Solar cell, battery assembly, and photovoltaic system

Abstract

The utility model discloses a solar cell, battery assembly and photovoltaic system, single crystal silicon rod has at least one first side, the first side with (111) system crystal face of single crystal silicon rod is parallel. Single crystal silicon wafer is obtained by slicing single crystal silicon rod, and the single crystal silicon wafer has at least one first side, and the first side with (111) system crystal face of single crystal silicon wafer is parallel. The single crystal silicon wafer and the edge of the piece provided by the utility model are even, and the amount of passivation liquid required for passivation edge is less, and the yield of solar cell wafer is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar cell technical field, especially in a kind of monocrystalline silicon rod, silicon wafer, piece, solar cell, battery pack and system. BACKGROUND

[0002] Silicon wafer is the core material of manufacturing solar cell, generally, the preparation steps of silicon wafer are first square of cylindrical silicon rod is carried out, and square rod with square section is obtained, and then the square rod is sliced to obtain silicon wafer.According to the need, the silicon wafer will generally be laser cutting along the edge direction thereof to obtain piece, the more the piece number is, the greater the damage of laser cutting to silicon wafer is, the more silicon loss is, and the longer laser processing time is;Correspondingly, the more passivation liquid required for edge passivation is, and the more time is spent, and the passivation recovery amount is also lower. SUMMARY

[0003] The utility model solves the technical problems in providing a kind of monocrystalline silicon rod, silicon wafer, piece, solar cell, battery pack and system, and the edge of silicon wafer and piece is flat, and the amount of passivation liquid required for passivation edge is less, and the yield of solar cell wafer is high.

[0004] To solve the above technical problems, the utility model provides a kind of monocrystalline silicon rod, the monocrystalline silicon rod has at least one first side, and the first side is parallel to the (111) system crystal face of the monocrystalline silicon rod.

[0005] As the improvement of the above scheme, the first side is flat side.

[0006] As the improvement of the above scheme, the shape of the monocrystalline silicon rod is quadrangular prism, the monocrystalline silicon rod has first side, second side, third side and fourth side, the first side and third side are parallel to each other, and the first side is parallel to the (111) system crystal face of the monocrystalline silicon rod.

[0007] As the improvement of the above scheme, the second side and fourth side are parallel to each other, and the first side and second side are respectively parallel to two adjacent (111) system crystal faces of the monocrystalline silicon rod.

[0008] As the improvement of the above scheme, the bottom surface and top surface of the monocrystalline silicon rod are parallel to each other, and the bottom surface is parallel to the (110) system crystal face of the monocrystalline silicon rod.

[0009] Correspondingly, the utility model also provides a kind of monocrystalline silicon wafer, which is obtained by slicing the above monocrystalline silicon rod.

[0010] As the improvement of the above scheme, the monocrystalline silicon wafer has at least one first side, and the first side is parallel to the (111) system crystal face of the monocrystalline silicon wafer.

[0011] As an improvement to the above scheme, the first side is a straight side.

[0012] As an improvement to the above scheme, the shape of the monocrystalline silicon wafer is quadrilateral, and the monocrystalline silicon wafer has a first side, a second side, a third side and a fourth side. The first side and the third side are parallel to each other, and the first side is parallel to the (111) system crystal plane of the monocrystalline silicon wafer.

[0013] As an improvement to the above scheme, the second side and the fourth side are parallel to each other, and the first side and the second side are respectively parallel to two adjacent (111) crystal planes of the single crystal silicon wafer.

[0014] As an improvement to the above scheme, the surface of the monocrystalline silicon wafer is parallel to the (110) system crystal plane of the monocrystalline silicon wafer.

[0015] Accordingly, this utility model also provides a single-crystal silicon wafer slicing method, wherein the single-crystal silicon wafer slicing method is obtained by the above-mentioned single-crystal silicon wafer splitting.

