Solar cell, cell assembly and photovoltaic system

Abstract

The invention provides a solar cell, a cell assembly and a photovoltaic system. The solar cell comprises a first surface and a second surface which are opposite to each other, and a cutting side surface connecting the first surface and the second surface; a plurality of first texture structures are formed on the cutting side surface, the included angle between the extension direction of the first texture structures and the thickness direction of the solar cell is a first included angle, and the first included angle is smaller than or equal to 70 degrees. According to the solar cell provided by the embodiment of the invention, the included angle between the extension direction of the first texture structure in the cutting side surface and the thickness direction of the solar cell is smaller than or equal to 70 degrees, so that the specific surface area of the cutting side surface can be reduced, and when the cutting side surface is passivated, the passivation film can cover the cutting side surface more uniformly; and the recombination loss of the cutting side surface is reduced.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a solar cell, a battery assembly and a photovoltaic system. Background Art

[0002] In the related art, a solar cell is usually cut to cut the entire solar cell into at least two sliced ​​solar cells, for example, two sliced ​​solar cells. These sliced ​​solar cells are used to make a battery module. However, in the process of cutting the solar cell to form a sliced ​​solar cell, cutting loss occurs, which affects the efficiency of the battery module.

[0003] Based on this, how to reduce the cutting loss of solar cells has become an urgent problem to be solved. Summary of the invention

[0004] The invention provides a solar cell, a cell assembly and a photovoltaic system to solve the technical problem of how to reduce the cutting loss of the solar cell.

[0005] The embodiment of the present invention is implemented as follows: the present invention provides a solar cell, a battery assembly and a photovoltaic system. A solar cell comprises a first surface and a second surface opposite to each other, and a cut side surface connecting the first surface and the second surface, wherein the first surface is a light-facing surface, the second surface is a backlight surface, and the cut side surface is formed with a plurality of first texture structures, wherein the angle between the extension direction of the first texture structure and the thickness direction of the solar cell is a first angle, and the first angle is less than or equal to 70°.

[0006] Furthermore, the first angle is 0° to 45°.

[0007] Furthermore, a plurality of second texture structures and a plurality of crack structures are formed on the cut side surface, the extension direction of the crack structure intersects with the cut side surface, the second texture structure is located on the side of the crack structure facing the cut side surface, the extension direction of the second texture structure and the thickness direction of the solar cell form a second angle, and the second angle is greater than the first angle.

[0008] Furthermore, the second angle is 30° to 80°.

[0009] Further, the first texture structure or the second texture structure includes a plurality of protrusions, and in a direction perpendicular to the cut side surface, a height difference between the highest protrusion and the lowest protrusion is less than or equal to 5 μm.

[0010] Furthermore, a height difference between the highest protrusion and the lowest protrusion of the first texture structure is greater than a height difference between the highest protrusion and the lowest protrusion of the second texture structure.

[0011] Further, in a direction perpendicular to the cut side surface, a height of the protrusion is less than or equal to 50 μm.

[0012] Furthermore, the crack structure is located in a region of the cut side surface close to the second surface of the solar cell.

[0013] Furthermore, the crack structure is located in a region of the cut side surface close to the second surface of the solar cell.

[0014] Furthermore, the length of the first texture structure is 100 μm to 650 μm.

[0015] Further, in the length direction of the cut side surface, a distance between two adjacent first texture structures is 0.2 μm to 3 μm.

[0016] The cutting side surface comprises a first groove region, a middle region and a second groove region which are sequentially arranged along the length direction of the cutting side surface, and the plurality of first texture structures are all located in the middle region.

[0017] An embodiment of the present invention further provides a battery assembly, which includes the solar cell as described above.

[0018] An embodiment of the present invention further provides a photovoltaic system, which includes the battery assembly as described above.

