Solder strip, battery string, battery assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a solder strip, a cell string, a cell module and a photovoltaic system. The welding strip comprises a body and a polarized material layer, a connecting area and a non-connecting area are formed on the side, facing the first back contact cell and the to-be-connected piece, of the body, the first back contact cell and the to-be-connected piece are both arranged in the connecting area, and the polarized material layer covers and exceeds the non-connecting area. Thus, the polarizing material layer can disperse light waves in the non-connection area, the color of the exposed part of the welding strip is the same as the color of the front face of the first back contact cell and the front face of the to-be-connected piece, the welding-strip-free effect is visually achieved, and the color consistency of the cell string can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a welding ribbon, a battery string, a battery assembly and a photovoltaic system. Background Art

[0002] Solar cell power generation is a sustainable source of clean energy. It uses the photovoltaic effect of semiconductor pn junction to convert sunlight into electrical energy. In the related art, multiple solar cells are electrically connected through welding strips to form a battery string, and the battery string is packaged to form a battery module. However, the gaps between multiple solar cells will expose the welding strips, and the color of the exposed welding strips is very different from that of the solar cells, resulting in poor color consistency of the battery string. Based on this, how to improve the color consistency of the battery string has become an urgent problem to be solved. Utility Model Content

[0003] The present application provides a welding strip, a battery string, a battery assembly and a photovoltaic system, aiming to solve the problem of how to improve the color consistency of the battery string.

[0004] The welding strip provided in the present application is used to connect adjacent first back contact cells and parts to be connected. The welding strip includes a main body and a polarizing material layer. A connection area and a non-connection area are formed on the side of the main body facing the first back contact cell and the part to be connected. The first back contact cell and the part to be connected are both arranged in the connection area, and the polarizing material layer covers and exceeds the non-connection area.

[0005] Furthermore, the polarizing material layer is prepared by at least one of friction orientation, electric field orientation, magnetic field orientation, optical field orientation, stress orientation and stretching orientation.

[0006] Furthermore, the thickness of the polarizing material layer is 1 μm-100 μm.

[0007] Furthermore, the length of the polarizing material layer is 1 mm-100 mm.

[0008] Furthermore, the polarizing material layer is prepared by coating or pasting.

[0009] Furthermore, the length of the polarizing material layer extending beyond the non-connection area from the side close to the first back contact cell is less than or equal to 2 mm.

[0010] Furthermore, the polarizing material layer exceeds the non-connection area from the side close to the first back contact battery and extends into the connection area corresponding to the first back contact battery. A plurality of first welding parts are formed in the connection area. The first welding parts are used to connect the welding points of the first back contact battery, and the polarizing material layer avoids the first welding parts; or, the polarizing material layer covers a partial area of ​​the first welding parts.

[0011] Furthermore, the to-be-connected member includes a second back-contact cell, the second back-contact cell is adjacent to the first back-contact cell, and the welding ribbon connects the adjacent first back-contact cell and the second back-contact cell.

[0012] Furthermore, the polarizing material layer exceeds the non-connection area from the side close to the second back contact battery and extends into the connection area corresponding to the second back contact battery. A plurality of second welding parts are formed in the connection area. The second welding parts are used to connect the welding points of the second back contact battery, and the polarizing material layer avoids the second welding parts; or, the polarizing material layer covers a partial area of ​​the second welding parts.

[0013] Furthermore, the parts to be connected include bus bars, and the welding ribbon connects adjacent first back contact cells and the bus bars.

[0014] Furthermore, the polarizing material layer exceeds the non-connecting area from a side close to the bus bar and extends into the connecting area corresponding to the bus bar, and the polarizing material layer covers a part or all of the connecting area corresponding to the bus bar.

[0015] The battery string provided in the embodiments of the present application includes the welding strip described in any one of the above embodiments.

[0016] The battery assembly provided in the embodiments of the present application includes the battery string described in the above embodiments.

[0017] The photovoltaic system provided in the embodiments of the present application includes the battery assembly described in the above embodiments.

