Solar cell, cell assembly and photovoltaic system

Abstract

The invention discloses a solar cell, a cell module and a photovoltaic system. According to the solar cell, a first surface of a substrate comprises a first edge region, a central region and a second edge region which are oppositely arranged along a first direction; the first surface of the substrate is further provided with a connecting structure, the connecting structure comprises a plurality of first connecting structures and a plurality of second connecting structures, the first connecting structures are arranged in the first serial connection area, and the first connecting structures are electrically connected with the at least two first collecting grid lines; the second connecting structure is arranged in the second serial connection area, and the second connecting structure is in contact with at least two second collecting grid lines; the ratio of the width of the connecting structure in the first edge area along the second direction to the width of the connecting structure in the central area along the second direction is greater than 1; and / or the ratio of the width of the connecting structure in the second edge area along the second direction to the width of the connecting structure in the central area along the second direction is greater than 1. The reliability of the solar cell can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar energy, in particular to a solar cell, a cell module and a photovoltaic system. BACKGROUND

[0002] As a kind of efficient, clean energy conversion device, solar cell is widely used in various photovoltaic power generation systems. Solar cell includes substrate and grid line arranged on substrate, grid line and substrate ohmic contact, responsible for effectively collecting electrons and holes (carriers) generated by substrate under sunlight, and then converting into usable electric energy.

[0003] However, the existing solar cell photoelectric conversion efficiency welding quality is poor, and the reliability is low. SUMMARY

[0004] The present application provides a solar cell, a cell module and a photovoltaic system to improve the reliability of solar cell.

[0005] According to an aspect of the present application, a solar cell is provided, comprising:

[0006] The substrate has a first surface provided with a plurality of first collecting grid lines and a plurality of second collecting grid lines; the first collecting grid lines and the second collecting grid lines are alternately arranged in sequence along a first direction, and both extend along a second direction;

[0007] The first surface includes a first edge region and a second edge region oppositely arranged along the first direction, and a central region arranged between the first edge region and the second edge region;

[0008] The first surface is provided with at least one first stringing region and at least one second stringing region; the first stringing region and the second stringing region are used for arranging solder strips; the first collecting grid lines are continuous at the first stringing region and discontinuous at the second stringing region; the second collecting grid lines are continuous at the second stringing region and discontinuous at the first stringing region;

[0009] The first surface of the substrate is further provided with a connecting structure extending along the first direction, the connecting structure includes a plurality of first connecting structures and a plurality of second connecting structures, the first connecting structures are arranged in the first stringing region, and the first connecting structures are electrically connected with at least two first collecting grid lines; the second connecting structures are arranged in the second stringing region, and the second connecting structures are in contact with at least two second collecting grid lines;

[0010] The ratio of the width of the connecting structure located in the first edge region along the second direction to the width of the connecting structure located in the central region along the second direction is greater than 1; and / or, the ratio of the width of the connecting structure located in the second edge region along the second direction to the width of the connecting structure located in the central region along the second direction is greater than 1.

[0011] On the basis of the above-mentioned embodiments, optionally, a ratio of a width of the connection structure in the first edge area along the second direction to a width of the connection structure in the central area along the second direction ranges from 1 to 8; and / or,

[0012] A ratio of a width of the connection structure in the second edge area along the second direction to a width of the connection structure in the central area along the second direction ranges from 1 to 8.

[0013] On the basis of the above-mentioned embodiments, optionally, in the first edge area or the second edge area, a number of the first collection grid lines contacted by each first connection structure ranges from 2 to 10; and / or, in the first edge area or the second edge area, a number of the second collection grid lines contacted by each second connection structure ranges from 2 to 10.

[0014] On the basis of the above-mentioned embodiments, optionally, in the first stringing area, each end point of the first connection structure is located between adjacent first collection grid lines arranged along the first direction and does not contact the first collection grid line; in the second stringing area, each end point of the second connection structure is located between adjacent second collection grid lines arranged along the first direction and does not contact the second collection grid line; or,

[0015] In the first stringing area, at least one end point of the first connection structure contacts the first collection grid line, and in the second stringing area, at least one end point of the second connection structure contacts the second collection grid line.

[0016] On the basis of the above-mentioned embodiments, optionally, in the case that both end points of the first connection structure are located between adjacent first collection grid lines and both end points of the second connection structure are located between adjacent second collection grid lines,

[0017] In the first stringing area, a distance between an end point of the first connection structure and a preset first collection grid line is greater than 0 μm and less than or equal to 80 μm, and the preset first collection grid line is the nearest first collection grid line to the end point of the first connection structure; and / or, in the second stringing area, a distance between an end point of the second connection structure and a preset second collection grid line is greater than 0 μm and less than or equal to 80 μm, and the preset second collection grid line is the nearest second collection grid line to the end point of the second connection structure.