[0019] The solar cell in the embodiment of the present invention can reduce the specific surface area of ​​the cut side surface because the angle between the extension direction of the first texture structure in the cut side surface and the thickness direction of the solar cell is less than or equal to 70°. When the cut side surface is passivated, the passivation film can cover the cut side surface more evenly, thereby reducing the recombination loss of the cut side surface and improving the efficiency of the battery assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic diagram of a module of a photovoltaic system provided by an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of a module of a battery assembly provided by an embodiment of the present invention;

[0023] Figure 3 is a partial structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0024] Figure 4 is a partial structural schematic diagram of a solar cell provided by another embodiment of the present invention;

[0025] Figure 5 is a partial structural diagram of a first texture structure provided by an embodiment of the present invention;

[0026] Figure 6 is a partial structural schematic diagram of a cut side surface in a solar cell provided by another embodiment of the present invention;

[0027] Figure 7 is a partial structural schematic diagram of a cut side surface in a solar cell provided by another embodiment of the present invention;

[0028] Figure 8 is a partial structural schematic diagram of a cut side surface in a solar cell provided by another embodiment of the present invention;

[0029] Fig. 9 is a SEM image of a partially cut side surface of a solar cell provided by another embodiment of the present invention;

[0030] Fig.10 FIG. 4 is a SEM image of a partially cut side surface of a solar cell provided in another embodiment of the present invention.

[0031] Explanation of main component symbols: 1000, photovoltaic system; 1001, battery assembly; 100, solar cell; 10, first side; 20, second side; 30, cutting side surface; 301, first texture structure; 302, second texture structure; 303, crack structure; 3011, protrusion; 3012, first endpoint; 3013; second endpoint; 31, first groove area; 32, middle area; 33, second groove area; α1, first angle; α2, second angle. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "top", "bottom", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0037] See also Figure 1 and Figure 2 The photovoltaic system 1000 in the embodiment of the present invention may include the battery assembly 1001 in the embodiment of the present invention. The battery assembly 1001 in the embodiment of the present invention may include a plurality of solar cells 100. The plurality of solar cells 100 may be connected in series in sequence through welding strips to form a battery string. The battery strings in the battery assembly 1001 may be connected in series, in parallel, or in series-parallel combination to realize the current bus output. For example, the connection between the battery strings may be realized through a bus bar.

[0038] The drawings provided in this application are schematic diagrams, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solution and highlight the key points of the invention. It is not intended to limit the technical solution to not include these unshown elements. In other words, the drawings are only examples and do not represent a limitation on the specific form of the solar cell 100.

[0039] like Figures 3 to 10 As shown, the solar cell 100 in the embodiment of the present invention can be cut from a whole solar cell 100. After the solar cell 100 is cut, at least two solar cells 100 can be cut.

[0040] The solar cell 100 includes a first surface 10 and a second surface 20 opposite to each other, and a cut side surface 30 connecting the first surface 10 and the second surface 20. The first surface 10 is a light-facing surface, and the second surface 20 is a light-receiving surface.

[0041] The solar cell 100 has at least one cutting side surface 30, for example, the number of the cutting side surfaces 30 may be one, two, three or four. During the cutting process of the solar cell 100, mechanical cutting or laser irradiation may be used to cause certain damage to the first surface 10 or the second surface 20 of the solar cell 100, and then the entire solar cell 100 is broken by stress change, thereby forming a cutting side surface 30 of a complete solar cell 100. The cutting side surface 30 includes opposite cutting edges and breaking edges, the cutting edges are formed by mechanical cutting or laser irradiation, and the breaking edges are formed by breaking the solar cell 100.

[0042] like Figure 3 As shown, a plurality of first texture structures 301 are formed on the cut side surface 30 of the solar cell 100 , and the angle between the extension direction of the first texture structure 301 and the thickness direction of the solar cell 100 is a first angle α1 , which is less than or equal to 70°.

