Battery assembly and photovoltaic system

Abstract

The invention relates to the field of photovoltaic technology. A battery assembly and a photovoltaic system are provided. The battery assembly comprises a plurality of battery strings, each battery string comprises a plurality of welding strips and a plurality of back contact batteries, the plurality of back contact batteries comprise first battery pieces and second battery pieces which are arranged in sequence, and the first battery pieces and the second battery pieces are partially overlapped in an overlapping area. The welding strip is connected with at least one back contact battery; the part, arranged in the overlapping area, of the welding strip is a first component, the thickness of the first component is smaller than 0.28 mm, and the width of the first component is larger than 0.5 mm. Therefore, according to the battery assembly provided by the embodiment of the invention, the first component of the welding strip is arranged in the overlapping area, and the thickness of the first component in the welding strip is less than 0.28 mm, so that the thickness of the welding strip can be reduced, the thickness of the battery assembly is reduced, and the hidden crack and fragment risks of the back contact battery during lamination are further reduced.

Description

Technical Field

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

[0002] In a battery assembly, a welding strip is provided on the battery cell to collect current or conduct confluence. However, the battery assembly in the related art is relatively thick, which easily leads to hidden cracks and fragments of the battery cell during lamination. Based on this, how to design and reduce the thickness of the battery assembly has become an urgent problem to be solved. Summary of the invention

[0003] The present invention provides a battery assembly and a photovoltaic system to solve the technical problem of how to reduce the thickness of the battery assembly.

[0004] The embodiment of the present invention is implemented as follows: the present invention provides a battery assembly and a photovoltaic system. The battery assembly includes a plurality of battery strings, each of which includes a plurality of welding strips and a plurality of back-contact batteries, and the plurality of back-contact batteries include a first battery sheet and a second battery sheet arranged in sequence, the first battery sheet and the second battery sheet partially overlap in the overlapping area, and the welding strip is connected to at least one of the back-contact batteries; the portion of the welding strip provided in the overlapping area is a first component, the thickness of the first component is less than 0.28 mm, and the width of the first component is greater than 0.5 mm. In this way, in the battery assembly of the embodiment of the present invention, since the first component of the welding strip is provided in the overlapping area and the thickness of the first component in the welding strip is less than 0.28 mm, the thickness of the welding strip can be reduced, thereby reducing the thickness of the battery assembly, and further reducing the risk of hidden cracks and fragments of the back-contact battery during lamination.

[0005] Furthermore, in the thickness direction of the welding strip, the cross-sectional area of ​​the first component is 0.1 mm 2 Up to 0.5mm 2 In this way, while reducing the overall thickness of the battery assembly, the cross-sectional area of ​​the welding strip can be maintained appropriately to ensure the current collection of the welding strip.

[0006] Furthermore, the soldering strip further comprises a second component, and the thickness of the second component is greater than the thickness of the first component. In this way, the soldering strip may include the second component and the first component at the same time. When manufacturing the soldering strip, the soldering strip in the embodiment of the present invention may be obtained by thinning a part of the existing soldering strip, so as to reduce the manufacturing cost of the soldering strip.

[0007] Furthermore, the portion of the first cell and the second cell other than the overlapping area is a non-overlapping area, and the second component is arranged in the non-overlapping area. In this way, since the first component is arranged in the overlapping area, the total thickness of the adjacent back contact cells after overlapping can be reduced, thereby reducing the risk of hidden cracks and fragments of the back contact cells during lamination. At the same time, since the second component is arranged in the non-overlapping area, the current collection efficiency of the welding strip in the non-overlapping area can be increased, thereby improving the efficiency of the battery assembly.

[0008] Furthermore, it also includes a first bus bar, the first bus bar connects two adjacent battery strings, the welding strip is insulated or conductively connected to the first bus bar; in the thickness direction of the back contact battery, the projection of the first component on the back contact battery overlaps with the projection of the first bus bar on the back contact battery. In this way, the thickness of the overlapping part of the first bus bar and the welding strip can be reduced, thereby reducing the thickness of the battery assembly, thereby reducing the risk of hidden cracks and fragments of the back contact battery when the battery assembly is laminated.

[0009] Furthermore, the first bus bar includes a third component, and in the thickness direction of the back contact battery, the projection of the third component on the back contact battery overlaps with the projection of the welding strip on the back contact battery; the thickness of the third component is less than 0.5 mm, and the width of the third component is greater than 7 mm. In this way, the battery assembly of the embodiment of the present invention can reduce the first bus bar, thereby reducing the thickness of the battery assembly.

[0010] Furthermore, the first bus bar further includes a fourth component, and the thickness of the fourth component is greater than the thickness of the third component. In this way, the first bus bar can include the fourth component and the third component at the same time. When manufacturing the first bus bar, the first bus bar in the embodiment of the present invention can be obtained by thinning a part of the existing bus bar, so as to reduce the manufacturing cost of the first bus bar.

[0011] Furthermore, in the thickness direction of the back contact battery, the projection of the fourth component on the back contact battery avoids the projection of the welding strip on the back contact battery. In this way, the portion of the battery assembly where the welding strip does not overlap with the first bus bar can maintain a high mechanical strength, and the current collection efficiency of the fourth component is improved, thereby optimizing the stability and performance of the battery assembly.

[0012] Furthermore, the ratio of the length of the third component to the length of the first bus bar is 0.05 to 1. In this way, the flexibility of the first bus bar in application can be improved. The user can flexibly set the structure of the first bus bar according to actual conditions.

[0013] Furthermore, it also includes a second bus bar, which connects two adjacent battery strings; in the thickness direction of the back contact battery, the projection of the first component on the back contact battery overlaps with the projection of the second bus bar on the back contact battery; in the thickness direction of the back contact battery, the projection of the second component on the back contact battery avoids the projection of the second bus bar on the back contact battery. In this way, the thickness of the overlapping part of the second bus bar and the welding strip can be reduced, thereby reducing the thickness of the battery assembly, thereby reducing the risk of hidden cracks and fragments of the back contact battery when the battery assembly is laminated. At the same time, it ensures that the non-overlapping part of the second bus bar and the welding strip can maintain a high mechanical strength, and improves the current collection efficiency of the non-overlapping part of the second bus bar and the welding strip, thereby optimizing the stability and performance of the battery assembly.

[0014] Furthermore, the ratio of the length of the first component to the length of the welding strip is 0.05 to 1. In this way, the flexibility of the welding strip application can be improved. The user can flexibly set the structure of the welding strip according to actual conditions.

[0015] The embodiment of the present invention also provides another battery assembly, the battery assembly includes a plurality of battery strings, each of the battery strings includes a plurality of bus bars and a plurality of back contact batteries, the bus bars connect two adjacent battery strings, the plurality of back contact batteries include a first battery sheet and a second battery sheet arranged in sequence, the first battery sheet and the second battery sheet partially overlap in the overlapping area; the battery string also includes a first welding strip, the first welding strip is insulated or conductively connected to the bus bar; the bus bar includes a first section, in the thickness direction of the back contact battery, the projection of the first section on the back contact battery overlaps with the projection of the first welding strip on the back contact battery, the thickness of the first section is less than 0.5 mm, and the width of the first section is greater than 7 mm. In this way, the thickness of the first section in the bus bar is less than 0.5 mm, which can reduce the thickness of the overlapping portion of the first welding strip and the bus bar, thereby reducing the thickness of the battery assembly, thereby reducing the thickness of the battery assembly, and thereby reducing the risk of hidden cracks and fragments of the back contact battery during lamination.

[0016] Furthermore, in the thickness direction of the busbar, the cross-sectional area of ​​the first section is 0.8 mm 2 Up to 2mm 2 In this way, while reducing the overall thickness of the battery assembly, the cross-sectional area of ​​the busbar can be maintained appropriately to ensure the current collection of the busbar.

[0017] Furthermore, the busbar further includes a second section, and the thickness of the second section is greater than the thickness of the first section. In this way, the busbar can include the second section and the first section at the same time. When manufacturing the busbar, the busbar in the embodiment of the present invention can be obtained by thinning a part of the existing busbar, so as to reduce the manufacturing cost of the busbar.