[0018] On the basis of the above-mentioned embodiments, optionally, the connection structure is at least one straight line structure, or the connection structure is a gradually changing line structure with a gradually changing width along the first direction.

[0019] On the basis of the above-mentioned embodiments, optionally, the connection structure is at least two straight line structures, and the at least two straight line structures include at least two line segments.

[0020] On the basis of the above-mentioned embodiments, optionally, the interval between two adjacent straight line structures is 50-400 μm.

[0021] The width of each straight line structure along the second direction is 50-100 μm. On the basis of the above-mentioned embodiments, optionally, the straight line structures are arranged in parallel, or the included angle between two adjacent straight line structures along the second direction is greater than or equal to 70-90 degrees.

[0022] On the basis of the above-mentioned embodiments, optionally, the connecting structure is a gradient strip structure with a width gradually changing along the first direction.

[0023] Along the first direction, the width of the gradient strip structure gradually decreases; or, along the first direction, the width of the gradient strip structure gradually increases; or, along the first direction, the width of the gradient strip structure first decreases and then increases; or, along the first direction, the width of the gradient strip structure first increases and then decreases.

[0024] The width of the gradient strip structure is the dimension of the gradient strip structure along the second direction.

[0025] On the basis of the above-mentioned embodiments, optionally, the solar cell further comprises:

[0026] The connecting structure is electrically connected with part of the pads.

[0027] The pads comprise a first pad and a second pad, the first pad is located in the first series connection region, and the second pad is located in the second series connection region.

[0028] The first collecting grid line is connected with the first pad at the first series connection region and is interrupted at the second series connection region; and the second collecting grid line is connected with the second pad at the second series connection region and is interrupted at the first series connection region.

[0029] According to another aspect of the present application, a battery assembly is provided, comprising the solar cell according to any of the embodiments of the present application.

[0030] According to another aspect of the present application, a photovoltaic system is provided, comprising the battery assembly according to any of the embodiments of the present application.

[0031] In this embodiment, the technical solution sets the ratio of the width of the connecting structure in the first edge region along the second direction to the width of the connecting structure in the central region along the second direction to be greater than 1; and / or, the ratio of the width of the connecting structure in the second edge region along the second direction to the width of the connecting structure in the central region along the second direction to be greater than 1. This allows the width of the connecting structures in the first and second edge regions to be wider than the width of the connecting structure in the central region along the second direction. Since the weld strip in the edge region may shift, it is easy to cause poor welding or broken welding. Setting a wider connecting structure in the edge region can improve the welding success rate of the weld strip and effectively reduce the defect rate of poor welding or broken welding. Since the weld strip shift in the central region is smaller, setting the width of the connecting structure in the central region to be narrower can reduce the shading area of ​​the connecting structure and save paste, thereby improving power generation efficiency and reducing costs.

[0032] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a solar cell provided in an embodiment of this application.

[0035] Figure 2 This is a schematic diagram of a solar cell provided in an embodiment of this application.

[0036] Figures 3-4 This is a schematic diagram of a connection structure provided in an embodiment of this application.

[0037] Figures 5-6 yes Figure 1 The image includes a magnified view of a specific area.

[0038] Figure 7 This is a schematic diagram of another connection structure provided in the embodiments of this application.

[0039] Figure 8 This is a schematic diagram of another connection structure provided in the embodiments of this application.

[0040] Figures 9-11 This is a schematic diagram of another connection structure provided in the embodiments of this application.

[0041] 10 - substrate, 11 - first edge region, 12 - second edge region, 21 - first collecting busbar, 22 - second collecting busbar, 31 - first stringing region, 32 - second stringing region, 40 - connecting structure, 41 - first connecting structure, 42 - second connecting structure, 50 - pad, 51 - first pad, 52 - second pad, 61 - first common busbar, 62 - second common busbar. DETAILED DESCRIPTION

[0042] The embodiment of the present application provides a solar cell, Figure 1 is a schematic diagram of a solar cell provided by the embodiment of the present application, referring to Figure 1 The solar cell comprises:

[0043] The substrate 10 is provided with a plurality of first collecting busbars 21 and a plurality of second collecting busbars 22 on a first surface of the substrate 10; the first collecting busbars 21 and the second collecting busbars 22 are alternately arranged in sequence along a first direction X and extend along a second direction Y;

[0044] The first surface comprises a first edge region 11 and a second edge region 12 oppositely arranged along the first direction X, and a central region arranged between the first edge region 11 and the second edge region 12;

