Back contact battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell module and a photovoltaic system. The back contact battery assembly includes: an end bus bar; the first battery string comprises a first end part welding strip and a first end part battery piece, and the first end part battery piece is electrically connected with the end part bus bar through the first end part welding strip; the first end of the shading strip is arranged between the first end welding strip and the first end battery piece, and the second end of the shading strip is arranged on the face, away from the first end welding strip, of the end bus bar. Based on this, the width between the first end and the second end of the shading strip can cover the gap between the first end battery piece and the end bus bar, so that the width of the second shading strip and the width of the first shading strip can be matched with the width of the gap between the first end battery piece and the end bus bar.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, and particularly relates to a back-contact battery module and photovoltaic system. Background Technology

[0002] In related technologies, photovoltaic modules consist of busbars and cell strings, with shading strips typically placed in the gaps between them. However, poor matching between the shading strips and the gaps can easily lead to the cells being blocked or the gaps not being completely blocked, thus affecting the aesthetics and power generation efficiency of the photovoltaic modules.

[0003] Therefore, the width of the light-shielding strip is difficult to match the gap between the battery cells and the busbar, which has become an urgent problem to be solved. Summary of the Invention

[0004] This application provides a back-contact battery module and photovoltaic system, which aims to solve the problem that the width of the shading strip is difficult to match the gap between the battery cell and the busbar.

[0005] A first aspect of this application provides a back contact battery assembly, the back contact battery assembly comprising: End busbar; A first battery string, the first battery string including a first end solder strip and a first end battery cell, the first end battery cell being electrically connected to the end busbar through the first end solder strip; A light-shielding strip, wherein the first end of the light-shielding strip is located between the first end solder strip and the first end battery cell, and the second end is located in the end busbar on the side facing away from the first end solder strip.

[0006] Optionally, the thickness of the light-shielding strip is less than 200 μm.

[0007] Optionally, the width of the first end of the light-shielding strip is greater than or equal to 2 mm.

[0008] Optionally, the light-shielding strip is made of any one of PET, PO, or PI materials.

[0009] Optionally, the second end of the light-shielding strip can be fixedly connected to the end busbar by hot stamping.

[0010] Optionally, the distance by which the light-shielding strip extends beyond the end of the end busbar is greater than the distance by which the first end solder strip extends beyond the end of the end busbar.

[0011] Optionally, the back contact battery assembly includes a second battery string, and the first battery string and the second battery string are arranged along a first direction; both the first battery string and the second battery string include a plurality of back contact battery pieces arranged along a second direction and connected in series in sequence, the number of back contact battery pieces in the first battery string and the second battery string are the same, and the second direction intersects the first direction; In the first direction, the back contact battery assembly has a central busbar, and in the first battery string, the back contact battery cell closest to the central busbar is the second end battery cell; In the second battery string, the back contact battery cell closest to the end busbar is the third end battery cell, and the back contact battery cell closest to the middle busbar is the fourth end battery cell. The distance between the first end battery cell and the end busbar in the second direction is a first distance, and the distance between the third end battery cell and the end busbar in the second direction is a second distance. The second battery string has a second end solder strip, and the third end battery cell is electrically connected to the end busbar through the second end solder strip. Wherein, the second end battery cell in the first battery string and the fourth end battery cell in the second battery string are aligned in the first direction, and the first spacing is greater than the second spacing.

[0012] Optionally, the first end of the light-shielding strip is located between the second end solder strip and the third end battery cell, and the second end is located in the end busbar on the side facing away from the second end solder strip.

[0013] Optionally, the distance by which the light-shielding strip extends beyond the end of the end busbar is greater than the longest distance by which the first end solder strip and the second end solder strip extend beyond the end of the end busbar.

[0014] The second aspect of this application provides a photovoltaic system including the aforementioned first aspect and any optional back-contact battery module of the first aspect.