[0016] As an improvement to the above scheme, the edge of the single-crystal silicon wafer slab is parallel to the (111) system crystal plane of the single-crystal silicon wafer.

[0017] As an improvement to the above scheme, the area of ​​the single-crystal silicon wafer slice is 1 / 2, 1 / 3 or 1 / 4 of the area of ​​the single-crystal silicon wafer.

[0018] Accordingly, this utility model also provides a solar cell, comprising the above-mentioned monocrystalline silicon wafer and / or the above-mentioned monocrystalline silicon wafer slabs.

[0019] Accordingly, this utility model also provides a battery assembly, including the aforementioned solar cell.

[0020] Accordingly, this utility model also provides a photovoltaic system, including the aforementioned battery module.

[0021] The present invention has the following advantages: at least one side of the monocrystalline silicon rod of the present invention is parallel to the (111) crystal plane of the monocrystalline silicon rod. Therefore, at least one side of the silicon wafer obtained by slicing and the wafer obtained by splitting is parallel to the (111) crystal plane of the silicon wafer. As a result, the edge quality of the silicon wafer and / or wafer obtained is good, the amount of passivation liquid required for passivation of the edge is reduced, and the silicon loss during the processing of silicon wafer and / or wafer slicing is low, resulting in a high yield of solar cell wafers. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a cross-section of a round bar cut into a single-crystal silicon bar in the prior art; Figure 2This is a cross-sectional schematic diagram of a round bar cut into a single crystal silicon bar according to the present invention; Figure 3 This is a schematic diagram of the structure of the single-crystal silicon rod provided by this utility model; Figure 4 This is a schematic diagram of the structure of the single-crystal silicon wafer provided by this utility model; Figure 5 This is a schematic diagram of the structure of the single-crystal silicon wafer slab provided by this utility model. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the following will describe this utility model in further detail with reference to the accompanying drawings. It is hereby declared that the terms "up," "down," "left," "right," "front," "back," "inner," and "outer," etc., appearing or about to appear in this document, are based solely on the accompanying drawings and are not intended to specifically limit this utility model.

[0024] Silicon has a cubic zincblende crystal structure. For ease of description, the crystal planes and directions are defined along... <111> The crystal planes of the crystal orientations <1—11>, <11—1>, <111—>, <1—1—1>, <11—1—>, <1—1—>, and <1—1—1—> are (111) series crystal planes, and the corresponding crystal orientations are... <111> Crystal orientation; furthermore, the crystal orientation along the crystal plane is defined. <001> <001—> <010> <01-0> <100> The crystal planes of the <1-00> crystal orientations are (100) system crystal planes, and the corresponding crystal orientations are... <100> Crystal orientation; crystal plane orientation along <110> <1-10>, <11-0>, <1-1-0> <011> <01-1>, <01-1>, <01-1->, <101> The crystal planes of the crystal orientations <1—01>, <101—>, and <1—01—> are (110) system crystal planes, and the corresponding crystal orientations are... <110> Crystal orientation. Among them, <111> The atomic distribution is most uneven in the crystal direction, with a double-layer close-packed surface. The atoms in the double-layer close-packed surface have strong bonding forces, making chemical corrosion difficult and slow. The inter-plane bonding forces are weak, so the crystal is easy to cleave along the (111) system crystal plane. The crystal quality of the exposed surface after cleavage is good.