[0018] Furthermore, the first welding strip includes a third section; in the thickness direction of the back contact battery, the projection of the third section on the back contact battery overlaps with the projection of the bus bar on the back contact battery; the thickness of the third section is less than 0.28 mm, and the width of the first section is greater than 0.5 mm. In this way, the thickness of the overlapping portion of the first welding strip and the bus bar can be reduced, thereby reducing the thickness of the battery assembly, thereby reducing the risk of hidden cracks and fragments of the back contact battery when the battery assembly is laminated.

[0019] Furthermore, the first welding strip further includes a fourth section, and the thickness of the fourth section is greater than the thickness of the third section. In this way, the first welding strip may include the fourth section and the third section at the same time. When manufacturing the first welding strip, the first welding strip in the embodiment of the present invention can be obtained by thinning a part of the existing welding strip, so as to reduce the manufacturing cost of the first welding strip.

[0020] Furthermore, in the thickness direction of the back contact battery, the projection of the fourth section on the back contact battery avoids the projection of the bus bar on the back contact battery. In this way, the portion of the battery assembly where the first welding strip and the bus bar do not overlap can maintain a high mechanical strength, and the current collection efficiency of the fourth section is improved, thereby optimizing the stability and performance of the battery assembly.

[0021] Furthermore, the ratio of the length of the third section to the length of the first welding strip is 0.05 to 1. In this way, the flexibility of the first welding strip in application can be improved. The user can flexibly set the structure of the first bus bar according to actual conditions.

[0022] Furthermore, it also includes a second welding strip, which is insulated or conductively connected to the bus bar; in the thickness direction of the back contact battery, the projection of the first section on the back contact battery overlaps with the projection of the bus bar on the back contact battery; in the thickness direction of the back contact battery, the projection of the second section on the back contact battery avoids overlapping with the projection of the bus bar on the back contact battery. In this way, the thickness of the overlapping part of the second welding strip and the bus bar can be reduced, thereby reducing the thickness of the battery assembly, thereby reducing the risk of hidden cracks and fragments of the back contact battery when the battery assembly is laminated. At the same time, it ensures that the non-overlapping part of the second welding strip and the bus bar can maintain a high mechanical strength, and improves the current collection efficiency of the non-overlapping part of the second welding strip and the bus bar, thereby optimizing the stability and performance of the battery assembly.

[0023] Furthermore, the ratio of the length of the first section to the length of the welding strip is 0.05 to 1. In this way, the flexibility of the busbar application can be improved. The user can flexibly set the structure of the busbar according to actual conditions.

[0024] An embodiment of the present invention further provides a photovoltaic system, which includes the battery assembly as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 is a schematic diagram of a module of a photovoltaic system provided by an embodiment of the present invention;

[0027] Figure 2 is a top view of a partial structure of a battery assembly provided by an embodiment of the present invention;

[0028] Figure 3 is a side view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0029] Figure 4 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0030] Figure 5 is a schematic cross-sectional structural diagram of a first component in a battery assembly provided by an embodiment of the present invention;

[0031] Figure 6 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0032] Figure 7 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0033] Figure 8 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0034] Fig. 9 A side view of another part of the structure of a battery assembly provided by an embodiment of the present invention

[0035] Fig.10 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0036] Fig.11 is a front view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0037] Fig.12 is a front view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0038] Fig.13 is a top view of another part of the structure of a battery assembly provided by an embodiment of the present invention;

[0039] Fig.14 is a schematic cross-sectional structural diagram of a third component in a battery assembly provided by an embodiment of the present invention;

[0040] Fig.15 is a top view of a partial structure of a battery assembly provided by another embodiment of the present invention;

[0041] Fig.16 is a top view of another part of the structure of a battery assembly provided by another embodiment of the present invention;

[0042] Fig.17 is a top view of another part of the structure of a battery assembly provided by another embodiment of the present invention;

[0043] Fig.18 is a front view of a partial structure of a battery assembly provided by another embodiment of the present invention;

[0044] Fig.19 is a front view of another part of the structure of a battery assembly provided by another embodiment of the present invention;

[0045] Fig. 20 is a top view of another part of the structure of a battery assembly provided by another embodiment of the present invention;

[0046] Fig.21 is a top view of another part of the structure of a battery assembly provided by another embodiment of the present invention;

[0047] Fig. 22 A top view of another portion of a battery assembly provided by another embodiment of the present invention;

[0048] Fig.23 is a schematic cross-sectional structural diagram of the first section of a battery assembly provided by another embodiment of the present invention;

[0049] Fig.24 It is a schematic diagram of the cross-sectional structure of the third section of a battery assembly provided in another embodiment of the present invention.

[0050] Explanation of main component symbols: 1000, photovoltaic system; 100, battery assembly; 10, welding ribbon; 20, back contact battery; 30, first bus bar; 40, second bus bar; 50, insulating layer; 60, bus bar; 70, first welding ribbon; 80, second welding ribbon; 11, first component; 12, second component; 21, first battery cell; 22, second battery cell; 31, third component; 32, fourth component; 61, first section; 62, second section; 71, third section; 72, fourth section; 201, overlapping area; 202, non-overlapping area. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0052] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "top", "bottom", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] In the present invention, 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.

[0056] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use scenarios of other materials.

[0057] See also Figure 1 The photovoltaic system 1000 in the embodiment of the present invention may include the battery assembly 100 in the embodiment of the present invention. The battery assembly 100 in the embodiment of the present invention may include a plurality of battery cells, and the plurality of battery cells may be sequentially connected in series through the welding strip 10 to form a battery string. The battery strings in the battery assembly 100 may be connected in series, in parallel, or in series-parallel combination to realize current bus output. For example, the connection between the battery strings may be realized through the bus bar 60.

[0058] like Figures 2 to 14 As shown, an embodiment of the present invention provides a battery assembly 100, the battery assembly 100 includes a plurality of battery strings, each battery string includes a plurality of welding strips 10 and a plurality of back-contact batteries 20, the plurality of back-contact batteries 20 include a first battery cell 21 and a second battery cell 22 arranged in sequence, the first battery cell 21 and the second battery cell 22 partially overlap in an overlapping area 201, the welding strip 10 is connected to at least one back-contact battery 20; the portion of the welding strip 10 provided in the overlapping area 201 is a first component 11, the thickness H1 of the first component 11 is less than 0.28 mm, and the width K1 of the first component 11 is greater than 0.5 mm.

[0059] Thus, in the battery assembly 100 of the embodiment of the present invention, since the first component 11 of the welding strip 10 is disposed in the overlapping area 201, the thickness H1 of the first component 11 in the welding strip 10 is less than 0.28 mm, so the thickness of the welding strip 10 can be reduced, thereby reducing the thickness of the battery assembly 100, and further reducing the risk of hidden cracks and fragments of the back contact battery 20 during lamination. At the same time, since the width K1 of the first component 11 in the welding strip 10 is greater than 0.5 mm, the cross-sectional area of ​​the welding strip 10 can be maintained while reducing the thickness of the welding strip 10, thereby stabilizing the current collection efficiency of the welding strip 10, which is conducive to improving the power generation efficiency of the battery assembly 100.

[0060] Specifically, the battery assembly 100 includes a plurality of battery strings, and two adjacent battery strings may be connected via a bus structure.

[0061] Specifically, in order to eliminate the inter-cell spacing, in the embodiment of the present invention, there are provided several groups of partially overlapping first battery cells 21 and second battery cells 22. The first battery cells 21 and the second battery cells 22 are specifically two adjacent back contact batteries 20 in a battery string.

[0062] It is understandable that in the battery assembly 100, there may be only one group of partially overlapping first battery cells 21 and second battery cells 22. There may also be multiple groups of partially overlapping first battery cells 21 and second battery cells 22, which is not limited here.

[0063] Preferably, in the battery assembly 100 , two adjacent back-contact batteries 20 partially overlap, that is, all the back-contact batteries 20 in the battery assembly 100 are back-contact batteries 20 that overlap each other.

[0064] It is worth noting that “the first battery cell 21 and the second battery cell 22 partially overlap in the overlapping area 201 ” means that in the battery string, two adjacent back contact batteries 20 partially overlap. Specifically, the first battery cell 21 and the second battery cell 22 overlap in the overlapping area 201 .

[0065] It can be understood that the overlapping area 201 is specifically a portion where the first battery cell 21 overlaps with the second battery cell 22 in the first battery cell 21 ; and a portion where the second battery cell 22 overlaps with the first battery cell 21 in the second battery cell 22 .