[0043] In this way, the solar cell 100 in the embodiment of the present invention can reduce the specific surface area of ​​the cut side surface 30 because the angle between the extension direction of the first texture structure 301 in the cut side surface 30 and the thickness direction of the solar cell 100 is less than or equal to 70°. When the cut side surface 30 is passivated, the passivation film can cover the cut side surface 30 more evenly, thereby reducing the recombination loss of the cut side surface 30 and improving the efficiency of the battery assembly 1001.

[0044] At the same time, the first angle α1 is less than or equal to 70, which can also reduce surface defects of the cut side surface 30, reduce cutting losses of the solar cell 100, and improve the efficiency of the battery assembly 1001. In addition, the arrangement of each first texture structure 301 in the cut side surface 30 can be made more regular, which can improve the film quality when the cut side surface 30 is subsequently passivated, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0045] Specifically, Figures 3 to 9 As shown, the extension direction of the first texture structure 301 specifically refers to the propagation path or texture direction of the first texture structure 301. The thickness direction of the solar cell 100 may also be the height direction of the solar cell 100 when it is naturally placed. In the embodiment of the present invention, the thickness direction of the solar cell 100 is parallel to the vertical direction for illustration.

[0046] It is worth noting that the angle between the extension direction of the first texture structure 301 and the thickness direction of the solar cell 100 specifically refers to a smaller angle among the angles formed by the extension direction of the first texture structure 301 and the thickness direction of the solar cell 100 .

[0047] Optionally, the angle between the extension direction of the first texture structure 301 and the thickness direction of the solar cell 100 can be 70°, 50°, 55°, 46°, 45°, 30°, 25°, 20°, 18°, 15°, 13.5°, 10°, 8.5°, 5.5°, 5°, 4.5°, 4.4°, 4.2°, 4°, 3.5°, 3°, 2.8°, 2.5°, 2°, 1.5°, 1.2°, 1°, 0.8°, 0.5°, 0.3°, or 0°.

[0048] Preferably, the first angle α1 may be 0° to 45°, for example 45°, 30°, 25°, 20°, 18°, 15°, 13.5°, 10°, 8.5°, 5.5°, 5°, 4.5°, 4.4°, 4.2°, 4°, 3.5°, 3°, 2.8°, 2.5°, 2°, 1.5°, 1.2°, 1°, 0.8°, 0.5°, 0.3°, 0°. In this way, the arrangement regularity of each first texture structure 301 in the cut side surface 30 may be further improved, thereby further improving the passivation effect of the subsequent passivation of the cut side surface 30, and further improving the photoelectric conversion efficiency of the solar cell 100.

[0049] Specifically, for the first texture structure 301, the angle between any two points in the first texture structure 301 is less than or equal to 0° to 45°. In this way, the specific surface area of ​​the cut side surface 30 can be further reduced. When the cut side surface 30 is passivated, the passivation film can cover the cut side surface 30 more evenly, reduce the composite loss of the cut side surface 30, and improve the efficiency of the battery component 1001. At the same time, this makes the entire propagation path of the first texture structure 301 remain smooth and continuous, avoiding sharp changes or bends, so that the arrangement of the first texture structure 301 in the cut side surface 30 is more regular, which can further improve the film quality when the cut side surface 30 is passivated later, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0050] like Figures 3 to 5 As shown, in a possible implementation, the first texture structure 301 includes a first endpoint 3012 and a second endpoint 3013, and in the length direction of the cut side surface 30, the spacing D1 between the first endpoint 3012 and the second endpoint 3013 is less than or equal to 80μm to 200μm. For example, it is 80μm, 85μm, 90μm, 95μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 200μm. In this way, the specific surface area of ​​the cut side surface 30 can be further reduced. When the cut side surface 30 is passivated, the passivation film can cover the cut side surface 30 more evenly, reduce the composite loss of the cut side surface 30, and improve the efficiency of the battery assembly 1001. At the same time, the cut side surface 30 can be made more uniform and smooth, and the arrangement of each first texture structure 301 in the cut side surface 30 can be more regular, which can improve the film forming quality during the subsequent passivation of the cut side surface 30, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0051] Specifically, the first endpoint 3012 and the second endpoint 3013 of the first texture structure 301 are endpoints at both ends of the first texture structure 301, and the first endpoint 3012 and the second endpoint 3013 are respectively located at both ends of the first texture structure 301. The first endpoint 3012 is located at the cutting edge of the cutting side surface 30, and the second endpoint 3013 is located at the fracture edge of the cutting side surface 30, or the second endpoint 3013 is located at the cutting edge of the cutting side surface 30, and the first endpoint 3012 is located at the fracture edge of the cutting side surface 30.