[0045] The first surface is provided with at least one first stringing region 31 and at least one second stringing region 32; the first stringing region 31 and the second stringing region 32 are used for arranging a solder ribbon; the first collecting busbars 21 are continuous at the first stringing region 31 and discontinuous at the second stringing region 32; the second collecting busbars 22 are continuous at the second stringing region 32 and discontinuous at the first stringing region 31;

[0046] The first surface of the substrate 10 is further provided with a connecting structure 40, the connecting structure 40 extends along the first direction X, the connecting structure 40 comprises a plurality of first connecting structures 41 and a plurality of second connecting structures 42, the first connecting structures 41 are arranged in the first stringing region 31, each first connecting structure 41 is electrically connected with at least two first collecting busbars 21; the second connecting structures 42 are arranged in the second stringing region 32, each second connecting structure 42 is in contact with at least two second collecting busbars 32;

[0047] The ratio of the width of the connecting structure 40 located in the first edge region 11 along the second direction Y to the width of the connecting structure 40 located in the central region along the second direction Y is greater than 1; and / or the ratio of the width of the connecting structure 40 located in the second edge region 12 along the second direction Y to the width of the connecting structure 40 located in the central region along the second direction Y is greater than 1.

[0048] The solar cell can be a back contact solar cell. The substrate 10 is the base of the solar cell, and can include a substrate and a functional layer stacked on the substrate. The substrate can be a silicon substrate. The substrate 10 includes two surfaces arranged opposite to each other, which can be a light-receiving surface and a back surface. The light-receiving surface directly faces the sunlight and is not blocked by electrodes, so that the light absorption area can be maximized and the shadow loss can be reduced, and the photoelectric conversion efficiency of the solar cell can be significantly improved. The back surface is the other surface, and the first surface of the substrate 10 is the back surface. The substrate 10 can be a single crystal silicon wafer, a polycrystalline silicon wafer, or a silicon wafer similar to a single crystal silicon wafer. The functional layer includes at least a first doped layer and a second doped layer, and can further include a tunneling layer. The first doped layer can be an n-type doped layer, and the second doped layer can be a p-type doped layer. The substrate can be an n-type substrate or a p-type substrate, and the substrate and the first doped layer or the second doped layer form a p-n junction to generate a photovoltaic effect. When light shines on the solar cell, photons can excite electrons to transition from a valence band to a conduction band, forming electron-hole pairs. These carriers are separated at the p-n junction due to the electric field, generating an electric current.

[0049] The first collecting grid line 21 is arranged on the first doped layer of the substrate 10, and the first collecting grid line 21 is in contact with the first doped layer. The first collecting grid line 21 is used to collect carriers of the first doped layer. The second collecting grid line 22 is arranged on the second doped layer of the substrate 10, and the second collecting grid line 22 is in contact with the second doped layer. The second collecting grid line 22 is used to collect carriers of the second doped layer. The carriers collected by the first collecting grid line 21 are transmitted to the solder strip through the first connecting structure 41, and the carriers collected by the second collecting grid line 22 are transmitted to the solder strip through the second connecting structure 42.

[0050] In the first edge area 11, the first connecting structure 41 is included in at least part of the first string area 31, and the second connecting structure 42 is included in at least part of the second string area 32. In the second edge area 12, the first connecting structure 41 is included in at least part of the first string area 31, and the second connecting structure 42 is included in at least part of the second string area 32. In the central area, each first string area 31 can be provided with no first connecting structure 41 or at least one first connecting structure 41, and each second string area 32 can be provided with no second connecting structure 42 or at least one second connecting structure 42, which can be set as required, and the embodiments of the present application do not make specific limitations. Since the collection grid lines in the first edge area 11 and the second edge area 12 are prone to solder strip false welding, the first string area 31 and the second string area 32 in the first edge area 11 and the second edge area 12 are provided with the connecting structure 40, which can improve the welding quality; the connecting structure 40 connects at least two collection grid lines, and the solder strip collects carriers through the connecting structure 40, which can avoid the reduction of collection efficiency caused by false welding or broken welding of the solder strip.

[0051] The first string area 31 and the second string area 32 are respectively used for setting positive electrode solder strips and negative electrode solder strips, that is, one of the first string area 31 and the second string area 32 is a positive electrode string area, and the other is a negative electrode string area. The first string area 31 and the second string area 32 both extend along the first direction X and are alternately arranged along the second direction Y.

[0052] Specifically, the width of the connecting structure 40 along the second direction Y is the total width or the maximum width of the connecting structure 40 along the second direction Y; for example, if the connecting structure is one linear strip structure, the width of the connecting structure 40 along the second direction Y is the width of the linear strip structure; if the connecting structure is at least two linear strip structures, the width of the connecting structure 40 along the second direction Y is the total width of the at least two linear strips, that is, the total width of the at least two linear strips; if the connecting structure is a gradient strip structure with a gradually changing width along the second direction, the width of the connecting structure 40 along the second direction Y is the maximum width of the gradient strip structure.