[0018] In the welding strip, battery string, battery assembly and photovoltaic system of the embodiment of the present application, the welding strip includes a body and a polarizing material layer, the body is formed with a connection area and a non-connection area on the side facing the first back contact battery and the part to be connected, the first back contact battery and the part to be connected are both arranged in the connection area, and the polarizing material layer covers and exceeds the non-connection area. In this way, the polarizing material layer can disperse the light waves in the non-connection area, so that the color of the exposed part of the welding strip is the same as the front color of the first back contact battery and the part to be connected, visually achieving the effect of no welding strip, and can improve the color consistency of the battery string. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the structure of a battery string according to an embodiment of the present application;

[0020] Figure 2 is another structural schematic diagram of a battery string according to an embodiment of the present application;

[0021] Figure 3 is another structural schematic diagram of a battery string according to an embodiment of the present application;

[0022] Figure 4 is a schematic structural diagram of a battery assembly according to an embodiment of the present application;

[0023] Figure 5 It is a structural schematic diagram of a photovoltaic system according to an embodiment of the present application.

[0024] Description of main component symbols:

[0025] Battery string 100 , welding ribbon 10 , body 11 , connection area 111 , non-connection area 112 , polarizing material layer 12 , first back contact battery 20 , to-be-connected component 30 , second back contact battery 31 , bus bar 32 , black film 321 , battery assembly 200 , photovoltaic system 300 . DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below 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 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 application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0027] In the description of the present application, 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 application 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 should not be understood as a limitation on the present application.

[0028] 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. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the description of this application, 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 this application can be understood according to specific circumstances.

[0030] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is 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 that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0032] In the related art, the gaps between multiple solar cells will expose the solder strips, and the color of the exposed solder strips is very different from that of the solar cells, resulting in poor color consistency of the battery string. In the present application, a polarizing material layer can be set at the position of the solder strips exposed between the gaps of the solar cells. The polarizing material layer can disperse the light waves in the non-connection area, so that the color of the exposed part of the solder strip is the same as the color of the front of the first back contact cell and the part to be connected, visually achieving the effect of no solder strips, and improving the color consistency of the battery string.

[0033] Embodiment 1

[0034] See also Figure 1 , Figure 2 and Figure 3The welding strip 10 provided in the present application is used to connect adjacent first back contact cells 20 and parts to be connected 30. The welding strip 10 includes a main body 11 and a polarizing material layer 12. The main body 11 is formed with a connection area 111 and a non-connection area 112 on one side facing the first back contact cell 20 and the part to be connected 30. The first back contact cell 20 and the part to be connected 30 are both arranged in the connection area 111, and the polarizing material layer 12 covers and exceeds the non-connection area 112.

[0035] In the embodiment of the present application, the non-connection area 112 corresponds to the gap between the first back contact cell 20 and the part to be connected 30, and the connection area 111 is respectively connected to the first back contact cell 20 and the part to be connected 30. At the same time, a polarizing material layer 12 is arranged in the non-connection area 112. The polarizing material layer 12 can disperse the light waves around the object, making it invisible when observed by the human eye, and visually achieving the effect of no solder strip 10.

[0036] In the embodiment of the present application, the color displayed by the polarizing material layer 12 is the same as the color of the front side (i.e., the light-receiving side) of the first back contact battery 20 and the member to be connected 30, so as to improve the color consistency of the battery string 100. In one embodiment, the front sides of the first back contact battery 20 and the member to be connected 30 are both displayed in black, and at this time, the polarizing material layer 12 is adjusted to display black. It is understandable that in other embodiments, the front sides of the first back contact battery 20 and the member to be connected 30 can also display other colors, and the polarizing material layer 12 cooperates to display the same color, and the specific color types and parameters are not limited here.

[0037] In the embodiment of the present application, the part to be connected 30 may be a second back contact battery 31 or a bus bar 32 , that is, the welding strip 10 may be used to connect two adjacent back contact batteries, or may be used to connect adjacent back contact batteries and bus bars 32 .

[0038] Specifically, the body 11 includes a copper core and a tin layer covering the copper core. The tin layer may cover the entire surface or a portion of the surface of the copper core. For example, the tin layer may cover the entire surface of the copper core facing the first back contact battery 20 and the entire surface away from the first back contact battery 20, but does not cover the side of the copper core. For another example, the tin layer covers the entire surface of the copper core.