[0052] In a possible implementation, Figure 3As shown, in the length direction of the cut side surface 30, the spacing D2 between two adjacent first texture structures 301 is 0.2μm to 3μm. For example, it is 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.75μm, 0.85μm, 0.9μm, 1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 2μm, 2.5, 2.6μm, 2.8μm, 3μm. In this way, the arrangement of each first texture structure 301 in the cut side surface 30 can be made more regular, which can further improve the film quality when the cut side surface 30 is passivated later, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0053] Specifically, the spacing D2 between two adjacent first texture structures 301 refers to the shortest straight-line distance between two adjacent first texture structures 301 on the cutting side surface 30. The spacing between the first texture structures 301 reflects the density distribution of the texture. The smaller the spacing, the denser the first texture structures 301, and the larger the spacing, the sparser the first texture structures 301. The spacing D2 between two adjacent first texture structures 301 is 80 μm to 200 μm, which can increase the density of the first texture structures 301.

[0054] like Figure 3 , Figure 4 and Figure 5 As shown, in a possible implementation, the length D3 of the first texture structure 301 is 100 μm to 650 μm. For example, it is 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 360 μm, 368 μm, 450 μm, 500 μm, 600 μm, 650 μm. In this way, the specific surface area of ​​the cut side surface 30 can be further reduced. When the cut side surface 30 is passivated, the passivation film can cover the cut side surface 30 more evenly, reduce the composite loss of the cut side surface 30, and improve the efficiency of the battery assembly 1001. It can also make the arrangement of each first texture structure 301 in the cut side surface 30 more regular, which can further improve the film quality when the cut side surface 30 is passivated later, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0055] like Figure 3 , Figure 4 , Figure 6 , Figure 7 and Figure 8As shown, in a possible embodiment, the cut side surface 30 is also formed with a plurality of crack structures 303 and a plurality of second texture structures 302, the extension direction of the crack structure 303 intersects with the cut side surface 30, the second texture structure 302 is located on the side of the crack structure 303 facing the cut side surface 30, and the angle between the extension direction of the second texture structure 302 and the thickness direction of the solar cell 100 is a second angle α2, and the second angle α2 is greater than the first angle α1.

[0056] In this way, a variety of texture structures can be formed on the cut side surface 30. At the same time, the second angle α2 is greater than the first angle α1, which can further improve the regularity of the arrangement of the first texture structure 301, thereby further improving the passivation effect of the subsequent passivation of the cut side surface 30, and further improving the photoelectric conversion efficiency of the solar cell 100.

[0057] Specifically, two texture structures, namely, a first texture structure 301 and a second texture structure 302, may be formed on the cutting side surface 30. The crack structure 303 and the second texture structure 302 are formed correspondingly. Specifically, the area on the cutting side surface 30 where the crack structure 303 is formed may be formed with the second texture structure 302 correspondingly. The area on the cutting side surface 30 where the crack structure 303 is avoided may be formed with the first texture structure 301.

[0058] It is understandable that the second texture structure 302 is located on the side of the crack structure 303 facing the cutting side surface 30. This means that the second texture structure 302 is disposed below the crack structure 303. In other words, at least part of the second texture structure 302 is connected to one end of the crack structure 303 facing the cutting side surface 30.