[0015] As can be seen from the above technical solutions, this application has the following effects: In the back-contact battery module and photovoltaic system of this application embodiment, the first end of the shading strip is located between the first end solder strip and the first end battery cell, and the second end is located on the side of the end busbar facing away from the first end solder strip. The width between the first end and the second end of the shading strip can cover the gap between the first end battery cell and the end busbar, so that the width of the shading strip can match the width of the gap between the first end battery cell and the end busbar. This reduces the possibility of the first end battery cell being blocked or the gap between the first end battery cell and the end busbar not being completely blocked, thereby improving the aesthetics and power generation efficiency of the back-contact battery module. Attached Figure Description

[0016] Figure 1 This is a top view schematic diagram of a back contact battery assembly according to an embodiment of this application; Figure 2 This is a side view schematic diagram of a back contact battery assembly according to an embodiment of this application; Figure 3 This is a top view schematic diagram of a back contact battery assembly according to another embodiment of this application.

[0017] Explanation of key component symbols: End busbar-1, first battery string-2, first end solder strip-21, first end battery cell-22, second end battery cell-23, light shielding strip-3, second battery string-4, second end solder strip-41, third end battery cell-42, fourth end battery cell-43, intermediate busbar-5. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0019] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0024] Please see Figure 1 and Figure 2 The back contact battery assembly in this application embodiment includes: End busbar 1; The first battery string 2 includes a first end solder strip 21 and a first end battery cell 22. The first end battery cell 22 is electrically connected to the end busbar 1 through the first end solder strip 21. The light-shielding strip 3 has a first end located between the first end welding strip 21 and the first end battery cell 22, and a second end located in the end busbar 1 on the side facing away from the first end welding strip 21.

[0025] In this embodiment, the first end of the light-shielding strip 3 is located between the first end solder strip 21 and the first end battery cell 22, and the second end is located on the side of the end busbar 1 facing away from the first end solder strip 21. The width between the first and second ends of the light-shielding strip 3 can cover the gap between the first end battery cell 22 and the end busbar 1, so that the widths of the second and first light-shielding strips 3 can match the width of the gap between the first end battery cell 22 and the end busbar 1. This reduces the possibility of the first end battery cell 22 being blocked or the gap between the first end battery cell 22 and the end busbar 1 not being completely blocked, thereby improving the aesthetics and power generation efficiency of the back-contact battery assembly.

[0026] Specifically, the first battery string 2 includes a plurality of back contact battery cells. The plurality of back contact battery cells are connected in series along a first direction, and adjacent back contact battery cells are electrically connected by solder strips. It should be noted that the first direction can be a horizontal direction from left to right or a vertical direction from top to bottom, and the specific first direction can be determined according to the actual process layout requirements, and is not limited here.

[0027] It is understood that the number of back contact solar cells in the first battery string 2 is unlimited. For example, the number of back contact solar cells in the first battery string 2 can be 5, 6, 7, or 8, or it can be 12, 13, 14, or 15. The specific number can be set according to the actual power generation requirements and is not limited here.

[0028] Specifically, the end busbar 1 is located at the end of the first battery string 2 in the first direction. For example, if the first direction is a horizontal direction from left to right, the end busbar 1 is located at the leftmost or rightmost side of the first battery string 2.

[0029] Among them, the back contact battery cell closest to the end busbar 1 in the first battery string 2 is the first end battery cell 22, and the connecting solder strip between the first end battery cell 22 and the end busbar 1 is the first end solder strip 21.

[0030] Specifically, the first end of the light-shielding strip 3 (such as...) Figure 2As shown, A1) is fixed between the connecting surfaces of the first end solder strip 21 and the first end battery cell 22. The portion of the solder strip 21 located on the first end battery cell 22 is not entirely fixed to the first end battery cell 22; rather, a portion is fixed to the first end battery cell 22, and the other portion is inserted into the first end of the light-shielding strip 3 and stacked above the first end A1 of the light-shielding strip 3. The first end A1 of the light-shielding strip 3 serves as a fixing fulcrum, used to fix the entire light-shielding strip 3 to the first end battery cell 22, preventing the light-shielding strip 3 from falling off.

