Battery string, photovoltaic module and design method for breaking length of connecting band

Abstract

The invention relates to the technical field of photovoltaic module processing, in particular to a battery string, a photovoltaic module and a design method for the breaking length of a connecting band. The battery string comprises a first battery piece and a second battery piece which are arranged at an interval along a first direction, wherein the first direction is the width direction of the first battery piece and / or the second battery piece; the connecting band is connected to the positive electrode of the first battery piece and the negative electrode of the second battery piece, the length of the connecting band protruding out of the edge of the first battery piece and / or the second battery piece in the first direction is d, and d is larger than or equal to 0.035 mm and smaller than or equal to 0.30 mm. According to the battery string, the length d of the edges of the first battery piece and the second battery piece is controlled within the range, so that the thermal damage of the battery pieces can be reduced, and the short circuit of the battery string can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic module processing, in particular to a battery string, a photovoltaic module and a design method of a connection band breaking length. BACKGROUND

[0002] In the processing of a photovoltaic module, battery pieces are welded into a string by using a welding band, and the strings are connected in series to form a photovoltaic module whole plate. The positive and negative poles of two battery pieces are connected by a welding band. In the welding process, the battery pieces are prone to thermal damage, and the battery string is prone to short circuit.

[0003] The information disclosed in this section of background art is only intended to increase the understanding of the general background of the application and should not be considered as admitting or implying that the information constitutes prior art in any form. SUMMARY

[0004] Therefore, it is necessary to provide a battery string, a photovoltaic module and a design method of a connection band breaking length to solve the problems that the battery pieces are prone to thermal damage and the battery string is prone to short circuit in the welding process.

[0005] In a first aspect, a battery string includes:

[0006] a first battery piece and a second battery piece arranged at intervals along a first direction, the first direction being a width direction of the first battery piece and / or the second battery piece;

[0007] a connection band connected to a positive pole of the first battery piece and a negative pole of the second battery piece, the connection band protruding from an edge of the first battery piece and / or the second battery piece along the first direction by a length d, satisfying: 0.035mm≤d≤0.30mm.

[0008] In one embodiment, the length d satisfies: 0.035mm≤d≤0.055mm.

[0009] In one embodiment, the battery string further includes a first positioning point and a second positioning point, the first positioning point being arranged on the first battery piece, and the second positioning point being arranged on the second battery piece.

[0010] In one embodiment, at least one of the two edges of the first battery piece and the second battery piece close to each other includes a chamfered end or a right-angled end along at least one end of the length thereof.

[0011] In one of the embodiments, the battery string further comprises a third battery sheet, the connecting band comprises a first connecting band and a second connecting band, the first battery sheet, the second battery sheet and the third battery sheet are sequentially and spacedly arranged along the first direction, the first connecting band is connected to the positive electrode of the first battery sheet and the negative electrode of the second battery sheet, the second connecting band is connected to the positive electrode of the second battery sheet and the negative electrode of the third battery sheet, the first connecting band and the second connecting band are alternately arranged along a second direction, the second direction intersects the first direction, the first connecting band protrudes from the edge of the first battery sheet and / or the second battery sheet along the first direction by a length d, the second connecting band protrudes from the edge of the second battery sheet and / or the third battery sheet along the first direction by the length d.

[0012] In one of the embodiments, the length d satisfies: wherein H is the interval of the first battery sheet and the second battery sheet along the first direction, is the first machining precision, is the second machining precision, wherein 0≤H≤0.6mm; 0≤ ≤0.035mm; 0≤ ≤0.49mm.

[0013] In one of the embodiments, , , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.025mm≤X2≤0.025mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; wherein D is the interval between the central axis of the first battery sheet and the central axis of the second battery sheet, W is half of the sum of the width of the first battery sheet and the width of the second battery sheet, is the chamfer machining precision, is the laser breaking precision; is the laminating displacement precision; is the swing sheet precision; is the laser movement precision.

