Solar cell, cell assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a solar cell, a cell module and a photovoltaic system. The solar cell comprises two opposite surfaces and a plurality of side surfaces, and the side surfaces are located between the two opposite surfaces. A middle area and an edge area are formed on at least one surface, and the edge area surrounds the middle area; a plurality of first suede structures and a plurality of second suede structures are respectively formed in the middle area and the edge area; the second suede structure and the first suede structure are in a cone shape, and the vertex angle of the second suede structure in the first preset proportion is larger than that of the first suede structure. Therefore, the vertex angle of the second suede structure in the first preset proportion in the edge area is larger than the vertex angle of the first suede structure in the middle area, so that the passivation effect of the second suede structure is better, and the antireflection effect of the first suede structure is better; and the photoelectric conversion efficiency of the solar cell is improved on the whole.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of solar cells, and particularly relates to a solar cell, a battery assembly and a photovoltaic system. BACKGROUND

[0002] Solar cell power generation is a sustainable clean energy source, which can convert sunlight into electrical energy by using the photovoltaic effect of a semiconductor p-n junction. In the related art, a solar cell is usually formed with a textured surface to perform antireflection and passivation. However, the current textured surface is difficult to balance antireflection and passivation, resulting in poor photoelectric conversion efficiency of the solar cell.

[0003] Therefore, how to design the textured surface of the solar cell to improve the photoelectric conversion efficiency has become a problem to be solved. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a solar cell, a battery assembly and a photovoltaic system, aiming to solve the problem of how to design the textured surface of the solar cell to improve the photoelectric conversion efficiency.

[0005] The solar cell provided by the present application comprises two opposite surfaces and a plurality of side surfaces, the side surfaces being located between the two opposite surfaces; at least one of the surfaces is formed with an intermediate region and an edge region, the edge region surrounding the intermediate region; the intermediate region and the edge region are respectively formed with a plurality of first textured surface structures and a plurality of second textured surface structures; the second textured surface structures and the first textured surface structures are in the shape of a cone, and the apex angle of the second textured surface structures in a first preset proportion is greater than the apex angle of the first textured surface structures.

[0006] Specifically, the first preset proportion is 50%-100%.

[0007] Specifically, the difference between the maximum value of the apex angle of the second textured surface structures and the maximum value of the apex angle of the first textured surface structures is 0.5°-15°.

[0008] Specifically, the apex angle of at least part of the second textured surface structures is 75°-85°; and / or, the apex angle of at least part of the first textured surface structures is 70°-82°.

[0009] Specifically, the surface comprises a plurality of edges, and the ratio of the width of the edge region to the width of the surface is 1:(5-100).

[0010] Specifically, the edge region is in the shape of a ring and continuously surrounds the intermediate region.

[0011] Specifically, the size of the second textured surface structures in a second preset proportion is smaller than the size of the first textured surface structures.

[0012] Specifically, the second preset proportion is 50%-100%.

[0013] Specifically, the difference between the size of the largest size of the second textured structure and the size of the largest size of the first textured structure is 0.01-3.7 μm.

[0014] The battery assembly provided in the application comprises the solar cell of any one of the above.

[0015] The photovoltaic system provided in the application comprises the battery assembly of any one of the above.

[0016] The solar cell, the battery assembly and the photovoltaic system of the embodiments of the application can make the passivation effect of the second textured structure better and the antireflection effect of the first textured structure better, and overall, improve the photoelectric conversion efficiency of the solar cell, because the top angle of the first preset proportion of the second textured structure located in the edge region is larger than the top angle of the first textured structure located in the middle region. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of a solar cell of an embodiment of the application;

[0018] Figure 2 is a structural schematic diagram of a solar cell of an embodiment of the application;

[0019] Figure 3 is a structural schematic diagram of a solar cell of an embodiment of the application;

[0020] Figure 4 is a SEM electron microscope diagram of a middle region of a solar cell of an embodiment of the application;

[0021] Figure 5 is a SEM electron microscope diagram of a middle region of a solar cell of an embodiment of the application;

[0022] Figure 6 is a SEM electron microscope diagram of an edge region of a solar cell of an embodiment of the application;

[0023] Figure 7 is a SEM electron microscope diagram of an edge region of a solar cell of an embodiment of the application;

[0024] MAIN ELEMENT SYMBOL EXPLANATION:

[0025] solar cell 10, surface 11, edge 110, middle region 111, edge region 112, side surface 12, first textured structure 131, top angle of first textured structure α1, size of first textured structure d1, second textured structure 132, top angle of second textured structure α2, size of second textured structure d2. DETAILED DESCRIPTION

[0026] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar notations denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only and are merely used to explain the present application, and cannot be understood as a limitation to the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and cannot be used to limit the present application.