[0039] Furthermore, the thickness of the copper core is 0.01mm-0.5mm. For example, 0.01mm, 0.02mm, 0.05mm, 0.08mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm. In this way, the thickness of the copper core is within a suitable range, which can avoid the poor strength and poor conductivity caused by the copper core being too thin, and can also avoid the waste of materials and increase in cost caused by the copper core being too thick.

[0040] Furthermore, the thickness of the tin layer is 0.01 mm-0.1 mm, for example 0.01 mm, 0.02 mm, 0.05 mm, 0.08 mm, 0.1 mm. In this way, the thickness of the tin layer is within a suitable range, which can avoid poor welding effect caused by too thin tin layer, and can also avoid waste of materials and increase of cost caused by too thick tin layer.

[0041] In the embodiments of the present application, the specific type of the tin layer is not limited to meet various requirements. For example, the tin layer can be a single tin layer or a tin alloy layer. The tin alloy layer includes but is not limited to at least one of a SnPb layer, a SnBi layer, and a SnAg layer.

[0042] Exemplarily, the width of the body 11 is 0.01mm-2.5mm. For example, it is 0.01mm, 0.02mm, 0.05mm, 0.08mm, 0.1mm, 0.5mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.5mm. In this way, the width of the body 11 is within a suitable range, which can avoid the poor strength and poor conductive effect caused by the body 11 being too narrow, and can also avoid the body 11 being too wide, which causes the body 11 to be connected to the opposite grid line of the first back contact battery 20, waste materials, and increase costs.

[0043] Specifically, “the first back contact cell 20 and the member to be connected 30 are both arranged in the connection area 111” means that the area of ​​the body 11 covered by the first back contact cell 20 and the member to be connected 30 is the connection area 111, and the area of ​​the body 11 not covered by the first back contact cell 20 and the member to be connected 30 is the non-connection area 112. Similarly, “the polarizing material layer 12 covers and exceeds the non-connection area 112” means that the polarizing material layer 12 not only covers the entire area of ​​the non-connection area 112, but also extends from the non-connection area 112 to the connection area 111. In other words, part of the polarizing material layer 12 is covered by the first back contact cell 20 or the member to be connected 30.

[0044] Furthermore, the projections of the first back contact cell 20 and the member to be connected 30 on the body 11 are the connection area 111 , and the position of the gap between the first back contact cell 20 and the member to be connected 30 facing the body 11 is the non-connection area 112 .

[0045] Embodiment 2

[0046] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the polarizing material layer 12 is prepared by at least one of friction orientation, electric field orientation, magnetic field orientation, optical field orientation, stress orientation and stretching orientation.

[0047] In this embodiment, the specific type of the polarizing material layer 12 is not limited to meet different requirements.

[0048] Embodiment 3

[0049] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the thickness of the polarizing material layer 12 is 1 μm-100 μm. For example, the thickness of the polarizing material layer 12 can be 1 μm, 2 μm, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0050] In this way, the thickness of the polarizing material layer 12 is within an appropriate range, which can avoid the polarizing material layer 12 being too light in color due to the thickness of the polarizing material layer 12 being too small, exposing the silver-white body 11 and affecting the color consistency, and can also avoid the high cost caused by the thickness of the polarizing material layer 12 being too large and the large height difference of the welding strip 10 causing cold soldering.

[0051] Optionally, the thickness of the polarizing material layer 12 is 5 μm-20 μm, for example 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm. In this way, the thickness of the polarizing material layer 12 is in a more suitable range, and the cost and the risk of cold solder joints are further reduced while ensuring color consistency, and the overall effect is better.

[0052] Embodiment 4

[0053] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the length of the polarizing material layer 12 is 1 mm-100 mm. For example, the length of the polarizing material layer 12 can be 1 mm, 2 mm, 5 mm, 7 mm, 10 mm, 15 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm.

[0054] In this way, the length of the polarizing material layer 12 is within an appropriate range, which can avoid the exposure of the silver-white body 11 between the first back contact battery 20 and the connected component 30 due to a too short length, which is beneficial to ensure the color consistency of the battery string 100 and can also avoid the high cost caused by an excessive length.

[0055] Embodiment 5

[0056] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the polarizing material layer 12 is prepared by coating or pasting.

[0057] In this way, the polarizing material layer 12 can be prepared on the body 11 of the solder strip 10 in a variety of preparation methods, which can meet the needs of various scenarios.