[0014] In one of the embodiments, , , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.025mm≤X2≤0.025mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; wherein, D is the distance between the central axis of the first cell piece and the central axis of the second cell piece, W is half of the sum of the width of the first cell piece and the second cell piece, is the scribing precision, is the laser breaking precision; is the laminating displacement precision; is the swinging piece precision; is the laser moving precision.

[0015] In a second aspect, a photovoltaic module includes a cell string and a photovoltaic frame for supporting the cell string, the cell string being the cell string as described in the first aspect.

[0016] In a third aspect, a design method of a connecting band breaking length is used to obtain the length d of the cell string as described in the first aspect, the method including the following steps:

[0017] respectively obtaining the distance D between the central axis of the first cell piece (1) and the central axis of the second cell piece (2), half W of the sum of the width of the first cell piece (1) and the second cell piece (2), the chamfer breaking error or scribing precision of the first cell piece (1) and / or the second cell piece (2) , the laser breaking precision , the laminating displacement precision , the swinging piece precision , the laser moving precision ;

[0018] According to the formula , the convex length d of the edges of the first cell piece and the second cell piece of the cell string (100) is obtained.

[0019] The above cell string controls the convex length d of the edges of the first cell piece and the second cell piece within the above range, which not only can reduce the thermal damage of the cell piece, but also can reduce the short circuit of the cell string. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the disclosed drawings.

[0021] Figure 1 A structural schematic diagram of a battery string is provided for an embodiment of the present application.

[0022] Figure 2 A design method for breaking length of a connecting band is provided for an embodiment of the present application.

[0023] Legend: 100, battery string; 1, first battery piece; 2, second battery piece; 4, connecting band; 41, first connecting band; 42, second connecting band; 51, first positioning point; 52, second positioning point. DETAILED DESCRIPTION

[0024] In order to make the above objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, and therefore the present application is not limited by the specific embodiments disclosed below.

[0025] In the processing of a photovoltaic module, battery pieces are welded into a string by using a welding band, and the strings are connected in series to form a photovoltaic module whole plate, and the positive and negative electrodes of two battery pieces are connected by a welding band. In the welding process, the battery pieces are prone to heat damage or the battery string is prone to short circuit.

[0026] It should be noted that the problems of heat damage of battery pieces and short circuit of battery string occurring in the welding process are caused by the possible reasons of high welding temperature or long welding time, or multiple welding leading to local temperature accumulation, or hidden cracks in the battery pieces expanding after being heated leading to damage, etc. The problem of short circuit of battery string may be caused by the displacement of welding band leading to short circuit of adjacent electrodes, or the failure of the insulating layer of the battery piece leading to short circuit, or the local high temperature burning the insulating layer of the battery piece itself after being heated leading to the connection of adjacent electrodes of the battery piece itself forming a short circuit, etc.

[0027] However, the applicant found in the research process that the two problems of heat damage of battery pieces and short circuit of battery string are caused by the welding band itself. In the processing of a battery string, a welding band is used to weld the positive main grid of one battery piece and the negative main grid of an adjacent battery piece, and the welding length of the welding band extends along the width direction of the battery piece. Since one welding band only connects two adjacent battery pieces, the welding band needs to be broken by using an external laser when welding the battery string. When the breaking distance is too close to the edge of the battery piece, the heat conduction of the laser causes heat damage to the battery piece. When the breaking distance is too far from the edge of the battery piece, the welding band is too long, and the adjacent two welding bands are prone to overlap and short circuit.

[0028] Based on the above, please refer to Figure 1 In the first aspect, the embodiments of the present application provide a battery string 100, comprising a first battery piece 1, a second battery piece 2 and a connecting strip 4. The first battery piece 1 and the second battery piece 2 are arranged at intervals along a first direction, and the first direction is the width direction of the first battery piece 1 and the second battery piece 2. The connecting strip 4 is connected to the positive electrode of the first battery piece 1 and the negative electrode of the second battery piece 2, and the length of the connecting strip 4 protruding from the edge of the first battery piece 1 and the second battery piece 2 along the first direction is d, which satisfies: 0.035mm≤d≤0.30mm. Controlling the length d of the edge of the first battery piece 1 and the second battery piece 2 within the above range can not only reduce the thermal damage of the battery piece, but also reduce the short circuit of the battery string 100.

