Battery assembly and photovoltaic system

Abstract

The present invention is applicable to the field of photovoltaic technology and provides a battery assembly and a photovoltaic system. The battery assembly includes a battery string, a welding ribbon, a bus bar, and a spacer. The welding ribbon extends along a first direction and is arranged on the back of a battery cell. The welding ribbon includes a first welding ribbon and a second welding ribbon. The end of the first welding ribbon and a portion of the end of the second welding ribbon partially overlap in an orthographic projection plane to form an overlapping region. The overlapping region is located at an end of the second battery cell adjacent to the first battery cell. The bus bar and the spacer are disposed between the first welding ribbon and the second welding ribbon. Along a second direction, the battery cell has a first edge. The distance d1 between the first welding ribbon closest to the first edge and the end of the bus bar is located. The distance a between the first welding ribbon closest to the first edge and the first edge is located. The first welding ribbon has a thickness H1 and a width w. The second welding ribbon has a thickness H2. The bus bar has a thickness H3, satisfying the following: 2.6×(H1+H2+H3)+0.3×w≤d1≤a. This ensures the structural stability of the battery assembly and prevents hidden cracks in the battery cells.

Description

Technical Field

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

[0002] In the field of solar cell modules, busbars and solder ribbons are key components for achieving electrical connections between cells. Busbars are responsible for collecting and transmitting the current generated by multiple cells, while solder ribbons are used to connect adjacent cells to form a circuit.

[0003] During production, welding and lamination processes generate internal stresses. Vibration and collision during transportation and installation also contribute to the accumulation of mechanical stresses. In actual use, thermal cycles caused by diurnal temperature swings and seasonal changes generate thermal stresses due to differences in the thermal expansion coefficients of materials. Repeated effects can easily lead to material fatigue. Furthermore, the inherent hardness and toughness of the material, as well as improper welding process parameters, can increase the risk of hidden cracks.

[0004] Hidden cracks are extremely harmful. They increase the connection resistance between cells, leading to increased power loss and reduced power generation efficiency. In severe cases, some cells may become disconnected, affecting the normal operation of the module and increasing operation and maintenance costs. Therefore, it is imperative to address the problem of hidden cracks in busbars and solder ribbons. Summary of the Invention

[0005] Embodiments of the present invention provide a battery assembly and a photovoltaic system, aiming to solve the problem of hidden cracks caused by overlapping bus bars and welding ribbons.

[0006] The embodiment of the present invention is implemented as follows: a battery assembly includes: a battery string, a welding ribbon, a bus bar and an isolation bar;

[0007] The battery string includes a plurality of battery cells arranged along a first direction, adjacent battery cells are connected in series via the welding ribbon, and the battery cells include a first battery cell and a second battery cell arranged along the first direction;

[0008] The welding strip extends along the first direction, is arranged on the back side of the battery cell, and includes a first welding strip and a second welding strip;

[0009] The isolation bars and the bus bars are both extended along a second direction, the bus bars and the isolation bars are stacked, and the first direction intersects the second direction;

[0010] An end portion of the first welding ribbon and a portion of an end portion of the second welding ribbon partially overlap on an orthographic projection plane to form an overlapping region, the overlapping region being located at an end of the second battery cell close to the first battery cell, the bus bar and the isolation bar being disposed between the first welding ribbon and the second welding ribbon, the first welding ribbon being in contact with the bus bar, and the second welding ribbon being in contact with the isolation bar;

[0011] Along the second direction, the battery cell has a first edge, the distance between the first welding ribbon closest to the first edge and the end of the bus bar is d1, the distance between the first welding ribbon closest to the first edge and the first edge is a, the thickness of the first welding ribbon is H1, the width of the first welding ribbon is w, the thickness of the second welding ribbon is H2, and the thickness of the bus bar is H3, satisfying:

[0012] 2.6×(H1+H2+H3)+0.3×w≤d1≤a.

[0013] Optionally, the first edge welding strip closest to the first edge among the first welding strips is the first edge welding strip, and the second edge welding strip closest to the first edge is the second edge welding strip, and the first edge welding strip and the second edge welding strip at least partially overlap in the orthographic projection plane.