[0059] Furthermore, on the cut side surface 30, the second texture structure 302 is formed near the crack structure 303. The crack structure 303 is not formed near the first texture structure 301.

[0060] Furthermore, different from the first texture structure 301 or the second texture structure 302, the crack structure 303 is not parallel to the cutting surface, but crosses the cutting surface at a certain angle, such that the crack structure 303 and the cutting side surface 30 are on the same plane, but present a cross state.

[0061] In a possible implementation, the second angle α2 is 30° to 80°. For example, it is 80°, 70°, 65°, 60°, 55°, 50°, 48°, 45°, 40°, 35°, 30.5°, 30°. In this way, the specific surface area of ​​the cut side surface 30 can be further reduced. When the cut side surface 30 is passivated, the passivation film can cover the cut side surface 30 more evenly, reduce the composite loss of the cut side surface 30, and improve the efficiency of the battery assembly 1001.

[0062] At the same time, the second angle α2 is 30° to 80°, which can also reduce the surface defects of the cut side surface 30, reduce the cutting loss of the solar cell 100, and improve the efficiency of the battery assembly 1001. At the same time, the arrangement of each first texture structure 301 in the cut side surface 30 can be made more regular, which can further improve the film quality when the cut side surface 30 is subsequently passivated, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100. The film quality when the cut side surface 30 is subsequently passivated can be improved, thereby improving the passivation effect, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100. The regularity of the arrangement of the second texture structure 302 can also be improved, thereby further improving the overall regularity of the cut side surface 30, which is beneficial to improving the passivation effect when the cut side surface 30 is subsequently passivated, and further improving the photoelectric conversion efficiency of the solar cell 100.

[0063] like Figure 8 As shown, in a possible implementation, the crack structure 303 is located in the area of ​​the cut side surface 30 close to the second surface 20 of the solar cell 100. Specifically, when the solar cell 100 is actually laser cut, thermal cracking laser scanning may be performed on the second surface 20 of the solar cell 100, and then the crack structure 303 is formed in the area close to the second surface 20 of the solar cell 100. It can be understood that the thermal cracking laser scanning is performed on the second surface 20 of the solar cell 100. That is, the thermal cracking laser scanning is performed on the backlight surface of the solar cell 100.

[0064] like Figure 7 As shown, in a possible implementation, the crack structure 303 is located in the area of ​​the cut side surface 30 close to the first surface 10 of the solar cell 100. Specifically, when the solar cell 100 is actually laser cut, thermal cracking laser scanning may be performed on the first surface 10 of the solar cell 100, and then the crack structure 303 is formed in the area close to the first surface 10 of the solar cell 100. It can be understood that thermal cracking laser scanning is performed on the first surface 10 of the solar cell 100. That is, thermal cracking laser scanning is performed on the light-facing surface of the solar cell 100.

[0065] Therefore, in the embodiment of the present invention, the solar cell 100 can be split at different positions, thereby improving the flexibility of cutting the solar cell 100.

[0066] In a possible implementation, Figures 6 to 10 As shown, the first texture structure 301 or the second texture structure 302 includes a plurality of protrusions 3011, and in a direction perpendicular to the cutting side surface 30, the height difference between the highest protrusion 3011 and the protrusion 3011 is less than or equal to 5 μm, for example, 5 μm, 4.5 μm, 4 μm, 3.5 μm, 3 μm, 2.5 μm, 2 μm, 1.5 μm, 1 μm, 0.8 μm, 0.5 μm, 0.15 μm.

[0067] In this way, the arrangement of each texture structure in the cut side surface 30 can be made more regular, thereby making the cut side surface 30 more uniform and smooth. At the same time, the unevenness of the cut side surface 30 can be reduced, and the overall uniformity of the cut side surface 30 can be improved, so that the coating of the cut side surface 30 in the subsequent passivation process is more uniform, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0068] In addition, when the cut side surface 30 is passivated, the cut side surface 30 does not need to match a thicker passivation film, and the phenomenon of reduced plating and surrounding plating occurs, which further increases the passivation effect of the cut side surface 30, thereby further improving the photoelectric conversion efficiency of the solar cell 100.