[0029] Exemplarily, the length d can be any value within the above range, for example, it can be 0.035mm, 0.040mm, 0.045mm, 0.05mm, 0.055mm, 0.1mm, 0.2mm, 0.3mm, etc.

[0030] In some embodiments, the length d satisfies: 0.035mm≤d≤0.055mm. It needs to be pointed out that during the process of laser breaking the connecting strip, there will be laser breaking precision, which can be ±0.025mm or ±0.035mm. Controlling the length d within the above range can further take into account the laser breaking precision, and when the laser breaking precision deviates, it can also reduce the thermal damage or short circuit of the battery piece.

[0031] Exemplarily, the length d can be any value within the above range, for example, it can be 0.035mm, 0.040mm, 0.045mm, 0.050mm, 0.055mm, etc.

[0032] Please refer to Figure 1In some embodiments, the battery string 100 further comprises a third battery sheet, the connecting belt 4 comprises a first connecting belt 414 and a second connecting belt 424, the first battery sheet 1, the second battery sheet 2 and the third battery sheet are sequentially and spacedly arranged along a first direction, the first connecting belt 414 is connected to the positive electrode of the first battery sheet 1 and the negative electrode of the second battery sheet 2, the second connecting belt 424 is connected to the positive electrode of the second battery sheet 2 and the negative electrode of the third battery sheet, the first connecting belt 414 and the second connecting belt 424 are alternately arranged along a second direction, the second direction intersects the first direction, the length of the first connecting belt 414 protruding from the edge of the first battery sheet 1 and / or the second battery sheet 2 along the first direction is d, and the length of the second connecting belt 424 protruding from the edge of the second battery sheet 2 and / or the third battery sheet along the first direction is d. The battery string 100 can be manufactured by alternately connecting the first connecting belt 414 and the second connecting belt 424. It can be understood that the positive electrode and the negative electrode in the battery string 100 are located on the same surface, and can be arranged on the back surface of the battery string 100, which can reduce the arrangement of the electrode on the front surface of the battery string 100, reduce the shading effect of the electrode on the front surface of the battery string 100, and improve the light absorption effect of the front surface of the battery string 100. In an optional embodiment, the first battery sheet 1, the second battery sheet 2 and the third battery sheet can be back contact battery.

[0033] Referring to Figure 1 In some embodiments, the battery string 100 further comprises a first positioning point 51 and a second positioning point 52, the first positioning point 51 is arranged on the first battery sheet 1, and the second positioning point 52 is arranged on the second battery sheet 2. The first positioning point 51 and the second positioning point 52 are used as mark points to be recognized by the visual recognition system of the screen printing machine during printing, and the positions of the first positioning point 51 and the second positioning point 52 are used to adjust the printing screen plate, so as to reduce the deviation of the printed electrode.

[0034] Referring to Figure 1 In an optional embodiment, the first positioning point 51 can comprise two, and the second positioning point 52 can comprise two, the two first positioning points 51 are arranged on the two sides of the first battery sheet 1 along the first direction, and the two second positioning points 52 are arranged on the two sides of the first battery sheet 1 along the first direction. Arranging multiple first positioning points 51 and multiple second positioning points 52 can improve the printing accuracy.

[0035] Referring to Figure 1 In some embodiments, at least one of the two edges of the first battery sheet 1 and the second battery sheet 2 close to each other comprises a chamfered end or a right-angled end along at least one end of the length direction thereof. Arranging chamfered ends on both ends of the two edges of the first battery sheet 1 and the second battery sheet 2 close to each other along the length direction thereof can reduce stress concentration and reduce cracks or damage.