[0014] Optionally, the positions of the first welding strip and the second welding strip partially overlap.

[0015] Optionally, the first welding strip and the second welding strip have the same thickness.

[0016] Optionally, the first edge welding strip closest to the first edge among the first welding strips is the first edge welding strip, and the second edge welding strip closest to the first edge is the second edge welding strip, and there is a horizontal distance between the first edge welding strip and the second edge welding strip.

[0017] Optionally, the second welding strip that is next closest to the first edge is a secondary edge second welding strip, and the secondary edge second welding strip and the edge first welding strip at least partially overlap in the orthographic projection plane.

[0018] Optionally, the orthographic projection of the first edge welding strip is placed between the orthographic projection of the second edge welding strip and the first edge.

[0019] Optionally, the second welding strip that is next closest to the first edge is a secondary edge second welding strip, and the orthographic projection of the edge first welding strip is placed between the orthographic projection of the edge second welding strip and the orthographic projection of the secondary edge second welding strip.

[0020] Optionally, the battery cells are arranged in an overlapping manner along the first direction.

[0021] Optionally, the thickness H1 of the first welding strip is 0.06-0.3 mm, and / or the width w is 0.5-2.5 mm.

[0022] Optionally, the thickness H2 of the second welding strip is 0.06-0.3 mm.

[0023] Optionally, the thickness H3 of the busbar is 0.15-0.45 mm.

[0024] Optionally, the distance from the end of the isolation bar to the first edge is greater than the distance from the end of the bus bar to the first edge.

[0025] The embodiment of the present invention further provides a photovoltaic system, comprising the above-mentioned battery assembly

[0026] The present invention achieves beneficial effects by providing a battery string, welding ribbons, busbars, and spacers. The battery string includes several battery cells arranged along a first direction. Along a second direction, the battery cells have a first edge. The distance between the first welding ribbon closest to the first edge and the end of the busbar is d1. The distance between the first welding ribbon closest to the first edge and the first edge is a. The thickness of the first welding ribbon is H1, the width of the first welding ribbon is w, the thickness of the second welding ribbon is H2, and the thickness of the busbar is H3. The following conditions are satisfied: 2.6 × (H1 + H2 + H3) + 0.3 × w ≤ d1 ≤ a. This ensures the structural stability of the battery assembly and prevents hidden cracks in the batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a structural schematic diagram of a first battery assembly provided by an embodiment of the present invention;

[0028] Figure 2 It is a structural diagram of AA;

[0029] Figure 3 is a structural schematic diagram of a second battery assembly provided by an embodiment of the present invention;

[0030] Figure 4 It is a structural diagram of BB;

[0031] Figure 5 is a schematic structural diagram of a third battery assembly provided by an embodiment of the present invention;

[0032] Figure 6 It is a structural diagram of CC;

[0033] Figure 7 is a schematic structural diagram of a fourth battery assembly provided by an embodiment of the present invention;

[0034] Figure 8 It is a structural diagram of DD.

[0035] Description of reference numerals:

[0036] 100, battery assembly; 110, battery string; 111, battery cell; 1111, first battery cell; 1112, second battery cell; 120, welding ribbon; 121, first welding ribbon; 122, second welding ribbon; 130, bus bar; 140, isolation strip. DETAILED DESCRIPTION

[0037] 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 with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to 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.

[0038] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present 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.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0040] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0042] 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 are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use of other materials.

[0043] The present invention provides a battery string, welding ribbons, busbars, and spacers. The battery string includes several battery cells arranged along a first direction. Along a second direction, the battery cells have a first edge. The distance between the first welding ribbon closest to the first edge and the end of the busbar is d1, and the distance between the first welding ribbon closest to the first edge and the first edge is a. The thickness of the first welding ribbon is H1, the width of the first welding ribbon is w, the thickness of the second welding ribbon is H2, and the thickness of the busbar is H3. The following conditions are met: 2.6 × (H1 + H2 + H3) + 0.3 × w ≤ d1 ≤ a. This ensures the structural stability of the battery assembly and prevents hidden cracks in the batteries.

