Back contact solar cell and photovoltaic module

Abstract

The utility model provides a back contact solar cell and a photovoltaic assembly, and relates to the field of photovoltaic technology. The back contact solar cell comprises a first cell body and a first electrode structure located on the back side of the first cell body. The first electrode structure comprises a plurality of collector grid lines extending along a first direction; the plurality of interconnection parts are arranged along the first direction and the second direction and are electrically connected with the collector grid lines; along the second direction, the plurality of interconnection parts comprise edge first interconnection parts adjacent to the edge of the first battery and middle interconnection parts distributed at intervals with the edge first interconnection parts; in the second direction, the distance between the geometric center of the edge first interconnection part and the edge of the first battery is L1, the distance between the geometric centers of the adjacent middle interconnection parts is L2, and L1 is larger than or equal to 0.5 * L2 and smaller than 0.9 * L2. According to the utility model, mass production is easy, the hidden crack risk is small, collection of current carriers and conduction of current are facilitated, and the electrical performance of a formed photovoltaic assembly is good.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a back contact solar cell and a photovoltaic module. Background Art

[0002] A back-contact solar cell refers to a cell in which the electrode structure is located on the back side of the cell body. The electrode structure in the cell has little shading effect, so it has higher photoelectric conversion efficiency and broad application prospects.

[0003] In existing back-contact solar cells, the location of the interconnection portion is usually rather random, resulting in the conductive interconnection being difficult to achieve mass production during the process of forming photovoltaic modules, and the resulting photovoltaic modules having poor electrical performance and a high risk of hidden cracks. Utility Model Content

[0004] The utility model provides a back-contact solar cell and a photovoltaic module, aiming to solve the problem that in the existing back-contact solar cells, the arrangement position of the interconnection part is usually rather random, resulting in that in the process of forming the photovoltaic module, the conductive interconnection is not easy to realize mass production, and the electrical performance of the formed photovoltaic module is poor, and the risk of hidden cracks is high.

[0005] In a first aspect of the utility model, a back contact solar cell is provided, comprising:

[0006] A first battery body and a first electrode structure located on the back side of the first battery body; the first electrode structure includes:

[0007] A plurality of collector grid lines extending along a first direction;

[0008] A plurality of interconnecting portions arranged in a first direction and a second direction and electrically connected to the collector grid line; wherein the first direction is different from the second direction; and along the second direction, the plurality of interconnecting portions have at least a portion of regions that are collinear;

[0009] The first battery body includes a first battery edge, wherein the first battery edge has at least a portion parallel to the first direction;

[0010] Along the second direction, the plurality of interconnecting portions include: an edge first interconnecting portion adjacent to an edge of the first battery, and an intermediate interconnecting portion spaced apart from the edge first interconnecting portion;

[0011] In the second direction: the distance between the geometric center of the edge first interconnection portion and the edge of the first battery is L1, the distance between the geometric centers of adjacent middle interconnections is L2, and 0.5×L2≤L1<0.9×L2.

[0012] In the embodiment of the utility model, 0.5×L2≤L1<0.9×L2, that is, in the second direction: the distance L1 between the geometric center of the first interconnection part of the edge and the edge of the first battery is greater than or equal to half of the distance L2 between the geometric centers of the adjacent middle interconnections in the second direction. L1 is large. In the process of forming a battery string or a photovoltaic module, the edge of the battery has a large conductive interconnection position, such as a welding position, or the reserved operation space is large. The conductive interconnection is easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the edge of the battery is large, and the risk of hidden cracks is small. In addition, L1<0.9×L2, the size of L1 is not too large, and the uniform distribution of the interconnection part is achieved as much as possible, which is conducive to the collection of carriers and the conduction of current, and the formed photovoltaic module has good electrical performance.

[0013] Optionally, along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to an edge of the first battery;

[0014] In the second direction: the distance between the geometric center of the edge first interconnection portion and the edge collector grid line is L3, L3<L1, and 0.5×L2≤L3<0.9×L2.

[0015] Optionally, the first battery body includes: an isolation region located between the edge collector grid line and the edge of the first battery along the second direction;

[0016] In the second direction: the distance between the geometric center of the edge first interconnection portion and the isolation region is L4, L4<L1, and 0.5×L2≤L4<0.9×L2.

[0017] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; in the second direction: a size of the interconnection portion is b, and a distance between adjacent collector grid lines of the same polarity is L5;

[0018] 0.5×L5≤b≤3×L5.

[0019] Optionally, the first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge; the second battery edge has a chamfer;

[0020] In the first direction: the geometric center of the edge second interconnection portion is further away from the second battery edge than the chamfer, and the distance between the geometric center of the edge second interconnection portion and the point of the chamfer closest to the edge second interconnection portion is a, and a≥0.3 mm.

[0021] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; in the second direction: a distance between adjacent collector grid lines of the same polarity is L5;

[0022] The ratio of L3 / L5 is 3 to 16.

[0023] Optionally, in the second direction, the size of the first battery body is L6;

[0024] The number of interconnections arranged in the second direction is n;

[0025] 0.5×L6÷n≤L1.

[0026] Optionally, the first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection portions are electrically connected; along the first direction, the size of the interconnection portions is greater than or equal to the size of the busbar lines;

[0027] In the first direction, the size of the first battery body is L7;

[0028] The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge;

[0029] Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery;

[0030] In the first direction: the distance between the geometric center of the edge second interconnection portion and the edge busbar line is c;

[0031] The L7 / c ratio ranges from 33 to 105.

[0032] Optionally, the first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection portions are electrically connected; along the first direction, the size of the interconnection portions is greater than or equal to the size of the busbar lines;

[0033] The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge;

[0034] Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery;

[0035] In the first direction: the distance between the geometric center of the edge second interconnection portion and the edge busbar line is c;

[0036] The ratio of c / L3 is 0.1 to 1.

[0037] Optionally, the plurality of collector grid lines include: a positive polarity collector grid line and a negative polarity collector grid line;

[0038] The positive polarity collector grid lines and the negative polarity collector grid lines are alternately distributed along the second direction;

[0039] The plurality of interconnecting parts include: a third interconnecting part electrically connected to the positive polarity collector grid line, and a fourth interconnecting part electrically connected to the negative polarity collector grid line; the third interconnecting part and the fourth interconnecting part are alternately distributed along the first direction;

[0040] Along the second direction, the third interconnection portion and the fourth interconnection portion both include: an edge first interconnection portion adjacent to the edge of the first battery, and an intermediate interconnection portion spaced apart from the edge first interconnection portion; in the third interconnection portion and / or the fourth interconnection portion, the intermediate interconnections are equidistantly distributed along the second direction.

[0041] Optionally, in the first direction, at least some areas of the plurality of third interconnected portions are collinear, and at least some areas of the plurality of fourth interconnected portions are collinear;

[0042] Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to an edge of the first battery; and a gap is provided between the edge collector grid line and the third interconnection portion or the fourth interconnection portion.

[0043] Optionally, the first electrode structure further includes: a plurality of busbar lines extending along the second direction; the plurality of busbar lines include: a positive polarity busbar line and a negative polarity busbar line;

[0044] The positive polarity busbar lines and the negative polarity busbar lines are alternately distributed along the first direction;

[0045] The positive bus grid line, the positive collector grid line and the third interconnection portion are all electrically connected; the negative bus grid line, the negative collector grid line and the fourth interconnection portion are all electrically connected.