[0066] A welding strip 10 is provided in the battery assembly 100, and the welding strip 10 is specifically conductively connected to an electrode of at least one back contact battery 20. It can be understood that the "electrode of the back contact battery 20" refers to the main grid and / or fine grid in the back contact battery 20. The back contact battery 20 can be a back contact battery 20 with a main grid, or a back contact battery 20 without a main grid, which is not limited here.

[0067] It is understood that “the soldering ribbon 10 is specifically conductively connected to the electrode of at least one back-contact battery 20 ” means that the soldering ribbon 10 can be conductively connected to only one electrode of the back-contact battery 20 . The soldering ribbon 10 can also be conductively connected to the electrodes of two back-contact batteries 20 .

[0068] For example, the soldering ribbon 10 may be conductively connected only to the positive electrode of the first battery cell 21 ; or, the soldering ribbon 10 may be conductively connected only to the negative electrode of the first battery cell 21 .

[0069] For example, the soldering ribbon 10 is conductively connected to the positive electrode of the first battery cell 21, and the soldering ribbon 10 is conductively connected to the negative electrode of the second battery cell 22; or, the soldering ribbon 10 is conductively connected to the negative electrode of the first battery cell 21, and the soldering ribbon 10 is conductively connected to the positive electrode of the second battery cell 22.

[0070] The back contact battery 20 is provided with a welding strip 10, which is specifically conductively connected to the electrode of the back contact battery 20. In order to reduce the thickness of the battery assembly 100, the welding strip 10 specifically includes a first component 11, and the thickness H1 of the first component 11 is less than 0.28 mm, for example, 0.27 mm, 0.25 mm, 0.2 mm, 0.15 mm, 0.13 mm, 0.11 mm, 0.1 mm, 0.08 mm.

[0071] In this way, the thickness of the battery assembly 100 in the lamination direction can be reduced, thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 during lamination.

[0072] The following table shows the value of tensile strength corresponding to the thickness H1 of the first component 11 in the welding strip 10 when the welding strip 10 is a copper welding strip 10 .

[0073]

[0074]

[0075] It is understandable that the tensile strength expresses the anti-fracture capability of the first component 11. Obviously, although the thickness of the battery assembly 100 can be reduced while reducing the thickness H1 of the first component 11, the tensile strength of the first component 11 will also be reduced at the same time, thereby reducing the anti-fracture capability of the welding ribbon 10, and thus increasing the risk of the welding ribbon 10 breaking in the battery assembly 100.

[0076] Thus, while reducing the thickness H1 of the first member 11 , the thickness H1 of the first member 11 cannot be too thin.

[0077] Preferably, the thickness H1 of the first component 11 is 0.1 mm to 0.28 mm. In this way, the thickness of the battery assembly 100 can be reduced while ensuring the tensile strength of the welding ribbon 10 and reducing the risk of the welding ribbon 10 breaking in the battery assembly 100.

[0078] See also Figures 2 to 13 The portion of the welding ribbon 10 disposed in the overlapping area 201 is the first component 11. It is understandable that although the overlapping arrangement of the first battery cell 21 and the second battery cell 22 can eliminate the cell spacing of the battery assembly 100, the thickness of the battery assembly 100 will be increased at the same time.

[0079] Therefore, in order to prevent the thickness of the battery assembly 100 from being too thick, thereby increasing the risk of hidden cracks in the back contact battery 20, in the embodiment of the present invention, the first component 11 is disposed in the overlapping area 201. By thinning the portion of the soldering strip 10 disposed in the overlapping area 201, the thickness of the soldering strip 10 can be reduced, thereby reducing the thickness of the battery assembly 100, and further reducing the risk of hidden cracks and fragments in the back contact battery 20 during lamination.

[0080] At the same time, after reducing the thickness of the welding strip 10, in order to maintain the current collection efficiency of the welding strip 10. In the embodiment of the present invention, the width K1 of the first component 11 is greater than 0.5 mm. For example, it is 0.6 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm. In this way, while reducing the thickness H1 of the first component 11 in the welding strip 10, the width K1 of the first component 11 can be increased to maintain the current collection efficiency of the welding strip 10 and improve the power generation efficiency of the battery assembly 100.

[0081] It can be understood that the current collection efficiency of the welding strip 10 is positively correlated with the cross-sectional area of ​​the welding strip 10. The larger the cross-sectional area, the smaller the resistance and the higher the current collection efficiency. Therefore, while the thickness of the first component 11 of the welding strip 10 is reduced, the width K1 of the first component 11 can be increased to maintain an appropriate cross-sectional area to ensure the current collection of the welding strip 10.

[0082] In a possible implementation, Figure 5 As shown, in the thickness direction of the welding strip 10, the cross-sectional area S1 of the first component 11 is 0.1 mm 2 Up to 0.5mm 2 For example, 0.1 mm 2 , 0.12mm 2 , 0.13mm 2 , 0.15mm 2 , 0.17mm 2 , 0.2mm 2 , 0.25mm 2 , 0.3mm 2, 0.35mm 2 , 0.4mm 2 , 0.45mm 2 , 0.5mm 2 In this way, while reducing the overall thickness of the battery assembly 100 , the cross-sectional area of ​​the welding ribbon 10 can be kept appropriate to ensure the current collection of the welding ribbon 10 .

[0083] In a possible implementation, Figure 2 , Figure 3 , Figure 4 and Figure 7 As shown, the welding ribbon 10 further includes a second member 12, and a thickness H2 of the second member 12 is greater than a thickness H1 of the first member 11. The second member 12 may be connected to the first member 11.

[0084] Specifically, in the embodiment of the present invention, the soldering strip 10 can be manufactured by thinning the existing soldering strip 10 , without re-manufacturing the soldering strip 10 , so as to reduce the manufacturing cost of the soldering strip 10 .

[0085] Specifically, the width K2 of the second member 12 is smaller than the width K1 of the first member 11 .

[0086] Thus, the soldering strip 10 may include both the second component 12 and the first component 11. When manufacturing the soldering strip 10, the soldering strip 10 in the embodiment of the present invention may be obtained by thinning a portion of the existing soldering strip 10, so as to reduce the manufacturing cost of the soldering strip 10.

[0087] For example, the soldering strip 10 in the prior art may be thinned, the thinned portion of the soldering strip 10 is the first component 11 of the soldering strip 10 , and the portion that is not thinned is the second component 12 of the soldering strip 10 .

[0088] Specifically, regarding the arrangement of the second components 12 and the first components 11, the number of the second components 12 can be one or more, and the number of the first components 11 can be one or more, which can be made according to actual conditions.

[0089] In a possible implementation, Figure 6 As shown, the soldering strips 10 are all first components 11. Specifically, all existing soldering strips 10 can be thinned so that all soldering strips 10 are first components 11. When the soldering strips 10 are applied to the battery assembly 100, the thickness of the battery assembly 100 can be reduced to the maximum extent.

[0090] In a possible implementation, Figure 3 and Figure 4As shown, the portion of the first battery cell 21 and the second battery cell 22 other than the overlapping area 201 is a non-overlapping area 202 , and the second component 12 is disposed in the non-overlapping area 202 .

[0091] Thus, since the first component 11 is disposed in the overlapping region 201, the total thickness of the adjacent back contact cells 20 after overlapping can be reduced, thereby reducing the risk of cracking and fragmentation of the back contact cells 20 during lamination. At the same time, since the second component 12 is disposed in the non-overlapping region 202, the current collection efficiency of the welding ribbon 10 in the non-overlapping region 202 can be increased, thereby improving the efficiency of the battery assembly 100.

[0092] Specifically, in the battery assembly 100, the overlapping portion of the first battery cell 21 and the second battery cell 22 has a great influence on the thickness of the battery assembly 100, so it is necessary to reduce the thickness of the overlapping area 201 in the battery assembly 100. Therefore, the first battery cell 21 and the second battery cell 22 partially overlap in the overlapping area 201, the first component 11 is arranged in the overlapping area 201, and the second component 12 is arranged in the non-overlapping area 202. Therefore, the arrangement of the first component 11 and the second component 12 in the welding strip 10 can effectively reduce the thickness of the overlapping area 201 with a larger thickness in the battery assembly 100, thereby effectively reducing the overall thickness of the battery assembly 100, while ensuring that the welding strip 10 portion in the non-overlapping area 202 with a smaller thickness in the battery assembly 100 can maintain a higher mechanical strength, and improve the current collection efficiency of the welding strip 10 in the non-overlapping area 202, thereby optimizing the stability and performance of the battery assembly 100.