[0044] Example 1

[0045] like Figure 1-8 As shown, this embodiment provides a battery assembly 100, characterized by comprising: a battery string 110, a welding ribbon 120, a bus bar 130 and an isolation bar 140;

[0046] The battery string 110 includes a plurality of battery cells 111 arranged along a first direction. Adjacent battery cells 111 are connected in series via a welding ribbon 120. The battery cells 111 include a first battery cell 1111 and a second battery cell 1112 arranged along the first direction.

[0047] The welding ribbon 120 extends along the first direction and is arranged on the back side of the battery cell 111 , and includes a first welding ribbon 121 and a second welding ribbon 122 ;

[0048] The isolation bars 140 and the bus bars 130 are both extended along the second direction. The bus bars 130 and the isolation bars 140 are stacked, and the first direction intersects the second direction.

[0049] The end of the first welding ribbon 121 and the end of the second welding ribbon 122 partially overlap on the orthographic projection plane to form an overlapping area. The overlapping area is provided at one end of the second battery cell 1112 close to the first battery cell 1111. A bus bar 130 and an isolation bar 140 are provided between the first welding ribbon 121 and the second welding ribbon 122. The first welding ribbon 121 contacts the bus bar 130, and the second welding ribbon 122 contacts the isolation bar 140.

[0050] Along the second direction, the battery cell 111 has a first edge, the distance between the first welding ribbon 121 closest to the first edge and the end of the bus bar 130 is d1, the distance between the first welding ribbon 121 closest to the first edge and the first edge is a, the thickness of the first welding ribbon 121 is H1, the width of the first welding ribbon 121 is w, the thickness of the second welding ribbon is H2, and the thickness of the bus bar 130 is H3, satisfying:

[0051] 2.6×(H1+H2+H3)+0.3×w≤d1≤a.

[0052] The battery string 110 includes a plurality of battery cells 111, which can specifically be back-contact solar cells 111. The positive and negative electrodes of the back-contact solar cells 111 are both arranged on the back side of the back-contact solar cells 111. Compared with the traditional structure in which the positive and negative electrodes are respectively located on the front and back sides of the back-contact solar cells 111, the front electrode reduces the blocking of light and improves the efficiency of the battery cells 111 in absorbing sunlight.

[0053] The back-contact solar cell 111 includes a first cell 1111 and a second cell 1112. The first cell 1111 and the second cell 1112 are arranged along a first direction, that is, the second cell 1112 is arranged after the first cell 1111 is arranged. The backlight surface of the first cell 1111 overlaps the light-facing surface of the second cell 1112.

[0054] The soldering ribbon 120 is used to collect the carriers generated by each back-contact solar cell 111. It connects two adjacent back-contact solar cells 111. The soldering ribbon 120 includes a first soldering ribbon 121 and a second soldering ribbon 122. The first soldering ribbon 121 is electrically connected to the bus bar 130, connecting the adjacent first solar cell 1111 in series with the other solar cells 111 (not the second solar cell 1112), ensuring smooth current conduction within the solar cell string 110. It is also electrically connected to the bus bar 130, transmitting the current generated by the solar cell string 110 to the bus bar 130 for further electrical energy output. The second soldering ribbon 122 is not electrically connected to the bus bar 130, but connects the solar cells 111 other than the one connected to the first soldering ribbon 121. This can be connecting the adjacent second solar cell 1112 with another solar cell 111 (possibly the first solar cell 1111).

[0055] Specifically, the length of the first welding ribbon 121 is greater than that of the second welding ribbon 122 . The first welding ribbon 121 has an overlapping portion extending along the first direction. The overlapping portion is electrically connected to the bus bar 130 .

[0056] The busbars 130 and isolation bars 140 are stacked and extend along the second direction. The busbars 130 collect the current conducted by the multiple first welding ribbons 121, concentrating the dispersed current and ultimately delivering it to the output terminal of the battery assembly 100. The isolation bars 140 are made of an insulating material to prevent circuit connectivity.

