Back contact battery, battery assembly, and photovoltaic system

Abstract

A back contact battery, a battery assembly, and a photovoltaic system. The back contact battery comprises a body and a transparent protrusion, wherein two fine grids distributed in a staggered mode are formed on the back face of the body, the transparent protrusion is arranged on the front face of the body, the thickness of the transparent protrusion is 28μm-98μm, and the ratio of the coverage area of the transparent protrusion on the front face to the total area of the front face is 1%-4%. In this way, since a transparent protrusion having a thickness of 28μm-98μm and a coverage area ratio of 1％-4％ is provided on the front face of a body, when another battery is stacked on the front face of a back contact battery, a gap can be formed between two batteries, so as to prevent the batteries stacked on the front face from scratching the front face of the back contact battery, thereby facilitating an improvement to the quality of the back contact battery.

Description

Back-contact cells, battery modules, and photovoltaic systems Technical Field

[0001] The present disclosure belongs to the technical field of solar cells, and in particular relates to a back-contact cell, a cell assembly, and a photovoltaic system. Background Art

[0002] Solar cells are a sustainable, clean energy source that convert sunlight into electricity using the photovoltaic effect of a semiconductor pn junction. Back-contact solar cells are those in which both polarity electrodes are formed on the back of the cell.

[0003] In the related art, multiple back-contact battery cells are usually stacked for transportation or storage. However, in this way, the front surface of the back-contact battery cell is easily scratched by the back electrode of another back-contact battery cell.

[0004] Based on this, how to prevent the front of the back contact battery from being scratched has become an urgent problem to be solved.

[0005] Utility Model Content

[0006] The present disclosure provides a back-contact cell, a cell assembly, and a photovoltaic system, aiming to solve the problem of how to prevent the front side of the back-contact cell from being scratched.

[0007] The back-contact battery provided by the present disclosure includes a main body and a transparent protrusion. Two types of fine grids are formed on the back of the main body and are distributed alternately. The transparent protrusion is arranged on the front of the main body. The thickness of the transparent protrusion is 28μm-98μm, and the ratio of the coverage area of ​​the transparent protrusion on the front to the total area of ​​the front is 1%-4%.

[0008] Optionally, the transparent protrusion includes a first protrusion, the first protrusion is strip-shaped, and an extension direction is perpendicular to an extension direction of the fine grid.

[0009] Optionally, the width of the first protrusion is 0.1 mm-2 mm.

[0010] Optionally, a ratio of the length of the first protrusion to the length of the front surface is greater than or equal to 18%.

[0011] Optionally, the transparent protrusion includes a second protrusion, and the second protrusion is parallel to the extension direction of the fine grid.

[0012] Optionally, the transparent protrusions include third protrusions, and the third protrusions are distributed along a diagonal line of the front surface.

[0013] Optionally, the transparent protrusions include a fourth protrusion, and the fourth protrusions are dot-shaped and are multiple in number.

[0014] Optionally, the area of ​​each of the fourth protrusions is 2 mm 2 -6mm 2 .

[0015] The battery assembly provided by the present disclosure includes any of the above-mentioned back-contact batteries.

[0016] The photovoltaic system provided by the present disclosure includes any one of the above-mentioned battery assemblies.

[0017] The back-contact cell, cell assembly, and photovoltaic system of the disclosed embodiments are provided with a transparent protrusion with a thickness of 28 μm-98 μm and a coverage area ratio of 1%-4% on the front side of the body. Therefore, when another cell is stacked on the front side of the back-contact cell, a gap can be formed between the two cells to prevent the cell stacked on the front side from scratching the front side of the back-contact cell, which is beneficial to improving the quality of the back-contact cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0019] FIG2 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0020] FIG3 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0021] FIG4 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0022] FIG5 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0023] FIG6 is a schematic structural diagram of a back-contact battery according to an embodiment of the present disclosure;

[0024] Explanation of main component symbols: 10, back contact battery; 11, body; 121, first protrusion; 122, second protrusion; 123, third protrusion; 124, fourth protrusion. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present disclosure more clear, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure and are not to be construed as limiting the present disclosure. In addition, it should be understood that the specific embodiments described herein are only used to explain the present disclosure and are not intended to limit the present disclosure.

[0026] In the description of the present disclosure, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure 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 disclosure.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. Throughout the present disclosure, "plurality" means two or more, unless otherwise specifically defined.