[0053] The ratio of the width of the connecting structure 40 in the first edge area 11 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is greater than 1; or, the ratio of the width of the connecting structure 40 in the second edge area 12 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is greater than 1; or, the ratio of the width of the connecting structure 40 in the first edge area 11 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is greater than 1, and the ratio of the width of the connecting structure 40 in the second edge area 12 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is greater than 1. Setting the ratio to be greater than 1 can make the width of the connecting structure in the first edge area 11 and the second edge area 12 along the second direction Y wider than the width of the connecting structure 40 in the central area. Since the solder strip in the edge area will be offset, it is easy to cause the solder strip to be virtual or broken. Setting the width of the connecting structure 40 in the edge area to be wider can improve the soldering success rate of the solder strip and effectively reduce the defective rate of virtual or broken soldering. Since the solder strip in the central area is less offset, setting the width of the connecting structure in the central area to be narrower can reduce the shielding area of the connecting structure 40 and save the paste, improve the power generation efficiency and reduce the cost. On the basis of the above embodiments, optionally, Figure 2 is a schematic diagram of a solar cell provided by an embodiment of the present application, referring to Figure 2 The ratio of the width of the connecting structure 40 in the first edge area 11 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is in the range of 1-8; and / or, the ratio of the width of the connecting structure 40 in the second edge area 12 along the second direction Y to the width of the connecting structure 40 in the central area along the second direction Y is in the range of 1-8.

[0054] The ratio range is 1-8, that is, greater than 1 and less than or equal to 8; for example, the ratio can be 2, 3, 4, 5, 6, 7 and 8, etc.

[0055] Setting the ratio range to be 1-8 can ensure that the width of the connecting structure 40 in the first edge area 11 and the second edge area 12 is wider, avoid the solder strip in the edge area from being offset, cause the solder strip to be virtual or broken, improve the soldering success rate of the solder strip, effectively reduce the defective rate of broken soldering, and improve the reliability of the solar cell. Setting the width of the connecting structure 40 in the central area to be narrower can reduce the shielding area of the connecting structure 40 and save the paste, improve the power generation efficiency and reduce the cost.

[0056] On the basis of the above embodiments, optionally, referring to Figure 1In the first edge region 11 or the second edge region 12, the number of first collection grid lines 21 contacted by each first connection structure 41 is 2-10; and / or, in the first edge region 11 or the second edge region 12, the number of second collection grid lines 22 contacted by each second connection structure 42 is 2-10.

[0057] The quantity is always between 2 and 10, meaning it is greater than or equal to 2 and less than or equal to 10. For example, the quantity can be 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0058] The connecting structure 40 extends along the first direction X; the number of such structures is 2-10, which can effectively prevent the solder strip from shifting in the first or second edge area, resulting in poor soldering or broken soldering, reducing the adverse factors of the solar cell and improving the reliability of the solar cell; it can also effectively control the material cost of the connecting structure 40. The connecting structure 40 should not be too long to avoid excessive shading area, which would affect the power generation efficiency.

[0059] Based on the above embodiments, optionally, refer to Figure 1 or Figures 4-5 Within the first serial connection area 31, each endpoint of the first connecting structure 41 is located between adjacent first collection grid lines 21 arranged along the first direction X, and none of them are in contact with the first collection grid lines 21; within the second serial connection area 32, each endpoint of the second connecting structure 42 is located between adjacent second collection grid lines 22 arranged along the first direction X, and none of them are in contact with the second collection grid lines 22; or, within the first serial connection area 31, at least one endpoint of the first connecting structure 41 is in contact with the first collection grid line 21, and within the second serial connection area 32, at least one endpoint of the second connecting structure 42 is in contact with the second collection grid line 22.

[0060] Among them, reference Figure 1 , Figure 1The connection structure is a straight strip structure. Within the first series connection area 31, both endpoints of the first connection structure 41 are located between adjacent first collection grid lines 21; within the second series connection area 32, both endpoints of the second connection structure 42 are located between adjacent second collection grid lines 22. In this case, both the first connection structure 41 and the second connection structure 42 are designed with protruding ends, meaning that each endpoint of each straight strip structure does not contact the collection grid line. Similarly, within the first series connection area 31, each endpoint of the first connection structure 41 does not contact either the first or second collection grid line 21; within the second series connection area 32, each endpoint of the second connection structure 42 does not contact either the first or second collection grid line 21. This protruding end design enhances the soldering capability of the solder strip, resulting in better soldering quality, and simultaneously improves the ability of the collection grid lines to transfer charge carriers to the solder strip, reducing losses during charge carrier migration. (A straight strip structure is a protruding end design.)