[0093] Further, in a possible implementation, the first component 11 is at least partially located in the overlapping area 201. It is worth noting that "the first component 11 is at least partially located in the overlapping area 201" means that part of the first component 11 is located in the overlapping area 201, or the entire first component 11 is located in the overlapping area 201. In other words, the portion of the welding strip 10 outside the overlapping area 201 can be the first component 11 or the second component 12, which is not limited here.

[0094] In a possible implementation, Figures 6 to 12 As shown, the battery assembly 100 further includes a first bus bar 30, the first bus bar 30 connects two adjacent battery strings, and the welding ribbon 10 is insulated or conductively connected to the first bus bar 30. In the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20.

[0095] In this way, the thickness of the overlapping portion of the first bus bar 30 and the welding ribbon 10 can be reduced, thereby reducing the thickness of the battery assembly 100, thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 when the battery assembly 100 is laminated.

[0096] Specifically, the battery assembly 100 further includes a first bus bar 30 , which connects two adjacent battery strings. When arranged, the first bus bar 30 partially overlaps with the welding ribbon 10 .

[0097] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20” means that the projections of the first component 11 and the first bus bar 30 on the back contact battery 20 coincide with each other in the thickness direction of the back contact battery 20.

[0098] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first member 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20” can mean that the projection of part of the first member 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20; or the projection of the entire first member 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20. This is not limited here.

[0099] It is worth noting that “the first bus bar 30 partially overlaps with the welding ribbon 10”, which means that the first bus bar 30 and the welding ribbon 10 are partially stacked in the thickness direction of the battery assembly 100. The first bus bar 30 partially overlaps with the welding ribbon 10, which may mean that the welding ribbon 10 and the first bus bar 30 are directly in contact and overlapped, or that other elements are provided between the first bus bar 30 and the welding ribbon 10, and the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20.

[0100] In practical applications, the welding ribbon 10 and the first bus bar 30 are partially overlapped to achieve insulation or conductive connection between the first bus bar 30 and the welding ribbon 10. The portion of the welding ribbon 10 covering the first bus bar 30 is the first component 11. Of course, the portion of the welding ribbon 10 covering the first bus bar 30 can be the first component 11 or the second component 12, which is not limited here.

[0101] Specifically, the first bus bar 30 is conductively connected to the solder ribbon 10 through solder paste or conductive glue, and the first bus bar 30 is insulated from the solder ribbon 10 through an isolation strip.

[0102] Specifically, when the first bus bar 30 is connected to the welding ribbon 10, the overlapped portion of the first bus bar 30 and the welding ribbon 10 increases the thickness of the battery assembly 100. Therefore, in the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20, so that the portion of the welding ribbon 10 covering the first bus bar 30 is the first component 11, and the thickness of the battery assembly 100 can be reduced.

[0103] In a possible implementation, Figure 6 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 , Fig.12 , Fig.13 As shown, the first bus bar 30 includes a third member 31. In the thickness direction of the back contact battery 20, the projection of the third member 31 on the back contact battery 20 overlaps with the projection of the welding ribbon 10 on the back contact battery 20. The thickness H3 of the third member 31 is less than 0.5 mm, and the width K3 of the third member 31 is greater than 7 mm. For example, the thickness H3 of the third member 31 is 0.45 mm, 0.4 mm, 0.25 mm, 0.2 mm, 0.18 mm, 0.15 mm, 0.1 mm, and 0.05 mm. The width K3 of the third member 31 is 8 mm, 8.5 mm, 9 mm, 10 mm, and 15 mm.

[0104] Thus, in the battery assembly 100 of the embodiment of the present invention, since the projection of the third member 31 on the back contact battery 20 overlaps with the projection of the welding ribbon 10 on the back contact battery 20, the thickness H3 of the third member 31 is less than 0.5 mm, and the width K3 of the third member 31 is greater than 7 mm, the first bus bar 30 can be reduced, thereby reducing the thickness of the battery assembly 100. At the same time, the cross-sectional area of ​​the first bus bar 30 is maintained, thereby stabilizing the current collection efficiency of the first bus bar 30, which is conducive to improving the power generation efficiency of the battery assembly 100.

[0105] like Fig.14 As shown, in the thickness direction of the first bus bar 30, the cross-sectional area S2 of the third member 31 is 0.8 mm 2 Up to 2mm 2 For example, 0.8 mm 2 , 0.83mm 2 , 0.85mm 2 、0.88mm 2 , 0.9mm 2 , 0.95mm 2 , 1mm 2 , 1.15mm 2 , 1.3mm 2 , 1.32mm2 、1.35m 2 , 1.4mm 2 , 1.6mm 2 , 1.7mm 2 , 1.8mm 2 , 2mm 2 In this way, while reducing the overall thickness of the battery assembly 100 , the cross-sectional area S2 of the first bus bar 30 can be kept appropriate, thereby ensuring current collection of the first bus bar 30 .

[0106] Specifically, the projection of the third member 31 on the back contact battery 20 overlaps with the projection of the solder ribbon 10 on the back contact battery 20, which means that the projection of the third member 31 and the solder ribbon 10 on the back contact battery 20 coincide with each other in the thickness direction of the back contact battery 20. At the same time, the projection of the first member 11 and the first bus bar 30 on the back contact battery 20 coincides with each other in the thickness direction of the back contact battery 20.

[0107] In this way, when the welding ribbon 10 is insulated or conductively connected to the first bus bar 30, the portion of the welding ribbon 10 overlapping the first bus bar 30 is the first component 11; at the same time, the portion of the first bus bar 30 overlapping the welding ribbon 10 is the third component 31. In this way, the thickness of the structure formed by the overlap of the welding ribbon 10 and the first bus bar 30 in the battery assembly 100 can be reduced, thereby further reducing the thickness of the battery assembly 100.

[0108] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the third member 31 on the back contact battery 20 overlaps with the projection of the solder ribbon 10 on the back contact battery 20” may mean that the projection of part of the third member 31 on the back contact battery 20 overlaps with the projection of the solder ribbon 10 on the back contact battery 20; or the projection of all the third member 31 on the back contact battery 20 overlaps with the projection of the first bus bar 30 on the back contact battery 20. This is not limited here.

[0109] In a possible implementation, Figure 8 and Fig.11 As shown, the first bus bar 30 further includes a fourth member 32 , and a thickness H4 of the fourth member 32 is greater than a thickness H3 of the third member 31 .

[0110] Specifically, in the embodiment of the present invention, the first bus bar 30 can be manufactured by thinning the existing bus bar 60 , without re-manufacturing the first bus bar 30 , so as to reduce the manufacturing cost of the first bus bar 30 .

[0111] Thus, the first bus bar 30 may include both the fourth component 32 and the third component 31. When manufacturing the first bus bar 30, the first bus bar 30 in the embodiment of the present invention may be obtained by thinning a portion of the existing bus bar 60, so as to reduce the manufacturing cost of the first bus bar 30.

[0112] For example, the bus bar 60 in the prior art may be thinned, the thinned portion of the bus bar 60 is the third component 31 of the first bus bar 30 , and the portion not thinned is the fourth component 32 of the first bus bar 30 .

[0113] Specifically, the width K4 of the fourth member 32 is smaller than the width K3 of the third member 31 .

[0114] Specifically, regarding the arrangement of the fourth component 32 and the third component 31, the number of the fourth component 32 can be one or more, and the number of the third component 31 can be one or more, which can be made according to actual conditions.

[0115] In a possible implementation, the ratio of the length of the third member 31 to the length of the first bus bar 30 is 0.05 to 1. In this way, the flexibility of the first bus bar 30 when applied can be improved. The user can flexibly set the structure of the first bus bar 30 according to actual conditions.

[0116] In a possible implementation, Fig.10 As shown, the first busbars 30 may all be third components 31. Specifically, all existing busbars 60 may be thinned so that all first busbars 30 are third components 31. When the first busbars 30 are applied to the battery assembly 100, the thickness of the battery assembly 100 may be reduced to the maximum extent.