[0046] Optionally, the plurality of collector grid lines include: a positive polarity collector grid line and a negative polarity collector grid line;

[0047] In the second direction, the distance between adjacent collector grid lines of the same polarity is L5; L5 is 0.5 mm to 1.2 mm; and / or,

[0048] Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to the edge of the first battery, in the second direction: a distance L8 between the edge collector grid line and the edge of the first battery, L8 being 0.3 mm to 1 mm; and / or,

[0049] L1>6.5mm; and / or

[0050] In the second direction: the distance between the geometric center of the first interconnection portion of the edge and the geometric center of the adjacent interconnection portion is L9, L1<L9≤L2.

[0051] Optionally, the first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection portions are electrically connected; along the first direction, the size of the interconnection portions is greater than or equal to the size of the busbar lines;

[0052] The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge;

[0053] Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery;

[0054] In the first direction, the edge busbar line is located between the second battery edge and the edge second interconnection portion;

[0055] Several collector grid lines include: in the second direction, an adjacent collector grid line is separated from the second edge interconnection portion and is closest to the second edge interconnection portion, and a bending structure is provided at the end of the adjacent collector grid line close to the second battery edge, and the size of the portion of the adjacent collector grid line that exceeds the second edge interconnection portion in both the first and second directions in the first direction is greater than the size of the bending structure in the second direction.

[0056] Optionally, the bending structure is only located on one side of the first battery body parallel to the second direction, so as to minimize the number of bent collector grid lines, avoid interrupting the collector grid lines in more different polarity areas, and avoid forming more dead zones. At the same time, reducing the number of bends can also reduce the difficulty of printing and avoid poor printing.

[0057] In a second aspect of the utility model, there is provided a back-contact solar cell, comprising: a second cell body and a second electrode structure located on the back side of the second cell body;

[0058] In the second direction, the second electrode structure is composed of m electrode substructures; m is a positive integer;

[0059] The electrode substructure is the first electrode structure in any of the aforementioned back-contact solar cells.

[0060] Optionally, the m electrode substructures include: adjacent first electrode substructures and second electrode substructures, a collector grid line in the first electrode substructure adjacent to the second electrode substructure and a collector grid line in the second electrode substructure adjacent to the first electrode substructure being at a distance h from each other;

[0061] Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to the edge of the first battery, and in the second direction: a distance between the edge collector grid line and the edge of the first battery is L8;

[0062] The ratio of L8 / h is greater than 0 and less than or equal to 1.

[0063] A third aspect of the present invention provides a photovoltaic module, comprising: a plurality of any of the aforementioned back-contact solar cells.

[0064] Optionally, the photovoltaic assembly further includes: a conductive interconnection member extending along the second direction and electrically connected to the interconnection portion;

[0065] In the first direction, the orthographic projection of the conductive interconnection member on the back side of the first battery body is only

[0066] On back contact solar cells.

[0067] The above-mentioned back-contact solar cells and photovoltaic modules both have the same or similar beneficial effects, and in order to avoid repetition, they are not described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0069] Figure 1 A schematic structural diagram of a back-contact solar cell in an embodiment of the utility model is shown;

[0070] Figure 2 A partial enlarged structural schematic diagram of a first back-contact solar cell in an embodiment of the utility model is shown;

[0071] Figure 3 A partial enlarged structural schematic diagram of a second back-contact solar cell in an embodiment of the utility model is shown;

[0072] Figure 4 A partial enlarged structural schematic diagram of a third back-contact solar cell in an embodiment of the utility model is shown;

[0073] Figure 5 A partial enlarged structural schematic diagram of a fourth back-contact solar cell in an embodiment of the utility model is shown.

[0074] Description of the accompanying drawings:

[0075] 1-first battery body, 111-first battery edge, 112-second battery edge, 1121-chamfer, 12-collector grid line, 121-edge collector grid line, 122-adjacent collector grid line, 1221-bending structure, 13-interconnection part, 131-edge first interconnection part, 132-middle interconnection part, 133-edge second interconnection part, 14-collector grid line, 141-edge collector grid line. DETAILED DESCRIPTION

[0076] The following will combine the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work belong to the utility model.

[0077] Scope of new types of protection.

[0078] The utility model provides a back contact solar cell. Figure 2 yes Figure 1 The enlarged schematic diagram of the dotted line frame in the upper right corner of Figure 3 yes Figure 1 An enlarged schematic diagram of the portion framed by the dotted line in the lower right corner of . Figure 4 yes Figure 1 The enlarged schematic diagram of the upper left corner of Figure 5 yes Figure 4 See the enlarged diagram of the upper left corner of Figures 1 to 5 The back-contact solar cell may include: a first cell body 1 and a first electrode structure located on the back side of the first cell body 1. The first cell body 1 has a pn junction that can separate carriers. During normal operation of the back-contact solar cell, the surface that mainly receives light is its light-facing side, and the backlight side and the light-facing side are relatively distributed. The first electrode structure here includes all electrodes of the back-contact solar cell, or most of the electrodes, and the first electrode structure is used to collect and conduct current in the first cell body 1.

[0079] Figures 1 to 5 In the figure, p represents the first direction, and q represents the second direction. The first electrode structure includes: a plurality of collector grid lines 12 extending along the first direction p, and the collector grid lines 12 are used to collect carriers or current.

[0080] The first electrode structure also includes: a plurality of interconnecting parts 13 arranged along the first direction p and the second direction q and electrically connected to the collector grid line 12. There is no specific limitation on the arrangement of the plurality of interconnecting parts 13. For example, the plurality of interconnecting parts 13 may be arranged in an array along the first direction p and the second direction q. Wherein, the first direction p is different from the second direction q, and the angle between the two is not specifically limited. For example, the first direction p and the second direction q are perpendicular. Along the second direction q, the size of the interconnecting part 13 is greater than or equal to the size of the collector grid line 12. Along the second direction q, when the size of the interconnecting part 13 is equal to the size of the collector grid line 12, a conductive interconnection can be performed by a method other than the welding process. For example, a laminating process can be used to directly attach the carrier film of the conductive interconnection member to the surface of the back contact solar cell, and further pressing can be performed to achieve reliable conductive interconnection. Along the second direction q, when the size of the interconnecting part 13 is greater than the size of the collector grid line 12, a conductive interconnection can be performed by a welding process, or a conductive interconnection can be performed by a method other than the welding process, and there is no specific limitation on this. The interconnection 13 is used to collect and conduct the current on the collector grid line 12 to the outside, so the current passing through the interconnection 13 is relatively large.

[0081] Along the second direction q, several interconnections 13 have at least partial areas collinear, or in other words, at least partial areas of a row of interconnections 13 in the second direction q are collinear, and subsequently in the process of forming a battery string or photovoltaic module, the conductive interconnection member can be arranged at the above-mentioned collinear position.

[0082] The first battery body 1 includes: a first battery edge 111, a first battery of the first battery body 1

[0083] The edge 111 is the position where the contour line of the first battery body 1 in the first direction p is located. The first battery edge 111 has at least a portion parallel to the first direction p. For example, Figures 1 to 5 In the embodiment of the present invention, the portion of the first battery edge 111 that is not chamfered is parallel to the first direction p. Along the second direction q, the plurality of interconnects 13 include: an edge first interconnect 131 that is adjacent to the first battery edge 111, and an intermediate interconnect 132 that is spaced apart from the edge first interconnect 131. That is, in the second direction q, the first interconnect 131 is closer to the first battery edge 111 than the intermediate interconnect 132. In a back-contact solar cell, the relative size of the number of edge first interconnects 131 and the number of intermediate interconnects 132 is not specifically limited.