[0031] Understandably, in the actual assembly process of the back-contact battery assembly, after completing the welding process of the first end solder strip 21, the first end battery cell 22, and the end busbar 1, the end busbar 1 is lifted upwards as a whole, so that the first end solder strip 21 and the first end battery cell 22 form a certain angle. At this time, the first end A1 of the light-shielding strip 3 can be embedded in the angled area between the first end solder strip 21 and the first end battery cell 22, and fixed on the welding plane of the first end battery cell 22 where it is welded to the first end solder strip 21. The angle between the welding plane of the first end solder strip 21 and the first end battery cell 22 can be set to be greater than or equal to 5°, such as 5°, 6°, 7°, or 8°, and is not specifically limited here. By limiting the angle between the welding plane of the first end solder strip 21 and the first end battery cell 22 to this range, the embedding difficulty of the light-shielding strip 3 can be reduced, making it easier for the first end A1 of the light-shielding strip 3 to be embedded between the first end solder strip 21 and the first end battery cell 22.

[0032] Specifically, the second end of the light-shielding strip 3 (such as...) Figure 2 As shown, A2 is located on the side of the end busbar 1 facing away from the first end solder strip 21. For example, if the top plane of the end busbar 1 is connected to the first end solder strip 21, then the second end A2 of the light-shielding strip 3 is located below the bottom plane of the end busbar 1 facing away from the top plane. The second end A2 of the light-shielding strip 3 is used to shield the end busbar 1 and the first end solder strip 21 connecting the end busbar 1. The second end A2 of the light-shielding strip 3 can be parallel to the bottom plane of the end busbar 1, or form a certain inclined angle with the bottom plane; the specific details are not limited here. It should be noted that the second end A2 of the light-shielding strip 3 does not need to contact the end busbar 1; it can be fixed by the first end A1 of the light-shielding strip 3, thus saving the connection process between the second end A2 of the light-shielding strip 3 and the end busbar 1, thereby reducing the process difficulty in the production of back-contact battery modules.

[0033] It is understood that the middle end of the light-shielding strip 3 is located between its first end A1 and its second end A2. Since the first end A1 and the second end A2 of the light-shielding strip 3 are respectively located at the first end battery cell 22 and the end busbar 1, its middle end can cover the gap between the first end battery cell 22 and the end busbar 1, thereby completely blocking the first end solder strip 21 located in the gap between the first end battery cell 22 and the end busbar 1. The middle end of the light-shielding strip 3 can be partially parallel to the first end solder strip 21, partially forming a certain angle with the first end solder strip 21, or entirely forming a certain angle with the first end solder strip 21; the specific details are not limited here.

[0034] In some embodiments, the thickness of the light-shielding strip 3 is less than 200 μm.

[0035] Specifically, the thickness of the light-shielding strip 3 can be 195μm, 190μm, 180μm, or 170μm, and is not limited here. Since the first end A1 of the light-shielding strip 3 is embedded between the first end solder strip 21 and the first end battery cell 22, and part of the first end solder strip 21 is fixed to the first end battery cell 22, while the other part is stacked with the first end of the light-shielding strip 3, if the thickness of the light-shielding strip 3 is too high, it will cause the other part of the first end solder strip 21 to arch upwards. Since part of the first end solder strip 21 is fixed to the first end battery cell 22, this can lead to cracking of the first end solder strip 21, thus affecting the power generation efficiency of the back-contact battery module. By limiting the thickness of the light-shielding strip 3 to this range, the occurrence of cracking of the first end solder strip 21 can be reduced, thereby improving the power generation efficiency of the back-contact battery module.

[0036] In some embodiments, the width of the first end A1 of the light-shielding strip 3 is greater than or equal to 2 mm.

[0037] Specifically, the width of the first end A1 of the light-shielding strip 3 can be 2mm, 2.5mm, 3mm, or 4mm, and is not limited here. The first end A1 of the light-shielding strip 3 serves as the overall fixing point of the light-shielding strip 3. By limiting the width of the first end to this range, the connection stability between the first end A1 and the first end battery cell 22 can be improved, thereby improving the overall stability of the light-shielding strip 3 and reducing the possibility of the light-shielding strip 3 falling off.

[0038] In some embodiments, the light-shielding strip 3 is made of any one of PET, PO, or PI materials.