[0027] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation to the present application.

[0028] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0029] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements or the interaction between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0030] In the present application, unless specifically defined and limited otherwise, "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "over" of a first feature to a second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. "Under", "below" and "underneath" of a first feature to a second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0031] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the application of other processes and / or the use of other materials.

[0032] Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 And Figure 7 , the solar cell 10 of the embodiment of the present application includes two opposite surfaces 11 and a plurality of side surfaces 12, the side surfaces 12 are located between the two opposite surfaces 11; at least one surface 11 is formed with an intermediate region 111 and an edge region 112, the edge region 112 surrounds the intermediate region 111; the intermediate region 111 and the edge region 112 are respectively formed with a plurality of first textured structures 131 and a plurality of second textured structures 132; the second textured structure 132 and the first textured structure 131 are in the shape of a cone, and the top angle α2 of the second textured structure 132 of the first preset proportion is greater than the top angle α1 of the first textured structure 131.

[0033] The solar cell 10 of the embodiment of the present application, because the top angle of the second textured structure 132 of the first preset proportion located in the edge region 112 is greater than the top angle of the first textured structure 131 located in the intermediate region 111, can make the passivation effect of the second textured structure 132 better, and make the antireflection effect of the first textured structure 131 better, which is overall conducive to improving the photoelectric conversion efficiency of the solar cell 10.

[0034] It can be understood that the larger the top angle of the textured structure is, the better the passivation effect is, but the worse the antireflection effect is. In the solar cell 10 of the embodiments of the present application, the second textured structure 132 with a larger top angle is arranged at the edge region 112 with greater damage and recombination and better passivation is required, so that the edge region 112 can be better passivated; meanwhile, the first textured structure 131 with a smaller top angle is arranged at the middle region 111 with relatively smaller damage and recombination, so that the middle region 111 can have a better antireflection effect. In this way, the photoelectric conversion efficiency of the solar cell 10 as a whole is better.

[0035] Specifically, the solar cell 10 can be a PERC cell, an HJT cell, a TopCon cell, an MWT cell, a BC cell, a stacked cell, or the like. The solar cell 10 can be a back contact cell, or a double-sided contact cell. The specific form of the solar cell 10 is not limited herein.

[0036] Specifically, the number of the side surface 12 can be 1, 2, 3, 4, 5, or any other number. In Figure 1 In an example, the number of the side surface 12 is 4. In Figure 2 In an example, the number of the side surface 12 is 8. The specific number of the side surface 12 is not limited herein.

[0037] Specifically, the side surface 12 can also include a middle region and an edge region, the edge region surrounds the middle region, and the middle region and the edge region are respectively formed with two kinds of textures in the form of a cone, and the top angle of the texture of a predetermined proportion of the edge region is greater than the top angle of the texture of the middle region. That is to say, the explanation and description of the middle region 111 and the edge region 112 of the surface 11 can be applicable to the side surface 12. To avoid redundancy, no further description is given herein.

[0038] Specifically, in some examples, one of the two surfaces 11 is formed with the middle region 111 and the edge region 112. In other examples, both of the two surfaces 11 are formed with the middle region 111 and the edge region 112.

[0039] Specifically, the edge region 112 surrounds the middle region 111. It can mean that the edge region 112 is annular and continuously surrounds the middle region 111. It can also mean that the number of the edge region 112 is multiple and dispersively surrounds the middle region 111.

[0040] Specifically, the number of the first textured structure 131 can be 1, 2, 3, 4, 5, or any other number. The number of the second textured structure 132 can be 1, 2, 3, 4, 5, or any other number. No limitation is given herein.

[0041] Specifically, the conical finger nap structure is a structure similar to a cone or a pyramid. For example, a pyramidal structure. Further, the size of the nap structure refers to the width of the base of the cone. For example, the width of the base of the pyramid. It can be understood that when the base shape is irregular, the size can refer to the maximum width of the base, or the width of each position of the base. The width of each position of the base refers to the distance between the position and the opposite position.

[0042] Specifically, the top angle refers to the included angle between two opposite sides 12 of the nap structure.