[0028] In the description of this disclosure, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0029] In the present disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] The disclosure below provides many different embodiments or examples for realizing different structures of the present disclosure. In order to simplify the disclosure of the present disclosure, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art will recognize the application of other processes and / or the use scenarios of other materials.

[0031] In the present disclosure, since a transparent protrusion with a thickness of 28μm-98μm and a coverage area ratio of 1%-4% is provided on the front side of the main body, when another battery is stacked on the front side of the back contact battery, a gap can be formed between the two batteries to prevent the battery stacked on the front side from scratching the front side of the back contact battery, which is beneficial to improving the quality of the back contact battery.

[0032] Example 1

[0033] Please refer to Figures 1, 2, 3, 4, 5 and 6. The back-contact battery 10 of the embodiment of the present disclosure includes a main body 11 and a transparent protrusion. Two types of fine grids are formed on the back of the main body 11 in an alternating manner. The transparent protrusion is provided on the front of the main body 11. The thickness of the transparent protrusion is 28μm-98μm, and the ratio of the coverage area of ​​the transparent protrusion on the front to the total area of ​​the front is 1%-4%.

[0034] The back contact battery 10 of the embodiment of the present disclosure is provided with a transparent protrusion with a thickness of 28μm-98μm and a coverage area ratio of 1%-4% on the front side of the main body 11. Therefore, when another battery is stacked on the front side of the back contact battery 10, a gap can be formed between the two batteries to prevent the battery stacked on the front side from scratching the front side of the back contact battery 10, which is beneficial to improving the quality of the back contact battery 10.

[0035] Specifically, the body 11 of the back-contact cell 10 may include a silicon substrate. The back side of the silicon substrate may be formed with alternating conductive regions of two polarities and alternating fine grids of two polarities. A back surface passivation layer may also be formed on the back side of the silicon substrate, and a front surface passivation layer may be formed on the front side of the silicon substrate. Examples of surface passivation layers include silicon nitride layers, silicon oxynitride layers, and silicon oxide layers. A main grid may be formed on the back side of the body 11, or only fine grids may be formed without a main grid. In other words, the back-contact cell 10 may be a cell with a main grid or a cell without a main grid. The specific structure of the body 11 of the back-contact cell 10 is not limited herein.

[0036] Specifically, the thickness of the transparent protrusion is, for example, 28 μm, 30 μm, 32 μm, 40 μm, 60 μm, 65 μm, 73 μm, 90 μm, or 98 μm. The specific thickness of the transparent protrusion is not limited here.

[0037] It can be understood that the thickness of the transparent protrusion is 28μm-98μm, which makes the thickness of the transparent protrusion in an appropriate range, which can avoid the smaller gap with another battery cell and poor anti-scratch effect caused by too small thickness, and can also avoid the waste of raw materials and increased costs caused by too large thickness.

[0038] Preferably, the thickness of the transparent protrusion is 60 μm-65 μm, for example, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, or 65 μm. This can achieve both scratch protection and cost reduction, achieving the best overall effect.

[0039] Specifically, the ratio of the area covered by the transparent protrusion on the front surface to the total area of ​​the front surface is, for example, 1%, 1.2%, 1.8%, 2%, 2.39%, 2.46%, 2.48%, 2.5%, 2.53%, 2.61%, 3%, 3.8%, and 4%. The specific value of the ratio of the area covered by the transparent protrusion on the front surface to the total area of ​​the front surface is not limited here.

[0040] It can be understood that the ratio of the coverage area of ​​the transparent protrusion on the front side to the total area of ​​the front side is 1%-4%, so that the coverage ratio of the transparent protrusion on the front side is within an appropriate range, which can avoid the poor anti-scratch effect caused by a too small ratio, and can also avoid the impact on photoelectric conversion efficiency and increased cost caused by a too large ratio.

[0041] Preferably, the ratio of the area covered by the transparent protrusions on the front surface to the total area of ​​the front surface is 2%-2.48%, for example, 2%, 2.1%, 2.39%, 2.46%, or 2.48%. This balances scratch resistance, photoelectric conversion efficiency, and cost, achieving the best overall effect.

[0042] In the example of FIG1 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.53%; in the example of FIG2 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.61%; in the example of FIG3 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.48%; in the example of FIG4 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.39%; in the example of FIG5 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.5%; and in the example of FIG6 , the ratio of the transparent protrusion covering the front surface to the total area of ​​the front surface is 2.46%. These are merely examples and do not represent limitations on the contrast ratio.

