Solar cell and photovoltaic module

Abstract

The invention discloses a solar cell and a photovoltaic module, relates to the technical field of photovoltaic, and aims to reduce interconnection stress formed after adjacent solar cells are interconnected and reduce the cracking risk of the solar cells. The solar cell includes a cell body, a collector electrode, and a first interconnect structure. At least partial areas of the different first interconnection structures distributed at intervals in the second direction are located on the same connecting line. The number of the connecting lines located in the same target plane is N1, and the number of the first interconnection structures intersecting with the target line segments located in the target plane is N2. The # imgabs0 # target line segment is a connecting line segment of a midpoint of the longer one of two oppositely distributed edges extending along the first direction of the target surface and a vertex angle endpoint corresponding to the shorter one of the two edges; or, the number of the connecting lines intersecting with the vector line segment with the inclination angle of 45 degrees is N3, the number of the first interconnection structures intersecting with the same vector line segment with the inclination angle of 45 degrees is N4, and N3 is larger than N4.

Description

[0001] This application is a divisional application of the application number 202410517763.7, and the invention title is "A solar cell and photovoltaic module". The application date of the patent application with application number 202410517763.7 is April 28, 2024. Technical Field

[0002] The invention relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Art

[0003] Solar cells are now being used more and more widely as a new energy alternative. Among them, photovoltaic solar cells are devices that convert sunlight into electrical energy. Specifically, solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead the carriers out, thereby facilitating the effective use of electrical energy.

[0004] However, in existing solar cells, the distribution position of the interconnection structure on the cell body is not set reasonably, resulting in large interconnection stress formed after interconnecting adjacent solar cells, greatly increasing the risk of cracking, and reducing the structural reliability of photovoltaic modules. Summary of the invention

[0005] The object of the present invention is to provide a solar cell and a photovoltaic module, which are used to reduce the interconnection stress formed after adjacent solar cells are interconnected, thereby reducing the risk of solar cell cracking and improving the structural reliability of the photovoltaic module.

[0006] In order to achieve the above-mentioned objectives, in a first aspect, the present invention provides a solar cell, which comprises: a battery body, a collecting electrode and a first interconnection structure. The battery body has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collecting electrode is arranged on the target surface. Different collecting electrodes located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure forms an array on the target surface. Each first interconnection structure is electrically connected to at least one collecting electrode. At least partial areas of different first interconnection structures spaced apart along the second direction are located on the same connecting line, and different connecting lines are spaced apart along the first direction. Among them, the number of connecting lines located in the same target surface is N1, the number of first interconnection structures intersecting with the target line segment located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the longer one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoint corresponding to the smaller one of the two edges; or, the number of connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of first interconnect structures intersecting with the same vector line segment with an inclination angle of 45° is N4, N3>N4.

[0007] In the case of adopting the above technical solution, in the solar cell provided by the present invention, a first interconnection structure is arranged on the target surface of the battery body, and the first interconnection structures form an array on the target surface. Each first interconnection structure is electrically connected to at least one collector electrode. Moreover, at least partial areas of different first interconnection structures spaced apart along the second direction are located on the same connecting line, and different connecting lines are spaced apart along the first direction. In this case, when adjacent solar cells are interconnected along the extension direction of the connecting line through in-string interconnections such as welding strips, the in-string interconnections corresponding to the connecting lines can be electrically connected to the collector electrodes with the same polarity located on the target surface at least through the first interconnection structure, so that the carriers collected by the collector electrodes are sequentially guided out through the first interconnection structure and the in-string interconnections to form a photocurrent. After the adjacent solar cells are interconnected, due to the different materials and thermal expansion coefficients of the first interconnection structure and the battery body, interconnection stress will be generated after the interconnection. Based on this, the target line segment only contacts with at most half of all the connecting lines located on the same target surface. Moreover, when When the target surface is connected to the target line segment, it can be ensured that the first interconnection structure electrically contacting each of the at least one connecting line that can intersect with the target line segment is not arranged on the target line segment, so that after the adjacent solar cells are interconnected along the extension direction of the connecting line through the in-string interconnection member, all the corresponding first interconnection structures electrically contacting each of the at least one in-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, since the direction of the inner diagonal line of the surface of the semiconductor wafer used to manufacture solar cells is roughly parallel to the cleavage plane, and the cleavage plane is a plane with the property that a mineral crystal breaks strictly along a certain crystallization direction under the action of an external force and can crack into a smooth plane, corresponding to the silicon wafer, a single crystal silicon crystal rod will form a nearly square silicon wafer after wire cutting, and the cleavage plane intersects with the surface of the silicon wafer and is not parallel to the edge of the silicon wafer. It can be understood that there are countless mutually parallel cleavage planes in the crystal rod, which form countless mutually parallel target line segments with the surface of the silicon wafer, among which the target line segment corresponding to the diagonal line of the silicon wafer is the longest and faces a greater stress challenge. After the silicon wafer is cut in half, the position of the target line segment remains unchanged from that before the silicon wafer is cut in half. Therefore, when the target line segment is a line segment connecting the midpoint of the larger one of the two edges (such as the non-chamfered edge) of the target surface extending along the first direction and relatively distributed and the vertex end point corresponding to the smaller one of the two edges (such as the chamfered edge), the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the battery body. At this time, reducing the interconnection stress formed along the extension direction of the target line segment is equivalent to reducing the interconnection stress formed along the cleavage plane direction, reducing the risk of cracking of the solar cell after being subjected to external force due to large interconnection stress, and improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, when the number N3 of connecting lines corresponding to the vector line segment with an inclination angle of 45° is greater than the number N4 of first interconnection structures intersecting with itself, all first interconnection structures on at least one connecting line are not arranged on the vector line segment with an inclination angle of 45°, so that after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all corresponding first interconnection structures electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the vector line segment with an inclination angle of 45°, thereby shortening the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45°. Secondly, the cleavage plane of the battery body is roughly parallel to the vector line segment with an inclination angle of 45°. Therefore, when the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45° is shortened, it is also beneficial to shorten the length of the interconnection stress band formed along the cleavage plane direction, thereby reducing the risk of cracking of the solar cell after being subjected to external force due to the long interconnection stress band, thereby improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0008] As a possible implementation scheme, the thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1.

[0009] In the case of adopting the above technical solution, when other factors are the same and within a certain range, the thickness of the first interconnection structure is inversely proportional to its own transmission loss. However, the materials and thermal expansion coefficients of the first interconnection structure and the battery body are different. Based on this, within a certain range, after the adjacent solar cells are interconnected, the magnitude of the interconnection stress at the junction of the first interconnection structure and the battery body is proportional to the thickness of the first interconnection structure. In the above case, the ratio between the thickness H2 of the first interconnection structure and the thickness H1 of the battery body is within the above range, which can prevent the transmission loss of the carrier at the first interconnection structure from being large due to the small thickness of the first interconnection structure caused by the small ratio, thereby ensuring that the solar cell has a higher power. In addition, it can also prevent the interconnection stress between the first interconnection structure and the battery body from being large after interconnection due to the large thickness of the first interconnection structure caused by the large ratio, further reducing the risk of solar cells cracking under the action of external force after interconnection, and improving the structural reliability of photovoltaic modules.

[0010] As a possible implementation scheme, the cross-sectional area of ​​the battery body is S1, the cross-sectional area of ​​the first interconnection structure is S2, and the ratio of S2 to S1 is greater than or equal to 0.0003 and less than or equal to 0.02. The beneficial effects in this case are similar to the beneficial effects described above in that the thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1, and will not be repeated here.

[0011] As a possible implementation scheme, N2 is equal to 0. In this case, the number of first interconnect structures intersecting with the target line segment is 0. Since the direction of the inner diagonal line of the surface of the semiconductor wafer used to manufacture the solar cell is roughly parallel to the cleavage plane, the number of first interconnect structures set on the cleavage plane of the battery body parallel to the extension direction of the target line segment is 0, which can minimize the risk of the solar cell being split at the cleavage plane after being subjected to external force, and improve the structural reliability of the photovoltaic module formed based on the solar cell.

[0012] As a possible implementation scheme, the distance between the geometric center of the first interconnection structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the midline of the solar cell along the second direction is D3, and the distance between the geometric center of the first interconnection structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the edge of the solar cell along the second direction is D4. D3>D4. In this case, the distance between the geometric center of the first interconnection structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the edge of the solar cell along the second direction is smaller, which is conducive to preventing the first interconnection structure intersecting the target line segment or the vector line segment with an inclination angle of 45° from being densely distributed at the midline of the solar cell along the second direction, reducing the risk of cracks at the intersection of the midline of the solar cell along the second direction and the target line segment (or the vector line segment with an inclination angle of 45°) after interconnection, and further improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, it is also possible to achieve a balance between the uniformity of current collection by the collector electrode and the feasibility of interconnection between adjacent solar cells as the number of first interconnection structures increases, which is conducive to improving the working performance of the photovoltaic module.

[0013] As a possible implementation scheme, the solar cell is a busbar-free solar cell. Along the second direction, the target surface includes a middle area and an edge area. At least part of the collector electrode located in the middle area is in direct contact with the first interconnection structure.

[0014] When the above technical solution is adopted, when the solar cell is a main grid-less solar cell, the carriers collected by the corresponding collecting electrode can be directly transmitted to the welding tape and other in-string interconnections through the first interconnection structure in contact with itself and exported, without the need to conduct the carriers through the bus electrode and transmit them to the first interconnection structure and the in-string interconnections in sequence, thereby eliminating the transmission loss of the carriers on the bus electrode, while reducing the shading loss and improving the working efficiency of the solar cell.

[0015] As a possible implementation scheme, the solar cell is a back contact cell, and the above-mentioned collector electrode includes a first collector electrode and a second collector electrode with opposite polarities. The first collector electrode and the second collector electrode are alternately spaced and distributed along the second direction. At least part of the first collector electrode on the middle area is in direct contact with the first interconnection structure, and at least part of the second collector electrode on the middle area is in direct contact with the first interconnection structure.