[0043] In some embodiments, the first preset proportion is 50%-100%. For example, 50%, 52%, 60%, 80%, 90%, or 100%. In this way, the proportion of the second nap structure 132 with a larger top angle is in a suitable range, which can avoid the poor passivation effect of the edge region 112 caused by a small proportion of the second nap structure 132 with a larger top angle, and can ensure the passivation effect of the edge region 112 of the solar cell 10.

[0044] Specifically, the first preset proportion is 80%-90%. For example, 80%, 82%, 85%, 88%, or 90%. In this way, the proportion of the second nap structure 132 with a larger top angle is further optimized, which can ensure the passivation effect of the edge region 112 while reserving a space for the second nap structure 132 with a smaller top angle, and can reduce the process difficulty.

[0045] Please refer to Figure 3 , Figure 5 and Figure 7 In some embodiments, the difference between the maximum value of the top angle α2 of the second nap structure 132 and the maximum value of the top angle α1 of the first nap structure 131 is 0.5°-15°. For example, 0.5°, 0.6°, 1°, 3°, 5°, 10°, 12°, or 15°.

[0046] In this way, the difference between the maximum values of the top angles of the second nap structure 132 and the first nap structure 131 is in a suitable range, which can avoid the poor passivation effect of the edge region 112 or the poor antireflection effect of the middle region 111 caused by a small difference, and can also avoid the large process difficulty and low production efficiency caused by a large difference.

[0047] Please refer to Figure 3 and Figure 5 In some embodiments, the angle of the top angle α1 of at least part of the first nap structure 131 is 70°-82°. For example, 70°, 71°, 75°, 78°, 80°, or 82°.

[0048] In this way, the top angle a1 of the first rough structure 131 is in a proper range, which can avoid the passivation effect being poor due to the top angle a1 of the first rough structure 131 being small, and can avoid the reflection reduction effect being too poor due to the top angle a1 of the first rough structure 131 being too large.

[0049] Specifically, the angle of the top angle a1 of the first rough structure 131 can be 70°-82°. For example, the angle of the top angle a1 of the largest first rough structure 131 is 70°-82°. Alternatively, the angle of the top angle a1 of all the first rough structures 131 is 70°-82°. This is not limited herein.

[0050] Preferably, the angle of the top angle a1 of the first rough structure 131 is 73.9°-79.8°. For example, the angle of the top angle a1 is 73.9°, 74°, 75°, 78°, 79.8°, or 80°. In this way, the angle of the top angle a1 of the first rough structure 131 is further optimized, and the photoelectric conversion efficiency of the battery is further improved as a whole.

[0051] Please refer to Figure 3 and Figure 7 In some embodiments, the angle of the top angle a2 of at least part of the second rough structure 132 is 75°-85°. For example, the angle of the top angle a2 is 75°, 76°, 78°, 80°, 82°, or 85°.

[0052] In this way, the top angle a2 of the second rough structure 132 is in a proper range, which can avoid the passivation effect being too poor due to the top angle a2 of the second rough structure 132 being small, and can avoid the reflection reduction effect being too poor due to the top angle a2 of the second rough structure 132 being too large, and cannot meet the basic reflection reduction requirement of the edge region 112.

[0053] Specifically, the angle of the top angle a2 of the second rough structure 132 can be 75°-85°. For example, the angle of the top angle a2 of the largest second rough structure 132 is 75°-85°. Alternatively, the angle of the top angle a2 of all the second rough structures 132 is 75°-85°. This is not limited herein.

[0054] Preferably, the angle of the top angle a2 of the second rough structure 132 is 80.44°-82.57°. For example, the angle of the top angle a2 is 80.44°, 80.5°, 80.8°, 81°, 81.5°, 82°, or 82.57°. In this way, the angle of the top angle a2 of the second rough structure 132 is further optimized, and the photoelectric conversion efficiency of the battery is further improved as a whole.

[0055] Please refer to Figure 1 and Figure 2In some embodiments, the surface 11 comprises a plurality of edges 110, and the ratio of the width w1 of the edge region 112 to the width w0 of the surface is 1:(5-100). For example, 1:5, 1:8, 1:10, 1:30, 1:50, 1:80, 1:90, 1:100.

[0056] In this way, the ratio of the width w1 of the edge region 112 to the width w0 of the surface is in a suitable range, which can avoid the overall passivation effect being poor due to the width being too small, and can also avoid the passivation effect improving less as the width continues to increase due to the width being too large. In this way, it is beneficial to improve the photoelectric conversion efficiency of the solar cell 10 as a whole.

[0057] Specifically, the width of the edge region 112 and the width of the surface 11 are the sizes of the edge region 112 and the surface 11 in the same direction, respectively.