[0058] In one embodiment, the polarizing material layer 12 may be provided on the body 11 by using a dip coating process. The non-connection area 112 of the body 11 and the side away from the first back contact cell 20 may be shielded first, and then the body 11 may be immersed in a polarizing material solution, and after the polarizing material is solidified to form the polarizing material layer 12, the shielding film used for shielding may be removed, and the solder strip 10 required by the present application may be obtained.

[0059] In another embodiment, the polarizing material layer 12 may be provided on the body 11 by using a pasting process, that is, the corresponding polarizing material layer 12 may be directly pasted on the non-connection area 112. In this embodiment, a formed polarizing material layer 12 may be pasted, or an existing polarizer may be pasted, which is not specifically limited here.

[0060] In the example, the polarizing material can be sprayed on the body 11, and then the polarizing material can be cured to form the polarizing material layer 12. In this way, the polarizing material layer 12 can be set more accurately, the polarizing material layer 12 can be set faster, and the spraying equipment does not need to be in direct contact with the body 11, which can reduce pollution and damage to the body 11. Furthermore, at least one of light curing and heat curing can be performed, and the duration of light curing is less than or equal to 2s.

[0061] It is understandable that in other embodiments, other process methods may be used to form the polarizing material layer 12 , which are not specifically limited herein, to meet different requirements.

[0062] Embodiment 6

[0063] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the first back contact cell 20 is less than or equal to 2 mm. For example, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the first back contact cell 20 may be 2 mm, 1.9 mm, 1.5 mm, 1.3 mm, 1 mm, 0.8 mm, 0.5 mm, 0.2 mm, or 0.1 mm.

[0064] In this way, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the first back contact battery 20 is within an appropriate range, which can avoid the exposure of the silver-white body 11 on the side of the first back contact battery 20 due to a short length, which is beneficial to ensuring the color consistency of the battery string 100. It can also avoid covering the area of ​​the body 11 corresponding to the welding point of the first back contact battery 20 due to a long length, thereby avoiding interfering with the electrical conduction between the body 11 and the welding point of the first back contact battery 20.

[0065] Optionally, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the first back contact cell 20 may be 1 mm to 2 mm. For example, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 1.9 mm, or 2 mm. In this way, the color consistency of the battery string 100, the electrical conduction of the solder joints of the body 11 and the first back contact cell 20, and the cost of the soldering ribbon 10 are taken into consideration, and the overall effect is better.

[0066] Embodiment 7

[0067] See also Figure 1 , Figure 2 and Figure 3 In some optional embodiments, the polarizing material layer 12 extends beyond the non-connection area 112 from the side close to the first back contact battery 20 and extends into the connection area 111 corresponding to the first back contact battery 20. The connection area 111 is formed with a plurality of first welding portions (not shown in the figure). The first welding portions are used to connect the welding points of the first back contact battery 20, and the polarizing material layer 12 avoids the first welding portions; or, the polarizing material layer 12 covers a partial area of ​​the first welding portions.

[0068] In this way, the polarizing material layer 12 does not completely cover the first welding portion, thereby preventing the polarizing material layer 12 from interfering with the welding of the first welding portion and the first back contact cell 20 , ensuring that the first welding portion and the first back contact cell 20 can be electrically connected, thereby drawing out the current of the first back contact cell 20 .

[0069] In the implementation manner of the present application, the number of the first welding parts is not limited to meet different requirements. For example, the number of the first welding parts can be 2, 3, 4 or other numbers.

[0070] Specifically, a plurality of first welding portions are arranged at intervals, and each first welding portion corresponds to a welding point of the first back contact battery 20. It can be understood that in other embodiments, a plurality of first welding portions may correspond to a welding point of the first back contact battery 20. It should be noted that the polarizing material layer 12 may be an insulating layer.

[0071] Furthermore, “the polarizing material layer 12 avoids the first welding portion” means that the polarizing material layer 12 does not cover any area of ​​the first welding portion. In this way, the entire area of ​​the first welding portion can be electrically connected to the first back contact cell 20 .

[0072] Furthermore, “the polarizing material layer 12 covers a portion of the first welding portion” means that the polarizing material layer 12 does not cover the entire first welding portion. Thus, the area of ​​the first welding portion not covered by the polarizing material layer 12 can be electrically connected to the first back contact cell 20 .