[0057] The second direction intersects the first direction. That is, the first direction may be the lateral direction of the back-contact cell, and the second direction may be the longitudinal direction of the back-contact cell, with the two being perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, for example, they may both be diagonal directions of the silicon substrate, and this is not a limitation here.

[0058] The second battery cell 1112 has an overlapping area, which is located at one end of the second battery cell 1112 close to the first battery cell 1111, that is, the boundary area of ​​the second battery cell 1112 in the direction close to the adjacent first battery cell 1111. It can be understood that the overlapping area is close to or at least partially covers the stacking area of ​​the first battery cell 1111 and the second battery cell 1112.

[0059] Within the overlapping region, the end of the first welding ribbon 121 partially overlaps the end of the second welding ribbon 122. "End" refers to the portion along the extension direction of the welding ribbon 120, either at the beginning or end. It is not necessarily the exact endpoint, but rather includes the endpoint and a small area near the endpoint. A busbar 130 and a spacer bar 140 are disposed between the first welding ribbon 121 and the second welding ribbon 122. The spacer bar 140 contacts the end of the second welding ribbon 122 on the side facing the back contact solar cell 111, while the busbar 130 contacts the end of the first welding ribbon 121 on the side facing away from the back contact solar cell 111.

[0060] It is understood that the first welding ribbon 121 is electrically connected to the bus bar 130, that is, the end of the first welding ribbon 121 can be in direct contact with the bus bar 130 or in indirect contact through a conductive medium. The second welding ribbon 122 is not electrically connected to the bus bar 130. The isolation bar 140 is provided between the bus bar 130 and the second welding ribbon 122, isolating the electrical path between the second welding ribbon 122 and the bus bar 130. The second welding ribbon 122 and the isolation bar 140 can be in direct contact or indirect contact through other media, which is not limited here.

[0061] During assembly, the cells 111 in the battery string 110 are connected in series, an insulating strip is provided at one end of the second cell 1112 close to the first cell 1111, and a bus bar 130 is provided on the side of the insulating strip that is in contact with the back of the solar cell 111. The welding ribbon 120 is electrically connected to the effective welding position of the first cell 1111, and the end of the welding ribbon 120 close to the second cell 1112 is electrically connected to the bus bar 130, thereby enabling the bus bar 130 to draw current from the battery string 110.

[0062] Along the second direction, the battery cell 111 has a first edge, the distance between the first welding strip 121 closest to the first edge and the end of the bus bar 130 is d1, the distance between the first welding strip 121 closest to the first edge and the first edge is a, the thickness of the first welding strip 121 is H1, the width is w, and the thickness of the bus bar 130 is H2.

[0063] The lower limit of the formula is 2.6 × (H1 + H2 + H3) + 0.3 × w. H1 + H2 + H3 takes into account the thickness of the two layers of solder ribbon 120 (first solder ribbon 121 and second solder ribbon 122) and the busbar 130. The multiplication by 2.6 ensures sufficient space within the overlapping area to accommodate the stacked structure of these components. This also takes into account factors such as deformation and thermal expansion that may occur during the welding process. The coefficient of 2.6 is an empirical value obtained through multiple experiments.

[0064] The factor 0.3×w takes into account the effect of the width of the solder ribbon 120 on electrical connection and current conduction. A wider solder ribbon 120 increases its current carrying capacity, but sufficient space is also required in the connection area with the busbar 130 to ensure good electrical contact. The factor of 0.3 was determined through extensive experimentation and actual production experience. It ensures an appropriate contact area between the solder ribbon 120 and the busbar 130 while meeting electrical performance requirements, reducing resistance and improving current transmission efficiency.

[0065] a is the upper limit of the formula. The distance d1 between the first welding ribbon 121 closest to the first edge and the end of the busbar 130 cannot exceed the distance a between the first welding ribbon 121 closest to the first edge and the first edge. This is because the end of the busbar 130 cannot extend beyond the range where the welding ribbon 120 is located. Otherwise, the overall structural layout of the battery assembly 100 will be disrupted, and the busbar 130 may interfere with other components, affecting the assembly and normal use of the battery assembly 100.