[0061] When the connection structure is a straight strip structure, in the first serial connection area 31, at least one end of the first connection structure 41 is in contact with the first collection grid line 21, that is, one end of the first connection structure 41 is in contact with the first collection grid line 21, or all ends of the first connection structure 41 are in contact with the first collection grid line 21; in the second serial connection area 32, at least one end of the second connection structure 42 is in contact with the adjacent second collection grid line 22; it can be understood that one end of the second connection structure 42 is in contact with the second collection grid line 22, or all ends of the second connection structure 42 are in contact with the second collection grid line 22. One end of the first connecting structure 41 contacts the first collecting grid line 21, and one end of the second connecting structure 42 contacts the second collecting grid line 22. In this case, both the first connecting structure 41 and the second connecting structure 42 are designed with one end protruding and the other end concealed. All ends of the first connecting structure 41 contact the first collecting grid line 21, and all ends of the second connecting structure 42 contact the second collecting grid line 22. Again, both the first connecting structure 41 and the second connecting structure 42 are designed without protruding ends; that is, the ends of both linear structures contact their corresponding collecting grid lines. Within the first series connection area 31, the ends of both linear structures contact the first collecting grid line 21, and within the second series connection area 32, the ends of both linear structures contact the second collecting grid line 22. This concealed protruding end design reduces the shading area of ​​the connecting structure 40, thereby improving the power generation efficiency of the solar cell.

[0062] The connecting structure 40 consists of two straight strip structures, which are a whole and include both ends. The two straight strip structures can be designed as a straight line, with protruding ends, non-protruding ends, or one end protruding while the other end does not. Figures 3-4 This is a schematic diagram of a connection structure provided in an embodiment of this application.Figure 3 and Figure 4 The design features two straight, strip-shaped structures without any protrusions. (This design does not apply to two such structures.)

[0063] Optional, Figures 5-6 yes Figure 1 The enlarged view included in the image is for reference. Figures 1-6 The connecting structure 40 is at least one straight strip structure, or... Figure 7 This is a schematic diagram of another connection structure 40 provided in an embodiment of this application, see reference. Figure 7 The connecting structure 40 is a gradient strip structure with a width that gradually changes along the first direction X, and the width is the dimension along the second direction Y.

[0064] Among them, reference Figure 1 The connecting structure 40 is a straight strip structure. This straight strip structure can be designed with an extended end, which can effectively prevent the solder strip from shifting at the edge, causing poor soldering and improving component yield. (Reference) Figure 3 and Figure 4 The connecting structure 40 consists of two straight strip structures, or at least two straight strip structures. It can be configured with either an extended or non-extended design. The design with at least two straight strips divides the connecting structure 40 into at least two straight lines for electron transport and collection, reducing electron transport loss. It also effectively prevents lateral misalignment of the solder ribbon, which can lead to incomplete soldering, and improves the soldering success rate in the first and second edge regions. (Reference) Figure 7 The connecting structure 40 is a gradient strip structure with a gradually changing width along the first direction X, which can effectively prevent the solder strip from shifting to the left or right, resulting in a poor weld, and can also reduce the slurry cost of the connecting structure 40.

[0065] Based on the above embodiments, optionally, Figure 5 for Figure 1 A magnified view of a section within the green ellipse. Figure 6 for Figure 1 Enlarged view of a section within the red ellipse; for reference. Figure 1 , Figure 5 and Figure 6When both endpoints of the first connecting structure 41 are located between adjacent first collecting grid lines 21, and both endpoints of the second connecting structure 42 are located between adjacent second collecting grid lines 22, within the first serial connection area 31, the distance D1 between the endpoint of the first connecting structure 41 and the preset first collecting grid line 21 is greater than 0 μm and less than or equal to 80 μm, and the preset first collecting grid line 21 is the first collecting grid line 21 that is closest to the endpoint of the first connecting structure 41 in contact with the first connecting structure 41; and / or, within the second serial connection area 32, the distance D2 between the endpoint of the second connecting structure 42 and the preset second collecting grid line 22 is greater than 0 μm and less than or equal to 80 μm, and the preset second collecting grid line 22 is the second collecting grid line 22 that is closest to the endpoint of the second connecting structure 42 in contact with the second connecting structure 42.

[0066] Wherein, D1 and D2 are the size range of the protrusion design of the first connection structure and the second connection structure, and D1 and D2 can be 1μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, etc.