[0073] Embodiment 8

[0074] See also Figure 1 and Figure 2 In some optional embodiments, the component 30 to be connected includes a second back contact cell 31 , the second back contact cell 31 is adjacent to the first back contact cell 20 , and the welding ribbon 10 connects the adjacent first back contact cell 20 and the second back contact cell 31 .

[0075] In this way, when the member to be connected 30 is a back contact battery, two adjacent back contact batteries are connected by the welding ribbon 10 so that the two adjacent back contact batteries are electrically conductive.

[0076] Specifically, the specifications of the first back contact cell 20 and the second back contact cell 31 may be the same or different; the structures of the first back contact cell 20 and the second back contact cell 31 may be the same or different. The specific relationship between the first back contact cell 20 and the second back contact cell 31 is not limited herein.

[0077] It can be understood that the "first" and "second" in the first back contact battery 20 and the second back contact battery 31 are relative concepts, which means that the two back contact batteries are different. Figure 1 In the example, the back contact battery on the left is marked as the first back contact battery 20, and the back contact battery on the right is marked as the second back contact battery 31, which is to use the back contact battery on the right as the component to be connected 30 of the back contact battery on the left. It can be understood that the back contact battery on the left can also be used as the component to be connected 30 of the back contact battery on the right.

[0078] In the embodiment of the present application, the spacing between the second back contact cell 31 and the first back contact cell 20 is not limited to meet different requirements. For example, the spacing between the second back contact cell 31 and the first back contact cell 20 can be 0.3mm-5mm. In this way, the spacing between the second back contact cell 31 and the first back contact cell 20 is within a suitable range, which can avoid the small operating space and high welding difficulty caused by too small spacing, and can also avoid the waste of component space and increased cost caused by too large spacing.

[0079] Embodiment 9

[0080] See also Figure 1 and Figure 2 In some optional embodiments, the polarizing material layer 12 extends beyond the non-connection area 112 from the side close to the second back contact battery 31 and extends into the connection area 111 corresponding to the second back contact battery 31. The connection area 111 is formed with a plurality of second welding portions (not shown in the figure). The second welding portions are used to connect the welding points of the second back contact battery 31, and the polarizing material layer 12 avoids the second welding portions; or, the polarizing material layer 12 covers a portion of the second welding portions.

[0081] In this way, the polarizing material layer 12 does not completely cover the second welding portion, thereby preventing the polarizing material layer 12 from interfering with the welding of the second welding portion and the second back contact battery 31 , ensuring that the second welding portion and the second back contact battery 31 can be electrically connected, thereby drawing out the current of the second back contact battery 31 .

[0082] In the embodiment of the present application, the number of the second welding parts is not limited to meet different requirements. For example, the number of the second welding parts can be 2, 3, 4 or other numbers.

[0083] Specifically, the plurality of second welding portions are arranged at intervals, and each second welding portion corresponds to a welding point of the second back contact battery 31. It can be understood that in other embodiments, the plurality of second welding portions may correspond to a welding point of the second back contact battery 31.

[0084] Furthermore, “the polarizing material layer 12 avoids the second welding portion” means that the polarizing material layer 12 does not cover any area of ​​the second welding portion. In this way, the entire area of ​​the second welding portion can be electrically connected to the second back contact cell 31 .

[0085] Furthermore, “the polarizing material layer 12 covers a part of the second welding part” means that the polarizing material layer 12 does not cover the entire second welding part. Thus, the area of ​​the second welding part not covered by the polarizing material layer 12 can be electrically connected to the second back contact cell 31 .

[0086] In some optional embodiments, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the second back contact cell 31 is less than or equal to 2 mm, for example, 2 mm, 1.9 mm, 1.5 mm, 1.3 mm, 1 mm, 0.8 mm, 0.5 mm, 0.2 mm, or 0.1 mm.

[0087] In this way, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the second back contact battery 31 is within an appropriate range, which can avoid the exposure of the silver-white body 11 on the side of the second back contact battery 31 due to a short length, which is beneficial to ensuring the color consistency of the battery string 100. It can also avoid covering the area of ​​the body 11 corresponding to the welding point of the second back contact battery 31 due to a long length, thereby avoiding interfering with the electrical conduction between the welding point of the body 11 and the second back contact battery 31.