[0043] Specifically, the light transmittance of the transparent protrusions is greater than or equal to 80%. For example, it can be 80%, 82%, 85%, 90%, 92%, or 98%. This can reduce the light blocking caused by the transparent protrusions, allowing more light to enter the back-contact cell 10. Preferably, the light transmittance of the transparent protrusions is greater than or equal to 90%. Specifically, the light transmittance of the transparent protrusions can refer to the transmittance of light in the 200nm-350nm wavelength range.

[0044] Specifically, the transparent protrusions have a lower transmittance for light in the 200nm-350nm wavelength range than for light in the 500nm-600nm wavelength range. This allows the transparent protrusions to transmit more light that is more usable by the back-contact cell 10, thereby improving the photoelectric conversion efficiency of the back-contact cell 10.

[0045] Furthermore, the transparent protrusions can be made of a slurry containing a light conversion agent, so that light in other wavelength bands can be converted into light in the 500nm-600nm wavelength band, thereby improving the transmittance of light in the 500nm-600nm wavelength band.

[0046] Specifically, the hardness of the transparent protrusion is greater than or equal to 4H. Examples include 4H, 4.2H, 4.5H, 4.8H, 5H, and 10H. This ensures that the hardness of the transparent protrusion is within an appropriate range, thereby preventing the problem of difficulty in supporting batteries stacked on the front surface of the back-contact battery 10 due to a low hardness, thereby improving the scratch protection of the front surface of the back-contact battery 10.

[0047] Example 2

[0048] Referring to FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 , in some optional embodiments, the transparent protrusion includes a first protrusion 121 . The first protrusion 121 is strip-shaped, and its extension direction is perpendicular to the extension direction of the fine grid.

[0049] In this way, when another battery is stacked on the front side of the back-contact battery 10, the first protrusion 121 presses against the fine grid of the other battery in a vertical direction. When the stacked battery has a main grid, it can press against its main grid in a direction parallel to the main grid, which can better support the battery stacked on the front side of the back-contact battery 10 and form a gap between the two batteries, thereby preventing the battery stacked on the front side from scratching the front side of the back-contact battery 10.

[0050] Specifically, the number of first protrusions 121 can be multiple. This provides a wider range for supporting the cells stacked on the front of the back-contact battery 10, better supporting the cells stacked on the front of the back-contact battery 10, and more stably forming a gap between the two cells. It is understood that in other embodiments, the number of first protrusions 121 can also be one. The specific number of first protrusions 121 is not limited herein.

[0051] Specifically, a busbar can be formed on the back of the body 11, and the position of the first protrusion 121 can correspond to the position of the busbar. In this way, when a battery with the same specifications as the back-contact battery 10 is stacked on the front, the first protrusion 121 can directly contact its busbar, preventing the busbar from scratching the front of the body 11.

[0052] Specifically, in the examples of Figures 1 and 2 , the length of first protrusion 121 is the same as the length of body 11. In other words, the two ends of first protrusion 121 connect to two opposite sides of body 11. This allows for better support for batteries stacked on the front of back-contact battery 10 along the length of body 11.

[0053] It is understood that the length of the first protrusion 121 can also be smaller than the length of the body 11, as shown in Figures 3 and 4. In this way, the cost can be reduced as much as possible while providing support.

[0054] Specifically, in the examples of Figures 1 and 2 , there are multiple first protrusions 121, and the spacing between two adjacent first protrusions 121 is the same. Thus, the multiple first protrusions 121 are evenly arranged on the front surface of the body 11, so that the support for the battery stacked on the front surface of the back contact battery 10 is more uniform, the support is more stable, and the scratch protection effect is better.

[0055] Furthermore, in the example of FIG1 , the spacing between two adjacent first protrusions 121 is 6 mm to 9 mm, preferably 7.88 mm. In the example of FIG2 , the spacing between two adjacent first protrusions 121 is 14 mm to 17 mm, preferably 15.75 mm.

[0056] It is understood that there may be multiple first protrusions 121, and the spacing between two adjacent first protrusions 121 may also be different, as shown in Figure 3. In the example of Figure 3, the spacing between the two first protrusions 121 on the right is 19.94 mm, the spacing between the two first protrusions 121 on the left is 19.94 mm, and the spacing between the two first protrusions 121 in the middle is 93.24 mm.

[0057] Please note that the distance between two adjacent first protrusions 121 mentioned here refers to the distance between the center lines of the two adjacent first protrusions 121 .