[0066] In summary, by comprehensively considering the structural stability, electrical performance and overall layout requirements of the battery assembly 100, and after a large number of experimental verifications and optimizations, the formula 2.6×(H1+H2+H3)+0.3×w≤d1≤a was derived to ensure the reliability and performance of the battery assembly 100 in actual production and use, and to avoid hidden cracks in the battery.

[0067] In a specific embodiment, the distance a between the first welding ribbon 121 closest to the first edge and the first edge is 4.3 mm, the thicknesses H1 and H2 of the first welding ribbon 121 and the second welding ribbon 122 are both 0.15 mm (usually the thicknesses of the first welding ribbon 121 and the second welding ribbon 122 are equal), the width is 0.9 mm, and the busbar thickness is 0.3 mm. Substituting into the formula: 2.6 × (H1 + H2 + H3) + 0.3 × w ≤ d1 ≤ a, the calculated range of d1 is: 1.8 mm ≤ d1 ≤ 4.3 mm. Experimental verification of the risk of hidden cracks in cells with different lengths d1 is conducted, and the verification results are as follows:

[0068]

[0069] Within the range of 1.8mm≤d1≤4.3mm, the risk of hidden cracks in the cell during the component packaging process is less than 3%.

[0070] In another specific embodiment, the distance a between the first welding ribbon 121 closest to the first edge and the first edge is 4.7 mm. The thickness H1 and H2 of the first welding ribbon 121 and the second welding ribbon 122 are both 0.25 mm, the width is 0.6 mm, and the busbar thickness is 0.35 mm. Substituting into the formula: 2.6 × (H1 + H2 + H3) + 0.3 × w ≤ d1 ≤ a, the calculated range of d1 is: 2.4 mm ≤ d1 ≤ 4.7 mm. Experimental verification of the hidden crack risk of solar cells with different lengths d1 is as follows:

[0071]

[0072] Within the range of 2.4mm≤d1≤4.7mm, the risk of hidden cracks in battery cells during component packaging is less than 3%.

[0073] The above experiments have verified that when the length of d1 is within the range of 2.6×(H1+H2+H3)+0.3×w≤d1≤a, the risk of hidden cracks in the battery cell is relatively small. When it exceeds this range, the risk of hidden cracks in the battery cell increases sharply.

[0074] In this embodiment, a battery string 110, welding ribbons 120, busbars 130, and spacer bars 140 are provided. The battery string 110 includes a plurality of battery cells 111 arranged along a first direction. Along a second direction, the battery cells 111 have a first edge. The distance d1 between the first welding ribbon 121 closest to the first edge and the end of the busbar 130 is the distance a. The thickness of the first welding ribbon 121 is H1, the width of the first welding ribbon 121 is w, the thickness of the second welding ribbon 122 is H2, and the thickness of the busbar 130 is H3. The following conditions are satisfied: 2.6 × (H1 + H2 + H3) + 0.3 × w ≤ d1 ≤ a. This ensures the structural stability of the battery assembly 100 and prevents hidden cracks in the batteries.

[0075] like Figure 1 and Figure 2 As shown, in some embodiments, the first welding strip 121 closest to the first edge is the first edge welding strip, and the second welding strip 122 closest to the first edge is the second edge welding strip, and the first edge welding strip and the second edge welding strip at least partially overlap in the orthographic projection plane.

[0076] Specifically, the first welding strip 121 and the second welding strip 122 extend along the first direction and are arranged on the back side of the battery cell 111 group, and the adjacent battery cells 111 are connected in series through them. The edge first welding strip and the edge second welding strip at least partially overlap in the orthographic projection plane, that is, the orthographic projections of the edge first welding strip and the edge second welding strip have an overlapping area, and the overlapping area is located at one end of the second battery cell 1112 close to the first battery cell 1111, and a bus bar 130 and an isolation bar 140 are arranged between the edge first welding strip and the edge second welding strip.