[0039] Specifically, polyethylene terephthalate (PET) is a polymer obtained by transesterification of dimethyl terephthalate with ethylene glycol or by esterification of terephthalic acid with ethylene glycol to synthesize diethyl terephthalate, followed by polycondensation. It possesses excellent electrical insulation and physical-mechanical properties. Polyolefin (PO) is a polymer derived from olefin monomers, exhibiting good processing adaptability and physical-mechanical properties. Polyimide (PI) is an aromatic heterocyclic polymer containing imide groups in its molecular structure, possessing excellent mechanical properties and electrical insulation. By using any of the materials PET, PO, or PI, the processing convenience and stability of the light-shielding strip 3 can be improved.

[0040] In some embodiments, the second end A2 of the light-shielding strip 3 is fixedly connected to the end busbar 1 by hot stamping.

[0041] Specifically, the second end A2 of the light-shielding strip 3 can be fixed to the end manifold 1 by hot stamping to further improve the overall stability of the light-shielding strip 3 and prevent the light-shielding strip 3 from falling off.

[0042] In some embodiments, the distance from the end of the light-shielding strip 3 to the end of the end busbar 1 is greater than the distance from the end of the first end solder strip 21 to the end of the end busbar 1.

[0043] Specifically, the distance from the end of the light-shielding strip 3 to the end of the busbar 1 is... Figure 2 As shown in the diagram, A20, the distance by which the first end weld strip 21 extends beyond the end of the end busbar 1 is... Figure 2 C is shown in the diagram. During the production of the back-contact battery assembly, the length of the first battery string 2 may vary due to process precision issues. When the length of the first battery string 2 is too long, the width of the first end solder strip 21 connecting to the end busbar 1 may be greater than the width of the end busbar 1. In this case, the distance A20 from the end of the light-shielding strip 3 extending beyond the end of the end busbar 1 can be set to be greater than the distance C from the end of the first end solder strip 21 extending beyond the end of the end busbar 1, thus blocking the portion of the first end solder strip 21 that extends beyond the end busbar 1, reducing the leakage of the first end solder strip 21, and thereby improving the aesthetic appearance of the back-contact battery assembly. It should be noted that the end of the end busbar 1 is the plane of the end busbar 1 away from the first end battery cell 22 in the direction from the first end solder strip 21 towards the end busbar 1, and this plane is perpendicular to the first end solder strip 21.

[0044] Please see Figure 3In some embodiments, the back contact battery assembly includes a second battery string 4, and the first battery string 2 and the second battery string 4 are arranged along a first direction; both the first battery string 2 and the second battery string 4 include a plurality of back contact battery pieces arranged along a second direction and connected in series in sequence, the number of back contact battery pieces in the first battery string 2 and the second battery string 4 are the same, and the second direction intersects the first direction. In the first direction, the back contact battery assembly has a central busbar 5, and in the first battery string 2, the back contact battery cell closest to the central busbar 5 is the second end battery cell 23. In the second battery string 4, the back contact battery cell closest to the end busbar 1 is the third end battery cell 42, and the back contact battery cell closest to the middle busbar 5 is the fourth end battery cell 43. The distance between the first end battery cell 22 and the end busbar 1 in the second direction is the first distance (e.g., ...). Figure 3 As shown in H1), the distance between the third end battery cell 42 and the end busbar 1 in the second direction is the second distance (e.g., H1). Figure 3 (H2 shown); the second battery string 4 has a second end solder strip, and the third end battery cell 42 is electrically connected to the end busbar 1 through the second end solder strip; In this configuration, the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 43 in the second battery string 4 are aligned in the first direction, and the first spacing H1 is greater than the second spacing H2.

[0045] Specifically, the second battery string 4 includes a plurality of back-contact battery cells. These back-contact battery cells are connected in series along the second direction, and adjacent back-contact battery cells are electrically connected by solder strips. It is understood that the number of back-contact battery cells in the second battery string 4 is unlimited, and the number of back-contact battery cells in the first battery string 2 is the same as the number of back-contact battery cells in the second battery string 4. For example, the number of back-contact battery cells in both the first battery string 2 and the second battery string 4 can be 5, 6, 7, or 8, or it can also be 12, 13, 14, or 15. The specific number can be set according to the actual power requirement and is not limited here.

[0046] The second battery string 4 and the first battery string 2 are connected in series along the first direction. It should be noted that the first direction and the second direction are not specific fixed directions, but two opposite directions that intersect each other.