[0025] like Figure 1 As shown, in the prior art, the edge 11' of the single-crystal silicon rod 1' obtained by cutting a round rod 2' generally has an angle with the (111) system crystal plane. Therefore, when the single-crystal silicon wafer obtained by slicing the single-crystal silicon rod 1' is to be split into half-wafers or multiple wafers, laser cutting is required. The more wafers there are, the greater the damage from laser cutting and the greater the silicon loss. Correspondingly, the more passivation liquid is required for edge passivation of the laser-cut wafers, the more time is spent, and the lower the passivation recovery amount. For example Figure 2 and Figure 3As shown, this embodiment of the present invention provides a monocrystalline silicon rod 1, which has at least one first side surface 11. The first side surface 11 is parallel to the (111) crystal plane of the monocrystalline silicon rod 1. That is, during the process of cutting the monocrystalline silicon rod 1 from the round rod 2, at least one cutting path extends parallel to the (111) crystal plane. After cutting, the monocrystalline silicon rod 1 can naturally cleave along the cutting path, which improves the surface quality of the cut surface, reduces the amount of passivation liquid required for subsequent passivation, and reduces silicon loss during the cutting process, thereby improving the yield of solar cells. In a preferred embodiment, the first side surface 11 is a straight side surface. A straight first side surface 11 has better surface quality, which is beneficial for subsequent passivation treatment and the fabrication of solar cells.

[0026] Optionally, the bottom surface 15 of the monocrystalline silicon rod 1 is perpendicular to the axis of the monocrystalline silicon rod 1. Preferably, the bottom surface 15 and the top surface 16 of the monocrystalline silicon rod 1 are parallel to each other, and the axis of the monocrystalline silicon rod 1 is oriented as follows: <110> The system crystal orientation, that is, the bottom surface 15 is parallel to the (110) system crystal plane of the single crystal silicon rod 1.

[0027] It is understandable that the shape, side length, and number of sides of the bottom surface of the single-crystal silicon rod 1 can be selected according to actual needs. In a preferred embodiment, the single-crystal silicon rod 1 is a quadrangular prism with a first side 11, a second side 12, a third side 13, and a fourth side 14. The first side 11 and the third side 13 are parallel to each other, and the first side 11 is parallel to the (111) crystal plane of the single-crystal silicon rod 1. The single-crystal silicon rod 1 with this structure can provide easier-to-operate sides for subsequent dicing. Cutting along the first side 11 or the third side 13 results in at least one side of the obtained slice having good crystal quality.

[0028] More preferably, the second side 12 and the fourth side 14 are parallel to each other, and the first side 11 and the second side 12 are parallel to two adjacent (111)-system crystal planes of the single-crystal silicon rod 1, respectively. It is understood that both the first side 11 and the second side 14 are parallel to the (111)-system crystal planes, but there must be an angle between them. Therefore, the two (111)-system crystal planes parallel to the first side 11 and the second side 12 are not two (111)-system crystal planes along the exact same crystal orientation. For ease of understanding, the crystal plane parallel to the first side 11 can be defined as the first crystal plane, and the crystal plane parallel to the second side 12 as the second crystal plane. Specifically, the first crystal plane can be a crystal plane with crystal orientation along... <111> The first crystal plane is the crystal plane with the crystal orientation, and the second crystal plane can be the crystal plane along the crystal orientation. <111> Crystal planes of the (111) system other than crystal orientation and <1—1—1—> crystal orientation, such as crystal planes with crystal orientation along <11—1> crystal orientation, crystal planes with crystal orientation along <111—> crystal orientation, etc.

[0029] Correspondingly, such as Figure 4As shown, this embodiment of the present invention also provides a single-crystal silicon wafer 3, which is obtained by slicing the single-crystal silicon rod 1 described above. Specifically, the single-crystal silicon wafer 3 is obtained by slicing the single-crystal silicon rod 1 described above along a direction perpendicular to the bottom surface 15.

[0030] Specifically, the monocrystalline silicon wafer 3 has at least one first side 31, which is parallel to the (111) crystal plane of the monocrystalline silicon wafer 3. The first side 31 facilitates subsequent slicing along the side of the monocrystalline silicon wafer 3. The monocrystalline silicon wafer 3 naturally cleaves along the cutting path parallel to the first side 31, improving the surface quality of the cut surface while reducing silicon loss during the cutting process. Preferably, the first side 31 is a straight side, and the edge of the monocrystalline silicon wafer 3 has better surface quality.