[0084] In the second direction q: the distance between the geometric center of the edge first interconnection part 131 and the first battery edge 111 is L1. In the second direction q: the distance between the geometric centers of adjacent intermediate interconnections 132 is L2, 0.5×L2≤L1<0.9×L2.

[0085] In the embodiment of the utility model, 0.5×L2≤L1<0.9×L2, that is, in the second direction q: the distance L1 between the geometric center of the edge first interconnection part 131 and the first battery edge 111 is greater than or equal to half of the distance L2 between the geometric centers of the adjacent intermediate interconnection parts 132 in the second direction q. L1 is large. In the process of forming a battery string or a photovoltaic module, the position of the first battery edge 111 has a large conductive interconnection position, such as a welding position, or the reserved operation space is large, and the conductive interconnection is easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the first battery edge 111 is large, and the risk of hidden cracks is small. In addition, L1<0.9×L2, the size of L1 is not too large, and the uniform distribution of the effective power generation area is ensured as much as possible, and the uniform distribution of the interconnection part 13 is achieved, which is conducive to the collection of carriers and the conduction of current, and the formed photovoltaic module has good electrical performance.

[0086] For example, L1 can be 0.5 times L2, 0.51 times L2, 0.55 times L2, 0.6 times L2, 0.61 times L2, 0.67 times L2, 0.7 times L2, 0.72 times L2, 0.75 times L2, 0.8 times L2, 0.83 times L2, 0.85 times L2, 0.87 times L2, or 0.897 times L2.

[0087] Optionally, L1>6.5mm, L1 is larger, and in the process of forming a battery string or a photovoltaic module, the edge 111 of the first battery has a larger conductive interconnection position, such as a welding position, or the reserved operating space is larger, and the conductive interconnection is easy to realize mass production with high production efficiency, and the distance between the conductive interconnection position and the edge 111 of the first battery is large, and the risk of hidden cracks is small.

[0088] For example, L1 can be 6.51mm, 6.53mm, 6.55mm, 6.59mm, 6.6mm, 6.63mm, 6.67mm, 6.73mm, 6.78mm, 6.8mm, 6.85mm, 6.9mm, 6.95mm, 7mm, or 7.32mm.

[0089] Optional, see Figures 1 to 5 , along the second direction q, the plurality of collector grid lines 12 include: an edge collector grid line 121 adjacent to the edge 111 of the first battery. Figure 2 , Figure 3 and Figure 5, in the second direction q: the distance between the geometric center of the edge first interconnection part 131 and the edge collector grid line 121 is L3, L3<L1, and 0.5×L2≤L3<0.9×L2. That is, in the second direction q: the distance L3 between the geometric center of the edge first interconnection part 131 and the edge collector grid line 121 is greater than or equal to half of the distance L2 between the geometric centers of adjacent intermediate interconnections 132 in the second direction q. L3 is large. In the process of forming a battery string or a photovoltaic module, the first battery edge 111 has a large conductive interconnection position, such as a welding position, or a large reserved operating space. The conductive interconnection is easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the first battery edge 111 is large, and the risk of hidden cracks is small. In addition, L3<0.9×L2, and the size of L3 is not too large, while ensuring the uniform distribution of the effective power generation area as much as possible, the uniform distribution of the carrier collection area is also achieved, and the uniform distribution of the interconnection portion 13 is achieved, which is conducive to the collection of carriers and the conduction of current, and the formed photovoltaic module has good electrical performance. This is equivalent to further appropriately expanding the conductive interconnection position at the edge 111 of the first battery, which is further easy to achieve mass production, with high production efficiency and a lower risk of hidden cracks, and the size of L3 is not too large, which is conducive to the collection of carriers and the conduction of current.

[0090] For example, on the basis that L3<L1, L3 can be 0.5 times L2, 0.52 times L2, 0.55 times L2, 0.6 times L2, 0.62 times L2, 0.68 times L2, 0.7 times L2, 0.73 times L2, 0.75 times L2, 0.8 times L2, 0.84 times L2, 0.86 times L2, 0.88 times L2, or 0.892 times L2.

[0091] Optionally, the first battery body includes: an isolation region located between the edge collector grid line 121 and the edge of the first battery along the second direction q, and the isolation region is used to reduce the leakage risk that may exist between the p region and the n region near the edge position of the first battery. In the second direction q: the distance between the geometric center of the edge first interconnection part 131 and the isolation region is L4, L4<L1, and 0.5×L2≤L4<0.9×L2. That is, in the second direction q: the distance L4 between the geometric center of the edge first interconnection part 131 and the isolation region is greater than or equal to half of the distance L2 between the geometric centers of adjacent intermediate interconnections 132 in the second direction q. L4 is larger. In the process of forming a battery string or a photovoltaic module, the edge 111 of the first battery has a larger conductive interconnection position, such as a welding position, or the reserved operation space is larger, and the conductive interconnection is easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the edge 111 of the first battery is larger, and the risk of hidden cracks is small. In addition, L4<0.9×L2, the size of L4 is not too large, and while ensuring the uniform distribution of the effective power generation area as much as possible, the uniform distribution of the carrier collection area is also achieved, and the uniform distribution of the interconnection part 13 is achieved, which is conducive to the collection of carriers and the conduction of current, and the formed photovoltaic module has good electrical performance. Here, it is equivalent to further appropriately expanding the conductive interconnection position at the edge 111 of the first battery, further facilitating mass production, high production efficiency, and a smaller risk of hidden cracks, and the size of L4 is not too large, which is conducive to the collection of carriers and the conduction of current. It should be noted that in the second direction q, the distance between the geometric center of the edge first interconnection part 131 and the geometric center of the isolation zone is L4, or, in the second direction q, the arithmetic average of the maximum distance and the minimum distance between the geometric center of the edge first interconnection part 131 and the side of the isolation zone away from the first battery edge 111 is L4, or, in the second direction q, the maximum distance between the geometric center of the edge first interconnection part 131 and the side of the isolation zone away from the first battery edge 111 is L4, and there is no specific limitation on this.

[0092] For example, on the basis that L4<L1, L4 can be 0.5 times L2, 0.53 times L2, 0.55 times L2, 0.6 times L2, 0.64 times L2, 0.67 times L2, 0.7 times L2, 0.74 times L2, 0.75 times L2, 0.8 times L2, 0.83 times L2, 0.87 times L2, 0.88 times L2, or 0.895 times L2.

[0093] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line, referring to Figure 5, in the second direction q: the size of the interconnection 13 is b, and in the second direction q, the distance between adjacent collector grid lines 12 of the same polarity is L5, where the polarity includes: positive polarity or negative polarity. That is to say, in the second direction q, the distance between adjacent positive collector grid lines is L5, and the distance between adjacent negative collector grid lines is also L5, 0.5×L5≤b≤3×L5. Specifically, in the second direction q: the size b of the interconnection 13 is too large, and the number of collector grid lines 12 with different polarities from the interconnection 13 that need to be interrupted is large, and there will be more dead zones for carrier collection. It is necessary to set a bending structure 1221 for the collector grid lines of opposite polarities to reduce the dead zones. However, the above-mentioned bending structure 1221 may bring problems with setting quality, such as poor printing quality. Therefore, 0.5×L5≤b≤3×L5, the dead zones for carrier collection are small, and the setting quality problems such as printing quality brought by the bending structure 1221 are small, and the two have reached a good balance.