[0047] For example, if the first battery string 2 and the second battery string 4 are arranged from top to bottom, the first direction is the "vertical direction"; if the back-contact battery pieces in the first battery string 2 and the second battery string 4 are arranged from left to right, the second direction is the "horizontal direction". At this time, the first direction and the second direction are perpendicular to each other.

[0048] For example, if the first battery string 2 and the second battery string 4 are arranged from left to right, the first direction is the "horizontal direction"; if the back-contact battery pieces in the first battery string 2 and the second battery string 4 are arranged from top to bottom, the second direction is the "vertical direction". At this time, the first direction and the second direction are still perpendicular to each other.

[0049] The intermediate busbar 5 and the end busbar 1 are respectively disposed on the two ends of the first battery string 2 and the second battery string 4 in the second direction. The intermediate busbar 5 and the end busbar 1 may be hidden on the back of the first battery string 2 and the second battery string 4, or they may not be hidden on the back of the first battery string 2 and the second battery string 4. The solder strip connecting the third end battery piece 42 and the end busbar 1 is the second end solder strip.

[0050] It is understood that the end busbar 1 and the intermediate busbar 5 are parallel to each other, and the first direction and the second direction are perpendicular to each other. The second direction can be a direction perpendicular to the end busbar 1, or it can be understood as a direction perpendicular to the intermediate busbar 5. The first direction can be a direction parallel to the end busbar 1, or it can be understood as a direction parallel to the intermediate busbar 5.

[0051] Specifically, the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 43 in the second battery string 4 are aligned in the first direction. This can be understood as the spacing between the second end battery piece 23 in the first battery string 2 and the intermediate busbar 5 being the same as the spacing between the fourth end battery piece 43 in the second battery string 4 and the intermediate busbar 5. By aligning the second end battery piece 23 in the first battery string 2 and the fourth end battery piece 43 in the second battery string 4 in the first direction, the stability of current conduction can be ensured.

[0052] The first distance H1 between the first end battery cell 22 and the end busbar 1 in the first battery string 2 is greater than the second distance H2 between the third end battery cell 42 and the end busbar 1 in the second battery string 4.

[0053] Therefore, in the manufacturing process of back-contact battery modules, it is not necessary to precisely align the first end cell 22, the third end cell 42, and the end busbar 1 in different cell strings. This reduces the need for repeated adjustments to the positions of the first cell string 2 and the second cell string 4 by adding additional visual inspection equipment and moving equipment. This reduces the complexity of the process, increases the cycle time of manufacturing back-contact battery modules, and ultimately improves the production and manufacturing efficiency of back-contact battery modules.

[0054] Meanwhile, since the second spacing H2 is smaller than the first spacing H1, the shadow will first block the third end cell 42 in the second battery string 4, and then move towards the first end cell 22 in the first battery string 2, gradually blocking the first end cell 22 in the first battery string 2. When the third end cell 42 is blocked by the shadow, the power generation capacity will drop sharply, becoming a load that consumes the power of other cells, which will lead to a local temperature increase and form a hot spot effect. After the temperature detection device detects the hot spot effect of the third end cell 42, for example, if the temperature difference between the third end cell 42 and other cells is greater than a preset temperature value or the current difference between the third end cell 42 and other cells is greater than a preset current value, the shadow blocking triggering mechanism will be triggered immediately. When the shadow blocking triggering mechanism starts to operate, the central control system adjusts the bracket, causing it to move the first battery string 2 and the second battery string 4 simultaneously away from the shadow. In this way, the third end cell 42 can be changed from a state of being shaded to a state of not being shaded, thereby reducing the power generation loss during the time from when the third end cell 42 is shaded to when the shading is removed.

[0055] In some embodiments, the first end of the light-shielding strip 3 is located between the second end solder strip and the third end battery cell 42, and the second end is located on the side of the end busbar 1 facing away from the second end solder strip.

[0056] Specifically, the second battery string 4 and the first battery string 2 can share the same light-shielding strip 3. Since the first end and the second end of the light-shielding strip 3 are respectively located on the third end battery piece 42 and the end busbar 1, its middle end can cover the gap between the third end battery piece 42 and the end busbar 1, thereby completely blocking the second end solder strip located in the gap between the third end battery piece 42 and the end busbar 1.