[0069] Specifically, on the cutting side surface 30, the first texture structure 301 or the second texture structure 302 is a texture structure having a protrusion 3011. The protrusion 3011 is a local convex portion in the first texture structure 301 or the second texture structure 302. The protrusion 3011 can specifically protrude in a direction perpendicular to the cutting side surface 30. In the direction perpendicular to the cutting side surface 30, the height difference between the highest protrusion 3011 and the lowest protrusion 3011 is less than or equal to 5 μm. In this way, the height change of the first texture structure 301 or the second texture structure 302 is small, thereby ensuring that the cutting side surface 30 remains relatively flat, avoiding unnecessary ups and downs, and improving the flatness of the cutting side surface 30.

[0070] In a possible implementation, in a direction perpendicular to the cut side surface 30, the height D4 of the protrusion 3011 is less than or equal to 50 μm. For example, 50 μm, 45.15 μm, 45 μm, 40 μm, 31.14 μm, 35.25 μm, 35 μm, 30 μm, 27.69 μm, 27.13 μm, 25.53 μm, 22.21 μm, 18.09 μm, 14.56 μm, 14.27 μm. In this way, when the cut side surface 30 is passivated, the cut side surface 30 does not need to match a thicker passivation film, and the phenomenon of reducing the plating film around the plating is generated, which further increases the passivation effect of the cut side surface 30, so as to further improve the photoelectric conversion efficiency of the solar cell 100.

[0071] In addition, the flatness of the cut side surface 30 can be further improved, and the protrusions of the first texture structure 301 can be reduced, which can further improve the overall flatness of the cut side surface 30, thereby making the coating of the cut side surface 30 more uniform during the subsequent passivation process, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0072] In a possible embodiment, in a direction perpendicular to the cutting side surface 30 , a height difference between the highest protrusion 3011 and the lowest protrusion 3011 of the first texture structure 301 is greater than a height difference between the highest protrusion 3011 and the lowest protrusion 3011 of the second texture structure 302 .

[0073] Thus, the second texture structure 302 is flatter than the first texture structure 301, and the second texture structure 302 is flatter and smoother than the first texture structure 301. Thus, the passivation effect of the cut side surface 30 at the second texture structure 302 can be improved, so that the coating of the cut side surface 30 is more uniform in the subsequent passivation process, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0074] Specifically, the cut side surface 30 may only be provided with the first texture structure 301, or in other words, the cut side surface 30 is formed with the first texture structure 301, and the cut side surface 30 is not formed with the second texture structure 302. In this way, the unevenness of the cut side surface 30 can be reduced, so that the cut side surface 30 is smoother as a whole, the surface defects of the cut side surface 30 can be reduced, the cutting loss of the solar cell 100 is reduced, and the efficiency of the battery assembly 1001 is improved. At the same time, it is also beneficial to improve the passivation effect of the cut side surface 30, which is beneficial to improve the photoelectric conversion efficiency of the solar cell 100.

[0075] In addition, the cut side surface 30 may be formed with the first texture structure 301 and the second texture structure 302 at the same time, or the first texture structure 301 and the second texture structure 302 may be formed on the cut side surface 30 .

[0076] like Figure 3 As shown, in a possible implementation, the cutting side surface 30 includes a first groove region 31 , a middle region 32 , and a second groove region 33 arranged in sequence along the length direction of the cutting side surface 30 , and the plurality of first texture structures 301 are all located in the middle region 32 .