[0094] For example, b can be 0.5 times L5, 0.53 times L5, 0.55 times L5, 0.6 times L5, 0.65 times L5, 0.73 times L5, 0.87 times L5, 0.93 times L5, 1 times L5, 1.18 times L5, 1.5 times L5, 1.86 times L5, 2 times L5, 2.5 times L5, 2.75 times L5,

[0095] 2.84 times of L5, 3 times of L5.

[0096] It should be noted that, on the basis of 0.5×L5≤b≤3×L5, in order to facilitate conductive interconnection, in the same back-contact solar cell, in the second direction q, the b of the edge first interconnection portion 131 adjacent to the first cell edge 111 can be greater than the b of the middle interconnection portion 132 spaced from the edge first interconnection portion 131 in the second direction q, which further facilitates mass production and high production efficiency. The difference between the two is not specifically limited here.

[0097] Optional, see Figures 1 to 5 , the first electrode structure also includes: a plurality of busbar lines 14 extending along the second direction q, the busbar lines 14 and the collector grid lines 12 and the interconnection 13 are all electrically connected. Specifically, the busbar lines 14 include a positive polarity busbar line electrically connected to the positive polarity collector grid line and the third interconnection, and a negative polarity busbar line electrically connected to the negative polarity collector grid line and the fourth interconnection. Along the first direction p, the size of the interconnection 13 is greater than or equal to the size of the busbar line 14, and the current passing through the interconnection 13 is large, so the size of the interconnection 13 is large, which is conducive to the passage of current. The first battery body 1 includes a second battery edge 112, and the second battery edge 112 has at least a portion parallel to the second direction q, for example, Figures 1 to 5In the embodiment, the portion of the second battery edge 112 without chamfer is parallel to the second direction q. Along the first direction p, the plurality of interconnecting portions 13 include: an edge second interconnecting portion 133 adjacent to the second battery edge 112. Along the first direction p, the plurality of busbar lines 14 include: an edge busbar line 141 adjacent to the second battery edge 112.

[0098] In the first direction p, the edge busbar line 141 is located between the second battery edge 112 and the edge second interconnection portion 133, that is, in the first direction, the edge second interconnection portion 133 and the edge busbar line 141 are not colinear, and the edge second interconnection portion 133 is farther away from the second battery edge 112. In the first direction p, the reserved conductive interconnection position is larger and the risk of hidden cracks is smaller.

[0099] Reference Figures 1 to 5 , several collector grid lines 12 include: in the second direction q, the adjacent collector grid line 122 is spaced from the edge second interconnection part 133 and is closest to the edge second interconnection part 133. A bending structure 1221 is provided at the end of the adjacent collector grid line 122 close to the second battery edge 112, and the size e of the part of the adjacent collector grid line 122 that exceeds the edge second interconnection part 133 in both the first direction p and the second direction q in the first direction is greater than the size f of the bending structure in the second direction q, which can effectively reduce the dead zone area and maximize the carrier collection area of ​​the positive polarity collector grid line and the negative polarity collector grid line. There is no specific limitation on the size of the difference between e and f.

[0100] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line, L5

[0101] The distance L5 between adjacent collector grid lines 12 of the same polarity in the second direction q is suitable, which is conducive to the uniform and sufficient collection of carriers and can avoid the waste of materials caused by the over-dense arrangement of adjacent collector grid lines 12 of the same polarity.

[0102] For example, L5 can be 0.5mm, 0.55mm, 0.61mm, 0.65mm, 0.68mm, 0.7mm, 0.72mm, 0.75mm, 0.78mm, 0.8mm, 0.85mm, 0.89mm, 0.9mm, 1mm, 1.07mm, 1.15mm, or 1.2mm.

[0103] Optional, see Figures 1 to 5 The first battery body 1 includes a second battery edge 112, and the second battery edge 112 has at least a portion parallel to the second direction q, for example, Figures 1 to 5In the embodiment, the portion of the second battery edge 112 without chamfer is parallel to the second direction q. Along the first direction p, the plurality of interconnecting portions 13 include: an edge second interconnecting portion 133 adjacent to the second battery edge 112, and the second battery edge 112 has a chamfer 1121. It should be noted that for the interconnecting portion close to the top corner of the first battery body, it may be both the edge second interconnecting portion 133 and the edge first interconnecting portion 131. For example, Figure 1 In the back-contact solar cell shown, the four interconnects located at the upper left corner, lower left corner, upper right corner, and lower right corner are both the edge second interconnects 133 and the edge first interconnects 131. In the first direction p: the geometric center of the edge second interconnect 133 is further away from the second battery edge 112 than the chamfer 1121, and the distance between the geometric center of the edge second interconnect 133 and the point in the chamfer 1121 closest to the edge second interconnect 133 is a, and a≥0.3 mm. Specifically, in the process of using the back-contact solar cell to form a cell string or a photovoltaic module, the extension direction of the conductive interconnection member such as the soldering strip is usually along the second direction q, and the width of the conductive interconnection member is usually along the first direction p. Half of the width of the commonly used conductive interconnection member such as the soldering strip is about 0.3 mm. In the first direction p, the geometric center of the edge second interconnection portion 133 is further away from the second cell edge 112 than the chamfer 1121, and a≥0.3 mm. On the basis of considering the setting error of the conductive interconnection member, in the first direction p, the conductive interconnection member basically does not exceed the back-contact solar cell, or in other words, in the first direction p, the positive projection of the conductive interconnection member on the back side of the first cell body is only located on the back-contact solar cell, thereby avoiding the conductive interconnection member such as the soldering strip being exposed from the back-contact solar cell in the first direction p, affecting the appearance, and avoiding the conductive interconnection member such as the soldering strip being excessively stressed at the chamfer 1121, resulting in hidden cracks.

[0104] For example, a can be 0.3 mm, 0.32 mm, 0.35 mm, 0.4 mm, 0.41 mm, 0.45 mm, 0.48 mm, 0.5 mm, 0.51 mm, 0.55 mm, or 0.6 mm.

[0105] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line, referring to

[0106] Figures 1 to 5 , in the second direction q: the distance between adjacent collector grid lines 12 of the same polarity is L5, and the polarity includes: positive polarity or negative polarity. L5 here can refer to the aforementioned related records. In order to avoid repetition, it is not repeated here. In the second direction q: the distance between the geometric center of the edge first interconnection part 131 and the edge collector grid line 121 is L3, and the ratio of L3 / L5 is 3 to 16, which is conducive to the uniform collection of carriers at each side position of the interconnection part 13.

[0107] For example, the ratio of L3 / L5 can be 3, 3.2, 3.5, 4, 4.3, 4.5, 4.8, 5.2, 5.5, 6.4, 7.2, 7.7, 8, 8.4, 9, 9.3, 10, 10.5, 10.8, 11, 11.7, 12, 13.5, 14.2, 15, 15.5, 16.