[0077] It can be understood that in this embodiment, the orthographic projection surface of the first edge welding strip and the second edge welding strip is the back of the battery cell. The orthographic projection is the projection formed on the orthographic projection surface under the illumination of light perpendicular to the orthographic projection surface, that is, the projection of the first edge welding strip and the second edge welding strip on the back of the battery cell.

[0078] By clearly defining the positions of the first and second edge welding ribbons, and combining this with the aforementioned formula, the battery assembly 100 can be designed and manufactured more accurately. For example, on an automated production line, the positions of the welding ribbons 120 and busbars 130 can be more accurately located, improving production efficiency and product quality consistency.

[0079] like Figure 3-Figure 8 As shown, in some embodiments, the first welding strip 121 closest to the first edge is the first edge welding strip, and the second welding strip 122 closest to the first edge is the second edge welding strip, and there is a lateral spacing between the first edge welding strip and the second edge welding strip.

[0080] That is, the orthographic projection of the first edge welding strip and the orthographic projection of the second edge welding strip do not have an overlapping area, and there is a certain distance between the two. There are many different situations depending on the size of the distance.

[0081] In the first case, the second welding strip 122 that is next closest to the first edge is the secondary edge second welding strip, and the secondary edge second welding strip and the edge first welding strip at least partially overlap in the orthographic projection plane.

[0082] That is, the orthographic projection of the first edge welding strip and the orthographic projection of the second edge welding strip have an overlapping area. d1 is the distance between the first welding strip 121 and the end of the busbar 130, and a is the distance between the first welding strip 121 closest to the first edge and the first edge. Both are calculated based on the first welding strip 121 as the reference, that is, calculated from the welding strip 120 next closest to the first edge.

[0083] In the second case, the second welding strip 122 that is next closest to the first edge is the secondary edge second welding strip, and the orthographic projection of the edge first welding strip is placed between the orthographic projection of the edge second welding strip shown and the orthographic projection of the secondary edge second welding strip.

[0084] That is, there is a horizontal spacing between the first edge welding strip, the second edge welding strip, and the second secondary edge welding strip. Usually, the portion of the first welding strip that overlaps the busbar is bent, which helps reduce the risk of hidden cracks during lamination.

[0085] In the third case, the orthographic projection of the first edge welding strip is placed between the orthographic projection of the second edge welding strip and the first edge. Similar to the second case, the portion of the first welding strip overlapping the busbar is bent, but in the opposite direction of the bending in the second case, which also helps reduce the risk of hidden cracks during lamination.

[0086] Clarifying the position of the first edge soldering strip helps adjust the production process. For example, during the placement and welding of soldering strip 120, the second soldering strip 122 needs to be more precisely positioned to ensure that its distance from the first edge meets the design requirements. Furthermore, when setting the parameters of the welding equipment, the special situation of the second soldering strip 122 at the edge should be taken into account. For example, the welding temperature, pressure, and other parameters may need to be adjusted to ensure welding quality.

[0087] In some embodiments, the first welding ribbon 121 has a thickness H1 of 0.06-0.3 mm and / or a width w of 0.5-2.5 mm. The specific thickness of the first welding ribbon can be 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, or other values ​​within the range of 0.06-0.3 mm, which are not limited herein.

[0088] Specifically, only the thickness H1 of the first welding strip may be within the range of 0.06~0.3mm, or only the width w of the first welding strip may be within the range of 0.5~2.5mm. Alternatively, the thickness H1 of the first welding strip may be within the range of 0.06~0.3mm, and the width w of the first welding strip may be within the range of 0.5~2.5mm.

[0089] Keeping the thickness of the first welding ribbon within an appropriate range ensures good conductivity without increasing the weight and cost of the battery assembly due to excessive thickness. Keeping the width of the first welding ribbon within an appropriate range provides sufficient welding area, ensuring a secure connection between the first welding ribbon and the fine grid of the battery cell and stable current transmission. In actual testing, when the first welding ribbon meets this range, the power generation efficiency of battery assemblies using the first welding ribbon is improved compared to assemblies using substandard welding ribbons. The connection is also more stable, and problems such as cold joints are rarely encountered during long-term use.