[0077] Specifically, the first groove region 31 and the second groove region 33 are located on both sides of the cutting side surface 30. The first groove region 31 and the second groove region 33 are guide groove regions opened by laser, and the first groove region 31 and the second groove region 33 are grooved regions formed by lossy laser cutting. The middle region 32 is located between the first groove region 31 and the second groove region 33, and the middle region 32 is formed by lossless laser cutting.

[0078] Specifically, the plurality of second texture structures 302 are also located in the middle region 32. That is, the second texture structures 302 and the first texture structures 301 can be formed in the middle region 32 at the same time.

[0079] It is understandable that in such an embodiment, the battery assembly 1001 may also include a frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the battery cell and the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0080] Photovoltaic glass can cover the adhesive film on the front of the cell. Photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the cell without affecting the efficiency of the cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the cell together. The presence of the adhesive film can seal and insulate the cell and make it waterproof and moisture-proof.

[0081] The back plate can be attached to the adhesive film on the back of the battery cell. The back plate can protect and support the battery cell and has reliable insulation, water resistance and aging resistance. There are multiple options for the back plate, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the back plate, battery cell, adhesive film and photovoltaic glass can be set on the frame. The frame serves as the main external support structure of the entire battery assembly 1001 and can stably support and install the battery assembly 1001. For example, the battery assembly 1001 can be installed at the required location through the frame.

[0082] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0083] In addition, the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A solar cell, comprising a first surface and a second surface opposite to each other, and a cut side surface connecting the first surface and the second surface, wherein the first surface is a light-facing surface and the second surface is a backlight surface; characterized in that: A plurality of first texture structures are formed on the cut side surface, and an angle between an extension direction of the first texture structure and a thickness direction of the solar cell is a first angle, and the first angle is less than or equal to 70°.

2. The solar cell according to claim 1, characterized in that The first angle is 0° to 45°.

3. The solar cell according to claim 1, characterized in that A plurality of second texture structures and a plurality of crack structures are formed on the cut side surface, wherein an extension direction of the crack structure intersects with the cut side surface, the second texture structure is located on a side of the crack structure facing the cut side surface, and an angle between an extension direction of the second texture structure and a thickness direction of the solar cell is a second angle, and the second angle is greater than the first angle.

4. The solar cell according to claim 3, characterized in that: The second angle is 30° to 80°.

5. The solar cell according to claim 3, characterized in that: The first texture structure or the second texture structure includes a plurality of protrusions, and in a direction perpendicular to the cut side surface, a height difference between the highest protrusion and the lowest protrusion is less than or equal to 5 μm.

6. The solar cell according to claim 5, characterized in that: A height difference between the highest protrusion and the lowest protrusion of the first texture structure is greater than a height difference between the highest protrusion and the lowest protrusion of the second texture structure.

7. The solar cell according to claim 5, characterized in that: The height of the protrusion in a direction perpendicular to the cut side surface is less than or equal to 50 μm.

8. The solar cell according to claim 3, characterized in that: The crack structure is located in a region of the cut side surface close to the second surface of the solar cell.

9. The solar cell according to claim 3, characterized in that: The crack structure is located in a region of the cut side surface close to the second surface of the solar cell.

10. The solar cell according to claim 1, characterized in that: The first texture structure includes a first end point and a second end point. In the length direction of the cut side surface, a distance between the first end point and the second end point is 80 μm to 200 μm.

11. The solar cell according to claim 1, characterized in that: The length of the first texture structure is 100 μm to 650 μm.

12. The solar cell according to claim 1, characterized in that In the length direction of the cut side surface, a distance between two adjacent first texture structures is 0.2 μm to 3 μm.

13. The solar cell according to claim 1, characterized in that The cutting side surface includes a first groove area, a middle area, and a second groove area which are sequentially arranged along the length direction of the cutting side surface, and the plurality of first texture structures are all located in the middle area.

14. A battery assembly, characterized in that: Comprising the solar cell according to any one of claims 1 to 13.

15. A photovoltaic system, characterized in that: Comprising the battery assembly as claimed in claim 14.

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