[0058] Referring to Figure 1 and Figure 2 In some embodiments, the edge region 112 is annular and continuously surrounds the middle region 111.

[0059] In this way, by setting the edge region 112 to be annular, the area near all the edges 110 of the surface 11 is provided with the second textured structure 132 with a larger top corner, thereby ensuring that better passivation is performed at all the edges 110 of the surface 11 without omission or gaps, which is beneficial to improve the photoelectric conversion efficiency of the solar cell 10.

[0060] Referring to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 In some embodiments, the size d2 of the second textured structure 132 of the second predetermined proportion is smaller than the size d1 of the first textured structure 131.

[0061] In this way, the size of at least part of the second textured structure 132 located in the edge region 112 is smaller, so that the passivation effect of the second textured structure 132 can be better. At the same time, the size of at least part of the first textured structure 131 of the middle region 111 is larger, so that the anti-reflection effect of the middle region 111 is better, and more sunlight can be incident to the middle region 111 of the solar cell 10. In this way, it is beneficial to improve the photoelectric conversion efficiency of the solar cell 10.

[0062] As mentioned above, the conical texture refers to a structure similar to a cone or a pyramid. For example, a pyramidal structure. Further, the size of the texture refers to the width of the base of the cone. For example, the width of the base of the pyramid. It can be understood that when the base is irregular, the size can refer to the maximum width of the base or the width of each part of the base.

[0063] Specifically, the second preset ratio is 50%-100%. For example, 50%, 52%, 60%, 80%, 90%, or 100%. In this way, the ratio of the second texture 132 with a smaller size is in an appropriate range, which can avoid poor passivation effect of the edge region 112 caused by a small ratio of the second texture 132 with a smaller size, and ensure the passivation effect of the edge region 112 of the solar cell 10.

[0064] Specifically, the second preset ratio is 80%-90%. For example, 80%, 82%, 85%, 88%, or 90%. In this way, the ratio of the second texture 132 with a smaller size is further optimized, which can reduce the process difficulty while ensuring the passivation effect of the edge region 112 and reserving space for the second texture 132 with a larger size.

[0065] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 In some embodiments, the difference between the size d2 of the second texture 132 with the largest size and the size d1 of the first texture 131 with the largest size is 0.01 μm-3.7 μm. For example, 0.01 μm, 0.02 μm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 3.5 μm, or 3.7 μm.

[0066] In this way, the difference between the size d2 of the second texture 132 with the largest size and the size d1 of the first texture 131 with the largest size is in an appropriate range, which can avoid poor passivation effect of the edge region 112 or poor antireflection effect of the middle region 111 caused by too small difference, and can avoid large process difficulty and low production efficiency caused by too large difference.

[0067] Specifically, the size d1 of at least part of the first texture 131 is 0.3 μm-4 μm. For example, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 2.818 μm, 3 μm, 3.8 μm, or 4 μm. In this way, the size d1 of the first texture 131 is in an appropriate range, which can avoid poor antireflection effect caused by too small size, and can avoid failure to meet the basic antireflection requirement of the middle region 111 caused by too large size. Preferably, the size d1 of the first texture 131 is 2.818 μm.

[0068] Further, the size d1 of the first rough structure 131 can be partially 0.3-4 μm. For example, the size d1 of the largest first rough structure 131 can be 0.3-4 μm. The size d1 of all the first rough structures 131 can also be 0.3-4 μm.

[0069] Specifically, the size d2 of the second rough structure 132 can be 0.3-3 μm. For example, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 1.63 μm, 2 μm, 2.818 μm, 3 μm. In this way, the size d2 of the second rough structure 132 is in a suitable range, which can avoid the situation that the size is too small to meet the basic antireflection requirement of the edge region 112, and also avoid the situation that the size is too large to cause poor passivation effect. Preferably, the size d2 of the second rough structure 132 is 1.63 μm.

[0070] The battery assembly of the embodiment of the application comprises the solar cell 10 of any one of the above.

[0071] The battery assembly of the embodiment of the application can make the passivation effect of the second rough structure 132 better and the antireflection effect of the first rough structure 131 better, and thus improve the photoelectric conversion efficiency of the solar cell 10 as a whole, because the top angle of the second rough structure 132 in the first preset proportion of the edge region 112 is larger than the top angle of the first rough structure 131 in the middle region 111.

[0072] In the embodiment, the plurality of solar cells 10 in the battery assembly can be connected in series to form a cell string, so as to realize the series connection of the current. For example, the solar cells can be connected in series by means of welding strips (bus bars, interconnection strips), conductive back plates, etc.