[0088] Optionally, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the second back contact battery 31 is 1 mm to 2 mm. For example, 1 mm, 1.2 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2 mm. In this way, the color consistency of the battery string 100, the electrical conduction of the solder joints of the body 11 and the second back contact battery 31, and the cost of the soldering ribbon 10 are taken into consideration, and the overall effect is better.

[0089] Embodiment 10

[0090] See also Figure 2 and Figure 3 In some optional embodiments, the member to be connected 30 includes a bus bar 32 , and the welding ribbon 10 connects the adjacent first back contact cells 20 and the bus bar 32 .

[0091] In this way, when the member to be connected 30 is a bus bar 32 , the welding ribbon 10 is used to connect the adjacent back contact cells and the bus bar 32 , so that the adjacent back contact cells and the bus bar 32 are electrically conductive.

[0092] In the embodiment of the present application, the bus bar 32 may be a middle bus bar 32 located in the middle of the battery string 100. The bus bar 32 may also be an end bus bar 32 located at the end of the battery string 100. The specific position and specific form of the bus bar 32 are not limited here to meet various requirements.

[0093] In some optional embodiments, when the first back contact cell 20 and the polarizing material layer 12 are black, a black film 321 is provided on a side of the bus bar 32 facing away from the solder ribbon 10 .

[0094] Specifically, the black film 321 may cover the entire area of ​​the side of the bus bar 32 away from the soldering ribbon 10. In this way, the side of the bus bar 32 away from the soldering ribbon 10 is completely black, and the color consistency of the battery string 100 is better. It can be understood that in other embodiments, the black film 321 may cover a partial area of ​​the side of the bus bar 32 away from the soldering ribbon 10.

[0095] Furthermore, the RGB color value of the black film 321 is (0-20, 0-20, 0-20). In this way, the color with a color value in this range is considered to be black, which provides a suitable range for the color value of the black film 321, which can not only ensure the visual color consistency of the battery string 100 to the human eye, but also provide a certain fluctuation space for the color value of the black film 321, reduce the requirements for color value accuracy, thereby reducing costs and improving production efficiency.

[0096] Preferably, the RGB color value of the black film 321 is (0, 0, 0). In this way, the color of the black film 321 is standard black, so that the color consistency of the battery string 100 is the best.

[0097] Specifically, a black material may be sprayed on the bus bar 32, and then the black material may be cured to form a black film 321. In this way, the black film 321 is more accurately positioned, the black film 321 is faster to position, and the spraying equipment does not need to be in direct contact with the bus bar 32, thereby reducing contamination and damage to the bus bar 32. Furthermore, at least one of light curing and thermal curing may be performed, and the duration of light curing is less than or equal to 2 seconds.

[0098] It is understood that in still other embodiments, a black material may be disposed on the bus bar 32 using a dip coating process.

[0099] In some optional embodiments, the thickness of the black film 321 is 5 μm-150 μm, for example, 5 μm, 7 μm, 10 μm, 15 μm, 30 μm, 50 μm, 80 μm, 100 μm, 120 μm, 145 μm, or 150 μm.

[0100] In this way, the thickness of the black film 321 is within an appropriate range, which can avoid the black film 321 being too light in color and exposing the silvery-white bus bar 32 to affect the color consistency due to the thickness of the black film 321 being too small, and can also avoid the black film 321 being too thick and causing high costs.

[0101] Preferably, the thickness of the black film 321 is 5 μm-20 μm, for example, 5 μm, 7 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm. In this way, the thickness of the black film 321 is in a more suitable range, and the cost and the risk of cold solder joint are further reduced while ensuring the color consistency, and the overall effect is better.

[0102] Embodiment 11

[0103] See also Figure 2 and Figure 3In some optional embodiments, the polarizing material layer 12 extends beyond the non-connection area 112 from the side close to the bus bar 32 and into the connection area 111 corresponding to the bus bar 32 , and the polarizing material layer 12 covers part or all of the connection area 111 corresponding to the bus bar 32 .

[0104] In this way, the main body 11 of the welding ribbon 10 is covered by the polarizing material layer 12 at the junction with the bus bar 32 to avoid light leakage at the junction, which is beneficial to improving the color consistency of the battery string 100.