[0058] Example 3

[0059] In some optional embodiments, the width of the first protrusion 121 is 0.1 mm-2 mm, for example, 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.32 mm, 1.39 mm, 1.8 mm, or 2 mm.

[0060] In this way, the width of the first protrusion 121 is within an appropriate range, which can avoid the poor supporting effect on the battery stacked on the front of the back-contact battery 10 caused by the smaller width of the first protrusion 121, and can also avoid the impact on the photoelectric conversion efficiency and higher cost caused by the larger width of the first protrusion 121.

[0061] Example 4

[0062] In some optional embodiments, the ratio of the length of the first protrusion 121 to the length of the front surface is greater than or equal to 18%, for example, 18%, 20%, 21.45%, 27.17%, 42.89%, 50%, 80%, 81.52%, 98%, or 100%.

[0063] In this way, the ratio of the length of the first protrusion 121 to the length of the front face is within an appropriate range, which can avoid the poor supporting effect caused by a too small ratio.

[0064] Specifically, in the examples of Figures 1 and 2 , the ratio of the length of first protrusions 121 to the length of the front face is 100%. In the example of Figure 3 , the ratio of the length of the two center first protrusions 121 to the length of the front face is 21.45%, and the ratio of the length of the left and right first protrusions 121 to the length of the front face is 42.89%. In the example of Figure 4 , the ratio of the length of the two center first protrusions 121 to the length of the front face is 27.17%, and the ratio of the length of the left and right first protrusions 121 to the length of the front face is 81.52%.

[0065] Example 5

[0066] Referring to FIG. 2 , FIG. 3 and FIG. 4 , in some optional embodiments, the transparent protrusion includes a second protrusion 122 , and the second protrusion 122 is parallel to the extension direction of the fine grid.

[0067] In this way, when another battery is stacked on the front side of the back-contact battery 10, the second protrusion 122 presses against the fine grid of the other battery in a parallel direction. When the stacked battery has a main grid, it can press against its main grid in a direction perpendicular to the main grid, and can support the battery stacked on the front side of the back-contact battery 10 in a direction parallel to the extension direction of the fine grid, forming a gap between the two batteries, thereby preventing the battery stacked on the front side from scratching the front side of the back-contact battery 10.

[0068] Specifically, the number of second protrusions 122 can be multiple. This provides a wider range for supporting the cells stacked on the front of the back-contact battery 10, better supporting the cells stacked on the front of the back-contact battery 10, and more stably forming a gap between the two cells. It is understood that in other embodiments, the number of second protrusions 122 can also be one. The specific number of second protrusions 122 is not limited herein.

[0069] Specifically, in the example of FIG2 , the length of the second protrusion 122 is the same as the width of the body 11. In other words, the two ends of the second protrusion 122 are connected to two opposite sides of the body 11. This allows for better support of the battery cells stacked on the front of the back-contact battery 10 in the width direction of the body 11.

[0070] It is understood that the length of the second protrusion 122 can also be smaller than the width of the body 11, as shown in Figures 3 and 4. In this way, the cost can be reduced as much as possible while providing support.

[0071] Specifically, the width range of the second protrusion 122 may be the same as the width range of the first protrusion 121. For the description of the width of the second protrusion 122, reference may be made to the above description of the width of the first protrusion 121, which will not be repeated here to avoid redundancy.

[0072] Specifically, in the example of FIG2 , there are multiple second protrusions 122, and the spacing between two adjacent second protrusions 122 is the same. Thus, the multiple second protrusions 122 are evenly arranged on the front surface of the body 11, so that the support for the battery stacked on the front surface of the back contact battery 10 is more uniform, the support is more stable, and the scratch protection effect is better.

[0073] Furthermore, in the example of FIG2 , the distance between two adjacent second protrusions 122 is 14 mm to 17 mm, preferably 15.75 mm.

[0074] It is understood that there may be multiple second protrusions 122, and the spacing between two adjacent second protrusions 122 may also be different, as shown in Figure 3. In the example of Figure 3, the spacing between the two upper second protrusions 122 is 19.94 mm, the spacing between the two lower second protrusions 122 is 19.94 mm, and the spacing between the two middle second protrusions 122 is 93.24 mm.

[0075] Please note that the distance between two adjacent second protrusions 122 mentioned here refers to the distance between the center lines of the two adjacent second protrusions 122 .