[0036] In optional embodiments, the two edges of the first cell piece 1 and the second cell piece 2 close to each other are both chamfered edges or both right-angled edges along the two ends in the length direction of the edges. Alternatively, the two edges of the first cell piece 1 close to the second cell piece 2 are both chamfered edges along the two ends in the length direction of the edges, and the two edges of the second cell piece 2 close to the first cell piece 1 are both right-angled edges along the two ends in the length direction of the edges. Alternatively, one edge of the first cell piece 1 close to the second cell piece 2 is a chamfered edge along one end in the length direction of the edge, and the other edge is a right-angled edge along the other end in the length direction of the edge, and one edge of the second cell piece 2 close to the second cell piece 2 is a chamfered edge along one end in the length direction of the edge, and the other edge is a right-angled edge along the other end in the length direction of the edge.

[0037] In some embodiments, the length d satisfies: wherein H is the distance between the first cell piece 1 and the second cell piece 2 along the first direction, is the first machining precision, is the second machining precision, wherein 0≤H≤0.6mm; 0≤ ≤0.035mm; 0≤ ≤0.49mm. The range of the length d is calculated according to the above formula, which can further reduce the occurrence of laser thermal damage or short circuit of the first cell piece 1 and the second cell piece 2. The range of the length d calculated according to the above formula is 0.035mm≤d≤0.30mm.

[0038] In this case, for example, H can be any value in the above range, such as 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc. may be any value in the above range, such as 0mm, 0.01mm, 0.02mm, 0.03mm, 0.035mm, etc. may be any value in the above range, such as 0mm, 0.01mm, 0.02mm, 0.03mm, 0.49mm, etc.

[0039] Two cases of obtaining the length d will be introduced as follows:

[0040] Please refer to Figure 1 In the first case, when the two edges of the first cell piece 1 and the second cell piece 2 close to each other are both chamfered edges along the two ends in the length direction of the edges, in some embodiments, ,

[0041] , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.035mm≤X2≤0.035mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; wherein, D is the distance between the central axis of the first cell piece 1 and the central axis of the second cell piece 2, W is half of the sum of the widths of the first cell piece 1 and the second cell piece 2, is the chamfering machining precision, is the laser breaking precision; is the laminating displacement precision; is the pendulum piece precision; is the laser movement precision. It needs to be pointed out that when the two edges of the first cell piece 1 and the second cell piece 2 adjacent to each other are chamfered ends along the two ends of the length direction, due to the machining precision error of the chamfered end, the width of the first cell piece 1 and the second cell piece 2 along the first direction exists error fluctuation. The chamfering machining precision error range of a single first cell piece 1 or second cell piece 2 is between [-0.1mm, 0.1mm]. Considering the chamfering machining precision error, the laser breaking precision, the laminating displacement precision, the pendulum piece precision and the laser movement precision, the range of the length d can be more accurate, further reducing the laser thermal damage and short circuit when breaking.

[0042] In this embodiment, since 105.25mm≤D≤105.85mm; W=105.25mm; D-W (i.e. H) ∈[0, 0.6]. Since -0.1mm≤X1≤0.1mm; -0.035mm≤X2≤0.035mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm, 0≤ ≤0.51mm. Thus, by deduction d≤0.3mm.

[0043] Exemplarily, D can be any value within the above range, for example, can be 105.25 mm, 105.35 mm, 105.45 mm, 105.55 mm, 105.65 mm, 105.75 mm, 105.85 mm, etc. X1 can be any value within the above range, for example, can be -0.10 mm, -0.05 mm, 0 mm, 0.05 mm, 0.10 mm, etc. X2 can be any value within the above range, for example, can be -0.025 mm, -0.020 mm, -0.015 mm, -0.010 mm, -0.005 mm, 0 mm, 0.005 mm, 0.010 mm, 0.015 mm, 0.020 mm, 0.025 mm, etc. X3 can be any value within the above range, for example, can be -0.18 mm, -0.10 mm, 0 mm, 0.1 mm, 0.18 mm, etc. X4 can be any value within the above range, for example, can be -0.025 mm, -0.020 mm, -0.015 mm, -0.010 mm, -0.005 mm, 0 mm, 0.005 mm, 0.010 mm, 0.015 mm, 0.020 mm, 0.025 mm, etc. X5 can be any value within the above range, for example, can be -0.010 mm, -0.005 mm, 0 mm, 0.005 mm, 0.010 mm, etc.