[0016] As a possible implementation scheme, the solar cell further includes a second interconnect structure arranged on the target surface. Each second interconnect structure is electrically connected to at least one collector electrode, and the size of the second interconnect structure is smaller than that of the first interconnect structure. At least part of the area of ​​the second interconnect structure is located on the same straight line and is collinear with the connecting line. Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnect structure, and the remaining collector electrodes are in contact with the second interconnect structure. Among them, the collector electrode in contact with the first interconnect structure is a connecting electrode. Along the second direction, the spacing between two adjacent connecting electrodes is D1. At least one connecting electrode located in the middle area is in contact with multiple first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced apart along the first direction. The geometric center spacing between two adjacent first interconnect structures in contact with the same connecting electrode is D2. D2 corresponding to at least one pair of first interconnect structures is not equal to D1, and each pair of first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode.

[0017] When the above technical solution is adopted, among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnection structure with a larger size to increase the contact area between the part of the collector electrode and the interconnection member in the string, which is beneficial to reduce the contact resistance between the interconnection member in the string and the collector electrode, and to improve the connection strength between the interconnection member in the string and the collector electrode. Secondly, the remaining collector electrodes are in contact with the second interconnection structure with a smaller size to reduce the metal composite loss on one side of the target surface and improve the working efficiency of the solar cell. In addition, in the solar cell, the first interconnection structure that contacts different connection electrodes and is in the same layer number is aligned along the first direction to reduce the connection difficulty of automatic interconnection equipment such as string welding machines that interconnect adjacent solar cells. In this case, when D2 corresponding to at least one pair of first interconnect structures is not equal to D1, the inclination angle of the line between a certain layer of first interconnect structure arranged on a certain connecting electrode and an adjacent layer of first interconnect structure arranged on an adjacent connecting electrode is not equal to 45°, so that the inclination angle of the interconnect stress band corresponding to the pair of first interconnect structures is not equal to 45°, which is beneficial to shortening the length of the interconnect stress band formed in the extension direction of the vector line segment with an inclination angle of 45°, and is also beneficial to shortening the length of the interconnect stress band formed along the cleavage plane direction, thereby helping to reduce the risk of cracking problems caused by the solar cell being subjected to external force due to the long interconnect stress band, and improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0018] As a possible implementation scheme, the solar cell further includes a bus electrode disposed on the target surface. Different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction. Each bus electrode is electrically connected to a collector electrode having the same polarity as itself and is in contact with at least one first interconnect structure. Different bus electrodes correspond one to one with different connection lines.

[0019] When the above technical solution is adopted, in actual application, the longitudinal dimension of the collector electrode is usually small to reduce its own light shielding area, but this will make the collector electrode relatively easy to break. The existence of the bus electrode can make the carriers collected by the collector electrode on both sides of the break be transmitted and led out to the bus electrode connected to it, thereby improving the current collection capacity and reducing power loss.

[0020] As a possible implementation scheme, the above-mentioned bus electrode is a connecting electrode. Among them, along the first direction, the spacing between two adjacent connecting electrodes is D1. At least one connecting electrode is in contact with multiple first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced along the second direction. The spacing between the geometric centers of two adjacent first interconnect structures in contact with the same connecting electrode is D2. D2 corresponding to at least one pair of first interconnect structures is not equal to D1, and each pair of first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode. The beneficial effects in this case can be referred to the previous text and will not be repeated here.

[0021] As a possible implementation scheme, the above-mentioned collector electrode includes a first collector electrode and a second collector electrode with opposite polarities. The first collector electrode and the second collector electrode are alternately spaced along the second direction. In addition, the bus electrode includes a first bus electrode and a second bus electrode with opposite polarities. The first bus electrode and the second bus electrode are alternately spaced along the first direction. The bus electrode and the collector electrode with opposite polarities are insulated from each other.

[0022] As a possible implementation solution, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures is greater than or equal to 1.06 and less than or equal to 1.16.

[0023] In the case of adopting the above technical solution, it can be understood that, when the length of the connecting electrode is fixed, the larger the ratio of D2 to D1 corresponding to at least one pair of first interconnecting structures, the larger the spacing between the two adjacent first interconnecting structures corresponding to the same connecting electrode. On the contrary, the smaller the ratio of D2 to D1 corresponding to at least one pair of first interconnecting structures, the smaller the spacing between the two adjacent first interconnecting structures corresponding to the same connecting electrode, but when the ratio is closer to 1, the inclination angle of the connection line between the pair of first interconnecting structures is closer to 45°, that is, closer to the extension direction of the cleavage plane. In the above case, the ratio of D2 to D1 corresponding to at least one pair of first interconnecting structures is within the above range, which is conducive to preventing the extension direction of the interconnection stress band corresponding to at least one pair of first interconnecting structures from being close to the extension direction of the cleavage plane due to the small ratio, and ensuring that the length of the interconnection stress band formed along the cleavage plane direction can be shortened. At the same time, it is also conducive to preventing the transmission loss of carriers on the connecting electrode from being large due to the large spacing between the two adjacent first interconnecting structures corresponding to the same connecting electrode due to the large ratio, which is conducive to improving the working efficiency of the solar cell.

[0024] In a second aspect, the present invention provides another solar cell, which includes: a battery body, a collector electrode and a first interconnection structure. The battery body has a first face and a second face opposite to each other. At least one of the first face and the second face is a target face. The collector electrode is arranged on the target face. Different collector electrodes located on the same target face all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure forms an array on the target face. Each first interconnection structure is electrically connected to at least one collector electrode. At least part of the regions of the different first interconnection structures spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction. Among them, the number of connection lines located in the same target face is N1, and the number of first interconnection structures intersecting with the target line segment located in the target face is N2, N1>N2, and the target line segment is a diagonal line of the target face and intersects with each connection line.

[0025] In the case of adopting the above technical solution, the target line segment is a diagonal line of the target surface and intersects with each connection line. Moreover, when N2<N1, it can be ensured that the first interconnection structure electrically contacting each of the at least one connection line on the target surface that can intersect with the target line segment is not arranged on the target line segment, so that after the adjacent solar cells are interconnected along the extension direction of the connection line through the intra-string interconnection member, all the corresponding first interconnection structures electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, because the direction of the diagonal line on the surface of the semiconductor wafer used to manufacture solar cells is roughly parallel to the cleavage plane, and the cleavage plane is a plane with the property that the mineral crystal breaks strictly along a certain crystallization direction under the action of external force and can crack into a smooth plane, corresponding to the silicon wafer, the single crystal silicon crystal rod will form a nearly square silicon wafer after wire cutting, and the cleavage plane intersects with the surface of the silicon wafer and is not parallel to the edge of the silicon wafer. It can be understood that there are countless mutually parallel cleavage planes in the crystal rod, which form countless mutually parallel target line segments with the surface of the silicon wafer, among which the target line segment corresponding to the diagonal of the silicon wafer is the longest and faces greater stress challenges. Therefore, when the target line segment is the diagonal of the target surface, the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the battery body. At this time, reducing the interconnection stress formed along the extension direction of the target line segment is equivalent to reducing the interconnection stress formed along the cleavage plane direction, reducing the risk of solar cells cracking after being subjected to external force due to large interconnection stress, and improving the structural reliability of photovoltaic modules formed based on solar cells.

[0026] As a possible implementation scheme, the above-mentioned solar cell also includes a bus electrode arranged on the target surface. Different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction. Each bus electrode is electrically connected to a collector electrode with the same polarity as itself and is in contact with at least one first interconnection structure. Different bus electrodes correspond one to one with different connecting lines. In this case, in actual application, the longitudinal dimension of the collector electrode is usually small to reduce its own shading area, but this will make the collector electrode relatively easy to break. The presence of the bus electrode can make the carriers collected by the part of the collector electrode located on both sides of the break be transmitted and conducted to the bus electrodes connected thereto respectively, thereby improving the current collection capacity and reducing power loss.

[0027] As a possible implementation scheme, in the case where the solar cell includes at least two slice battery units spaced apart and distributed along the second direction, there is a cutting path between two adjacent slice battery units. The collector electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or, the first interconnection structures with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or, the bus electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path. In this case, in the two adjacent slice battery units, at least one of the collector electrodes with opposite polarities, the first interconnection structure and the bus electrode is symmetrically arranged about the cutting path, which facilitates the interconnection between the two, prevents misalignment, improves the interconnection yield, and reduces the difficulty of interconnection.

[0028] As a possible implementation scheme, the solar cell comprises M slice battery units spaced apart along the second direction, where M is a positive integer greater than or equal to 1. In the same slice battery unit, the geometric centers of the two first interconnect structures located at the edge along the second direction are respectively equal to the number of pairs of collector electrodes between the edges of the slice battery unit. Each pair of collector electrodes comprises two collector electrodes having the same polarity as the corresponding first interconnect structures and adjacent to each other along the second direction.

[0029] When the above technical solution is adopted, for the same slice battery unit, the geometric centers of the two first interconnection structures located at the edge along the second direction are respectively arranged logarithmically symmetrically with the collecting electrodes between the edges of the slice battery unit, which is conducive to enabling automatic interconnection equipment such as a string welding machine to interconnect different slice battery units at the same starting position, and prevent the misalignment between the interconnection parts in the string such as welding strips and the first interconnection structure arranged on the battery body due to the different starting positions corresponding to different slice battery units, thereby causing the carriers on the connecting electrode corresponding to the first interconnection structure that is not electrically connected to the interconnection part in the string to be unable to be exported through the interconnection part in the string, resulting in power loss, or causing the corresponding first interconnection structure to become a load, resulting in reduced working efficiency of the solar cell, thereby ensuring that the photovoltaic module formed by the solar cell provided by the present invention has good working performance.