[0031] It is understandable that when the bottom surface 15 of the single crystal silicon rod 1 is parallel to the (110) system crystal plane of the single crystal silicon rod 1, since the single crystal silicon wafer 3 is obtained by slicing the single crystal silicon rod 1 in a direction perpendicular to the bottom surface 15, the surface of the single crystal silicon wafer 3 is parallel to the (110) system crystal plane of the single crystal silicon wafer 3.

[0032] In a preferred embodiment, the monocrystalline silicon wafer 3 is quadrilateral in shape and has a first side 31, a second side 32, a third side 33 and a fourth side 34. The first side 31 and the third side 33 are parallel to each other, and the first side 31 is parallel to the (111) system crystal plane of the monocrystalline silicon wafer 3.

[0033] More preferably, the second side 32 and the fourth side 34 are parallel to each other, and the first side 31 and the second side 32 are parallel to two adjacent (111) crystal planes of the monocrystalline silicon wafer 3, respectively. Since the monocrystalline silicon wafer 3 is obtained by slicing the monocrystalline silicon rod 1, the structure of the monocrystalline silicon wafer 3 and the beneficial effects of the structure are the same as those of the monocrystalline silicon rod 1.

[0034] Correspondingly, such as Figure 5 As shown, this utility model also provides a single-crystal silicon wafer slicing 4, which is obtained by slicing the single-crystal silicon wafer 3 as described above. Specifically, the edge of the single-crystal silicon wafer slicing 4 is parallel to the (111) crystal plane of the single-crystal silicon wafer 3, that is, the single-crystal silicon wafer slicing 4 is obtained by slicing the single-crystal silicon wafer 3 along a direction parallel to the edge. Since the side of the single-crystal silicon rod 1 obtained by cutting is parallel to the (111) crystal plane, the side of the single-crystal silicon wafer 3 obtained by slicing is parallel to the (111) crystal plane. Therefore, when slicing, the silicon wafer cleavage characteristics can be utilized to directly cleave the silicon wafer on the side, without the need for laser cutting. Almost perfect slicing can be achieved at the cleavage point, with almost no silicon loss, and the cleavage surface is flat and smooth. The amount of passivation liquid required for subsequent edge passivation is significantly reduced. Specifically, the area of ​​the single-crystal silicon wafer slicing 4 is 1 / 2, 1 / 3, or 1 / 4 of the area of ​​the single-crystal silicon wafer 3, but is not limited to this.

[0035] Accordingly, this utility model also provides a solar cell, including the aforementioned monocrystalline silicon wafer 3 and / or the aforementioned monocrystalline silicon wafer slab 4. Specifically, the monocrystalline silicon wafer 3 and / or the monocrystalline silicon wafer slab 4 are subjected to diffusion, junction formation, passivation, coating, screen printing, etc., according to the corresponding battery technology, thereby forming a solar cell. The battery technology can be BC technology, PERC technology, etc., selected according to actual needs, and is not specifically limited here.

[0036] Accordingly, this utility model also provides a battery assembly, including a first cover plate, a first adhesive film, at least one battery string, a second adhesive film, and a second cover plate stacked in sequence.

[0037] Specifically, the first cover plate is typically made of a material with high light transmittance and strong weather resistance, including but not limited to glass and polycarbonate. Its main function is to protect the sensitive components inside the battery assembly from external environmental damage, while providing necessary mechanical support to ensure the structural integrity of the battery assembly.

[0038] The first adhesive film is located between the first cover plate and the battery string, and mainly serves to bond and seal, ensuring that the battery assembly will not experience delamination or leakage during long-term use. The materials of the first adhesive film include, but are not limited to, ethylene-vinyl acetate copolymer (EVA) and polyolefin (POE).

[0039] The second adhesive film is located between the battery string and the second cover plate. Similar to the first adhesive film, it mainly serves to bond and seal the battery.

[0040] The second cover is usually made of weather-resistant materials, including but not limited to aluminum plates and backsheet films. Its main function is to protect the back of the battery assembly from the influence of the external environment and provide additional mechanical support. It can also serve as an insulating layer for the battery assembly to ensure safe use.