[0044] In a specific embodiment, when D is 105.85 mm, W is 105.25 mm, the chamfer breaking precision is 0.1 mm, the laser breaking precision is 0.035 mm, the laminating displacement precision is 0.18 mm; the swing piece precision is 0.025 mm; the laser moving precision is 0.01 mm, and the range of d calculated by the above formula is: d = 0.045 mm.

[0045] Please refer to Figure 1 In the second case, when the first cell piece 1 and the second cell piece 2 are both right-angled at both ends along the length thereof, some embodiments of the present application, ,

[0046] , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.035mm≤X2≤0.035mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; wherein, D is the distance between the central axis of the first cell piece 1 and the central axis of the second cell piece 2, W is half of the sum of the widths of the first cell piece 1 and the second cell piece 2, is the scribing precision, is the laser breaking precision; is the laminating displacement precision; is the swinging piece precision; is the laser movement precision. It needs to be explained that when the edges of the first cell piece 1 and the second cell piece 2 adjacent to each other are right angles, the first cell piece 1 and the second cell piece 2 are standard width, W=105.25mm. But the right angle edges of the first cell piece 1 and the second cell piece 2 are affected by the scribing precision . Considering the scribing precision, the laser breaking precision, the laminating displacement precision, the swinging piece precision and the laser movement precision, the range of the length d can be more accurate, and the laser thermal damage and short circuit during breaking can be further reduced.

[0047] In this embodiment, since 105.25mm≤D≤105.85mm; W=105.25mm; D-W (i.e. H) ∈[0,0.6]. Since -0.1mm≤X1≤0.1mm; -0.035mm≤X2≤0.035mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm, 0≤ ≤0.51mm. Thus, by derivation d≤0.3mm.

[0048] In a specific embodiment, when the value of D is 105.85mm, the value of W is 105.25mm, the scribing precision is 0.1mm, the laser breaking precision is 0.025mm, the laminating displacement precision is 0.18mm; the swinging piece precision is 0.025mm; the laser movement precision is 0.01mm, the range of d calculated by the above formula is: 0.035mm≤d≤0.055mm.

[0049] In a second aspect, the embodiments of the present application further provide a photovoltaic module, the photovoltaic module comprising a cell string 100 and a photovoltaic frame, the photovoltaic frame being configured to support the cell string 100, the cell string 100 being the cell string 100 of the first aspect, and the photovoltaic module being a back contact cell photovoltaic module.

[0050] In a third aspect, the embodiments of the present application further provide a method for designing a length of a break of a connecting belt 4, the method being configured to obtain the length d of the cell string 100 of the first aspect, and the method comprising the following steps:

[0051] Referring to Figure 2 , the interval D between the central axis of the first cell piece 1 and the central axis of the second cell piece 2, half of the sum of the widths of the first cell piece 1 and the second cell piece 2 W, the chamfer break error or the slicing accuracy of the first cell piece 1 and / or the second cell piece 2 , the laser break accuracy , the lamination displacement accuracy , the piece swinging accuracy , the laser movement accuracy are obtained respectively.

[0052] According to the formula , the convex length d of the cell string 100 is obtained.

[0053] In the description of the present application, it should be understood that if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0054] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "multiple" appears, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0055] In this application, unless otherwise clearly indicated and limited, if there are terms such as "mount", "connect", "connect", "fix", etc., these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0056] In this application, unless otherwise clearly indicated and limited, if there are terms such as "mount", "connect", "connect", "fix", etc., these terms should be understood in a broad sense. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0057] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation.

[0058] The technical features of the above-described embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the description.

[0059] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be construed as limiting the scope of the patent application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A battery string (100), characterized in that, include: A first battery cell (1) and a second battery cell (2) are spaced apart along a first direction, wherein the first direction is the width direction of the first battery cell (1) and / or the second battery cell (2); The connecting strip (4) is connected to the positive electrode of the first battery cell (1) and the negative electrode of the second battery cell (2). The length of the connecting strip (4) protruding from the edge of the first battery cell (1) and / or the second battery cell (2) along the first direction is d, which satisfies: 0.035mm≤d≤0.30mm.