[0067] If the connection structure 40 is located within the first serial connection area 31, and the distance D1 between the endpoint of the first connection structure 41 and the preset first collection gate line 21 is greater than 80 μm, and the distance D2 between the endpoint of the second connection structure 42 and the preset second collection gate line 22 is greater than 80 μm, the cost of the connection structure 40 will increase. Therefore, if the connection structure 40 is located within the first serial connection area 31, and the distance D1 between the endpoint of the first connection structure 41 and the preset first collection gate line 21 is greater than 0 μm and less than or equal to 80 μm, and the distance D2 between the endpoint of the second connection structure 42 and the preset second collection gate line 22 is greater than 0 μm and less than or equal to 80 μm, the welding capability between the solder ribbon and the connection structure 40 can be enhanced, the ability of the connection structure 40 to transfer electrons to the solder ribbon can be improved, the loss of electrons during migration can be reduced, and the cost can be controlled.

[0068] Optional, see reference Figures 1-3 The connecting structure 40 is at least one straight strip structure, or... Figure 6 This is a schematic diagram of another connection structure 40 provided in an embodiment of this application, see reference. Figure 6 The connecting structure 40 is a gradient strip structure with a gradually changing width in the second direction Y.

[0069] The connecting structure 40 is at least one straight strip structure, which is simple to manufacture and can be divided into at least two straight lines for electron transport and collection, reducing electron loss and effectively preventing solder strip misalignment that could lead to cold solder joints. Alternatively, the connecting structure 40 can be a gradient strip structure with a gradually changing width in the second direction Y, which can also effectively prevent solder strip misalignment that could lead to cold solder joints and reduce the cost of the solder paste used in the connecting structure 40.

[0070] Based on the above embodiments, optionally, refer to Figure 3 and Figure 4 The connecting structure 40 consists of at least two straight strip structures, each comprising at least two line segments.

[0071] Among them, at least two straight strip structures can include two, three, or four line segments. The more line segments there are, the smaller the width of a single line segment can be, which can reduce the loss of electronic transmission and effectively prevent the solder strip from shifting to the left or right, thus preventing incomplete soldering and improving the soldering success rate.

[0072] Based on the above embodiments, optionally, refer to Figure 3 Along the second direction, the spacing D2 between two adjacent linear strip structures ranges from 50μm to 400μm; the width W1 of each linear strip structure along the second direction Y is 50μm to 100μm.

[0073] The spacing D2 between two adjacent straight strip structures is set to a range of 50μm-400μm. For example, it can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 400μm, etc. The preparation process is relatively simple, and the connection structure can be set to at least two straight lines, which can reduce electron transmission loss; and effectively prevent the solder strip from shifting to the left or right, which can lead to poor soldering and improve the welding success rate.

[0074] The width W1 of each straight strip structure included in the connection structure 40 along the second direction Y is 50μm-100μm. For example, it can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc. The preparation process is simple and more straight strips can be set, thereby reducing electron transmission loss. It also effectively prevents the solder strip from shifting to the left or right, which would cause poor soldering, and improves the welding success rate of the first edge area and the second edge area.

[0075] Based on the above embodiments, optionally, refer to Figure 3 and Figure 4 All straight strip structures are arranged in parallel, or... Figure 8 This is a schematic diagram of another connection structure provided in the embodiments of this application, wherein at least one of the straight strip structures has an angle A greater than or equal to 70 degrees-90 degrees with the second direction Y.

[0076] The design involves setting all straight strip structures in parallel, which simplifies the manufacturing process and allows for the use of multiple straight lines, reducing electron transmission loss. It also effectively prevents the solder strip from shifting to the left or right, leading to incomplete or broken solder joints and improving the welding success rate.

[0077] Specifically, setting at least one of the straight strip structures to have an angle A greater than or equal to 70-90 degrees with the second direction Y can increase the coverage area of ​​each straight strip structure in the second direction Y, effectively preventing the weld strip from shifting to the left or right, which could lead to incomplete or broken welds and improve the welding success rate.

[0078] Based on the above embodiments, optionally, Figures 9-11 This is a schematic diagram of another connection structure provided in the embodiments of this application, see reference. Figure 7 , Figures 9-11 The connecting structure 40 is a gradient strip structure with a width that gradually changes along the first direction X; Reference Figure 9 Along the first direction X, the width of the gradient strip structure gradually decreases; or, refer to Figure 7 Along the first direction X, the width of the gradient strip structure gradually increases; or, refer to Figure 10 Along the first direction X, the width of the gradient strip structure first decreases and then increases; or, refer to... Figure 11 Along the first direction X, the width of the gradient strip structure first increases and then decreases; wherein, the width of the gradient strip structure is the dimension of the gradient strip structure along the second direction Y.

[0079] The aforementioned shape configurations can increase the coverage area of ​​the connecting structure 40 in the second direction Y, effectively preventing the solder strip from shifting to the left or right, which could lead to incomplete or broken solder joints and improve the welding success rate.