[0057] In some embodiments, the distance between the light-shielding strip 3 and the end of the end busbar 1 is greater than the longest distance between the first end solder strip 21 and the end solder strip extending from the end of the end busbar 1.

[0058] Specifically, since the first spacing between the first end cell 22 in the first battery string 2 and the end busbar 1 is greater than the second spacing between the third end cell 42 in the second battery string 4 and the end busbar 1, there may be a difference between the width of the first end solder strip 21 connected to the end busbar 1 and the width of the second end solder strip connected to the end busbar 1. In this case, the distance by which the light-shielding strip 3 extends beyond the end of the end busbar 1 can be set to be greater than the longest distance by which the first end solder strip 21 and the second end solder strip extend beyond the end of the end busbar 1, so that the portions of the first end solder strip 21 and the second end solder strip that extend beyond the end busbar 1 can be blocked simultaneously, reducing the leakage of the first end solder strip 21 and the second end solder strip, thereby improving the aesthetic effect of the back contact battery assembly.

[0059] The photovoltaic system of this application includes the back contact battery module in any of the above embodiments.

[0060] In the embodiments of this application, the photovoltaic system can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0061] In the description of this specification, the references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the 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 one or more embodiments or examples.

[0062] Furthermore, the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A back-contact battery assembly, characterized in that, The back contact battery assembly includes: End busbar; A first battery string, the first battery string including a first end solder strip and a first end battery cell, the first end battery cell being electrically connected to the end busbar through the first end solder strip; A light-shielding strip, wherein the first end of the light-shielding strip is located between the first end solder strip and the first end battery cell, and the second end is located in the end busbar on the side facing away from the first end solder strip.

2. The back contact battery assembly according to claim 1, characterized in that, The thickness of the light-shielding strip is less than 200 μm.

3. The back contact battery assembly according to claim 1, characterized in that, The width of the first end of the light-shielding strip is greater than or equal to 2 mm.

4. The back contact battery assembly according to claim 1, characterized in that, The light-shielding strip is made of any one of the following materials: PET, PO, or PI.

5. The back contact battery assembly according to claim 1, characterized in that, The second end of the light-shielding strip is fixedly connected to the end busbar by hot stamping.

6. The back contact battery assembly according to claim 1, characterized in that, The distance by which the light-shielding strip extends beyond the end of the end busbar is greater than the distance by which the first end solder strip extends beyond the end of the end busbar.

7. The back contact battery assembly according to claim 1, characterized in that, The back contact battery assembly includes a second battery string, and the first battery string and the second battery string are arranged along a first direction; both the first battery string and the second battery string include a plurality of back contact battery cells arranged along a second direction and connected in series in sequence, and the number of back contact battery cells in the first battery string and the second battery string are the same, and the second direction intersects the first direction; In the first direction, the back contact battery assembly has a central busbar, and in the first battery string, the back contact battery cell closest to the central busbar is the second end battery cell; In the second battery string, the back contact battery cell closest to the end busbar is the third end battery cell, and the back contact battery cell closest to the middle busbar is the fourth end battery cell. The distance between the first end battery cell and the end busbar in the second direction is a first distance, and the distance between the third end battery cell and the end busbar in the second direction is a second distance. The second battery string has a second end solder strip, and the third end battery cell is electrically connected to the end busbar through the second end solder strip. Wherein, the second end battery cell in the first battery string and the fourth end battery cell in the second battery string are aligned in the first direction, and the first spacing is greater than the second spacing.

8. The back contact battery assembly according to claim 7, characterized in that, The first end of the light-shielding strip is located between the second end solder strip and the third end battery cell, and the second end is located in the end busbar on the side facing away from the second end solder strip.

9. The back contact battery assembly according to claim 7, characterized in that, The distance by which the light-shielding strip extends beyond the end of the end busbar is greater than the longest distance by which the first end weld strip and the second end weld strip extend beyond the end of the end busbar.

10. A photovoltaic system, characterized in that, Includes the back contact battery assembly according to any one of claims 1 to 9.

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