[0105] Specifically, when the polarizing material layer 12 is an insulating layer, the polarizing material layer 12 covers a portion of the connection area 111 corresponding to the bus bar 32. In this way, the electrical connection between the body 11 and the bus bar 32 can be achieved from the area not covered by the polarizing material layer 12.

[0106] Furthermore, when the polarizing material layer 12 covers the entire area of ​​the connection area 111 corresponding to the bus bar 32, the polarizing material layer 12 may be a conductive layer, or include a conductive portion in the portion extending into the connection area 111. In this way, the conductive portion may be used to achieve electrical connection between the body 11 and the bus bar 32.

[0107] In some optional embodiments, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the bus bar 32 is less than or equal to 1.5 mm. For example, 1.5 mm, 1.3 mm, 1 mm, 0.8 mm, 0.7 mm, 0.5 mm, 0.2 mm, 0.1 mm. In this way, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the bus bar 32 is within a suitable range, and the main body 11 of the welding ribbon 10 can be covered by the polarizing material layer 12 at the junction with the bus bar 32, while avoiding the obstruction of the electrical connection between the welding ribbon 10 and the bus bar 32 and the high cost caused by the excessive length.

[0108] Optionally, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the bus bar 32 is less than or equal to 0.5 mm. 0.5 mm, 0.4 mm, 0.3 mm, 0.2 mm, 0.1 mm, 0.01 mm. In this way, the length of the polarizing material layer 12 extending beyond the non-connection area 112 from the side close to the bus bar 32 is in a more appropriate range, taking into account the electrical connection between the welding ribbon 10 and the bus bar 32 and the cost, and the overall effect is better.

[0109] Embodiment 12

[0110] See also Figure 1 , Figure 2 and Figure 3 The battery string 100 provided in the embodiment of the present application includes the welding strip 10 of any one of the above embodiments.

[0111] In the soldering ribbon 10 and the battery string 100 of the embodiment of the present application, the soldering ribbon 10 includes a body 11 and a polarizing material layer 12. The body 11 is formed with a connection area 111 and a non-connection area 112 on the side facing the first back contact battery 20 and the part to be connected 30. The first back contact battery 20 and the part to be connected 30 are both arranged in the connection area 111, and the polarizing material layer 12 covers and exceeds the non-connection area 112. In this way, the polarizing material layer 12 can disperse the light waves of the non-connection area 112, so that the color of the exposed part of the soldering ribbon 10 is the same as the color of the front of the first back contact battery 20 and the part to be connected 30, visually achieving the effect of no soldering ribbon 10, and improving the color consistency of the battery string 100.

[0112] Embodiment 13

[0113] See also Figure 4 The battery assembly 200 provided in the embodiment of the present application includes the battery string 100 of the above-mentioned embodiment twelve.

[0114] In the soldering ribbon 10, the battery string 100 and the battery assembly 200 of the embodiment of the present application, the soldering ribbon 10 includes a body 11 and a polarizing material layer 12. The body 11 is formed with a connection area 111 and a non-connection area 112 on the side facing the first back contact battery 20 and the part to be connected 30. The first back contact battery 20 and the part to be connected 30 are both arranged in the connection area 111, and the polarizing material layer 12 covers and exceeds the non-connection area 112. In this way, the polarizing material layer 12 can disperse the light waves of the non-connection area 112, so that the color of the exposed part of the soldering ribbon 10 is the same as the color of the front of the first back contact battery 20 and the part to be connected 30, visually achieving the effect of no soldering ribbon 10, and improving the color consistency of the battery string 100.

[0115] In this embodiment, multiple back-contact cells in the battery assembly 200 can be connected in series in sequence to form a battery string 100, thereby realizing the series bus output of current. For example, the series connection of battery cells can be achieved by setting a welding strip 10 (bus bar 32, interconnection bar), a conductive back plate, etc.

[0116] It is understandable that in such an embodiment, the battery assembly 200 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 back contact battery 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.

[0117] Photovoltaic glass can cover the adhesive film on the front of the back contact cell. The 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 back contact cell without affecting the efficiency of the back contact cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the back contact cell together. The presence of the adhesive film can seal and insulate the back contact cell and prevent water and moisture.