[0030] As a possible implementation scheme, the solar cell is a back contact cell, and the above-mentioned collector electrode includes a first collector electrode and a second collector electrode with opposite polarities. The first collector electrode and the second collector electrode are alternately spaced and distributed along the second direction. At least part of the first collector electrode on the middle area is in direct contact with the first interconnection structure, and at least part of the second collector electrode on the middle area is in direct contact with the first interconnection structure.

[0031] As a possible implementation scheme, when the polarities of the two bus electrodes located on the outside are opposite along the first direction, among all the first interconnection structures intersecting the target line segment, at least two first interconnection structures are equidistant from the midline of the target surface along the second direction and have the same polarity. In this case, it is beneficial to improve the distribution uniformity between different first interconnection structures located on the same target surface and with the same polarity, and to reduce the difficulty of interconnecting adjacent solar cells through automatic interconnection equipment such as stringing machines.

[0032] As a possible implementation scheme, in the case where the solar cell includes two slice battery units spaced apart along the second direction, the N2 corresponding to the two slice battery units is equal. In the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are opposite. The polarities of the two oppositely arranged bus electrodes located on the outside along the first direction and belonging to different slice battery units are opposite. In this case, it is beneficial to improve the symmetry between different first interconnection structures with opposite polarities located on the same target surface, and it is beneficial to reduce the difficulty of interconnecting adjacent solar cells through automatic interconnection equipment such as string welding machines.

[0033] As a possible implementation scheme, when the solar cell includes two slice battery units spaced apart along the second direction, the N2 corresponding to the two slice battery units are not equal. In the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are the same. The polarities of the two oppositely arranged bus electrodes located on the outside along the first direction, which belong to different slice battery units, are opposite. In this case, another possible implementation method is provided for the solar cell provided by the present invention, which improves the applicability of the solar cell provided by the present invention in different application scenarios.

[0034] In a third aspect, the present invention provides a photovoltaic module, which includes the solar cell provided by the first aspect and its various implementations, or includes the solar cell provided by the second aspect and its various implementations.

[0035] The beneficial effects of the third aspect of the present invention and its various implementations may refer to the analysis of the beneficial effects of the first aspect and its various implementations, or may refer to the analysis of the beneficial effects of the second aspect and its various implementations, and will not be repeated here.

[0036] In a fourth aspect, the present invention provides another photovoltaic module, which includes: a solar cell, and an intra-string interconnection member that connects two adjacent solar cells in series. The solar cell includes: a battery body, a collector electrode, and a first interconnection structure. The battery body has a first face and a second face opposite to each other. At least one of the first face and the second face is a target face. The collector electrode is arranged on the target face. Different collector electrodes located on the same target face extend along a first direction and are spaced apart along a second direction. The first direction is perpendicular to the second direction. Each first interconnection structure is electrically connected to at least one collector electrode. Each intra-string interconnection member is electrically in contact with a corresponding first interconnection structure. The number of first interconnection structures that intersect with a target line segment located in the target face is N2, and the target line segment is a line segment connecting the midpoint of the longer one of the two edges of the target face extending along the first direction and being relatively distributed and the vertex end point corresponding to the smaller one of the two edges. The number of intra-string interconnections located on the same target face is N5. The number of first interconnection structures that intersect with a vector line segment with an inclination angle of 45° is N4. The number of interconnections in a string that intersects the same vector line segment with an inclination angle of 45° is N6, wherein N2 < 1 / 2N5; or N6 > N4.

[0037] As a possible implementation scheme, N2 corresponding to at least two solar cells in a same photovoltaic module is equal.

[0038] The beneficial effects of the fourth aspect of the present invention and its various implementations can be analyzed by referring to the beneficial effects of the first aspect and its various implementations, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 A schematic diagram of a first structure of a solar cell provided by an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a second structure of a solar cell provided by an embodiment of the present invention;

[0042] Figure 3 A third structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0043] Figure 4 A fourth structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic diagram of a square opening of a semiconductor substrate used for manufacturing a battery body in an embodiment of the present invention;

[0045] Figure 6 Schematic diagram of the distribution of diagonal lines on a target surface in an embodiment of the present invention;

[0046] Figure 7 A schematic diagram of the distribution relationship between some connecting electrodes and some interconnecting structures in an embodiment of the present invention;

[0047] Figure 8 A fifth structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0048] Fig. 9 A sixth structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0049] Fig.10 A seventh structural schematic diagram of a solar cell provided by an embodiment of the present invention;

[0050] Fig.11 This is a schematic diagram of an eighth structure of a solar cell provided by an embodiment of the present invention.

[0051] Reference numerals: 11 is a battery body, 12 is a collecting electrode, 13 is a first interconnection structure, 14 is a second interconnection structure, 15 is a connecting electrode, and 16 is a bus electrode. DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0053] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0054] In the context of the present disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "under" the other layer / element. In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] Solar cells are now being used more and more widely as a new energy alternative. Among them, photovoltaic solar cells are devices that convert sunlight into electrical energy. Specifically, solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead the carriers out, thereby facilitating the effective use of electrical energy.

[0058] Specifically, existing solar cells generally include a cell body, a collector electrode and an interconnection structure. The collector electrode is arranged on the first surface and / or the second surface of the solar cell. Different collector electrodes located on the same surface all extend along the first direction and are spaced apart along the second direction. The first direction is different from the second direction. The interconnection structure is arranged on a surface of the cell body having the collector electrode. Each interconnection structure contacts at least one collector electrode to interconnect adjacent solar cells through an interconnection structure and intra-string interconnectors such as welding strips. Different interconnection structures located on the same surface form an array. At least part of the area of ​​different first interconnection structures spaced apart along the second direction is located on the same connection line, and different connection lines are spaced apart along the first direction.

[0059] However, in the above-mentioned existing solar cells, the distribution position of the interconnection structure on the battery body is not set reasonably. Specifically, taking the whole cell as an example, in the existing solar cell, the number of connecting wires is equal to or less than the number of interconnection structures intersecting with the diagonal line. Moreover, the diagonal line is the longest line segment in the surface of the battery body. In this case, after the adjacent solar cells are interconnected by the interconnection parts in the string such as the welding strip along the extension direction of the connecting wire, the interconnection structure is electrically connected to the interconnection structure, and stress is generated between the interconnection structure and the battery body after the interconnection. When the number of connecting wires is equal to or less than the number of interconnection structures intersecting with the diagonal line, there is at least one interconnection structure on each connecting wire that intersects with the diagonal line, and after the interconnection, a stress belt extending in the diagonal direction and having a large length will be formed, so that the interconnection stress in the diagonal extension direction is too large. The diagonal direction is roughly parallel to the cleavage plane of the battery body. In the case where the interconnection stress in the diagonal direction is too large, it is easy to cause a significant increase in the risk of cracking, resulting in a decrease in the structural reliability of the photovoltaic module.

[0060] In order to solve the above technical problems, in a first aspect, an embodiment of the present invention provides a solar cell. Specifically, the solar cell provided by the embodiment of the present invention can be any cell that can convert solar light energy into electrical energy.

[0061] In terms of the locations of the positive electrode and the negative electrode, the solar cell provided by the embodiment of the present invention may be a double-sided contact solar cell, that is, one of the positive electrode and the negative electrode of the solar cell is arranged on the front side of the solar cell, and the other is arranged on the back side. Alternatively, the solar cell provided by the embodiment of the present invention may also be a back contact cell, that is, the positive electrode and the negative electrode of the solar cell are both arranged on the back side of the solar cell.

[0062] In terms of the specific electrode structure of the positive electrode and the negative electrode, the solar cell provided by the embodiment of the present invention can be a "busbar-free solar cell"; in this case, the electrode structure in the solar cell only includes the collector electrode. Alternatively, the solar cell provided by the embodiment of the present invention can also be a "busbar-with solar cell"; in this case, the solar cell includes not only the collector electrode, but also the bus electrode, and different bus electrodes correspond to different connecting wires one by one.

[0063] Specifically, if Figure 2 and Figure 4 ,as well as Figure 5 and Figure 6 As shown, the solar cell provided by the embodiment of the present invention includes: a battery body 11, a collecting electrode 12 and a first interconnection structure 13. The battery body 11 has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collecting electrode 12 is arranged on the target surface. Different collecting electrodes 12 located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure 13 forms an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collecting electrode 12. At least partial areas of different first interconnection structures 13 spaced apart along the second direction are located on the same connecting line, and different connecting lines are spaced apart along the first direction. Among them, the number of connecting lines located in the same target surface is N1, the number of first interconnection structures 13 intersecting with the target line segment located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the longer one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoint corresponding to the smaller one of the two edges; or, the number of connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of first interconnect structures 13 intersecting with the same vector line segment with an inclination angle of 45° is N4, N3>N4.

[0064] Specifically, the number N1 of the above-mentioned connecting lines is a positive integer greater than or equal to 1. The number N2 of the first interconnecting structures intersecting the target line segment located in the target surface is an integer greater than or equal to 0. The specific sizes of the number N1 of the connecting lines, the number N2 of the first interconnecting structures intersecting the target line segment located in the target surface, the number N3 of the connecting lines intersecting the vector line segment with an inclination angle of 45°, and the number N4 of the first interconnecting structures 13 intersecting the vector line segment with an inclination angle of 45° can be determined according to the actual application scenario and are not specifically limited here.