[0108] Optional, see Figures 1 to 5 , in the second direction q, the size of the first battery body 1 is L6, and the number of interconnections 13 arranged in the second direction q is n, which means that the number of interconnections 13 in a row with at least a portion of the area collinear in the second direction q is n. For example, Figure 1 , the number n of interconnections 13 arranged in the second direction q is 8, where n is a positive integer. In the second direction q: the distance between the geometric center of the edge first interconnection 131 and the edge collector grid line 121 is L3, 0.5×L6÷n≤L1, L6÷n means that in the second direction q, a row of n interconnections 13 with at least a partial area collinear in the second direction q is equidistantly distributed on the size L6 of the first battery body 1, and 0.5×L6÷n is the distance between the geometric center of the edge first interconnection and the edge of the first battery in the second direction q when the n interconnections 13 are equidistantly distributed on the size L6 of the first battery body 1. L1=0.5×L6÷n means that the n interconnection parts 13 are equally spaced on the size L6 of the first battery body 1, and L1>0.5×L6÷n means that the n interconnection parts 13 are equally spaced as much as possible on the size L6 of the first battery body 1. Considering that in the process of forming a battery string, the edge 111 of the first battery needs a larger conductive interconnection position to facilitate mass production and reduce the risk of hidden cracks, the distance between the geometric center of the edge first interconnection part and the edge of the first battery in the second direction is appropriately increased, and then n, L6 and L1 are all set more appropriately. In the process of forming a battery string, the edge 111 of the first battery has a larger conductive interconnection position, such as a welding position, or the reserved operation space is larger, the conductive interconnection is easy to realize mass production, the production efficiency is high, and the distance between the conductive interconnection position and the edge 111 of the first battery is large, and the risk of hidden cracks is small. In addition, the size of L1 is not too large, and the uniform distribution of the effective power generation area is ensured as much as possible, and the uniform distribution of the interconnection part 13 is achieved, which is conducive to the collection of carriers and the conduction of current, and the formed photovoltaic module has good electrical performance. This is equivalent to further appropriately expanding the conductive interconnection position at the edge 111 of the first battery, further facilitating

[0109] It is convenient to realize mass production, with high production efficiency and lower risk of hidden cracks. In addition, the size of L1 is not too large, which is conducive to the collection of carriers and the conduction of current.

[0110] For example, L1 can be 0.5×L6÷n, 0.51×L6÷n, 0.55×L6÷n, 0.59×L6÷n, 0.6×L6÷n, 0.63×L6÷n, 0.65×L6÷n, 0.68×L6÷n, 0.7×L6÷n, 0.73×L6÷n, and 0.75×L6÷n.

[0111] It should be noted that the back-contact solar cell or back-contact solar cell of the present application may have a busbar line or may not have a busbar line, and this is not specifically limited. In the case of having a busbar line, the busbar line is used to collect carriers on the collector grid line of the same polarity electrically connected to it and conduct them to the interconnection portion electrically connected to the busbar line.

[0112] Optional, see Figures 1 to 5 The first electrode structure of the back-contact solar cell further includes: a plurality of busbar lines 14 extending along the second direction q, the busbar lines 14 are electrically connected to the collector grid lines 12 and the interconnection 13, more specifically, the positive busbar lines are electrically connected to the positive collector grid lines and the third interconnection, and the negative busbar lines are electrically connected to the negative collector grid lines and the fourth interconnection. Along the first direction p, the size of the interconnection 13 is greater than or equal to the size of the busbar line 14, which is conducive to the interconnection 13 to derive current, and the size of the difference between the two is not specifically limited.

[0113] Reference Figures 1 to 5 , in the first direction p, the size of the first battery body 1 is L7, the first battery body 1 includes a second battery edge 112, and the second battery edge 112 has at least a portion parallel to the second direction q. Here, reference can be made to the above-mentioned related records, and no further description is given here to avoid repetition. Along the first direction p, the plurality of interconnecting portions 13 include: an edge second interconnecting portion 133 adjacent to the second battery edge 112, and along the first direction p, the plurality of busbar lines 14 include: an edge busbar line 141 adjacent to the second battery edge 112. In the first direction p: the distance between the geometric center of the edge second interconnection part 133 and the edge busbar line 141 is c, and the ratio of L7 / c is 33 to 105. In the process of forming a battery string or a photovoltaic module, the second battery edge 112 has a larger conductive interconnection position, such as a welding position, or a larger reserved operation space, and the conductive interconnection is easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the second battery edge 112 is large, and the risk of hidden cracks is small; at the same time, the distance between the edge busbar line 141 and the edge second interconnection part is not too far, the carrier convergence path is not too long, and the transmission resistance does not increase. In addition, sufficient space can be left for junction isolation.

[0114] For example, the ratio of L7 / c can be 33, 33.2, 34.8, 35, 40, 44.5, 50, 55.2, 57, 60, 68, 69, 69.2, 76.5, 80.3, 89.7, 99.2, 100, 100.8, 102, 104.2, and 105.

[0115] It should be noted that the shape of the edge bus line 141 can be at least one of a straight line, a folded line, and a curve. When the edge bus line 141 includes: a folded line and / or a curve, the starting position of c on the side of the edge bus line 141 can be: the midpoint of the trough and the crest of the edge bus line 141 in the first direction. Alternatively, when the edge bus line 141 includes a straight line, the starting position of c on the side of the edge bus line 141 can be: the geometric center of the straight line segment.

[0116] Optional, see Figures 1 to 5 The first electrode structure of the back-contact solar cell also includes: a plurality of busbar lines 14 extending along the second direction q, the busbar lines 14 and the collector grid lines 12 and the interconnection portion 13 are electrically connected, and along the first direction p, the size of the interconnection portion 13 is greater than or equal to the size of the busbar line 14. Reference is made here to the aforementioned related records, and no further details are given to avoid repetition.

[0117] Reference Figures 1 to 5 , the first battery body 1 includes a second battery edge 112, and the second battery edge 112 has at least a portion parallel to the second direction q. Here, the aforementioned related records can be referred to. In order to avoid repetition, they are not repeated here. Along the first direction p, a plurality of interconnecting parts 13 include: an edge second interconnecting part 133 adjacent to the second battery edge 112, and along the first direction p, a plurality of busbar lines 14 include: an edge busbar line 141 adjacent to the second battery edge 112, and in the first direction p: the distance between the geometric center of the edge second interconnecting part 133 and the edge busbar line 141 is c. In the second direction q: the distance between the geometric center of the edge first interconnecting part 131 and the edge collector grid line 121 is L3, and the ratio of c / L3 is 0.1 to 1. Within this range, the ratio of c / L3 is easy to realize mass production for first battery bodies of different sizes, with high production efficiency and low risk of hidden cracks, while also avoiding the influence of broken grids on the carrier convergence effect.

[0118] For example, the ratio of c / L3 can be 0.1, 0.11, 0.14, 0.15, 0.19, 0.2, 0.25, 0.29, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.57, 0.6, 0.63, 0.7, 0.77, 0.8, 0.84, 0.9, 0.96, 1.

[0119] In this application, reference is made to Figures 1 to 5, a plurality of collector grid lines 12 include: positive collector grid lines and negative collector grid lines, the positive collector grid lines and the negative collector grid lines are alternately distributed along the second direction q, that is, along the second direction q, a positive collector grid line, followed by a negative collector grid line, followed by a positive collector grid line, and then a negative collector grid line are arranged in this way, and there is a gap between adjacent positive collector grid lines and negative collector grid lines to avoid leakage. A plurality of interconnecting parts 13 include: a third interconnecting part electrically connected to the positive collector grid line, and a fourth interconnecting part electrically connected to the negative collector grid line to achieve current conduction. The third interconnecting part and the fourth interconnecting part are alternately distributed along the first direction p, that is, along the first direction p, a third interconnecting part, followed by a fourth interconnecting part, followed by a third interconnecting part, and then a fourth interconnecting part are arranged in this way, and there is a gap between adjacent third interconnecting parts and fourth interconnecting parts to avoid leakage. Along the second direction q, the third interconnection part and the fourth interconnection part both include: the edge first interconnection part adjacent to the edge 111 of the first battery, and the middle interconnection part spaced apart from the edge first interconnection part. At the same time, in the third interconnection part and / or the fourth interconnection part, the middle interconnection parts are equally spaced along the second direction q, and the locations where the middle interconnection parts are located have relatively few problems such as hidden cracks caused during the conductive interconnection process. Therefore, the middle interconnection parts are equally spaced along the second direction q, which not only introduces fewer hidden cracks, but also achieves the uniform distribution of the interconnection parts as much as possible, which is beneficial to the collection of carriers and the conduction of current, and the formed photovoltaic module has better electrical performance.