[0090] In some embodiments, the thickness H2 of the second welding strip is 0.06-0.3 mm. The specific thickness of the second welding strip can be 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, or other values ​​within the range of 0.06-0.3 mm, which is not limited here.

[0091] The appropriate thickness ensures the second soldering ribbon has excellent mechanical strength and electrical conductivity. During use, the second soldering ribbon can stably transmit current without breaking during welding due to being too thin, or increasing welding difficulty and cost due to being too thick. Field verification has shown that this thickness of second soldering ribbon provides stable performance over the long-term operation of battery modules, with few electrical failures caused by soldering ribbon issues.

[0092] In some embodiments, the busbar thickness H3 is 0.15-0.45 mm. The specific thickness of the busbar can be 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or other values ​​within the range of 0.15-0.45 mm, which is not limited here.

[0093] Busbars play a vital role in collecting current within a battery assembly. Busbars of this thickness offer low resistance, efficiently collecting and transmitting current to external circuits. Furthermore, this moderate thickness ensures the busbars possess a certain degree of flexibility and mechanical strength, making them less susceptible to deformation or damage during assembly and installation of the battery assembly.

[0094] Example 2

[0095] In some embodiments, the first welding ribbon 121 and the second welding ribbon 122 have the same thickness.

[0096] The equal thickness of the first and second welding ribbons 121, 122 helps improve the structural stability of the overlapping region of the battery assembly 100. In this overlapping region, two layers of welding ribbons 120 of equal thickness are stacked with the busbars 130 and separator bars 140, ensuring uniform stress distribution and a tight fit between the components. Compared to welding ribbons 120 of varying thicknesses, welding ribbons 120 of the same thickness provide more uniform heat transfer during welding, reducing the risk of deformation and misalignment caused by uneven thermal stress, thereby reducing the likelihood of welding defects such as cold joints.

[0097] Example 3

[0098] In some embodiments, the battery cells 111 are arranged in an overlapping manner along the first direction.

[0099] The back-contact solar cell panels 111 are arranged in an overlapping manner along a first direction. That is, the back-contact solar cell panels 111 are arranged in the first direction, and adjacent back-contact solar cell panels 111 have a stacking region. Specifically, the back-contact solar cell panels 111 have a light-facing surface and a back-contact surface that are oppositely disposed. Along the extension direction of the back-contact solar cell, the back-contact solar cell panels 111 have a first edge and a second edge that are oppositely disposed. The back-contact surface of the preceding back-contact solar cell panel 111 near the second edge contacts the light-facing surface of the following back-contact solar cell panel 111 near the first edge. The overlapping region of the two back-contact solar cell panels 111 is the stacking region.

[0100] The cells 111 are arranged in an overlapping manner along the first direction, and the cells 111 can be arranged more closely within a limited space, which greatly reduces the gaps between the cells 111 and increases the effective light-receiving area of ​​the battery assembly 100, so that more sunlight can be absorbed by the cells 111 and converted into electrical energy, thereby improving the photoelectric conversion efficiency of the entire assembly.

[0101] Example 4

[0102] In some embodiments, the distance from the end of the isolation bar 140 to the first edge is greater than the distance from the end of the bus bar 130 to the first edge.

[0103] The busbar 130 is primarily used to collect and transmit current, while the isolation bar 140 is used to isolate different electrical components to prevent short circuits. If the distance from the end of the isolation bar 140 to the first edge is less than or equal to the distance from the end of the busbar 130 to the first edge, then during the actual operation of the battery assembly 100, due to environmental factors (such as humidity, dust, etc.) or slight deviations in the manufacturing process, it is possible that the busbar 130 and adjacent electrical components (such as other battery cells 111 or busbar 130) will be electrically connected through the area near the first edge, thereby causing a short circuit. When the distance between the ends of the isolation bar 140 is greater, it is equivalent to setting a wider isolation zone between the end of the busbar 130 and the possible conductive area in the outside world, which can effectively reduce the risk of short circuits.