[0065] When the above technical solution is adopted, Figure 2 and Figure 4As shown, in the solar cell provided by the embodiment of the present invention, a first interconnection structure 13 is provided on the target surface of the battery body 11, and the first interconnection structures 13 form an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collector electrode 12. Moreover, at least partial areas of different first interconnection structures 13 spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction. In this case, when adjacent solar cells are interconnected along the extension direction of the connection line through an intra-string interconnection member such as a welding strip, the intra-string interconnection member corresponding to the connection line can be electrically connected to the collector electrode 12 with the same polarity located on the target surface at least through the first interconnection structure 13, so that the carriers collected by the collector electrode 12 are sequentially guided out through the first interconnection structure 13 and the intra-string interconnection member to form a photocurrent. After the adjacent solar cells are interconnected, due to the different materials and thermal expansion coefficients of the first interconnection structure 13 and the battery body 11, interconnection stress will be generated after the interconnection. Based on this, the target line segment only contacts with at most half of all the connection lines located on the same target surface. Moreover, when When the target surface is connected to the target line segment, it can be ensured that the first interconnection structure 13 electrically contacting each of the at least one connecting line that can intersect with the target line segment is not arranged on the target line segment, so that after the adjacent solar cells are interconnected along the extension direction of the connecting line through the in-string interconnection member, all the corresponding first interconnection structures 13 electrically contacting each of the at least one in-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, since the direction of the inner diagonal line of the surface of the semiconductor wafer used to manufacture the solar cell is roughly parallel to the cleavage plane, and the cleavage plane is a plane with the property that a mineral crystal breaks strictly along a certain crystallization direction under the action of an external force and can crack into a smooth plane, corresponding to the silicon wafer, the single crystal silicon crystal rod will form a nearly square silicon wafer after wire cutting, and the cleavage plane intersects with the surface of the silicon wafer and is not parallel to the edge of the silicon wafer. It can be understood that there are countless mutually parallel cleavage planes in the crystal rod, which form countless mutually parallel target line segments with the surface of the silicon wafer, among which the target line segment corresponding to the diagonal line of the silicon wafer is the longest and faces a greater stress challenge. After the silicon wafer is cut in half, the position of the target line segment remains unchanged from that before the silicon wafer is cut in half. Therefore, when the target line segment is a line segment connecting the midpoint of the larger one of the two edges (such as the non-chamfered edge) of the target surface extending along the first direction and relatively distributed and the vertex end point corresponding to the smaller one of the two edges (such as the chamfered edge), the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the battery body 11. At this time, reducing the interconnection stress formed along the extension direction of the target line segment is equivalent to reducing the interconnection stress formed along the cleavage plane direction, reducing the risk of the solar cell cracking problem after being subjected to external force due to the large interconnection stress, and improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, when the number N3 of connecting lines corresponding to the vector line segment with an inclination angle of 45° is greater than the number N4 of the first interconnection structures 13 intersecting with itself, all the first interconnection structures 13 on at least one connecting line are not arranged on the vector line segment with an inclination angle of 45°, so that after the adjacent solar cells are interconnected along the extension direction of the connecting line through the intra-string interconnection member, all the corresponding first interconnection structures electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the vector line segment with an inclination angle of 45°, thereby shortening the length of the interconnection stress belt formed along the extension direction of the vector line segment with an inclination angle of 45°. Secondly, the cleavage plane of the battery body is roughly parallel to the vector line segment with an inclination angle of 45°. Therefore, when the length of the interconnection stress band formed along the extension direction of the vector line segment with an inclination angle of 45° is shortened, it is also beneficial to shorten the length of the interconnection stress band formed along the cleavage plane direction, thereby reducing the risk of cracking of the solar cell after being subjected to external force due to the long interconnection stress band, thereby improving the structural reliability of the photovoltaic module formed based on the solar cell.

[0066] In actual application, the embodiments of the present invention do not specifically limit the structure and materials of the battery body, which can be determined according to the type of solar cell and the actual application scenario, as long as they can be applied to the solar cell provided by the embodiments of the present invention.

[0067] Exemplarily, when the solar cell provided in the embodiment of the present invention is a double-sided contact solar cell, the above-mentioned cell body may include at least a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer. One of the first doped semiconductor layer and the second doped semiconductor layer is formed on a side of the semiconductor substrate corresponding to the front side, and the other is formed on a side of the semiconductor substrate corresponding to the back side. Moreover, the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types.

[0068] The semiconductor substrate may be a substrate made of any semiconductor material such as a silicon substrate, a silicon germanium substrate, a germanium substrate or a gallium arsenide substrate. The conductivity type of the semiconductor substrate may be N-type, P-type or intrinsic type.

[0069] For the above-mentioned first doped semiconductor layer and the second doped semiconductor layer, the material of the first doped semiconductor layer and / or the second doped semiconductor layer may include any semiconductor material such as silicon, silicon germanium or germanium. In terms of the arrangement of the material, the crystal phase of the first doped semiconductor layer and / or the second doped semiconductor layer may be amorphous, microcrystalline, nanocrystalline, single crystal or polycrystalline, etc. In terms of the conductivity type, the conductivity type of the first doped semiconductor layer may be N-type, in which case the conductivity type of the second doped semiconductor layer is P-type; or, the conductivity type of the first doped semiconductor layer is P-type, in which case the conductivity type of the second doped semiconductor layer is N-type. As for the thickness of the first doped semiconductor layer and the second doped semiconductor layer, it can be set according to actual needs and is not specifically limited here. For example: the thickness of the first doped semiconductor layer or the second doped semiconductor layer may be greater than or equal to 100nm and less than or equal to 500nm.

[0070] Exemplarily, the solar cell is a back contact cell, and the cell body may include at least a semiconductor substrate, a first doped semiconductor layer, and a second doped semiconductor layer. The first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types, and the first doped semiconductor layer and the second doped semiconductor layer are both arranged on one side of the corresponding back side of the semiconductor substrate. At least a portion of the first doped semiconductor layer is spaced apart from at least a portion of the second doped semiconductor layer. Information such as the materials and thickness of the semiconductor substrate, the first doped semiconductor layer, and the second doped semiconductor layer can be referred to above and will not be repeated here.

[0071] As for the battery body having a first surface and a second surface relative to each other, the first surface of the battery body may correspond to the front surface of the solar cell, and the second surface of the battery body may correspond to the back surface of the solar cell. In this case, since the connecting wire is arranged on the target surface of the battery body, the target surface is specifically which of the first surface and the second surface of the battery body, or whether both the first surface and the second surface are the target surface, which can be determined according to the type of solar cell and the actual application scenario.

[0072] When the solar cell is a double-sided contact solar cell, the target surface of the cell body may be only the first surface of the cell body, only the second surface of the cell body, or both the first surface and the second surface of the cell body. When the solar cell is a back-contact cell, the target surface of the cell body is one of the first surface and the second surface of the cell body that corresponds to the back surface of the solar cell.

[0073] Secondly, it should be noted that, when the vertex angle of the target surface is a sharp angle, the target line segment can be a line segment connecting the midpoint of any one of the two edges of the target surface extending along the first direction and relatively distributed and the vertex angle endpoint corresponding to the other. When the vertex angle of the target surface is a chamfer with a smooth transition or the like, the target line segment can be a line segment connecting the midpoint of the longer one of the two edges of the target surface extending along the first direction and relatively distributed (i.e., the non-chamfered edge) and the vertex angle endpoint corresponding to the shorter one of the two edges (i.e., the chamfered edge) (the vertex angle endpoint is the endpoint of the chamfer extension line).

[0074] In addition, the specific structure and distribution of the electrode structure formed on the target surface of the solar cell may be determined according to the type of the solar cell.

[0075] For example, Figure 2 As shown, in the case where the solar cell is a main grid-free solar cell, along the second direction, the target surface includes a middle area and an edge area. At least part of the collector electrode 12 located in the middle area is in direct contact with the first interconnection structure 13. In this case, the carriers collected by the corresponding collector electrode 12 can be directly transmitted to the interconnection parts in the string such as the welding strip through the first interconnection structure 13 in contact with itself and exported, without the need to conduct the carriers through the bus electrode to the first interconnection structure 13 and the interconnection parts in the string in turn, thereby eliminating the transmission loss of the carriers on the bus electrode, while reducing the shading loss and improving the working efficiency of the solar cell.

[0076] Wherein, in the target surface, the area between the two first interconnect structures located at the edge along the second direction and the edge of the battery body is defined as the edge area of ​​the target surface, and the remaining area is the middle area of ​​the target surface. In addition, in the above case, when the solar cell is a double-sided contact cell, the polarities of different collector electrodes located on the same target surface are the same (all collector electrodes included in the positive electrode or the negative electrode). When the solar cell is a back contact cell, all collector electrodes located on the same target surface include a first collector electrode and a second collector electrode with opposite polarities. The first collector electrode and the second collector electrode are alternately spaced and distributed along the second direction to prevent leakage; wherein, at least part of the first collector electrode on the middle area is in direct contact with the first interconnect structure, and at least part of the second collector electrode on the middle area is in direct contact with the first interconnect structure. Specifically, the first collector electrode can be a collector electrode included in the positive electrode, in which case the second collector electrode is a collector electrode included in the negative electrode; or, the first collector electrode can also be a collector electrode included in the negative electrode, in which case the second collector electrode is a collector electrode included in the positive electrode.

[0077] Specifically, in the case where the solar cell is a busbar-free solar cell, Figure 2 As shown, the solar cell may further include a second interconnect structure 14 disposed on the target surface. Each second interconnect structure 14 is electrically connected to at least one collector electrode 12, and the size of the second interconnect structure 14 is smaller than the size of the first interconnect structure 13. At least a portion of the second interconnect structure 14 is located on the same straight line and is collinear with the connection line. Moreover, among all the collector electrodes 12 located on the same target surface, some of the collector electrodes 12 are in contact with the first interconnect structure 13, and the remaining collector electrodes 12 are in contact with the second interconnect structure 14, so as to respectively guide the carriers collected by the collector electrodes 12 located on the same target surface through the first interconnect structure 13 and the second interconnect structure 14. In this case, among all the collector electrodes 12 located on the same target surface, some of the collector electrodes 12 are in contact with the first interconnect structure 13 with a larger size, so as to increase the contact area between the part of the collector electrode 12 and the interconnection member in the string, which is beneficial to reduce the contact resistance between the interconnection member in the string and the collector electrode 12, and to improve the connection strength between the interconnection member in the string and the collector electrode 12. Secondly, the remaining collector electrodes 12 are in contact with the second interconnection structure 14 with a smaller size, so as to reduce the metal composite loss on one side of the target surface and improve the working efficiency of the solar cell.