[0117] In a possible implementation, in the thickness direction of the back contact battery 20, the projection of the fourth member 32 on the back contact battery 20 avoids the projection of the welding ribbon 10 on the back contact battery 20. In this way, the portion of the battery assembly 100 where the welding ribbon 10 and the first bus bar 30 do not overlap can maintain a high mechanical strength, and the current collection efficiency of the fourth member 32 is improved, thereby optimizing the stability and performance of the battery assembly 100.

[0118] Specifically, in the battery assembly 100, the overlapping portion of the welding ribbon 10 and the first bus bar 30 has a great influence on the thickness of the battery assembly 100, so it is necessary to reduce the thickness of the overlapping portion of the welding ribbon 10 and the first bus bar 30 in the battery assembly 100. Therefore, in the thickness direction of the back contact battery 20, the projection of the third component 31 on the back contact battery 20 overlaps with the projection of the welding ribbon 10 on the back contact battery 20, and the projection of the fourth component 32 on the back contact battery 20 avoids the projection of the welding ribbon 10 on the back contact battery 20. Therefore, the arrangement of the third component 31 and the fourth component 32 in the first bus bar 30 can effectively reduce the thickness of the overlapping portion of the welding ribbon 10 and the first bus bar 30, thereby effectively reducing the overall thickness of the battery assembly 100, while ensuring that the portion of the battery assembly 100 that does not overlap with the first bus bar 30 can maintain a high mechanical strength, and improve the current collection efficiency of the fourth component 32, thereby optimizing the stability and performance of the battery assembly 100.

[0119] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the fourth component 32 on the back contact battery 20 avoids the projection of the solder ribbon 10 on the back contact battery 20” can mean that the projection of part of the fourth component 32 on the back contact battery 20 avoids the projection of the solder ribbon 10 on the back contact battery 20; or the projection of all the fourth component 32 on the back contact battery 20 avoids the projection of the solder ribbon 10 on the back contact battery 20. This is not limited here.

[0120] Specifically, in the thickness direction of the back contact battery 20, the projection of the third member 31 on the back contact battery 20 overlaps with the projection of the first member 11 on the back contact battery 20. In this way, when the first bus bar 30 is insulated or conductively connected to the welding ribbon 10, the thickness of the battery assembly 100 can be reduced to the maximum extent.

[0121] In a possible implementation, Fig.13 As shown, the battery assembly 100 further includes a second bus bar 40, which connects two adjacent battery strings, and the welding ribbon 10 is insulated or conductively connected to the second bus bar 40. In the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20; in the thickness direction of the back contact battery 20, the projection of the second component 12 on the back contact battery 20 avoids the projection of the second bus bar 40 on the back contact battery 20.

[0122] In this way, the thickness of the overlapping portion of the second bus bar 40 and the welding ribbon 10 can be reduced, thereby reducing the thickness of the battery assembly 100, thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 when the battery assembly 100 is laminated. At the same time, it ensures that the non-overlapping portion of the second bus bar 40 and the welding ribbon 10 can maintain a high mechanical strength, and improves the current collection efficiency of the non-overlapping portion of the second bus bar 40 and the welding ribbon 10, thereby optimizing the stability and performance of the battery assembly 100.

[0123] Specifically, the second bus bar 40 is conductively connected to the solder ribbon 10 through solder paste or conductive glue, and the second bus bar 40 is insulated from the solder ribbon 10 through an isolation strip.

[0124] Specifically, the battery assembly 100 further includes a second bus bar 40 , which connects two adjacent battery strings. When arranged, the second bus bar 40 partially overlaps with the welding ribbon 10 .

[0125] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20” means that the projections of the first component 11 and the second bus bar 40 on the back contact battery 20 coincide with each other in the thickness direction of the back contact battery 20.

[0126] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20” can mean that the projection of part of the first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20; or the projection of the entire first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20. This is not limited here.

[0127] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the second component 12 on the back contact battery 20 avoids the projection of the second bus bar 40 on the back contact battery 20” can mean that the projection of part of the second component 12 on the back contact battery 20 avoids the projection of the second bus bar 40 on the back contact battery 20; or the projection of the entire second component 12 on the back contact battery 20 avoids the projection of the second bus bar 40 on the back contact battery 20. This is not limited here.

[0128] It is worth noting that “the second bus bar 40 partially overlaps with the welding ribbon 10”, which means that the second bus bar 40 and the welding ribbon 10 are partially stacked in the thickness direction of the battery assembly 100. The second bus bar 40 partially overlaps with the welding ribbon 10, which may refer to the welding ribbon 10 directly contacting and overlapping with the second bus bar 40, or may refer to other elements being provided between the second bus bar 40 and the welding ribbon 10; the projection of the first component 11 on the back contact battery 20 overlaps with the projection of the second bus bar 40 on the back contact battery 20, and at the same time, the projection of the second component 12 on the back contact battery 20 avoids the projection of the second bus bar 40 on the back contact battery 20.

[0129] In a possible implementation, the ratio of the length of the first component 11 to the length of the welding strip 10 is 0.05 to 1. In this way, the flexibility of the welding strip 10 in application can be improved. The user can flexibly set the structure of the welding strip 10 according to actual conditions.

[0130] like Figures 15 to 24 As shown, an embodiment of the present invention further provides another battery assembly 100. The embodiment of the present invention provides a battery assembly 100, wherein the battery assembly 100 includes a plurality of battery strings, each battery string includes a plurality of bus bars 60 and a plurality of back-contact batteries 20, the bus bar 60 connects two adjacent battery strings, the plurality of back-contact batteries 20 include a first battery cell 21 and a second battery cell 22 arranged in sequence, the first battery cell 21 and the second battery cell 22 partially overlap in an overlapping area 201; the battery string also includes a first welding strip 70, the first welding strip 70 is insulated from or conductively connected to the bus bar 60; the bus bar 60 includes a first section 61, in the thickness direction of the back-contact battery 20, the projection of the first section 61 on the back-contact battery 20 overlaps with the projection of the first welding strip 70 on the back-contact battery 20, the thickness H5 of the first section 61 is less than 0.5 mm, and the width K5 of the first section 61 is greater than 7 mm.

[0131] In this way, the thickness H5 of the first section 61 of the busbar 60 is less than 0.5 mm, which can reduce the thickness of the overlapping portion of the first welding strip 70 and the busbar 60, thereby reducing the thickness of the battery assembly 100, thereby reducing the thickness of the battery assembly 100, and thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 during lamination. At the same time, since the width K5 of the first section 61 of the busbar 60 is greater than 7 mm, the cross-sectional area of ​​the busbar 60 can be maintained while reducing the thickness of the busbar 60, thereby stabilizing the current collection efficiency of the busbar 60, which is conducive to improving the power generation efficiency of the battery assembly 100.

[0132] Specifically, the battery assembly 100 further includes a first welding ribbon 70 , and when disposed, the first welding ribbon 70 partially overlaps with the bus bar 60 .

[0133] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first segment 61 on the back contact battery 20 overlaps with the projection of the first welding strip 70 on the back contact battery 20” means that the projection of the first segment 61 and the projection of the first welding strip 70 on the back contact battery 20 overlap in the thickness direction of the back contact battery 20.

[0134] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first segment 61 on the back contact battery 20 overlaps with the projection of the first welding ribbon 70 on the back contact battery 20” may mean that the projection of part of the first segment 61 on the back contact battery 20 overlaps with the projection of the first welding ribbon 70 on the back contact battery 20; or the projection of the entire first segment 61 on the back contact battery 20 overlaps with the projection of the first welding ribbon 70 on the back contact battery 20. This is not limited here.

[0135] It is worth noting that “the first welding ribbon 70 partially overlaps the bus bar 60”, which means that the first welding ribbon 70 and the bus bar 60 are partially stacked in the thickness direction of the battery assembly 100. The first welding ribbon 70 partially overlaps the bus bar 60, which may mean that the bus bar 60 and the first welding ribbon 70 are directly in contact and overlapped, or that other elements are provided between the first welding ribbon 70 and the bus bar 60, and the projection of the first section 61 on the back contact battery 20 overlaps with the projection of the first welding ribbon 70 on the back contact battery 20.