[0080] Based on the above embodiments, optionally, the solar cell further includes: a pad 50, and a connection structure 40 electrically connected to a portion of the pad 50; the pad 50 includes a first pad 51 and a second pad 52, the first pad 51 being located in a first series connection area 31, and the second pad 52 being located in a second series connection area 31; a first collection grid line 21 being connected to the first pad 51 at the first series connection area 31 and interrupted at the second series connection area 32; and a second collection grid line 22 being connected to the second pad 42 at the second series connection area 32 and interrupted at the first series connection area 31.

[0081] The pad 50 can be a separately fabricated pad structure or a thickened structure of the collection gate line. The first serial connection region 31 is provided with a first pad 51 connected to the solder ribbon, and the first pad 51 is electrically connected to the first collection gate line 21. The second serial connection region 32 is provided with a second pad 52 connected to the solder ribbon, and the second pad 52 is electrically connected to the second collection gate line 22. For example, the solder ribbon is electrically connected to the first collection gate line 21 through the first pad 51, collecting the carriers of the first collection gate line 21. The solder ribbon is electrically connected to the second collection gate line 22 through the second pad 52, collecting the carriers of the second collection gate line 22.

[0082] refer to Figure 1The solar cell also includes a first busbar 61 and a second busbar 62. The first busbar 61 is connected to at least a portion of the first collection grid 21 for collecting charge carriers on the first collection grid 21; the second busbar 62 is connected to at least a portion of the second collection grid 22 for collecting charge carriers on the second collection grid 22.

[0083] This application also provides a battery assembly, including the solar cell described in the above embodiments.

[0084] A battery module may include multiple solar cells, which can be connected in series to form a battery string. The battery strings can be connected in series, in parallel, or in a series-parallel combination to achieve current output. For example, the connection between individual cells can be achieved by welding ribbons, or the connection between battery strings can be achieved by busbars.

[0085] The battery module may also include a metal frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film can be filled between the light-facing side of the solar cell and the photovoltaic glass, the back-facing side and the backsheet, and adjacent cells. As a filler, it can be a transparent colloid with good light transmittance and aging resistance; for example, EVA film or POE film can be used, and the choice is based on the specific circumstances and is not limited here. The photovoltaic glass can cover the encapsulating film on the light-facing side of the solar cell. The photovoltaic glass can be ultra-clear glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of ultra-clear glass can reach over 92%, which can protect the solar cell while minimizing the impact on its efficiency. Simultaneously, the encapsulating film can bond the photovoltaic glass and the solar cell together, and its presence provides sealing, insulation, waterproofing, and moisture protection for the solar cell.

[0086] The backsheet can be attached to the encapsulating film on the back side of the solar cell. The backsheet protects and supports the solar cell, providing reliable insulation, water resistance, and aging resistance. Multiple backsheet options are available, typically including tempered glass, acrylic glass, and aluminum alloy TPT composite encapsulating film, etc., with specific choices depending on the circumstances. The backsheet, solar cell, encapsulating film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, providing stable support and installation. For example, the battery module can be installed at the desired location using the metal frame.

[0087] The battery module in this application embodiment belongs to the same application concept as the solar cell described in the above embodiments of this application and has corresponding beneficial effects. For technical details not covered in this embodiment, please refer to the solar cell described in any embodiment of this application.

[0088] This application also provides a photovoltaic module, including the battery module described in the above embodiments.

[0089] Photovoltaic systems can be applied in photovoltaic power plants, such as ground-mounted, rooftop, and floating power plants, as well as in equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it's understandable that the application scenarios for photovoltaic systems are not limited to these; that is, photovoltaic systems can be applied in all areas that require solar energy to generate electricity. Taking a photovoltaic power generation network as an example, a photovoltaic system can include photovoltaic arrays, combiner boxes, and inverters. A photovoltaic array can be a combination of multiple battery modules; for example, multiple battery modules can form multiple photovoltaic arrays. The photovoltaic arrays are connected to combiner boxes, which collect the current generated by the photovoltaic arrays. The collected current flows through an inverter, converts it into AC power required by the mains grid, and then connects to the mains grid to achieve solar power supply.

[0090] The beneficial effects of the photovoltaic system in this embodiment are equivalent to the beneficial effects of the battery module described above, and will not be repeated here.