[0078] Specifically, the size of the first interconnect structure being larger than the size of the second interconnect structure may mean that: along the first direction, only the length of the first interconnect structure is larger than the length of the second interconnect structure; or, along the second direction, only the width of the first interconnect structure is larger than the width of the second interconnect structure; or, the length and width of the first interconnect structure are larger than the length and width of the second interconnect structure, respectively. The specific sizes of the first interconnect structure and the second interconnect structure may be determined according to actual application scenarios and are not specifically limited here.

[0079] For example, Figure 4 As shown, the above-mentioned solar cell may also include a bus electrode 16 arranged on the target surface. Different bus electrodes 16 located on the same target surface extend along the second direction and are spaced apart along the first direction. Each bus electrode 16 is electrically connected to a collector electrode 12 with the same polarity as itself and is in contact with at least one first interconnect structure 13. Different bus electrodes 16 correspond one-to-one to different connecting lines. In this case, the solar cell provided by the embodiment of the present invention is a "main grid solar cell". Based on this, in actual application, the longitudinal dimension of the collector electrode 12 is usually small to reduce its own shading area, but this will make the collector electrode 12 relatively easy to break. The presence of the bus electrode 16 can enable the carriers collected by the collector electrode 12 on both sides of the break to be transmitted and conducted to the bus electrodes 16 connected thereto, respectively, thereby improving the current collection capacity and reducing power loss.

[0080] Wherein, in the above case, if the solar cell is a double-sided contact cell, the bus electrode located on the same target surface is electrically connected to all the collecting electrodes. If the solar cell is a back contact cell, the above collecting electrode includes a first collecting electrode and a second collecting electrode with opposite polarities, and the first collecting electrode and the second collecting electrode are alternately spaced along the second direction; the above bus electrode includes a first bus electrode and a second bus electrode with opposite polarities, and the first bus electrode and the second bus electrode are alternately spaced along the first direction; and the bus electrode and the collecting electrode with opposite polarities are insulated from each other. Specifically, the bus electrode can be electrically insulated from the collecting electrode with opposite polarity to itself by an insulating material such as an insulating glue; or the collecting electrode can be a discontinuous collecting electrode, and the bus electrode can be electrically insulated from the collecting electrode with opposite polarity to itself by the discontinuity of the discontinuous collecting electrode. Among them, the positive electrode of the back-contact battery may include the above-mentioned first collecting electrode and the first bus electrode, and the negative electrode of the back-contact battery may include the above-mentioned second collecting electrode and the second bus electrode; or, the negative electrode of the back-contact battery may include the above-mentioned first collecting electrode and the first bus electrode, and the positive electrode of the back-contact battery may include the above-mentioned second collecting electrode and the second bus electrode.

[0081] It should be noted that the collector electrode included in the positive electrode has opposite polarity to the collector electrode included in the negative electrode and the first interconnection structure (or second interconnection structure) electrically connected to the collector electrode included in the negative electrode. In addition, when the solar cell is a "busbar solar cell", the bus electrode included in the positive electrode has opposite polarity to the collector electrode included in the negative electrode, the bus electrode included in the negative electrode, and the first interconnection structure electrically connected to the bus electrode included in the negative electrode.

[0082] In addition, the embodiments of the present invention do not specifically limit the number and morphology of the collector electrodes included in the solar cell, and the spacing between adjacent collector electrodes. Specifically, the spacing between different pairs of collector electrodes may be equal or unequal. It can be understood that when the size of the collector electrode is a fixed value, the carrier collection range corresponding to the collector electrode is fixed. In this case, Figure 2 and Figure 4 As shown, the spacings between different pairs of collector electrodes 12 are equal, so that different collector electrodes 12 are evenly distributed along the second direction, which is beneficial to prevent at least one of the pair of collector electrodes 12 from being difficult to timely collect and export carriers within a larger spacing range due to the spacing between two adjacent collector electrodes 12 with the same polarity in at least one pair of collector electrodes 12 being larger than the spacing between two adjacent collector electrodes 12 with the same polarity in the remaining pairs of collector electrodes 12, thereby ensuring that one side of the target surface has a lower carrier recombination rate. At the same time, it is also beneficial to prevent the distribution density of the collector electrodes 12 on a part of one side of the target surface from being larger due to the spacing between two adjacent collector electrodes 12 with the same polarity in at least one pair of collector electrodes 12 being smaller than the spacing between two adjacent collector electrodes 12 with the same polarity in the remaining pairs of collector electrodes 12, resulting in a larger light shielding area of ​​the collector electrode 12 and a larger metal recombination loss between the collector electrode 12 and the battery body 11, which is beneficial to improving the photoelectric conversion efficiency of the solar cell.

[0083] Secondly, in the case where the solar cell provided in the embodiment of the invention includes a bus electrode, the number and morphology of the bus electrodes, and the spacing between adjacent bus electrodes in the embodiment of the invention can be determined according to the number and morphology of the connecting wires, and the spacing between adjacent connecting wires in the actual application scenario, and no specific limitation is made here.

[0084] The specific directions referred to by the first direction and the second direction can be based on actual needs, as long as they can be applied to the solar cell provided in the embodiment of the present invention. For example, when the shape of the target surface is a rectangle, the rectangle has a first side and a second side that are alternately distributed. The first direction can be parallel to the first side of the rectangle, and in this case, the second direction can be parallel to the second side of the rectangle.

[0085] As for the number N1 of connecting lines on the target surface and the number N2 of first interconnect structures intersecting with the target line segments within the target surface, they can be determined according to the spacing between two adjacent bus electrodes or the spacing between two adjacent collecting electrodes electrically contacting the first interconnect structure along the second direction, and the distribution of the first interconnect structure on the bus electrode or the collecting electrode, as long as they can be applied to the solar cell provided in the embodiment of the present invention.

[0086] For example, Figure 4 As shown, N2 can be equal to 0. In this case, the number of first interconnect structures 13 intersecting with the target line segment is 0. Because the direction of the inner diagonal line of the surface of the semiconductor wafer used to manufacture the solar cell is roughly parallel to the cleavage surface, and after the semiconductor wafer is cut in half, the position of the line segment (i.e., the target line segment) of the midpoint of the longer one of the two relatively distributed edges of the target surface extending along the first direction and the vertex end point corresponding to the smaller one of the two edges is part of the inner diagonal line of the original entire semiconductor wafer. It can be seen that the target line segment is roughly parallel to the cleavage surface. Therefore, at this time, the number of the first interconnect structures 13 set on the cleavage surface of the battery body 11 parallel to the extension direction of the target line segment is 0, which can minimize the risk of cracking problems at the cleavage surface after the solar cell is subjected to external force, and improve the structural reliability of the photovoltaic module formed based on the solar cell.

[0087] As for the number N3 of connecting lines intersecting with the vector line segment with an inclination angle of 45°, and the number N4 of first interconnect structures 13 intersecting with the vector line segment with an inclination angle of 45°, they can also be determined according to the spacing between two adjacent bus electrodes along the second direction or the spacing between two adjacent collecting electrodes electrically contacting the first interconnect structure, and the distribution of the first interconnect structure on the bus electrode or the collecting electrode, as long as they can be applied to the solar cell provided in the embodiment of the present invention.

[0088] In actual application, Figure 2As shown, in the case where the solar cell is a main grid-free solar cell, the collector electrode 12 in contact with the first interconnect structure 13 is defined as a connecting electrode 15. And the spacing between two adjacent connecting electrodes 15 along the second direction is defined as D1. At least one connecting electrode 15 located in the middle area is in contact with multiple first interconnect structures 13, and different first interconnect structures 13 in contact with the same connecting electrode 15 are spaced apart along the first direction. The geometric center spacing between two adjacent first interconnect structures 13 in contact with the same connecting electrode 15 is defined as D2. In the above case, it can be understood that different connecting electrodes 15 are arranged differently on the target surface. Correspondingly, the first interconnect structures 13 in electrical contact with different connecting electrodes 15 are also arranged at different positions on the target surface. And the setting position of the first interconnect structure 13 on the target surface will affect the numerical value of the above-mentioned N2. In the above case, among all the collecting electrodes 12 located on the same target surface, which part of the collecting electrodes 12 is electrically in contact with the first interconnect structure 13, and which part of the collecting electrodes 12 is electrically in contact with the second interconnect structure 14 can be determined according to the size requirements of N2 in the actual application scenario, and no specific limitation is made here.

[0089] Secondly, if Figure 4 As shown, in the case where the solar cell is a main grid solar cell, the above-mentioned busbar electrode 16 is defined as a connecting electrode 15. And the spacing between two adjacent connecting electrodes 15 along the first direction is defined as D1. At least one connecting electrode 15 is in contact with multiple first interconnect structures 13, and different first interconnect structures 13 in contact with the same connecting electrode 15 are spaced apart along the second direction. The spacing between the geometric centers of two adjacent first interconnect structures 13 in contact with the same connecting electrode 15 is defined as D2.

[0090] In the above case, in the solar cell, the first interconnection structures that contact different connection electrodes and are in the same layer are aligned along the first direction to reduce the connection difficulty of automatic interconnection equipment such as string welding machines that interconnect adjacent solar cells. Figure 7As shown, if D2 corresponding to each pair of first interconnect structures 13 is equal to D1, the inclination angle of the line between a certain layer of first interconnect structures 13 arranged on each connection electrode 15 and the adjacent layer of first interconnect structures 13 arranged on the adjacent connection electrode 15 is equal to 45°, so that N3 corresponding to each vector line segment with an inclination angle of 45° is equal to N4. When D2 corresponding to at least one pair of first interconnect structures is not equal to D1, there is a line between a certain layer of first interconnect structures arranged on a certain connection electrode and the adjacent layer of first interconnect structures arranged on the adjacent connection electrode, so that the inclination angle of the interconnection stress band corresponding to the pair of first interconnect structures is not equal to 45°, which is conducive to shortening the length of the interconnection stress band formed in the extension direction of the vector line segment with an inclination angle of 45°, and also to shortening the length of the interconnection stress band formed along the cleavage plane direction, so as to reduce the risk of the solar cell cracking problem caused by the longer interconnection stress band after being subjected to external force, and improve the structural reliability of the photovoltaic module formed based on the solar cell.