[0136] In practical applications, the bus bar 60 and the first welding strip 70 are partially overlapped to achieve insulation or conductive connection between the first welding strip 70 and the bus bar 60. The portion of the bus bar 60 covering the first welding strip 70 is the first section 61. Of course, the portion of the bus bar 60 covering the first welding strip 70 can be the first section 61 or the second section 62, which is not limited here.

[0137] Specifically, when the first welding ribbon 70 is connected to the bus bar 60, the overlapped portion of the first welding ribbon 70 and the bus bar 60 increases the thickness of the battery assembly 100. Therefore, in the thickness direction of the back contact battery 20, the projection of the first section 61 on the back contact battery 20 overlaps with the projection of the first welding ribbon 70 on the back contact battery 20, so that the portion of the bus bar 60 covering the first welding ribbon 70 is the first section 61, which can reduce the thickness of the battery assembly 100.

[0138] Specifically, the first welding ribbon 70 is conductively connected to the bus bar 60 through solder paste or conductive glue, and the first welding ribbon 70 is insulated from the bus bar 60 through an isolation strip.

[0139] Specifically, the battery assembly 100 includes a plurality of battery strings, and two adjacent battery strings may be connected via a bus bar 60. The bus bar 60 is specifically connected to the welding ribbon 10 in an insulated or conductive manner.

[0140] Specifically, the welding strip 10 is conductively connected to at least one electrode of the back contact battery 20. It can be understood that the "electrode of the back contact battery 20" refers to the main grid and / or fine grid in the back contact battery 20. The back contact battery 20 can be a back contact battery 20 with a main grid, or a back contact battery 20 without a main grid, which is not limited here.

[0141] It is understood that “the soldering ribbon 10 is specifically conductively connected to the electrode of at least one back-contact battery 20 ” means that the soldering ribbon 10 can be conductively connected to only one electrode of the back-contact battery 20 . The soldering ribbon 10 can also be conductively connected to the electrodes of two back-contact batteries 20 .

[0142] For example, the soldering ribbon 10 may be conductively connected only to the positive electrode of the first battery cell 21 ; or, the soldering ribbon 10 may be conductively connected only to the negative electrode of the first battery cell 21 .

[0143] For example, the soldering ribbon 10 is conductively connected to the positive electrode of the first battery cell 21, and the soldering ribbon 10 is conductively connected to the negative electrode of the second battery cell 22; or, the soldering ribbon 10 is conductively connected to the negative electrode of the first battery cell 21, and the soldering ribbon 10 is conductively connected to the positive electrode of the second battery cell 22.

[0144] Specifically, in order to eliminate the inter-cell spacing, in the embodiment of the present invention, there are provided several groups of partially overlapping first battery cells 21 and second battery cells 22. The first battery cells 21 and the second battery cells 22 are specifically two adjacent back contact batteries 20 in a battery string.

[0145] It is understandable that in the battery assembly 100, there may be only one group of partially overlapping first battery cells 21 and second battery cells 22. There may also be multiple groups of partially overlapping first battery cells 21 and second battery cells 22, which is not limited here.

[0146] Preferably, in the battery assembly 100 , two adjacent back-contact batteries 20 partially overlap, that is, all the back-contact batteries 20 in the battery assembly 100 are back-contact batteries 20 that overlap each other.

[0147] It is worth noting that “the first battery cell 21 and the second battery cell 22 partially overlap in the overlapping area 201 ” means that in the battery string, two adjacent back contact batteries 20 partially overlap. Specifically, the first battery cell 21 and the second battery cell 22 overlap in the overlapping area 201 .

[0148] It can be understood that the overlapping area 201 is specifically a portion where the first battery cell 21 overlaps with the second battery cell 22 in the first battery cell 21 ; and a portion where the second battery cell 22 overlaps with the first battery cell 21 in the second battery cell 22 .

[0149] A bus bar 60 is provided on the back contact battery 20, and the bus bar 60 specifically connects two adjacent battery strings. In order to reduce the thickness of the battery assembly 100, the bus bar 60 specifically includes a first section 61, and the thickness H5 of the first section 61 is less than 0.5mm. For example, 0.45mm, 0.4mm, 0.3mm, 0.28mm, 0.25mm, 0.2mm, 0.19mm, 0.18mm, 0.16mm, 0.15mm, 0.13mm, 0.11mm, 0.1mm, 0.08mm. In this way, the thickness dimension of the battery assembly 100 in the lamination direction can be reduced, thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 during lamination.

[0150] The following table shows the tensile strength values ​​corresponding to the thickness H5 of the first section 61 of the bus bar 60 when the bus bar 60 is a copper bus bar 60 .

[0151]

[0152]

[0153] It is understandable that the tensile strength expresses the anti-fracture capability of the first section 61. Obviously, although the thickness of the battery assembly 100 can be reduced while reducing the thickness H5 of the first section 61, the tensile strength of the first section 61 will also be reduced at the same time, thereby reducing the anti-fracture capability of the busbar 60, and thus increasing the risk of busbar 60 breaking in the battery assembly 100.

[0154] Thus, while reducing the thickness H5 of the first section 61 , the thickness H5 of the first section 61 cannot be too thin.

[0155] Preferably, the thickness H5 of the first section 61 is 0.08 mm to 0.2 mm. In this way, the thickness of the battery assembly 100 can be reduced while ensuring the tensile strength of the bus bar 60 and reducing the risk of the bus bar 60 breaking in the battery assembly 100.

[0156] At the same time, after reducing the thickness of the busbar 60, in order to maintain the current collection efficiency of the busbar 60. In the embodiment of the present invention, the width K5 of the first section 61 is greater than 7mm. For example, it is 7.1mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 11mm, 12mm, 13mm, 15mm. In this way, while reducing the first section 61 in the busbar 60, the width K5 of the first section 61 can be increased to maintain the current collection efficiency of the busbar 60 and improve the power generation efficiency of the battery assembly 100.

[0157] It is understandable that the current collection efficiency of the busbar 60 is positively correlated with the cross-sectional area of ​​the busbar 60. The larger the cross-sectional area, the smaller the resistance and the higher the current collection efficiency. Therefore, while the thickness of the first section 61 of the busbar 60 is reduced, the width K5 of the first section 61 can be increased to maintain an appropriate cross-sectional area to ensure the current collection of the busbar 60.

[0158] In a possible implementation, Fig.24 As shown, in the thickness direction of the busbar 60, the cross-sectional area S3 of the first section 61 is 0.8 mm 2 Up to 2mm 2 For example, 0.8 mm 2 , 0.83mm 2 , 0.85mm 2 、0.88mm 2 , 0.9mm 2 , 0.95mm 2 , 1mm 2 , 1.15mm 2 , 1.3mm 2 , 1.32mm 2 、1.35m 2 , 1.4mm 2 , 1.6mm 2 , 1.7mm 2 , 1.8mm 2 , 2mm 2 In this way, while reducing the overall thickness of the battery assembly 100 , the cross-sectional area of ​​the bus bar 60 can be kept appropriate to ensure current collection of the bus bar 60 .

[0159] In a possible implementation, Fig.15 , Fig.18 and Fig. 20 As shown, the bus bar 60 further includes a second segment 62, and a thickness H6 of the second segment 62 is greater than a thickness H5 of the first segment 61. The second segment 62 may be connected to the first segment 61.

[0160] Specifically, in the embodiment of the present invention, the bus bar 60 can be manufactured by thinning the existing bus bar 60 , without re-manufacturing the bus bar 60 , so as to reduce the manufacturing cost of the bus bar 60 .

[0161] Thus, the busbar 60 may include both the second section 62 and the first section 61. When manufacturing the busbar 60, the busbar 60 in the embodiment of the present invention may be obtained by thinning a portion of the existing busbar 60, so as to reduce the manufacturing cost of the busbar 60.

[0162] For example, the bus bar 60 in the prior art may be thinned, the thinned portion of the bus bar 60 is the first section 61 of the bus bar 60 , and the portion that is not thinned is the second section 62 of the bus bar 60 .

[0163] Specifically, the width K6 of the second segment is smaller than the width K5 of the first segment.

[0164] Specifically, regarding the arrangement of the second section 62 and the first section 61, the number of the second section 62 can be one or more, and the number of the first section 61 can be one or more, which can be made according to actual conditions.