[0120] Optional, see Figures 1 to 5 In the first direction p, the plurality of third interconnecting portions and the plurality of fourth interconnecting portions have at least a portion of the region being collinear, and when testing the cell and conducting interconnection of the photovoltaic module such as welding, it is not necessary to design different device fixtures for the difference between the positive polarity grid line and the negative polarity grid line, and it has better mass production compatibility. In particular, for the edge first interconnecting portion that is not electrically connected to the edge collector grid line 121, it has better mass production compatibility.

[0121] In the present application, along the second direction q, a plurality of collector grid lines 12 include: an edge collector grid line 121 adjacent to the first battery edge 111, and a gap is provided between the edge collector grid line 121 and the third interconnection portion or the fourth interconnection portion. That is to say, a gap is provided between the edge collector grid line 121 and the interconnection portion that collects carriers of opposite polarity therefrom to avoid short circuit. For example, along the second direction q, the edge collector grid line 121 is a positive polarity collector grid line, and the positive polarity collector grid line is electrically connected to the third interconnection portion, then, a gap is provided between the edge collector grid line 121 and the fourth interconnection portion to avoid short circuit between the edge collector grid line 121 and the fourth interconnection portion. For another example, along the second direction q, the edge collector grid line 121 is a negative polarity collector grid line, and the negative polarity collector grid line is electrically connected to the fourth interconnection portion, then, a gap is provided between the edge collector grid line 121 and the third interconnection portion to avoid short circuit between the edge collector grid line 121 and the third interconnection portion.

[0122] It should be noted that the edge collector grid line 121 here is the collector grid line closest to the first battery edge 111 on the entire first battery body 1. For example, Figure 5 Here, the edge collector grid line 121 is the uppermost collector grid line or the lowermost collector grid line on the entire first battery body 1 . Figure 5 In the figure, the uppermost edge collector grid line 121 is electrically connected to the leftmost interconnection portion. Therefore, the second interconnection portion from left to right is the interconnection portion that collects carriers on the collector grid line of opposite polarity. Therefore, the uppermost edge collector grid line 121 is disconnected at the position where the second interconnection portion extends in the second direction and intersects. The disconnection here can be understood as a spacing to avoid the uppermost edge collector grid line 121 from short-circuiting with the second interconnection portion from left to right.

[0123] Optionally, the first electrode structure of the back-contact solar cell also includes: a plurality of busbars 14 extending along the second direction q. The plurality of busbars 14 include: positive busbars and negative busbars, the positive busbars and negative busbars are alternately distributed along the first direction p, that is, along the first direction p, a positive busbar, followed by a negative busbar, followed by a positive busbar, and then a negative busbar are arranged in this way, and there is a gap d between adjacent positive busbars and negative busbars, and the size of d is not specifically limited. The positive busbars are electrically connected to the positive collector and the third interconnection, and the negative busbars are electrically connected to the negative collector and the fourth interconnection, so as to achieve current conduction through the busbars.

[0124] Optionally, the plurality of collector grid lines include: a positive collector grid line and a negative collector grid line, referring to Figures 1 to 5, along the second direction q, the plurality of collector grid lines 12 include: an edge collector grid line 121 adjacent to the first battery edge 111, in the second direction q: the distance between the edge collector grid line 121 and the first battery edge 111 is L8, L8 is 0.3mm to 1mm, L8 is relatively large, which can not only meet the requirements of PN isolation at the edge of the battery in the battery preparation process and avoid the risk of short circuit; at the same time, L8 is not too large, which is conducive to the uniform and sufficient collection of carriers.

[0125] For example, L8 can be 0.3mm, 0.34mm, 0.37mm, 0.39mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.69mm, 0.7mm, 0.73mm, 0.78mm, 0.8mm, 0.88mm, 0.92mm, or 1mm.

[0126] Optional, see Figures 1 to 5 , in the second direction q: the distance between the geometric center of the first interconnection part 131 of the edge and the geometric center of the adjacent interconnection part 13 is L9, L1<L9≤L2. Specifically, the adjacent interconnection part 13 here in the second direction q refers to: the second interconnection part in the second direction q, L9 may be appropriately compressed so that L1<L9≤L2, thereby leaving a larger conductive interconnection position, such as a welding position, for the first battery edge 111, or the reserved operation space is larger, the conductive interconnection is easy to realize mass production, the production efficiency is high, and the distance between the conductive interconnection position and the first battery edge 111 is large, the risk of hidden cracks is small, and at the same time, it is conducive to the uniform and sufficient collection of carriers.

[0127] For example, on the basis of L1<L9, L9 can be 1 times L2, 0.99 times L2, 0.97

[0128] times L2, 0.95 times L2, 0.93 times L2, 0.9 times L2, 0.89 times L2, 0.86 times L2, 0.85 times L2, 0.84 times L2, 0.8 times L2, 0.75 times L2.

[0129] Optionally, the bending structure is only located on one side of the first battery body parallel to the second direction, so as to minimize the number of bent collector grid lines, avoid interrupting more collector grid lines in different polarity regions, avoid forming more dead zones, and reduce the number of bends to reduce the difficulty of printing and avoid poor printing. For example, the first battery body has two second battery edges, and the bending structure is only located on one side of one second battery edge.

[0130] The present application also provides a back-contact solar cell, comprising: a second cell body and a second electrode structure located on the back side of the second cell body. During normal operation of the back-contact solar cell, the surface that mainly receives light is its light-facing side, and the backlight side and the light-facing side are relatively distributed. The second electrode structure here includes all electrodes of the back-contact solar cell, and the second electrode structure is used to collect and conduct current in the back-contact solar cell. The second cell body has a PN junction that can separate carriers. In the aforementioned second direction, the second electrode structure is composed of m electrode substructures, where m is a positive integer. The electrode substructure here is the first electrode structure in any of the aforementioned back-contact solar cells. After slicing the back-contact solar cell, m of the aforementioned back-contact solar cells will be obtained, each back-contact solar cell includes an electrode substructure here, and the electrode substructure in each back-contact solar cell is the first electrode structure in any of the aforementioned back-contact solar cells. Here, m can be a positive integer greater than or equal to 2.

[0131] For example, in the second direction q, the second electrode structure is composed of two electrode substructures, then, after the back-contact solar cell is sliced, two back-contact solar cells are obtained, and each back-contact solar cell has one electrode substructure. For another example, in the second direction q, the second electrode structure is composed of three electrode substructures, then, after the back-contact solar cell is sliced, three back-contact solar cells are obtained, and each back-contact solar cell has one electrode substructure. For another example, in the second direction q, the second electrode structure is composed of four electrode substructures, then, after the back-contact solar cell is sliced, four back-contact solar cells are obtained, and each back-contact solar cell has one electrode substructure.

[0132] It should be noted that whether the electrode substructures in the second electrode structure are the same is not specifically limited, and they can be the same or different. Whether two adjacent electrode substructures in the second electrode structure are symmetrically distributed is not specifically limited, and they can be symmetrical or asymmetrical.