[0091] Specifically, it can be understood that, when the length of the connecting electrode is fixed, the larger the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the larger the spacing between two adjacent first interconnect structures corresponding to the same connecting electrode. On the contrary, the smaller the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures, the smaller the spacing between two adjacent interconnect structures corresponding to the same connecting electrode. However, when the ratio is closer to 1, the inclination angle of the connection line between the pair of first interconnect structures is closer to 45°, that is, closer to the extension direction of the cleavage surface. In the above case, when D2 corresponding to at least one pair of first interconnect structures is not equal to D1, the specific ratio of D2 to D1 can be determined at least according to the inclination angle of the interconnection stress band formed after interconnection in the actual application scenario, and the transmission loss of carriers on the bus electrode, and is not specifically limited here.

[0092] Exemplarily, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures may be greater than or equal to 1.06 and less than or equal to 1.16. For example, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures may be 1.06, 1.1, 1.12, 1.14 or 1.16, etc. In this case, the ratio of D2 to D1 corresponding to at least one pair of first interconnect structures is within the above range, which is conducive to preventing the extension direction of the interconnect stress band corresponding to at least one pair of first interconnect structures from being close to the extension direction of the cleavage surface due to the small ratio, and ensuring that the length of the interconnect stress band formed along the cleavage surface direction can be shortened. At the same time, it is also conducive to preventing the transmission loss of carriers on the connecting electrode from being large due to the large spacing between two adjacent first interconnect structures corresponding to the same connecting electrode due to the large ratio, which is conducive to improving the working efficiency of the solar cell.

[0093] In addition, in the actual application process, in all the first interconnect structures contacting the same connecting line, the spacing between two adjacent first interconnect structures may be equal or unequal. And along the second direction, in all the first interconnect structures contacting the same connecting line, the spacing between the geometric centers of two adjacent first interconnect structures will affect the number of collector electrodes arranged between the geometric centers of the two adjacent first interconnect structures. Wherein, each pair of collector electrodes includes two collector electrodes with the same polarity as the corresponding first interconnect structure and adjacent along the second direction. Specifically, when the spacing between different pairs of collector electrodes is equal, if the spacing between the geometric centers of the two adjacent first interconnect structures is equal, the number of collector electrodes between the geometric centers of the two adjacent first interconnect structures is also equal; on the contrary, if the spacing between the geometric centers of the two adjacent first interconnect structures is unequal, the number of collector electrodes between the geometric centers of the two adjacent first interconnect structures is also unequal. In the above case, the spacing between the geometric centers of the two adjacent first interconnect structures can be controlled by adjusting the number of collector electrodes located between the geometric centers of the two adjacent first interconnect structures, thereby realizing the regulation of the extension direction of the interconnection stress band formed by the two adjacent first interconnect structures after interconnection.

[0094] As for the first interconnect structure, in terms of material, the material of the first interconnect structure may include any conductive material such as silver, copper, aluminum or tungsten.

[0095] Secondly, as mentioned above, the materials and thermal expansion coefficients of the battery body and the first interconnection structure are different, so after interconnection, interconnection stress will be generated at the junction of the battery body and the first interconnection structure, and when the size of the first interconnection structure is different, the magnitude of the interconnection stress generated at the junction of the battery body and the first interconnection structure after interconnection may also be different. Specifically, when other factors are the same and within a certain range, after adjacent solar cells are interconnected, the magnitude of the interconnection stress at the junction of the first interconnection structure and the battery body is proportional to the thickness of the first interconnection structure. In addition, within a certain range, the thickness of the first interconnection structure is inversely proportional to its own transmission loss. In the above case, the size of the first interconnection structure can be determined at least based on the requirements for the transmission loss and interconnection stress of the first interconnection structure in the actual application scenario, and no specific limitation is made here.

[0096] Exemplarily, the thickness of the battery body is H1, and the thickness of the first interconnection structure is H2. Based on this, the ratio of H2 to H1 can be greater than or equal to 0.005 and less than or equal to 0.1. For example, the ratio between the thickness H2 of the interconnection structure and the thickness H1 of the battery body can be 0.005, 0.01, 0.02, 0.04, 0.06, 0.08 or 0.1, etc. In this case, the ratio between the thickness H2 of the first interconnection structure and the thickness H1 of the battery body is within the above range, which can prevent the transmission loss of carriers at the first interconnection structure from being large due to the small ratio, thereby ensuring that the solar cell has a higher power. In addition, it can also prevent the interconnection stress between the first interconnection structure and the battery body from being large after interconnection due to the large ratio, thereby further reducing the risk of cracks in the solar cell under the action of external force after interconnection, and improving the structural reliability of the photovoltaic module.

[0097] Exemplarily, the cross-sectional area of ​​the battery body is defined as S1, and the cross-sectional area of ​​the first interconnection structure is defined as S2. Based on this, the ratio of S2 to S1 can be greater than or equal to 0.0003 and less than or equal to 0.02. For example: the ratio between the cross-sectional area S2 of the interconnection structure and the cross-sectional area S1 of the battery body can be 0.0003, 0.0008, 0.001, 0.003, 0.005, 0.008, 0.01 or 0.02, etc. The beneficial effects in this case are similar to the beneficial effects described above in that the thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1, and will not be repeated here.

[0098] When the solar cell provided in the embodiment of the present invention is a busbar-free solar cell, the thickness and cross-sectional area of ​​the second interconnect structure may be determined according to the actual application scenario, and are not specifically limited here.

[0099] As for the distribution of the first interconnection structure on the target surface, it can be determined according to the distribution and setting quantity of the above-mentioned collector electrodes and / or bus electrodes on the target surface, as long as it can be applied to the solar cell provided in the embodiment of the present invention.

[0100] For example, Figure 2 and Figure 4As shown, the spacing between the geometric center of the first interconnecting structure 13 intersecting the target line segment and the midline of the solar cell along the second direction is defined as D3, and the spacing between the geometric center of the first interconnecting structure 13 intersecting the target line segment and the edge of the solar cell along the second direction is defined as D4. Based on this, D3>D4. In this case, the spacing between the geometric center of the first interconnecting structure 13 intersecting the target line segment and the edge of the solar cell along the second direction is smaller, which is conducive to preventing the first interconnecting structure 13 intersecting the target line segment from being densely distributed at the midline of the solar cell along the second direction, reducing the risk of cracks at the intersection of the midline of the solar cell along the second direction and the target line segment after interconnection, and further improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, it is also possible to achieve a balance between the uniformity of current collection by the collector electrode 12 and the feasibility of interconnection between adjacent solar cells as the number of the first interconnecting structures 13 increases, which is conducive to improving the working performance of the photovoltaic module.

[0101] Of course, if Fig. 9 and Fig.11 As shown, the distance D3 between the geometric center of the first interconnect structure 13 intersecting the target line segment and the midline of the solar cell along the second direction may also be greater than or equal to the distance D4 between the geometric center of the first interconnect structure 13 intersecting the target line segment and the edge of the solar cell along the second direction. The specific values ​​of D3 and D4 can be determined according to the distribution of the first interconnect structure 13 and the collector electrode 12 on the target surface, and are not specifically limited here.

[0102] For example, when the polarities of the two bus electrodes located on the outside are opposite along the first direction, among all the first interconnect structures intersecting the target line segment, at least two first interconnect structures may be spaced equally from the midline of the target surface along the second direction, and may have the same polarity. In this case, it is beneficial to improve the distribution uniformity between different first interconnect structures located on the same target surface and having the same polarity, and to reduce the difficulty of interconnecting adjacent solar cells by automatic interconnection equipment such as a stringing machine.

[0103] Or, if Fig.11 As shown, when the polarities of the two bus electrodes 16 located on the outside are opposite along the first direction, among all the first interconnect structures 13 intersecting the target line segment, the distances between at least two first interconnect structures 13 and the midline of the target surface along the second direction can be equal and the polarities can also be opposite.

[0104] In a second aspect, an embodiment of the present invention provides another solar cell. Specifically, the solar cell provided by the embodiment of the present invention can be any cell that can convert solar light energy into electrical energy.

[0105] In terms of the locations of the positive electrode and the negative electrode, the solar cell provided by the embodiment of the present invention may be a double-sided contact solar cell, that is, one of the positive electrode and the negative electrode of the solar cell is arranged on the front side of the solar cell, and the other is arranged on the back side. Alternatively, the solar cell provided by the embodiment of the present invention may also be a back contact cell, that is, the positive electrode and the negative electrode of the solar cell are both arranged on the back side of the solar cell.

[0106] In terms of the specific electrode structure of the positive electrode and the negative electrode, the solar cell provided by the embodiment of the present invention can be a "busbar-free solar cell"; in this case, the electrode structure in the solar cell only includes the collector electrode. Alternatively, the solar cell provided by the embodiment of the present invention can also be a "busbar-with solar cell"; in this case, the solar cell includes not only the collector electrode, but also the bus electrode, and different bus electrodes correspond to different connecting wires one by one.

[0107] Specifically, if Figure 1 and Figure 3 As shown, the solar cell includes: a battery body 11, a collector electrode 12 and a first interconnection structure 13. The battery body 11 has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collector electrode 12 is arranged on the target surface. Different collector electrodes 12 located on the same target surface all extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. The first interconnection structure 13 forms an array on the target surface. Each first interconnection structure 13 is electrically connected to at least one collector electrode 12. At least part of the regions of different first interconnection structures 13 spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction. The number of connection lines located in the same target surface is N1, and the number of first interconnection structures 13 intersecting with the target line segment located in the target surface is N2, N1>N2, and the target line segment is a diagonal line of the target surface and intersects with each connection line.