[0076] Specifically, the second protrusion 122 may intersect the first protrusion 121, as shown in FIG2 . The end of the second protrusion 122 may be spaced apart from the first protrusion 121, as shown in FIG3 . The second protrusion 122 may be connected to the end of the first protrusion 121, as shown in FIG4 . The specific positional relationship between the second protrusion 122 and the first protrusion 121 is not limited herein.

[0077] Example 6

[0078] Referring to FIG. 3 , in some optional embodiments, the transparent protrusions include third protrusions 123 , and the third protrusions 123 are distributed along the diagonal line of the front surface.

[0079] In this way, when another battery is stacked on the front side of the back-contact battery 10, the third protrusion 123 presses against the grid line of the other battery in the diagonal direction, and can support the battery stacked on the front side of the back-contact battery 10 in the diagonal direction, forming a gap between the two batteries, thereby preventing the battery stacked on the front side from scratching the front side of the back-contact battery 10.

[0080] Specifically, in the example of FIG3 , the third protrusions 123 are continuously distributed along the diagonal line. It is understood that in other examples, the third protrusions 123 may also be discontinuously distributed along the diagonal line. The specific arrangement of the third protrusions 123 on the diagonal line is not limited here.

[0081] The width range of the third protrusion 123 may be the same as the width range of the first protrusion 121 . For the description of the width of the third protrusion 123 , reference may be made to the above description of the width of the first protrusion 121 , which will not be repeated here to avoid redundancy.

[0082] Example 7

[0083] Referring to FIG. 5 and FIG. 6 , in some optional embodiments, the transparent protrusions include a fourth protrusion 124 . The fourth protrusions 124 are dot-shaped and are multiple in number.

[0084] In this way, the dot-shaped protrusions can support the cells stacked on the front surface of the back-contact cell 10, forming a gap between the two cells, thereby preventing the stacked cells from scratching the front surface of the back-contact cell 10. Furthermore, because the fourth protrusions 124 are dot-shaped, the coverage area of ​​the fourth protrusions 124 can be reduced while ensuring a larger supporting range, thereby reducing costs.

[0085] Specifically, the fourth protrusion 124 can be circular, rectangular, triangular, annular, elliptical or other shapes. The shapes of the plurality of fourth protrusions 124 can be the same or different. The specific shape of the fourth protrusion 124 is not limited here.

[0086] Specifically, the plurality of fourth protrusions 124 are aligned in a direction perpendicular to the extension direction of the fine grid. Thus, the plurality of fourth protrusions 124 are all located in a direction perpendicular to the extension direction of the fine grid, providing better support for the cells stacked on the front surface of the back-contact cell 10. It will be appreciated that in other embodiments, the plurality of fourth protrusions 124 may be staggered in a direction perpendicular to the extension direction of the fine grid.

[0087] Specifically, the plurality of fourth protrusions 124 can be evenly distributed on the front surface. In other words, the spacing between two adjacent fourth protrusions 124 is the same. In this way, the force applied to the fourth protrusions 124 is more even, the support is more stable, and the anti-scratch effect is better.

[0088] It is understood that in other embodiments, the spacings between two adjacent fourth protrusions 124 in each group may be completely different, or partially the same and the rest different. The specific positional relationship of the plurality of fourth protrusions 124 is not limited herein.

[0089] Example 8

[0090] 5 and 6 , in some optional embodiments, the area of ​​each fourth protrusion 124 is 2 mm 2 -6mm 2 For example, 2mm 2 , 2.2mm 2 , 2.5mm 2 , 2.91mm 2 , 3.5mm 2 , 5.72mm 2 , 6mm 2 .

[0091] In this way, the area of ​​each fourth protrusion 124 is within an appropriate range, which can avoid unstable support caused by a too small area, and can also avoid the impact on photoelectric conversion efficiency and high cost caused by a too large area.

[0092] In the example of FIG5 , the fourth protrusions 124 are rectangular, each of the fourth protrusions 124 has a width of 1.32 mm, a length of 2.2 mm, and a coverage area of ​​2.91 mm. 2 The total number of the fourth protrusions 124 is 288, and the total coverage area of ​​all the fourth protrusions 124 is 838.08 mm 2 .

[0093] In the example of FIG6 , the fourth protrusions 124 are circular, the radius of each fourth protrusion 124 is 1.35 mm, and the coverage area of ​​each fourth protrusion 124 is 5.72 mm. 2 The total number of the fourth protrusions 124 is 144, and the total coverage area of ​​all the fourth protrusions 124 is 823.68 mm 2 .

