strength of the welding strip are enhanced, and the welding strip is reduced. Fractures caused by aging due to the influence of the natural environment prolong the service life of photovoltaic modules.

This embodiment also provides a method for preparing the above-mentioned reflective strip, the method comprising the following steps:

Step 1. Melt and compound ABS plastic, thermoplastic polyurethane TPU, PVC and thermoplastic polyurethane TPU into a layered base body in a top-down manner. The total thickness of the base body is 120 microns, and the temperature of the heating roller is controlled at 145 ℃—150℃, the line speed is 280-300 meters per minute, and after cooling, it can be harvested into large rolls. Compared with glass fiber or other plastic composite layers, the composite has a combination of rigidity and toughness, and has better tensile strength. The peel strength is as high as 25kg/cm, the aging resistance is good, and the service life can exceed 30 years;

Step 2. Prepare the mirror molding roller, use the mirror molding roller to hot-press the ABS surface into a reflective structure that reflects solar energy. 300 m/min, press into 10-12 isosceles triangle structures with a base angle of 30-45° within the range of ^1-2.8mm2 ;

Step 3, using an electroplating process to coat a layer of metal reflective film on the surface of the reflective structure in step 2, wherein the thickness of the metal reflective film is 0.35 microns;

Step 4. Move the large roll of the base body electroplated in step 3 to the polyurethane spraying machine, and evenly spray a layer of transparent polyurethane film (insulation protective layer) on the surface of the metal reflective film to insulate and cover the metal reflective film. Polyurethane spraying The polyurethane liquid temperature in the machine material barrel is 165-170°C, and the nozzle pressure is 2-2.4kg;

Step 5. According to the width specification of the battery string ribbon, use the imported slitting machine to cut the composite, hot-pressed and electroplated reflective film into long strips of a certain size. The cutting tension of the slitting machine is 0.15-0.40kg. The line speed is 380-400 m/min;

Step 6. Use precision laser etching equipment to cut the long reflective film down along the metal reflective film, and etch an insulating groove at a position equidistant from the lateral sides of the long reflective film to complete the reflective strip. Preparation, the width of the engraved insulating groove is 0.1mm, and the depth is 0.2mm. The function of this insulating groove is mainly to prevent the adjacent cells from being connected through the reflective strips, resulting in a short circuit.

After the above-mentioned reflective strips are applied to the battery components, according to tests and calculations, the photovoltaic components of the present invention not only reduce the cost by 5% compared with conventional photovoltaic components, but also reduce the shading surface by 5%, and also improve the light efficiency by 5% and increase the number of components. The power is more than 2.5%, and the innovation in the preparation of the reflective film not only reduces the cost by more than 15%, but also improves the tensile strength and peeling expansion of the reflective film, as well as other performance indicators. At the same time, it also reduces the occurrence of ribbon breakage, prolongs the service life of photovoltaic modules for five years, greatly improves the comprehensive economic benefits, and vigorously promotes the application and development of solar photovoltaic power generation.

In addition to the above-mentioned embodiments, the present invention also includes other implementations, and any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (4)

1. A reflective film used to increase the power generation power of a cell, characterized in that: the reflective film uses a PVC layer (1) as the base material, and is bonded with a thermoplastic polyurethane material on the front and back of the PVC layer (1). The TPU layer (2) is formed, the ABS layer (3) is glued on the TPU layer (2) on the front side of the PVC layer (1), and the surface of the ABS layer is hot-pressed to form a reflective structure (4) that reflects sunlight A metal reflective film (5) is coated on the surface of the reflective structure (4), and a transparent insulating protective layer (6) is evenly sprayed on the surface of the metal reflective film (5). 2. A reflective film for increasing the power generation power of a cell according to claim 1, characterized in that an insulating film is provided downward from the upper surface of the metal reflective film (5) at equidistant positions on both sides of the reflective film. Slot (7). 3. A method for preparing a light-reflective film for improving battery sheet power generation as claimed in claim 2, characterized in that: the method comprises the following steps: Step 1. Melt and compound ABS plastic, thermoplastic polyurethane TPU, PVC and thermoplastic polyurethane TPU into a layered base body in a top-down manner. During melting, the temperature of the heating roller is controlled at 145°C-150°C, and the line speed is 280-300 meters per minute, after cooling, harvest large rolls; Step 2: Prepare the mirror molding roller, use the mirror molding roller to hot-press the ABS surface into a reflective structure that reflects solar energy, the temperature of the molding roller is 145-150°C, and the line speed is 280-300 m/min. Step 3, using an electroplating process to coat a layer of metal reflective film on the surface of the reflective structure in step 2; Step 4: Spray evenly a layer of transparent polyurethane film on the surface of the electroplated metal reflective film in step 3, the temperature of the polyurethane liquid is 165-170°C, and the nozzle pressure is 2-2.4kg; Step 5. Cut the laminated, hot-pressed and electroplated reflective film into long strips of a certain size, with a cutting tension of 0.15-0.40kg and a line speed of 380-400 m/min; Step 6. Etch an insulating groove from the upper surface of the metal reflective film at positions equidistant from both sides of the long reflective film in step 5, and complete the preparation of the reflective strip. 4. A method for preparing a reflective film for increasing power generation of a cell according to claim 3, characterized in that: the reflective structure in step ² is pressed into 10-12 in the range of 1-2.8mm Isosceles triangle structure with a base angle of 30-45°.