[0108] Specifically, the number N1 of the connecting lines is a positive integer greater than or equal to 1. The number N2 of the first interconnecting structures intersecting the target line segment located in the target surface is an integer greater than or equal to 0. The specific sizes of the number N1 of the connecting lines and the number N2 of the first interconnecting structures intersecting the target line segment located in the target surface can be determined according to the actual application scenario and are not specifically limited here.

[0109] In the case of adopting the above technical solution, the target line segment is a diagonal line of the target surface and intersects with each connection line. Moreover, when N2<N1, it can be ensured that the first interconnection structure electrically contacting each of the at least one connection line on the target surface that can intersect with the target line segment is not arranged on the target line segment, so that after the adjacent solar cells are interconnected along the extension direction of the connection line through the intra-string interconnection member, all the corresponding first interconnection structures electrically contacting each of the at least one intra-string interconnection member will not generate interconnection stress on the target line segment, thereby reducing the interconnection stress formed along the extension direction of the target line segment. In this case, because the direction of the diagonal line on the surface of the semiconductor wafer used to manufacture solar cells is roughly parallel to the cleavage plane, and the cleavage plane is a plane with the property that the mineral crystal breaks strictly along a certain crystallization direction under the action of external force and can crack into a smooth plane, corresponding to the silicon wafer, the single crystal silicon crystal rod will form a nearly square silicon wafer after wire cutting, and the cleavage plane intersects with the surface of the silicon wafer and is not parallel to the edge of the silicon wafer. It can be understood that there are countless mutually parallel cleavage planes in the crystal rod, which form countless mutually parallel target line segments with the surface of the silicon wafer, among which the target line segment corresponding to the diagonal of the silicon wafer is the longest and faces greater stress challenges. Therefore, when the target line segment is the diagonal of the target surface, the extension direction of the target line segment is roughly parallel to the direction of the cleavage plane of the battery body. At this time, reducing the interconnection stress formed along the extension direction of the target line segment is equivalent to reducing the interconnection stress formed along the cleavage plane direction, reducing the risk of solar cells cracking after being subjected to external force due to large interconnection stress, and improving the structural reliability of photovoltaic modules formed based on solar cells.

[0110] It should be noted that, from the foregoing contents, the solar cell provided in the first aspect of the embodiment of the present invention is a half-sheet solar cell. The solar cell provided in the second aspect of the embodiment of the present invention is a whole-sheet solar cell. In this case, the solar cell provided in the first aspect of the embodiment of the present invention can be regarded as being obtained by cutting the solar cell provided in the second aspect of the embodiment of the present invention into half a sheet. Based on this, the structure and materials of the cell body in the solar cell provided in the second aspect of the embodiment of the present invention, as well as the distribution of the collector electrode and the first interconnection structure, etc. can be referred to in the foregoing text and will not be described in detail here.

[0111] The following only describes the differences between the solar cell provided in the second aspect of the embodiment of the present invention and the solar cell provided in the first aspect of the embodiment of the present invention:

[0112] Specifically, in the solar cell provided in the second aspect of the embodiment of the present invention, the specific distribution position of the target line segment within the target surface can be determined based on the distribution of the intersection line segments between the cleavage surface of the battery body and the target surface, and the shape of the target surface, and is not specifically limited here. Among them, when the top angle of the target surface is a sharp angle, the target line segment can be a line segment connecting the diagonal endpoints of the target surface. When the top angle of the target surface is a chamfer with a smooth transition or the like, the target line segment can be a line segment connecting the endpoints of the diagonal extension line of the target surface.

[0113] In addition, in the actual application process, such as Figure 1 and Figure 3 As shown, the number of connection lines that intersect with the target line segment is defined as N3. Based on this, N3>N2. In this case, the target line segment only intersects with the extension line of at least one connection line, so that interconnection stress will not be generated at the intersection, ensuring that the interconnection stress formed along the extension direction of the target line segment can be reduced, that is, it is beneficial to shorten the length of the interconnection stress band formed along the cleavage surface direction, further reducing the risk of cracking problems caused by the long interconnection stress band after the solar cell is subjected to external force, and improving the structural reliability of the photovoltaic module formed based on the solar cell. Secondly, the number of connection lines N1 on the above-mentioned target surface is greater than or equal to the number of connection lines that intersect with the target line segment N3. Among them, when part of the first interconnection structure included in the solar cell is arranged at the edge of the target surface along the first direction, and its connection line does not intersect with the target line segment, N1 is greater than N3; or, when the four vertices of the target surface are vertices with large chamfers, there are some connection lines passing through the chamfers, and N1 may be greater than N3 at this time. When all first interconnect structures included in the solar cell are arranged in the middle of the target surface along the first direction, N1 is equal to N3; or, when the four vertices of the target surface have no chamfers or have small chamfers, all connecting lines do not pass through the chamfers, in which case N1 may be equal to N3.

[0114] Secondly, the distribution of the collecting electrodes between different first interconnect structures and the distribution between the first interconnect structure at the edge and the boundary of the battery body along the second direction can be determined according to the sizes of N1 and N2 in the actual application scenario, and no specific limitation is made here.

[0115] For example, Figure 1 and Figure 3As shown, the solar cell may include M slice battery units spaced apart along the second direction, where M is a positive integer greater than or equal to 1. In the same slice battery unit, the geometric centers of the two first interconnect structures 13 located at the edge along the second direction may be equal to the number of pairs of collector electrodes 12 between the edges of the slice battery unit. Each pair of collector electrodes 12 includes two collector electrodes 12 having the same polarity as the corresponding first interconnect structures 13 and adjacent to each other along the second direction. In this case, for the same slice battery unit, the geometric centers of the two first interconnection structures 13 located at the edge along the second direction are symmetrically arranged with the logarithm of the collector electrode 12 between the edges of the slice battery unit, which is conducive to interconnecting different slice battery units at the same starting position with automatic interconnection equipment such as a string welding machine, and preventing the first interconnection structure 13 provided on the battery body 11 from being misaligned due to the different starting positions corresponding to different slice battery units, thereby causing the carriers on the connection line corresponding to the first interconnection structure 13 that is not electrically connected to the intra-string interconnection to be unable to be exported through the intra-string interconnection, resulting in power loss, or causing the corresponding first interconnection structure 13 to become a load, resulting in reduced working efficiency of the solar cell, ensuring that the photovoltaic module formed by the solar cell provided by the embodiment of the present invention has good working performance. Of course, for the same slice battery unit, the geometric centers of the two first interconnection structures 13 located at the edge along the second direction can also be asymmetrically arranged with the logarithm of the collector electrode 12 between the edges of the slice battery unit to reduce manufacturing requirements.

[0116] Exemplarily, when the number of first interconnect structures located on the same connection line is an odd number, along the second direction, in the same slice battery unit, except for the first interconnect structure located in the middle and the other two first interconnect structures adjacent to the first interconnect structure located in the middle, the remaining first interconnect structures are edge first interconnect structures; the number of pairs of collector electrodes located between the geometric centers of the two adjacent edge first interconnect structures is symmetrically arranged about the central axis of the first interconnect structure located in the middle. Alternatively, when the number of first interconnect structures located on the same connection line is an even number, along the second direction, in the same slice battery unit, except for the first interconnect structure located in the middle, the remaining first interconnect structures are edge first interconnect structures; the number of pairs of collector electrodes 12 located between the geometric centers of the two adjacent edge first interconnect structures is symmetrically arranged about the central axis of the first interconnect structure located in the middle.

[0117] In the case of adopting the above technical solution, for the same slice battery unit, when the number of first interconnection structures contacted by the same connection line is an odd number, it is defined that along the second direction, in the same slice battery unit, except for the first interconnection structure located in the middle and the other two first interconnection structures adjacent to the first interconnection structure located in the middle, the remaining first interconnection structures are edge first interconnection structures. In the above case, when the number of collector electrodes located between the geometric centers of two adjacent edge first interconnection structures is symmetrically arranged about the central axis of the first interconnection structure located in the middle, it is beneficial to arrange different collector electrodes as evenly as possible between the geometric centers of the two adjacent first interconnection structures along the second direction, thereby facilitating the overlap of the corresponding collector electrodes and the first interconnection structure, maximizing current collection, and facilitating the debugging of the interconnection equipment that interconnects adjacent solar cells to prevent interconnection misalignment. In addition, when the number of pairs of first interconnection structures located on the same connecting line is an even number, along the second direction, in the same slice battery unit, except for a pair of first interconnection structures located in the middle, the remaining first interconnection structures are edge first interconnection structures; and the beneficial effects of the pairs of collecting electrodes located between the geometric centers of two adjacent edge first interconnection structures being symmetrically arranged about the central axis of the pair of first interconnection structures located in the middle can be referred to the previous text and will not be repeated here.

[0118] The following takes the case where the number of first interconnect structures in contact with the same connection line is 7 and 92 collector electrodes with the same polarity (91 pairs of collector electrodes) are provided in the same slice battery unit as an example. When the number of first interconnect structures in contact with the same connection line is an odd number, the number of pairs of collector electrodes located between the geometric centers of two adjacent first interconnect structures in the same slice battery unit along the second direction is explained: the different first interconnect structures corresponding to the same connection line are sorted from top to bottom. At this time, the first interconnect structure located in the middle is the fourth first interconnect structure. In the same slice battery unit, the first to third first interconnect structures, and the fifth to seventh first interconnect structures are edge first interconnect structures. In the above case, the number of pairs of collector electrodes between the geometric centers of the first and second first interconnect structures is 12 pairs. The number of pairs of collector electrodes between the geometric centers of the second first interconnect structure and the third first interconnect structure is 11 pairs. The number of pairs of collector electrodes between the geometric centers of the fifth first interconnect structure and the sixth first interconnect structure is 11 pairs. The number of pairs of collector electrodes between the geometric centers of the sixth first interconnection structure and the seventh first interconnection structure is 12. Along the second direction, the number of pairs of collector electrodes between the geometric centers of the first interconnection structures located at the edge (i.e., the first first interconnection structure and the seventh first interconnection structure) and the edge of the battery body is 11.