[0073] It can be understood that in such an embodiment, the battery assembly can further comprise a metal frame, a back plate, photovoltaic glass and a glue film. The glue film can be filled between the front and back surfaces of the solar cell 10, the photovoltaic glass and the adjacent solar cells, and can be a transparent glue with good light transmission and aging resistance, for example, EVA glue film or POE glue film. The specific selection can be made according to the actual situation, which is not limited here.

[0074] The photovoltaic glass can be covered on the adhesive film on the front side of the solar cell 10. The photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of the super white glass can be above 92%, which can protect the solar cell 10 without affecting the efficiency of the solar cell 10 as much as possible. Meanwhile, the adhesive film can bond the photovoltaic glass and the solar cell 10 together, and the presence of the adhesive film can seal and insulate the solar cell 10 and prevent water and moisture.

[0075] The back plate can be attached to the adhesive film on the back side of the solar cell 10. The back plate can protect and support the solar cell 10, has reliable insulation, water resistance, and aging resistance. The back plate can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. The specific setting can be made according to the specific situation, which is not limited here. The whole composed of the back plate, the solar cell 10, the adhesive film, and the photovoltaic glass can be arranged on the metal frame. The metal frame serves as the main external support structure of the entire cell assembly, and can stably support and install the cell assembly. For example, the cell assembly can be installed at the desired installation position through the metal frame.

[0076] The photovoltaic system of the embodiment of the present application includes the above-mentioned cell assembly.

[0077] In the solar cell 10 of the cell assembly, the top angle of the first preset proportion of the second textured structure 132 located in the edge area 112 is greater than the top angle of the first textured structure 131 located in the middle area 111. Therefore, the passivation effect of the second textured structure 132 is better, and the antireflection effect of the first textured structure 131 is better, which is beneficial to improve the photoelectric conversion efficiency of the solar cell 10 as a whole.

[0078] In the embodiment, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc. It can also be applied to devices or apparatuses that use solar energy to generate electricity, such as user solar power sources, solar street lamps, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields that need to use solar energy to generate electricity. Taking a photovoltaic power generation system network 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 cell assemblies. For example, multiple cell assemblies can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box. The combiner box can combine the current generated by the photovoltaic array. The combined current flows through the inverter to convert into alternating current required by the power grid, and then is connected to the power grid to realize solar power supply.

[0079] In the description of the specification, the description of the terms "some embodiments", "exemplary embodiments", "example", "specific example", or "some examples" and the like means that the particular feature, structure, material or characteristic being described is included in at least one embodiment or example of the application. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily intended to refer to the same embodiment or example. Moreover, the particular features, structures, materials or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the above-mentioned terms are not intended to limit the application to a particular embodiment or example. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall fall within the scope of the application.

Claims

1. A solar cell, characterized by, The surface includes two opposite surfaces and a plurality of side surfaces, the side surfaces being located between the two opposite surfaces; at least one of the surfaces is formed with a middle region and an edge region, the edge region surrounding the middle region; the middle region and the edge region are respectively formed with a plurality of first pile structures and a plurality of second pile structures; The second pile structures and the first pile structures are conical, and the apex angle of a first preset proportion of the second pile structures is greater than the apex angle of the first pile structures.

2. The solar cell according to claim 1, characterized in that, The first preset proportion is 50%-100%.

3. The solar cell according to claim 1, characterized in that, The difference between the maximum value of the apex angle of the second pile structures and the maximum value of the apex angle of the first pile structures is 0.5°-15°.

4. The solar cell of claim 1, wherein At least part of the apex angle of the second pile structures is 75°-85°. And / or, at least part of the apex angle of the first pile structures is 70°-82°.

5. The solar cell of claim 1, wherein The ratio of the width of the edge region to the width of the surface is 1:(5-100).

6. The solar cell of claim 1, wherein The edge region is annular and continuously surrounds the middle region.

7. The solar cell of claim 1, wherein A second preset proportion of the second pile structures is smaller in size than the first pile structures.

8. The solar cell according to claim 7, characterized in that, The second preset proportion is 50%-100%.

9. The solar cell of claim 7, wherein, The difference between the size of the largest second pile structure and the size of the largest first pile structure is 0.01-3.7 μm.

10. A battery assembly characterized by, The solar cell comprises any one of claims 1-9.

11. A photovoltaic system characterized by, The battery assembly comprises claim 10.

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