[0091] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0092] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A solar cell, characterized in that, include: A substrate, wherein a first surface of the substrate is provided with a plurality of first collection grid lines and a plurality of second collection grid lines; the first collection grid lines and the second collection grid lines are arranged alternately along a first direction and both extend along a second direction; The first surface includes a first edge region and a second edge region disposed opposite to each other along a first direction, and a central region disposed between the first edge region and the second edge region; The first surface is provided with at least one first serial connection area and at least one second serial connection area; the first serial connection area and the second serial connection area are used to provide solder strips; the first collecting grid line is continuous at the first serial connection area and intermittent at the second serial connection area; the second collecting grid line is continuous at the second serial connection area and intermittent at the first serial connection area; The first surface of the substrate is further provided with a connection structure, the connection structure extends along a first direction, the connection structure includes a plurality of first connection structures and a plurality of second connection structures, the first connection structure is disposed in the first series connection area, and the first connection structure is electrically connected to at least two of the first collection grid lines. The second connection structure is disposed within the second serial connection area, and the second connection structure is in contact with at least two of the second collection grid lines; Wherein, the ratio of the width of the connecting structure located in the first edge region along the second direction to the width of the connecting structure located in the central region along the second direction is greater than 1; and / or, the ratio of the width of the connecting structure located in the second edge region along the second direction to the width of the connecting structure located in the central region along the second direction is greater than 1.

2. The solar cell according to claim 1, characterized in that: The ratio of the width of the connecting structure located in the first edge region along the second direction to the width of the connecting structure located in the central region along the second direction ranges from 1 to 8. And / or, The ratio of the width of the connecting structure located in the second edge region along the second direction to the width of the connecting structure located in the central region along the second direction ranges from 1 to 8.

3. The solar cell according to claim 1, characterized in that: In the first edge region or the second edge region, the number of first collection grid lines contacted by each of the first connection structures is 2-10; and / or, in the first edge region or the second edge region, the number of second collection grid lines contacted by each of the second connection structures is 2-10.

4. The solar cell according to claim 1, characterized in that: Within the first serial connection area, each endpoint of the first connection structure is located between adjacent first collection grid lines arranged along the first direction, and none of them contact the first collection grid lines; within the second serial connection area, each endpoint of the second connection structure is located between adjacent second collection grid lines arranged along the first direction, and none of them contact the second collection grid lines; or, In the first serial connection area, at least one end of the first connection structure is in contact with the first collection grid line, and in the second serial connection area, at least one end of the second connection structure is in contact with the second collection grid line.

5. The solar cell according to claim 4, characterized in that: When both endpoints of the first connection structure are located between adjacent first collection grid lines, and both endpoints of the second connection structure are located between adjacent second collection grid lines, Within the first serial connection area, the distance between the endpoint of the first connection structure and the preset first collection grid line is greater than 0 μm and less than or equal to 80 μm, wherein the preset first collection grid line is the first collection grid line that is closest to the endpoint of the first connection structure in contact with the first connection structure; and / or, within the second serial connection area, the distance between the endpoint of the second connection structure and the preset second collection grid line is greater than 0 μm and less than or equal to 80 μm, wherein the preset second collection grid line is the second collection grid line that is closest to the endpoint of the second connection structure in contact with the second connection structure.

6. The solar cell according to claim 2, characterized in that: The connecting structure is at least one straight strip structure, or the connecting structure is a gradient strip structure whose width gradually changes along the first direction.

7. The solar cell according to claim 2, characterized in that: The connection structure is at least two straight strip structures, and the at least two straight strip structures include at least two line segments.

8. The solar cell according to claim 7, characterized in that: Along the second direction, the spacing between two adjacent linear strip structures ranges from 50 μm to 400 μm; The width of each straight linear structure along the second direction is 50μm-100μm.

9. The solar cell according to claim 7, characterized in that: The linear strip structures are arranged in parallel, or at least one of the linear strip structures forms an angle greater than or equal to 70-90 degrees with the direction along the second direction.

10. The solar cell according to claim 4, characterized in that: The connecting structure is a gradient strip structure whose width gradually changes along the first direction; Along the first direction, the width of the gradient strip structure gradually decreases; or, along the first direction, the width of the gradient strip structure gradually increases; or, along the first direction, the width of the gradient strip structure first decreases and then increases. Alternatively, along the first direction, the width of the gradient strip structure first increases and then decreases; Wherein, the width of the gradient strip structure is the dimension of the gradient strip structure along the second direction.

11. The solar cell according to claim 1, characterized in that, Also includes: The pads, the connection structure, and a portion of the pads are electrically connected; The pads include a first pad and a second pad, the first pad being located in the first serial area and the second pad being located in the second serial area; The first collection gate line is connected to the first pad at the first serial connection area and is interrupted at the second serial connection area; the second collection gate line is connected to the second pad at the second serial connection area and is interrupted at the first serial connection area.

12. A battery assembly, characterized in that, Includes the solar cell described in any one of claims 1 to 11.

13. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 12.

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