[0094] Example 9

[0095] The battery assembly of the embodiment of the present disclosure includes the solar cells of embodiment 1 to embodiment 8.

[0096] In the battery assembly of the disclosed embodiment, since the back-contact battery 10 is provided with a transparent protrusion with a thickness of 28μm-98μm and a coverage area ratio of 1%-4% on the front side of the main body 11, when another battery is stacked on the front side of the back-contact battery 10, a gap can be formed between the two batteries to prevent the battery stacked on the front side from scratching the front side of the back-contact battery 10, which is beneficial to improving the quality of the back-contact battery 10.

[0097] In this embodiment, multiple back-contact cells 10 in the battery assembly can be connected in series in sequence to form a battery string, thereby realizing the series bus output of the current. For example, the series connection of the battery cells can be realized by setting welding strips (bus bars, interconnecting bars), conductive back plates, etc.

[0098] It is understood that in such an embodiment, the battery assembly may further include a metal frame, a backsheet, photovoltaic glass, and an adhesive film. The adhesive film may be placed between the front and back surfaces of the back-contact battery 10, the photovoltaic glass, adjacent cells, and the like. As a filler, it may be a transparent colloid with excellent light transmittance and aging resistance. For example, the adhesive film may be EVA or POE film. The specific choice may be based on actual conditions and is not limited here.

[0099] Photovoltaic glass can cover the adhesive film on the front surface of the back-contact cell 10. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and excellent physical, mechanical, and optical properties. For example, ultra-clear glass can have a light transmittance of over 92%, protecting the back-contact cell 10 while minimizing the impact on the efficiency of the back-contact cell 10. The adhesive film can also bond the photovoltaic glass and the back-contact cell 10 together, providing sealing, insulation, and waterproofing of the back-contact cell 10.

[0100] A backsheet can be attached to the film on the back of the back-contact cell 10. The backsheet protects and supports the back-contact cell 10, offering reliable insulation, water resistance, and aging resistance. A variety of backsheet options are available, typically including tempered glass, organic glass, and aluminum alloy TPT composite film. The specific configuration depends on the specific situation and is not limited here. The backsheet, back-contact cell 10, film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the primary external support structure for the entire cell assembly and provides stable support and installation for the cell assembly. For example, the metal frame can be used to mount the cell assembly in the desired location.

[0101] Example 10

[0102] The photovoltaic system of the embodiment of the present disclosure includes the battery assembly of the ninth embodiment.

[0103] In the photovoltaic system of the embodiment of the present disclosure, since the back-contact cell 10 is provided with a transparent protrusion with a thickness of 28μm-98μm and a coverage area ratio of 1%-4% on the front side of the main body 11, when another cell is stacked on the front side of the back-contact cell 10, a gap can be formed between the two cells to prevent the cell stacked on the front side from scratching the front side of the back-contact cell 10, which is beneficial to improving the quality of the back-contact cell 10.

[0104] In this embodiment, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, 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 require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction 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 junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to be converted into the alternating current required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0105] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0106] In addition, the above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A back-contact battery, comprising a body and a transparent protrusion, wherein two types of staggered fine grids are formed on the back of the body, the transparent protrusion is arranged on the front of the body, the thickness of the transparent protrusion is 28μm-98μm, and the ratio of the coverage area of ​​the transparent protrusion on the front to the total area of ​​the front is 1%-4%.

2. The back contact cell according to claim 1, wherein: The transparent protrusions include first protrusions, which are in a strip shape and extend in a direction perpendicular to the extending direction of the fine grid.

3. The back contact cell according to claim 2, wherein: The width of the first protrusion is 0.1 mm-2 mm.

4. The back contact cell according to claim 2, wherein: The ratio of the length of the first protrusion to the length of the front surface is greater than or equal to 18%.

5. The back contact cell according to claim 1, wherein: The transparent protrusion includes a second protrusion, and the second protrusion is parallel to the extension direction of the fine grid.

6. The back contact cell according to claim 1, wherein: The transparent protrusions include third protrusions, and the third protrusions are distributed along the diagonal line of the front surface.

7. The back contact cell according to claim 1, wherein: The transparent protrusions include fourth protrusions, and the fourth protrusions are dot-shaped and the number is multiple.

8. The back contact cell according to claim 7, wherein: The area of ​​each of the fourth protrusions is 2 mm 2 -6mm 2 .

9. A battery assembly comprising the back contact battery according to any one of claims 1 to 8.

10. A photovoltaic system comprising the battery assembly according to claim 9.

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