[0165] In a possible implementation, Fig.16 , Fig.17 and Fig.19 As shown, the busbars 60 are all first sections 61. Specifically, all existing busbars 60 may be thinned so that all busbars 60 are first sections 61. When the busbars 60 are applied to the battery assembly 100, the thickness of the battery assembly 100 may be reduced to the maximum extent.

[0166] In a possible implementation, Fig.17 , Fig.18 and Fig. 20 As shown, the first welding strip 70 includes a third segment 71. In the thickness direction of the back contact battery 20, the projection of the third segment 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20; the thickness H7 of the third segment 71 is less than 0.28 mm, and the width K7 of the third segment 71 is greater than 0.5 mm.

[0167] For example, the thickness H7 of the third section 71 is 0.25 mm, 0.2 mm, 0.19 mm, 0.18 mm, 0.16 mm, 0.15 mm, 0.13 mm, 0.11 mm, 0.1 mm, or 0.08 mm.

[0168] For example, the width K7 of the third section 71 is 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, or 5 mm.

[0169] Thus, in the battery assembly 100 of the embodiment of the present invention, since the projection of the third section 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20, the thickness H7 of the third section 71 is less than 0.28 mm, and the width K7 of the third section 71 is greater than 0.5 mm, the first welding strip 70 can be reduced, thereby reducing the thickness of the battery assembly 100. At the same time, the cross-sectional area of ​​the first welding strip 70 is maintained, thereby stabilizing the current collection efficiency of the first welding strip 70, which is conducive to improving the power generation efficiency of the battery assembly 100.

[0170] In a possible implementation, Fig.24 As shown, in the thickness direction of the first welding strip 70, the cross-sectional area S4 of the third section 71 is 0.1 mm 2 Up to 0.5mm 2 For example, 0.1 mm 2 , 0.12mm 2 , 0.13mm 2 , 0.15mm 2 , 0.17mm 2 , 0.2mm 2 , 0.25mm 2 , 0.3mm 2 , 0.35mm 2 , 0.4mm 2 , 0.45mm 2 , 0.5mm 2 In this way, while reducing the overall thickness of the battery assembly 100 , the cross-sectional area of ​​the first welding ribbon 70 can be kept appropriate to ensure current collection of the first welding ribbon 70 .

[0171] Specifically, Fig.17 , Fig.18 , Fig. 20 and Fig.21 As shown, the projection of the third segment 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20, which means that the projection of the third segment 71 and the bus bar 60 on the back contact battery 20 coincide with each other in the thickness direction of the back contact battery 20. At the same time, the projection of the first segment 61 and the first welding ribbon 70 on the back contact battery 20 coincides with each other in the thickness direction of the back contact battery 20.

[0172] In this way, when the bus bar 60 is insulated or conductively connected to the first welding ribbon 70, the portion of the bus bar 60 that overlaps with the first welding ribbon 70 is the first section 61; at the same time, the portion of the first welding ribbon 70 that overlaps with the bus bar 60 is the third section 71. In this way, the thickness of the structure formed by the overlap of the bus bar 60 and the first welding ribbon 70 in the battery assembly 100 can be reduced, thereby further reducing the thickness of the battery assembly 100.

[0173] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the third segment 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20” can mean that the projection of part of the third segment 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20; or the projection of the entire third segment 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20. This is not limited here.

[0174] In a possible implementation, Fig.17 , Fig.18 , Fig.19 and Fig. 20 As shown, the first welding strip 70 further includes a fourth section 72 , and a thickness H8 of the fourth section 72 is greater than a thickness H7 of the third section 71 .

[0175] Specifically, in the embodiment of the present invention, the first welding strip 70 can be manufactured by thinning the existing welding strip 10, without re-manufacturing the first welding strip 70, so as to reduce the manufacturing cost of the first welding strip 70.

[0176] Thus, the first welding strip 70 may include both the fourth section 72 and the third section 71. When manufacturing the first welding strip 70, the first welding strip 70 in the embodiment of the present invention may be obtained by thinning a portion of the existing welding strip 10, so as to reduce the manufacturing cost of the first welding strip 70.

[0177] For example, the soldering strip 10 in the prior art may be thinned, the thinned portion of the soldering strip 10 being the third section 71 of the first soldering strip 70 , and the portion not thinned being the fourth section 72 of the first soldering strip 70 .

[0178] Specifically, the width K8 of the fourth segment 72 is smaller than the width K7 of the third segment 71 .

[0179] Specifically, regarding the arrangement of the fourth segment 72 and the third segment 71, the number of the fourth segment 72 can be one or more, and the number of the third segment 71 can be one or more, which can be made according to actual conditions.

[0180] In a possible implementation, the ratio of the length of the third section 71 to the length of the first welding strip 70 is 0.05 to 1. In this way, the flexibility of the application of the first welding strip 70 can be improved. The user can flexibly set the structure of the first bus bar 30 according to actual conditions.

[0181] In a possible implementation, Fig.21 As shown, the first welding strips 70 may all be the third section 71. Specifically, all the existing welding strips 10 may be thinned so that all the first welding strips 70 are the third section 71. When the first welding strips 70 are applied to the battery assembly 100, the thickness of the battery assembly 100 may be reduced to the maximum extent.

[0182] In a possible implementation, in the thickness direction of the back contact battery 20, the projection of the fourth segment 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20. In this way, the portion of the battery assembly 100 where the first welding ribbon 70 and the bus bar 60 do not overlap can maintain a high mechanical strength, and the current collection efficiency of the fourth segment 72 is improved, thereby optimizing the stability and performance of the battery assembly 100.

[0183] Specifically, in the battery assembly 100, as Fig. 20 As shown, the overlapping portion of the bus bar 60 and the first welding strip 70 has a great influence on the thickness of the battery assembly 100, so it is necessary to reduce the thickness of the overlapping portion of the bus bar 60 and the first welding strip 70 in the battery assembly 100. Therefore, in the thickness direction of the back contact battery 20, the projection of the third section 71 on the back contact battery 20 overlaps with the projection of the bus bar 60 on the back contact battery 20, and the projection of the fourth section 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20. Therefore, the arrangement of the third section 71 and the fourth section 72 in the first welding strip 70 can effectively reduce the thickness of the overlapping portion of the bus bar 60 and the first welding strip 70, thereby effectively reducing the overall thickness of the battery assembly 100, while ensuring that the portion of the battery assembly 100 where the bus bar 60 and the first welding strip 70 do not overlap can maintain a high mechanical strength, and improve the current collection efficiency of the fourth section 72, thereby optimizing the stability and performance of the battery assembly 100.

[0184] It can be understood that “in the thickness direction of the back contact battery 20, the projection of the fourth segment 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20” means that in the thickness direction of the back contact battery 20, the projection of the fourth segment 72 on the back contact battery 20 does not overlap with the projection of the bus bar 60 on the back contact battery 20.

[0185] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the fourth segment 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20” can mean that the projection of part of the fourth segment 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20; or the projection of the entire fourth segment 72 on the back contact battery 20 avoids the projection of the bus bar 60 on the back contact battery 20. This is not limited here.

[0186] Specifically, the first welding ribbon 70 is conductively connected to the bus bar 60 through solder paste or conductive glue, and the first welding ribbon 70 is insulated from the bus bar 60 through an isolation strip.

[0187] In a possible implementation, Fig. 22As shown, the battery assembly 100 further includes a second welding ribbon 80, and the bus bar 60 is insulated or conductively connected to the second welding ribbon 80. In the thickness direction of the back contact battery 20, the projection of the first section 61 on the back contact battery 20 overlaps with the projection of the second welding ribbon 80 on the back contact battery 20; in the thickness direction of the back contact battery 20, the projection of the second section 62 on the back contact battery 20 avoids the projection of the second welding ribbon 80 on the back contact battery 20.

[0188] In this way, the thickness of the overlapping portion of the second welding ribbon 80 and the bus bar 60 can be reduced, thereby reducing the thickness of the battery assembly 100, thereby reducing the risk of hidden cracks and fragments of the back contact battery 20 when the battery assembly 100 is laminated. At the same time, it ensures that the non-overlapping portion of the second welding ribbon 80 and the bus bar 60 can maintain a high mechanical strength, and improves the current collection efficiency of the non-overlapping portion of the second welding ribbon 80 and the bus bar 60, thereby optimizing the stability and performance of the battery assembly 100.