[0041] The battery string includes the aforementioned solar cells. Each battery string comprises multiple solar cells connected in series. These solar cells can be partially overlapped to form a battery string. The contact areas between the overlaps are not electrically connected; that is, no conductive adhesive or other bonding agent is needed between the overlapping areas. The solar cells are simply overlapped together. Optionally, the solar cells are electrically connected in the form of a single sheet or multiple segments. Series solder strips are provided in the overlapping areas of adjacent solar cells within the battery string to securely connect adjacent solar cells, and these series solder strips connect adjacent solar cells in series. Different battery strings are obtained by connecting them in series and / or in parallel.

[0042] The battery assembly is formed by sequentially laying a first cover plate, a first adhesive film, several battery strings, a second adhesive film, and a second cover plate, followed by lamination. The lamination process includes preheating, pressurized heating, and cooling curing, the purpose of which is to tightly bond multiple layers of component materials under high temperature and pressure to form a single integrated structure. This invention does not specifically limit the lamination process.

[0043] Accordingly, this utility model embodiment also provides a photovoltaic system. It is understood that the photovoltaic system includes at least one battery module as described above. It is also understood that the battery modules can be electrically connected in parallel or in series, depending on actual needs. The photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system grid as an example, the photovoltaic system can include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array can be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0044] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A solar cell, characterized in that, Includes monocrystalline silicon wafers, which are obtained by slicing monocrystalline silicon rods; The single-crystal silicon rod has at least one first side surface, which is parallel to the (111) crystal plane of the single-crystal silicon rod. The monocrystalline silicon wafer has at least one first side edge, which is parallel to the (111) crystal plane of the monocrystalline silicon wafer; The single crystal silicon rod is in the shape of a quadrangular prism. The single crystal silicon rod has a first side, a second side, a third side and a fourth side. The first side and the third side are parallel to each other. The first side is parallel to the (111) crystal plane of the single crystal silicon rod. The second side and the fourth side are parallel to each other, and the first side and the second side are respectively parallel to two adjacent (111) crystal planes of the single crystal silicon rod; The bottom and top surfaces of the single-crystal silicon rod are parallel to each other, and the bottom surface is parallel to the (110) system crystal plane of the single-crystal silicon rod.

2. The solar cell as described in claim 1, characterized in that, The first side is a flat side.

3. The solar cell as described in claim 1, characterized in that, The first side is a straight side.

4. The solar cell as described in claim 1, characterized in that, The single-crystal silicon wafer is quadrilateral in shape and has a first side, a second side, a third side and a fourth side. The first side and the third side are parallel to each other, and the first side is parallel to the (111) crystal plane of the single-crystal silicon wafer.

5. The solar cell as described in claim 4, characterized in that, The second side and the fourth side are parallel to each other, and the first side and the second side are parallel to two adjacent (111) crystal planes of the single crystal silicon wafer, respectively.

6. The solar cell as claimed in claim 1, characterized in that, The surface of the monocrystalline silicon wafer is parallel to the (110) system crystal plane of the monocrystalline silicon wafer.

7. The solar cell according to claim 1, characterized in that, This includes the slicing of monocrystalline silicon wafers, wherein the monocrystalline silicon wafers are obtained by splitting monocrystalline silicon wafers as described in any one of claims 1 to 6.

8. The solar cell as claimed in claim 7, characterized in that, The edges of the single-crystal silicon wafer segments are parallel to the (111) crystal plane of the single-crystal silicon wafer.

9. The solar cell as claimed in claim 7, characterized in that, The area of ​​the single-crystal silicon wafer slices is 1 / 2, 1 / 3, or 1 / 4 of the area of ​​the single-crystal silicon wafer.

10. A battery assembly, characterized in that, Includes the solar cell described in any one of claims 1 to 9.

11. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 10.

Images