2. The battery string (100) according to claim 1, characterized in that, include: The length d satisfies: 0.035mm≤d≤0.055mm.

3. The battery string (100) according to claim 1, characterized in that, The battery string (100) further includes a first positioning point (51) and a second positioning point (52), the first positioning point (51) being located on the first battery cell (1) and the second positioning point (52) being located on the second battery cell (2).

4. The battery string (100) according to claim 1, characterized in that, At least one of the two edges of the first battery cell (1) and the second battery cell (2) that are close to each other has a chamfered end or a right-angled end at least one end along its own length direction.

5. The battery string (100) according to any one of claims 1 to 4, characterized in that, The battery string (100) further includes a third battery cell. The connecting strip (4) includes a first connecting strip (41) and a second connecting strip (42). The first battery cell (1), the second battery cell (2), and the third battery cell are arranged in a sequentially spaced array along the first direction. The first connecting strip (41) is connected to the positive electrode of the first battery cell (1) and the negative electrode of the second battery cell (2). The second connecting strip (42) is connected to the positive electrode of the second battery cell (2) and the negative electrode of the third battery cell. The first connecting strip (41) and the second connecting strip (42) are alternately arranged along the second direction, which intersects with the first direction. The length of the first connecting strip (41) protruding from the edge of the first battery cell (1) and / or the second battery cell (2) along the first direction is d. The length of the second connecting strip (42) protruding from the edge of the second battery cell (2) and / or the third battery cell along the first direction is d.

6. The battery string (100) according to any one of claims 1 to 4, characterized in that, The length d satisfies: Wherein, H is the distance between the first battery cell (1) and the second battery cell (2) along the first direction. For the first machining accuracy, For the second machining accuracy, where 0 ≤ H ≤ 0.6 mm; 0 ≤ ≤0.035mm; 0≤ ≤0.49mm.

7. The battery string (100) according to claim 6, characterized in that, , , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.025mm≤X2≤0.025mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; where D is the distance between the central axis of the first battery cell (1) and the central axis of the second battery cell (2), and W is half the sum of the widths of the first battery cell (1) and the second battery cell (2). To ensure chamfering accuracy, To ensure the precision of laser cutting; For lamination displacement accuracy; For the accuracy of the plate arrangement; For laser movement accuracy.

8. The battery string (100) according to claim 6, characterized in that, , , , 105.25mm≤D≤105.85mm; W=105.25mm; -0.1mm≤X1≤0.1mm; -0.025mm≤X2≤0.025mm; -0.18mm≤X3≤0.18mm; -0.025mm≤X4≤0.025mm; -0.01mm≤X5≤0.01mm; where D is the distance between the central axis of the first battery cell (1) and the central axis of the second battery cell (2), and W is half the sum of the widths of the first battery cell (1) and the second battery cell (2). For dicing accuracy, To ensure the precision of laser cutting; For lamination displacement accuracy; For the accuracy of the plate arrangement; For laser movement accuracy.

9. A photovoltaic module, characterized in that, The photovoltaic module includes a battery string (100) and a photovoltaic frame, the photovoltaic frame being used to support the battery string (100), the battery string (100) being the battery string (100) as described in any one of claims 1 to 8.

10. A method for designing the break length of a connecting strip, characterized in that, The method for obtaining the length d of the battery string (100) as described in any one of claims 1 to 8 includes the following steps: The following parameters are obtained: the distance D between the central axis of the first battery cell (1) and the central axis of the second battery cell (2); half of the sum of the widths of the first battery cell (1) and the second battery cell (2); and the chamfering error or dicing accuracy of the first battery cell (1) and / or the second battery cell (2). Laser cutting precision Lamination displacement accuracy Precision of the slide Laser movement accuracy ; According to the formula , obtain the protrusion length d of the battery string (100).

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