[0118] The backplane can be attached to the adhesive film on the back of the back contact battery. The backplane can protect and support the back contact battery and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the backplane, back contact battery, 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 200 and can stably support and install the battery assembly 200. For example, the battery assembly 200 can be installed at the required installation position through the frame.

[0119] Embodiment 14

[0120] See also Figure 5 The photovoltaic system 300 provided in the embodiment of the present application includes the battery assembly 200 of the above-mentioned embodiment thirteen.

[0121] In the welding strip 10, the battery string 100, the battery assembly 200 and the photovoltaic system 300 of the embodiment of the present application, the welding strip 10 includes a body 11 and a polarizing material layer 12. The body 11 is formed with a connection area 111 and a non-connection area 112 on the side facing the first back contact battery 20 and the part to be connected 30. The first back contact battery 20 and the part to be connected 30 are both arranged in the connection area 111, and the polarizing material layer 12 covers and exceeds the non-connection area 112. In this way, the polarizing material layer 12 can disperse the light waves of the non-connection area 112, so that the color of the exposed part of the welding strip 10 is the same as the front color of the first back contact battery 20 and the part to be connected 30, visually achieving the effect of no welding strip 10, and can improve the color consistency of the battery string 100.

[0122] In this embodiment, the photovoltaic system 300 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 300 are not limited to this, that is, the photovoltaic system 300 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 300 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery assemblies 200. For example, multiple battery assemblies 200 may 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 convert it into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0123] 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.

[0124] In addition, the above are only preferred embodiments of the present application and are 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 welding strip for connecting adjacent first back contact cells and a to-be-connected component, characterized in that: The welding strip includes a main body and a polarizing material layer, wherein a connection area and a non-connection area are formed on the side of the main body facing the first back contact cell and the part to be connected, the first back contact cell and the part to be connected are both arranged in the connection area, and the polarizing material layer covers and exceeds the non-connection area.

2. The welding strip according to claim 1, characterized in that The polarizing material layer is prepared by at least one of friction orientation, electric field orientation, magnetic field orientation, optical field orientation, stress orientation and stretching orientation.

3. The soldering strip according to claim 1, characterized in that: The thickness of the polarizing material layer is 1 μm-100 μm.

4. The welding strip according to claim 1, characterized in that The length of the polarizing material layer is 1 mm-100 mm.

5. The welding strip according to claim 1, characterized in that The polarizing material layer is prepared by coating or pasting.

6. The welding strip according to claim 1, characterized in that The length of the polarizing material layer extending beyond the non-connection area from the side close to the first back contact cell is less than or equal to 2 mm.

7. The welding strip according to claim 1, characterized in that: The polarizing material layer extends beyond the non-connection area from the side close to the first back contact battery and into the connection area corresponding to the first back contact battery. A plurality of first welding parts are formed in the connection area. The first welding parts are used to connect the welding points of the first back contact battery. The polarizing material layer avoids the first welding parts; or, the polarizing material layer covers a partial area of ​​the first welding parts.

8. The welding strip according to claim 1, characterized in that: The to-be-connected member includes a second back-contact cell, the second back-contact cell is adjacent to the first back-contact cell, and the welding ribbon connects the adjacent first back-contact cell and the second back-contact cell.

9. The welding strip according to claim 8, characterized in that: The polarizing material layer extends beyond the non-connection area from the side close to the second back contact battery and into the connection area corresponding to the second back contact battery. A plurality of second welding parts are formed in the connection area. The second welding parts are used to connect the welding points of the second back contact battery. The polarizing material layer avoids the second welding parts; or, the polarizing material layer covers a partial area of ​​the second welding parts.

10. The welding strip according to claim 1, characterized in that: The parts to be connected include bus bars, and the welding ribbon connects adjacent first back contact cells and the bus bars.

11. The welding strip according to claim 10, characterized in that: The polarizing material layer extends beyond the non-connecting area from a side close to the bus bar and into the connecting area corresponding to the bus bar. The polarizing material layer covers a part or all of the connecting area corresponding to the bus bar.

12. A battery string, characterized in that: Comprising a welding strip as described in any one of claims 1-11.

13. A battery assembly, characterized in that: Comprising the battery string as claimed in claim 12.

14. A photovoltaic system, characterized in that: Comprising the battery assembly as claimed in claim 13.

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