[0189] Specifically, the second welding ribbon 80 is conductively connected to the bus bar 60 through solder paste or conductive glue, and the second welding ribbon 80 is insulated from the bus bar 60 through an isolation strip.

[0190] Specifically, the battery assembly 100 further includes a second welding ribbon 80 , and when disposed, the second welding ribbon 80 partially overlaps with the bus bar 60 .

[0191] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first section 61 on the back contact battery 20 overlaps with the projection of the second welding strip 80 on the back contact battery 20” means that the projections of the first section 61 and the second welding strip 80 on the back contact battery 20 overlap in the thickness direction of the back contact battery 20.

[0192] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the first segment 61 on the back contact battery 20 overlaps with the projection of the second welding strip 80 on the back contact battery 20” may mean that the projection of part of the first segment 61 on the back contact battery 20 overlaps with the projection of the second welding strip 80 on the back contact battery 20; or the projection of the entire first segment 61 on the back contact battery 20 overlaps with the projection of the second welding strip 80 on the back contact battery 20. This is not limited here.

[0193] It is worth noting that “in the thickness direction of the back contact battery 20, the projection of the second segment 62 on the back contact battery 20 avoids the projection of the second welding strip 80 on the back contact battery 20” can mean that the projection of part of the second segment 62 on the back contact battery 20 avoids the projection of the second welding strip 80 on the back contact battery 20; or the projection of the entire second segment 62 on the back contact battery 20 avoids the projection of the second welding strip 80 on the back contact battery 20. This is not limited here.

[0194] It is worth noting that “the second welding strip 80 partially overlaps the bus bar 60”, which means that the second welding strip 80 and the bus bar 60 are partially stacked in the thickness direction of the battery assembly 100. The second welding strip 80 partially overlaps the bus bar 60, which may refer to the direct contact and overlap between the bus bar 60 and the second welding strip 80, or may refer to other elements being provided between the second welding strip 80 and the bus bar 60; the projection of the first section 61 on the back contact battery 20 overlaps with the projection of the second welding strip 80 on the back contact battery 20, and at the same time, the projection of the second section 62 on the back contact battery 20 avoids the projection of the second welding strip 80 on the back contact battery 20.

[0195] In a possible implementation, the ratio of the length of the first section 61 to the length of the bus bar 60 is 0.05 to 1. In this way, the flexibility of the application of the bus bar 60 can be improved. The user can flexibly set the structure of the bus bar 60 according to actual conditions.

[0196] It is understandable that in such an embodiment, the battery assembly 100 may also include a frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the battery cell and the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0197] Photovoltaic glass can cover the adhesive film on the front of the cell. Photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the cell without affecting the efficiency of the cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the cell together. The presence of the adhesive film can seal and insulate the cell and make it waterproof and moisture-proof.

[0198] The backplane can be attached to the film on the back of the battery cell. The backplane can protect and support the battery cell 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 film, etc. It can be set according to the specific situation and is not limited here. The whole composed of the backplane, battery cell, film and photovoltaic glass can be set on the frame. The frame serves as the main external support structure of the entire battery assembly 100 and can provide stable support and installation for the battery assembly 100. For example, the battery assembly 100 can be installed at the required installation position through the frame.

[0199] 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.

[0200] In addition, the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery assembly, characterized in that: The method comprises a plurality of battery strings, each of the battery strings comprises a plurality of welding strips and a plurality of back-contact batteries, the plurality of back-contact batteries comprises a first battery sheet and a second battery sheet arranged in sequence, the first battery sheet and the second battery sheet partially overlap in an overlap area, and the welding strip is connected to at least one of the back-contact batteries; The portion of the welding strip disposed in the overlapping area is a first component, the thickness of the first component is less than 0.28 mm, and the width of the first component is greater than 0.5 mm.

2. The battery assembly according to claim 1, characterized in that: In the thickness direction of the welding strip, the cross-sectional area of ​​the first component is 0.1 mm 2 Up to 0.5mm 2 .

3. The battery assembly according to claim 1, characterized in that: The welding strip further includes a second component, and a thickness of the second component is greater than a thickness of the first component.

4. The battery assembly according to claim 3, characterized in that: Portions of the first battery cell and the second battery cell other than the overlapping area are non-overlapping areas, and the second component is disposed in the non-overlapping areas.

5. The battery assembly according to claim 1, characterized in that: It also includes a first bus bar, the first bus bar connects two adjacent battery strings, and the welding strip is insulated or conductively connected to the first bus bar; In the thickness direction of the back-contact cell, a projection of the first member on the back-contact cell overlaps with a projection of the first bus bar on the back-contact cell.

6. The battery assembly according to claim 5, characterized in that: The first bus bar includes a third member, and in the thickness direction of the back contact battery, a projection of the third member on the back contact battery overlaps with a projection of the welding ribbon on the back contact battery; The thickness of the third component is less than 0.5 mm, and the width of the third component is greater than 7 mm.

7. The battery assembly according to claim 6, characterized in that: The first bus bar further includes a fourth member having a thickness greater than a thickness of the third member.

8. The battery assembly according to claim 7, characterized in that: In the thickness direction of the back-contact cell, the projection of the fourth member on the back-contact cell avoids the projection of the solder ribbon on the back-contact cell.

9. The battery assembly according to claim 6, characterized in that: A ratio of a length of the third member to a length of the first bus bar is 0.05 to 1.

10. The battery assembly according to claim 3, characterized in that: Also includes a second bus bar, wherein the second bus bar connects two adjacent battery strings; In the thickness direction of the back contact battery, a projection of the first member on the back contact battery overlaps with a projection of the second bus bar on the back contact battery; In the thickness direction of the back-contact cell, a projection of the second member on the back-contact cell avoids a projection of the second bus bar on the back-contact cell.

11. The battery assembly according to claim 1, characterized in that: The ratio of the length of the first member to the length of the welding strip is 0.05 to 1.

12. A battery assembly, characterized in that: The invention comprises a plurality of battery strings, each of which comprises a plurality of bus bars and a plurality of back-contact batteries, wherein the bus bars connect two adjacent battery strings, and the plurality of back-contact batteries comprise a first battery sheet and a second battery sheet arranged in sequence, wherein the first battery sheet and the second battery sheet partially overlap in an overlap area; The battery string further includes a first welding strip, wherein the first welding strip is insulated or conductively connected to the bus bar; The bus bar includes a first section, and in the thickness direction of the back contact battery, the projection of the first section on the back contact battery overlaps with the projection of the first welding strip on the back contact battery, the thickness of the first section is less than 0.5 mm, and the width of the first section is greater than 7 mm.

13. The battery assembly according to claim 12, characterized in that: In the thickness direction of the busbar, the cross-sectional area of ​​the first segment is 0.8 mm 2 Up to 2mm 2 .

14. The battery assembly according to claim 12, characterized in that: The bus bar further includes a second segment having a thickness greater than a thickness of the first segment.

15. The battery assembly according to claim 12, characterized in that: The first welding strip includes a third section; In the thickness direction of the back contact battery, a projection of the third segment on the back contact battery overlaps with a projection of the bus bar on the back contact battery; The thickness of the third section is less than 0.28 mm, and the width of the first section is greater than 0.5 mm.

16. The battery assembly according to claim 15, characterized in that: The first welding strip further includes a fourth section, and a thickness of the fourth section is greater than a thickness of the third section.

17. The battery assembly according to claim 16, characterized in that: In the thickness direction of the back-contact cell, a projection of the fourth segment on the back-contact cell avoids a projection of the bus bar on the back-contact cell.

18. The battery assembly according to claim 15, characterized in that: The ratio of the length of the third segment to the length of the first welding strip is 0.05 to 1.

19. The battery assembly according to claim 14, characterized in that: Also included is a second welding strip, wherein the second welding strip is insulated or conductively connected to the bus bar; In the thickness direction of the back contact battery, a projection of the first segment on the back contact battery overlaps with a projection of the bus bar on the back contact battery; In the thickness direction of the back-contact cell, the projection of the second segment on the back-contact cell avoids overlapping with the projection of the bus bar on the back-contact cell.

20. The battery assembly according to claim 12, characterized in that: A ratio of the length of the first segment to the length of the bus bar is 0.05 to 1.

21. A photovoltaic system, characterized in that: Comprising a battery assembly as claimed in any one of claims 1 to 20.

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