[0133] Optionally, the m electrode substructures include: an adjacent first electrode substructure and a second electrode substructure, and the distance between the collector grid line in the first electrode substructure adjacent to the second electrode substructure and the collector grid line in the second electrode substructure adjacent to the first electrode substructure is h. Figures 1 to 5 , along the second direction q, the plurality of collector grid lines 12 include: an edge collector grid line 121 adjacent to the first battery edge 111. In the second direction q: the distance between the edge collector grid line 121 and the first battery edge 111 is L8, and the ratio of L8 / h is greater than 0 and less than or equal to 1. The ratio of L8 / h is set appropriately, which can not only meet the requirements of the setting accuracy of the collector grid line, such as the printing accuracy, but also avoid the problem of leakage caused by the cutting of the collector grid line during the slicing process.

[0134] For example, L8 is 0.4 mm and h is also 0.4 mm, then the ratio of L8 / h is 1. For another example, the ratio of L8 / h can be 0.05, 0.08, 0.95, 0.1, 0.15, 0.19, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.58, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.99, 1.

[0135] The present application also provides a photovoltaic module, which includes: a plurality of any of the aforementioned back-contact solar cells. The photovoltaic module may also include packaging films located on both sides of the back-contact solar cells, etc., which are not specifically limited.

[0136] Optionally, the photovoltaic module further includes: a conductive interconnection extending along the aforementioned second direction q and electrically connected to the interconnection portion 13. The conductive interconnection mentioned in the full text of this application can be used to connect adjacent back-contact solar cells in series in the second direction q. In the first direction p: the positive projection of the conductive interconnection on the back side of the first cell body is only located on the back-contact solar cell, or in other words, in the aforementioned first direction p, the conductive interconnection does not extend beyond the back-contact solar cell, thereby avoiding problems such as the conductive interconnection such as the soldering strip being exposed to the back-contact solar cell in the first direction p, affecting the appearance, and the conductive interconnection such as the soldering strip being overstressed at the chamfer 1121, resulting in hidden cracks.

[0137] The relevant parts of the photovoltaic module and the aforementioned back-contact solar cell can be referenced to each other and have the same or similar beneficial effects. In order to avoid repetition, the relevant parts are omitted.

[0138] The present application is further explained below with reference to specific embodiments.

[0139] like Figures 1 to 5 In the back contact solar cell shown, in the second direction q, the size L6 of the first battery body 1 is 95 mm to 97 mm. Along the second direction q, the plurality of collector grid lines 12 include: edge collector grid lines adjacent to the first battery edge 111, and in the second direction q: the distance L8 between the edge collector grid lines and the first battery edge 111 is 0.54 mm to 0.66 mm. The number of collector grid lines of the same polarity in the back contact solar cell is 104, and then, in the second direction q: the distance L5 between adjacent collector grid lines of the same polarity is: [(95 to 97)-(0.54 to 0.66)×2)] / (104-1)=0.9095 mm to 0.9313 mm.

[0140] In this back-contact solar cell, the number n of interconnections 13 arranged in the second direction q is 8. In the second direction: the distance between the geometric centers of adjacent intermediate interconnections is L2, and L2 is usually an integer number L5. In the second direction q: the distance between the geometric center of the edge first interconnection and the geometric center of the adjacent interconnection is L9. L9 is also usually an integer number L5. In the case of L9=L2, L2 is 13 L5s, L9=L2=13×(0.9095 to 0.9313)=11.8235mm to 12.1069mm. Along the second direction q, a plurality of collector grid lines 12 include: an edge collector grid line adjacent to the first battery edge 111. In the second direction q: the distance between the geometric center of the edge first interconnection and the edge collector grid line is L3. When L9=L2=11.8235mm to 12.1069mm, L3=(104-13×7-1)×(0.9095 to 0.9313) / 2=5.457mm to 5.5878mm, L1=L3+L8=(5.457 to 5.5878)+(0.54 to 0.66)=5.997mm to 6.2478mm, L1<6.5mm. In the process of forming a battery string or a photovoltaic module, the conductive interconnection position, such as the welding position, or the reserved operating space, left at the edge 111 of the first battery is small, and the conductive interconnection is not easy to realize mass production, and the production efficiency is low. In addition, the distance between the conductive interconnection position and the edge 111 of the first battery is small, and the risk of hidden cracks is large. At this time, L9 needs to be fine-tuned. Specifically, L9 can be reduced by one L5, then L1 = (5.997 to 6.2478) + (0.9095 to 0.9313) = 6.9065mm to 7.1791mm, L1>6.5mm, which meets the requirements of mass production and low risk of hidden cracks. In this case, L9 = (11.8235 to 12.1069) - (0.9095 to 0.9313) = 10.8922mm to 11.1974mm.

[0141] Therefore, in the back contact solar cell of this embodiment, L1=6.9065mm to 7.1791mm, L1 is relatively large, which not only makes the first battery edge 111 have a larger conductive interconnection position, such as a welding position, or the reserved operation space is larger during the process of forming the battery string, but also makes the conductive interconnection easy to realize mass production, with high production efficiency, and the distance between the conductive interconnection position and the first battery edge 111 is large, and the risk of hidden cracks is small. At the same time, L1 is not too large, which is conducive to the uniform and sufficient collection of carriers. L2=11.8235mm to 12.1069mm, which is conducive to the uniform and sufficient collection of carriers. L8 = 0.54 mm to 0.66 mm, L3 = 6.2465 mm to 6.6397 mm, L5 = 0.9095 mm to 0.9313 mm, L6 = 95 mm to 97 mm, L9 = 10.8922 mm to 11.1974 mm, L1 / L2 = (6.9065 to 7.1791) / (11.8235 mm to 12.1069) = 0.5705 to 0.6072, that is, L1 is 0.5705 to 0.6072 times L2. L3 / L2 = (6.2465 to 6.6397) / (11.8235 to 12.1069) = 0.516 to 0.5616, that is, L3 is 0.516 to 0.5616 times L2. L3 / L5=(6.2465 to 6.6397) / (0.9095 to 0.9313)=6.7073 to 7.3. 0.5×L6÷n=0.5×(95 to 97)÷8=5.9375 to 6.0625, i.e. 0.5×L6÷n<L1. L9=10.8922mm to 11.1974mm, L2=11.8235mm to 12.1069mm, i.e. L1<L9<L2.

[0142] In summary, the back-contact solar cell of this embodiment not only allows the first battery edge 111 to have a larger conductive interconnection position, such as a welding position, or a larger reserved operating space during the process of forming a battery string or photovoltaic module, but also makes the conductive interconnection easy to mass-produce with high production efficiency, and the distance between the conductive interconnection position and the first battery edge 111 is large, and the risk of hidden cracks is small. At the same time, L1 is not too large, which is conducive to the uniform and sufficient collection of carriers. L2 = 11.8235mm to 12.1069mm, which is conducive to the uniform and sufficient collection of carriers, and can avoid the waste of materials caused by the dense arrangement of adjacent collector grid lines 12 of the same polarity. At the same time, it is conducive to the uniform collection of carriers at each side of the interconnection portion 13.