[0104] Example 5

[0105] This embodiment provides a photovoltaic system, including the above-mentioned battery assembly 100.

[0106] Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple battery assemblies 100. For example, multiple battery assemblies 100 can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to be converted into the alternating current required by the mains power grid and then connected to the mains power network to achieve solar power supply.

[0107] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0108] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A battery assembly, characterized in that: include: Cell strings, ribbons, bus bars, and spacers; The battery string includes a plurality of battery cells arranged along a first direction, adjacent battery cells are connected in series via the welding ribbon, and the battery cells include a first battery cell and a second battery cell arranged along the first direction; The welding strip extends along the first direction, is arranged on the back side of the battery cell, and includes a first welding strip and a second welding strip; The isolation bars and the bus bars are both extended along a second direction, the bus bars and the isolation bars are stacked, and the first direction intersects the second direction; An end portion of the first welding ribbon and a portion of an end portion of the second welding ribbon partially overlap on an orthographic projection plane to form an overlapping region, the overlapping region being located at an end of the second battery cell close to the first battery cell, the bus bar and the isolation bar being disposed between the first welding ribbon and the second welding ribbon, the first welding ribbon being in contact with the bus bar, and the second welding ribbon being in contact with the isolation bar; Along the second direction, the battery cell has a first edge, the distance between the first welding ribbon closest to the first edge and the end of the bus bar is d1, the distance between the first welding ribbon closest to the first edge and the first edge is a, the thickness of the first welding ribbon is H1, the width of the first welding ribbon is w, the thickness of the second welding ribbon is H2, and the thickness of the bus bar is H3, satisfying: 2.6×(H1+H2+H3)+0.3×w≤d1≤a.

2. The battery assembly according to claim 1, wherein The first edge welding strip closest to the first edge among the first welding strips is the first edge welding strip, and the second edge welding strip closest to the first edge is the second edge welding strip. The first edge welding strip and the second edge welding strip at least partially overlap in the orthographic projection plane.

3. The battery assembly according to claim 1, wherein: The first welding strip and the second welding strip are partially overlapped.

4. The battery assembly according to claim 1, wherein The first welding strip and the second welding strip have the same thickness.

5. The battery assembly according to claim 1, wherein: The first edge welding strip closest to the first edge among the first welding strips is a first edge welding strip, and the second edge welding strip closest to the first edge is a second edge welding strip. There is a horizontal distance between the first edge welding strip and the second edge welding strip.

6. The battery assembly according to claim 5, wherein: The second welding strip that is next closest to the first edge is a secondary edge second welding strip, and the secondary edge second welding strip and the edge first welding strip at least partially overlap in the orthographic projection plane.

7. The battery assembly according to claim 5, wherein: The orthographic projection of the first edge welding strip is placed between the orthographic projection of the second edge welding strip and the first edge.

8. The battery assembly according to claim 5, wherein: The second welding strip that is next closest to the first edge is a secondary edge second welding strip, and the orthographic projection of the edge first welding strip is placed between the orthographic projection of the edge second welding strip and the orthographic projection of the secondary edge second welding strip.

9. The battery assembly according to claim 1, wherein: The battery cells are arranged in an overlapping manner along a first direction.

10. The battery assembly according to claim 1, wherein: The thickness H1 of the first welding strip is 0.06-0.3 mm, and / or the width w is 0.5-2.5 mm.

11. The battery assembly according to claim 1, wherein: The thickness H2 of the second welding strip is 0.06-0.3 mm.

12. The battery assembly according to claim 1, wherein: The thickness H3 of the busbar is 0.15-0.45 mm.

13. The battery assembly according to claim 1, wherein: The distance from the end of the isolation bar to the first edge is greater than the distance from the end of the bus bar to the first edge.

14. A photovoltaic system, characterized in that: A battery assembly comprising any one of claims 1-13.

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