[0143] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0144] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A back contact solar cell, characterized in that: include: a first battery body and a first electrode structure located on a back side of the first battery body; The first electrode structure comprises: A plurality of collector grid lines extending along a first direction; A plurality of interconnecting portions arranged along a first direction and a second direction and electrically connected to the collector grid line; wherein the first direction is different from the second direction; along the second direction, the plurality of interconnecting portions have at least a portion of regions that are collinear; The first battery body includes a first battery edge, wherein the first battery edge has at least a portion parallel to the first direction; Along the second direction, the plurality of interconnecting portions include: an edge first interconnecting portion adjacent to an edge of the first battery, and an intermediate interconnecting portion spaced apart from the edge first interconnecting portion; In the second direction: the distance between the geometric center of the edge first interconnection portion and the edge of the first battery is L1, the distance between the geometric centers of adjacent middle interconnections is L2, and 0.5×L2≤L1<0.9×L2.

2. The back contact solar cell according to claim 1, characterized in that: Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to an edge of the first battery; In the second direction: the distance between the geometric center of the edge first interconnection portion and the edge collector grid line is L3, L3<L1, and 0.5×L2≤L3<0.9×L2.

3. The back contact solar cell according to claim 2, characterized in that: The first battery body comprises: an isolation region located between the edge collector grid line and the edge of the first battery along the second direction; In the second direction: the distance between the geometric center of the edge first interconnection portion and the isolation region is L4, L4<L1, and 0.5×L2≤L4<0.9×L2.

4. The back contact solar cell according to claim 1, characterized in that: The plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; in the second direction: the size of the interconnection portion is b, and the distance between adjacent collector grid lines of the same polarity is L5; 0.5×L5≤b≤3×L5.

5. The back contact solar cell according to any one of claims 1 to 4, characterized in that: The first battery body includes a second battery edge, wherein the second battery edge has at least a portion parallel to the second direction; Along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to an edge of the second battery; the edge of the second battery having a chamfer; In the first direction: the geometric center of the edge second interconnection portion is further away from the second battery edge than the chamfer, and the distance between the geometric center of the edge second interconnection portion and the point of the chamfer closest to the edge second interconnection portion is a, and a≥0.3 mm.

6. The back contact solar cell according to claim 2, characterized in that: The plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; in the second direction: a distance between adjacent collector grid lines of the same polarity is L5; The ratio of L3 / L5 is 3 to 16.

7. The back contact solar cell according to claim 1, characterized in that: In the second direction, the size of the first battery body is L6; The number of interconnections arranged in the second direction is n; 0.5×L6÷n≤L1.

8. The back-contact solar cell according to any one of claims 1 to 4, characterized in that: The first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection parts are all electrically connected; along the first direction, the size of the interconnection parts is greater than or equal to the size of the busbar lines; In the first direction, the size of the first battery body is L7; The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge; Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery; In the first direction: the distance between the geometric center of the edge second interconnection portion and the edge busbar line is c; The L7 / c ratio ranges from 33 to 105.

9. The back contact solar cell according to claim 2, characterized in that: The first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection parts are all electrically connected; along the first direction, the size of the interconnection parts is greater than or equal to the size of the busbar lines; The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge; Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery; In the first direction: the distance between the geometric center of the edge second interconnection portion and the edge busbar line is c; The ratio of c / L3 is 0.1 to 1.

10. The back contact solar cell according to any one of claims 1 to 4, characterized in that: The plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; The positive polarity collector grid lines and the negative polarity collector grid lines are alternately distributed along the second direction; The plurality of interconnecting parts include: a third interconnecting part electrically connected to the positive polarity collector grid line, and a fourth interconnecting part electrically connected to the negative polarity collector grid line; the third interconnecting part and the fourth interconnecting part are alternately distributed along the first direction; Along the second direction, the third interconnection portion and the fourth interconnection portion both include: an edge first interconnection portion adjacent to the edge of the first battery, and an intermediate interconnection portion spaced apart from the edge first interconnection portion; in the third interconnection portion and / or the fourth interconnection portion, the intermediate interconnections are equidistantly distributed along the second direction.

11. The back contact solar cell according to claim 10, characterized in that: In the first direction, at least some areas of the third interconnected portions are collinear, and at least some areas of the fourth interconnected portions are collinear; Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to an edge of the first battery; and a gap is provided between the edge collector grid line and the third interconnection portion or the fourth interconnection portion.

12. The back contact solar cell according to claim 10, characterized in that: The first electrode structure further includes: a plurality of busbar lines extending along the second direction; the plurality of busbar lines include: a positive busbar line and a negative busbar line; The positive polarity busbar lines and the negative polarity busbar lines are alternately distributed along the first direction; The positive bus grid line, the positive collector grid line and the third interconnection portion are all electrically connected; the negative bus grid line, the negative collector grid line and the fourth interconnection portion are all electrically connected.

13. The back contact solar cell according to any one of claims 1 to 4, characterized in that: The plurality of collector grid lines include: a positive collector grid line and a negative collector grid line; In the second direction, the distance between adjacent collector grid lines of the same polarity is L5; L5 is 0.5 mm to 1.2 mm; and / or, Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to the edge of the first battery, in the second direction: a distance L8 between the edge collector grid line and the edge of the first battery, L8 being 0.3 mm to 1 mm; and / or, L1>6.5mm; and / or In the second direction: the distance between the geometric center of the first interconnection portion of the edge and the geometric center of the adjacent interconnection portion is L9, L1<L9≤L2.

14. The back-contact solar cell according to any one of claims 1 to 4, characterized in that: The first electrode structure further includes: a plurality of busbar lines extending along the second direction, the busbar lines and the collector lines and the interconnection parts are all electrically connected; along the first direction, the size of the interconnection parts is greater than or equal to the size of the busbar lines; The first battery body includes a second battery edge, the second battery edge at least having a portion parallel to the second direction; along the first direction, the plurality of interconnecting portions include: an edge second interconnecting portion adjacent to the second battery edge; Along the first direction, the plurality of busbar lines include: an edge busbar line adjacent to an edge of the second battery; In the first direction, the edge busbar line is located between the second battery edge and the edge second interconnection portion; Several collector grid lines include: in the second direction, an adjacent collector grid line is separated from the second edge interconnection portion and is closest to the second edge interconnection portion, and a bending structure is provided at the end of the adjacent collector grid line close to the second battery edge, and the size of the portion of the adjacent collector grid line that exceeds the second edge interconnection portion in both the first and second directions in the first direction is greater than the size of the bending structure in the second direction.

15. The back contact solar cell according to claim 14, characterized in that: The bending structure is only located on one side of the first battery body parallel to the second direction.

16. A back contact solar cell, characterized in that: include: a second battery body and a second electrode structure located on a back side of the second battery body; In the second direction, the second electrode structure consists of m electrode substructures; m is a positive integer; The electrode substructure is the first electrode structure in the back-contact solar cell according to any one of claims 1 to 15.

17. The back contact solar cell according to claim 16, characterized in that: The m electrode substructures include: adjacent first electrode substructures and second electrode substructures, wherein the distance between the collector grid line in the first electrode substructure adjacent to the second electrode substructure and the collector grid line in the second electrode substructure adjacent to the first electrode substructure is h; Along the second direction, the plurality of collector grid lines include: an edge collector grid line adjacent to the edge of the first battery, and in the second direction: a distance between the edge collector grid line and the edge of the first battery is L8; The ratio of L8 / h is greater than 0 and less than or equal to 1.

18. A photovoltaic module, characterized in that: The photovoltaic module comprises: several back-contact solar cells as described in any one of claims 1 to 15.

19. The photovoltaic module according to claim 18, characterized in that: Also includes: a conductive interconnection member extending along the second direction and electrically connected to the interconnection portion; In the first direction, the orthographic projection of the conductive interconnect on the back side of the first cell body is located only on the back-contact solar cell.

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