[0119] Below Figure 1 and Figure 3Taking the structure shown in the figure as an example, when the number of first interconnect structures contacting the same connection line is an even number, the number of pairs of collector electrodes located between the geometric centers of two adjacent first interconnect structures in the same slice battery unit along the second direction is explained: Figure 1 and Figure 3 As shown, the number of first interconnect structures 13 in contact with the same connection line is 6, and 27 collector electrodes 12 with the same polarity are arranged in the same slice battery unit (26 pairs of collector electrodes 12). The different first interconnect structures 13 corresponding to the same connection line are sorted from top to bottom. At this time, the middle pair of first interconnect structures 13 are the third first interconnect structure 13 and the fourth first interconnect structure 13. The first first interconnect structure 13, the second first interconnect structure 13, the fifth first interconnect structure 13 and the sixth first interconnect structure 13 are all edge first interconnect structures. Specifically, the number of pairs of collector electrodes 12 between the geometric centers of the first first interconnect structure 13 and the second first interconnect structure 13 is 4 pairs. The number of pairs of collector electrodes 12 between the geometric centers of the fifth first interconnect structure 13 and the sixth first interconnect structure 13 is also 4 pairs. Along the second direction, the number of pairs of collector electrodes 12 between the geometric centers of the first interconnect structures 13 located at the edge (i.e., the first first interconnect structure 13 and the sixth first interconnect structure 13) and the edge of the battery body 11 is 3 pairs.

[0120] In the actual application process, the number of first interconnect structures in contact with the same connection line is defined as a, the length of the part of the battery body corresponding to each slice battery unit along the second direction is b, and the spacing between adjacent collector electrodes with the same polarity is c. By dividing b by c, the number of pairs of collector electrodes d1 that can be set on the slice battery unit can be obtained. By dividing d1 by (a+1), the geometric center of two adjacent first interconnect structures corresponding to the same connection line and the number of pairs of collector electrodes d2 that can be set within the spacing between the geometric center of the first interconnect structure located at the edge along the second direction and the edge of the battery body can be obtained. Among them, if d2 is an integer, the geometric center spacings of different pairs of first interconnect structures in contact with the same connection line (each pair of first interconnect structures is two adjacent first interconnect structures corresponding to the same connection line) are equal. If d2 has a remainder, the geometric center spacing of at least one pair of first interconnect structures in contact with the same connection line is not equal to the geometric center spacings of the remaining pairs of first interconnect structures. Specifically, when d2 has a remainder, the actual number of pairs of collector electrodes located between the geometric centers of each pair of first interconnect structures can be set according to the symmetry rule described above, which will not be repeated here.

[0121] Exemplarily, in the case where the solar cell is a back contact cell and the solar cell includes at least two slice battery units spaced apart and distributed along the second direction, there is a cutting path between two adjacent slice battery units. Furthermore, the collector electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or, the first interconnection structures with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path, and / or, the bus electrodes with opposite polarities in the two adjacent slice battery units are symmetrically arranged about the cutting path. In this case, in the two adjacent slice battery units, at least one of the collector electrodes with opposite polarities, the first interconnection structure, and the bus electrode is symmetrically arranged about the cutting path, which facilitates the interconnection between the two, prevents misalignment, improves the interconnection yield, and reduces the difficulty of interconnection.

[0122] Exemplarily, in the case where the target line segment is a diagonal line of the target surface, among all the first interconnect structures intersecting the target line segment, at least two first interconnect structures are symmetrically distributed with the geometric center of the target surface as the center, and the polarities of the symmetrically distributed first interconnect structures can be the same. In this case, it is beneficial to make the distribution of the first interconnect structures intersecting the target line segment uniform, and it is beneficial to make the interconnection stress generated by the first interconnect structures on the target line segment after interconnection uniformly distributed with the geometric center of the target surface as the center, so as to prevent the interconnection stress in some areas on the target line segment from being concentrated due to uneven distribution of the first interconnect structures on the target line segment, resulting in a higher risk of the battery body breaking in the area, and further improve the structural reliability of the photovoltaic module formed based on the solar cell.

[0123] Or, if Figure 8 and Fig.10 As shown, when the target line segment is a diagonal line of the target surface, among all the first interconnect structures 13 intersecting the target line segment, at least two first interconnect structures 13 are symmetrically distributed around the geometric center of the target surface, and the polarities of the symmetrically distributed first interconnect structures 13 may also be opposite.

[0124] Exemplarily, when the solar cell includes two cell segments spaced apart along the second direction, N2 corresponding to the two cell segments are equal. Fig.10 As shown, in the same slice battery unit, the polarities of the two bus electrodes 16 located outside along the first direction are opposite. The polarities of the two oppositely arranged bus electrodes 16 located outside along the first direction and belonging to different slice battery units are opposite. In this case, it is beneficial to improve the symmetry between different first interconnection structures 13 located on the same target surface and with opposite polarities, and it is beneficial to reduce the difficulty of interconnecting adjacent solar cells through automatic interconnection equipment such as stringing machines.

[0125] Exemplarily, in the case where the solar cell includes two slice battery units spaced apart along the second direction, the N2 corresponding to the two slice battery units are not equal. In the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are the same. The polarities of the two oppositely arranged bus electrodes located on the outside along the first direction, which belong to different slice battery units, are opposite. In this case, another possible implementation method is provided for the solar cell provided in the embodiment of the present invention, thereby improving the applicability of the solar cell provided in the embodiment of the present invention in different application scenarios.

[0126] In a third aspect, an embodiment of the present invention provides a photovoltaic module, which includes a solar cell and an intra-string interconnection member that connects two adjacent solar cells in series. The solar cell is the solar cell provided by the first aspect and its various implementations, or the solar cell provided by the second aspect and its various implementations. Each intra-string interconnection member is in electrical contact with the corresponding first interconnection structure.

[0127] It is understood that, when the solar cell is a double-sided contact solar cell, the interconnection element in the string can be located on different sides of two adjacent solar cells. Alternatively, when the solar cell is a back contact solar cell, the interconnection element in the string is located on the same side of two adjacent solar cells.

[0128] The beneficial effects of the third aspect and its various implementations in the embodiments of the present invention may refer to the analysis of the beneficial effects in the first aspect and its various implementations, or may refer to the analysis of the beneficial effects in the second aspect and its various implementations, and will not be repeated here.

[0129] In a fourth aspect, an embodiment of the present invention provides another photovoltaic module, the photovoltaic module comprising: a solar cell, and an intra-string interconnection element for connecting two adjacent solar cells in series. Figure 2 and Figure 4As shown, the solar cell comprises: a battery body 11, a collector electrode 12 and a first interconnection structure 13. The battery body 11 has a first surface and a second surface opposite to each other. At least one of the first surface and the second surface is a target surface. The collector electrode 12 is arranged on the target surface. Different collector electrodes 12 located on the same target surface extend along the first direction and are spaced apart along the second direction. The first direction is perpendicular to the second direction. Each first interconnection structure 13 is electrically connected to at least one collector electrode 12. Each intra-string interconnection member is electrically in contact with a corresponding first interconnection structure 13. The number of first interconnection structures 13 intersecting with a target line segment located in the target surface is N2, and the target line segment is a line segment connecting the midpoint of the longer one of the two edges extending along the first direction and relatively distributed on the target surface and the vertex end point corresponding to the smaller one of the two edges. The number of intra-string interconnections located on the same target surface is N5. The number of first interconnection structures 13 intersecting with a vector line segment with an inclination angle of 45° is N4. The number of interconnections in a string that intersects the same vector line segment with an inclination angle of 45° is N6, wherein N2 < 1 / 2N5; or N6 > N4.

[0130] As a possible implementation scheme, N2 corresponding to at least two solar cells in a same photovoltaic module is equal.

[0131] The beneficial effects of the fourth aspect and its various implementations in the embodiments of the present invention can be analyzed with reference to the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0132] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0133] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents. Without departing from the scope of the present disclosure, a person skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A solar cell, characterized in that: include: A battery body, the battery body having a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; A collector electrode is arranged on the target surface; different collector electrodes located on the same target surface all extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; first interconnect structures, forming an array on the target surface; each of the first interconnect structures is electrically connected to at least one of the collector electrodes; at least partial areas of different first interconnect structures spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction; The number of the connecting lines located in the same target surface is N1, the number of the first interconnecting structures intersecting with the target line segments located in the target surface is N2, The target line segment is a line segment connecting the midpoint of the larger one of the two relatively distributed edges of the target surface extending along the first direction and the vertex endpoints corresponding to the smaller one of the two edges; or, the number of the connecting lines intersecting with the vector line segment with an inclination angle of 45° is N3, and the number of the first interconnecting structures intersecting with the same vector line segment with an inclination angle of 45° is N4, N3>N4.

2. The solar cell according to claim 1, characterized in that: The thickness of the battery body is H1, the thickness of the first interconnection structure is H2, and the ratio of H2 to H1 is greater than or equal to 0.005 and less than or equal to 0.1; And / or, the cross-sectional area of ​​the battery body is S1, the cross-sectional area of ​​the first interconnection structure is S2, and the ratio of S2 to S1 is greater than or equal to 0.0003 and less than or equal to 0.

02.

3. The solar cell according to claim 1, characterized in that N2 is equal to 0.

4. The solar cell according to claim 1, characterized in that The distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the center line of the solar cell along the second direction is D3; The distance between the geometric center of the first interconnect structure intersecting the target line segment or the vector line segment with an inclination angle of 45° and the edge of the solar cell along the second direction is D4; D3>D4.

5. The solar cell according to claim 1, characterized in that: The solar cell is a busbar-less solar cell; along the second direction, the target surface includes a middle area and an edge area; at least a portion of the collector electrode located in the middle area is in direct contact with the first interconnection structure.

6. The solar cell according to claim 5, characterized in that: The solar cell is a back-contact cell, and the collecting electrode includes a first collecting electrode and a second collecting electrode with opposite polarities, the first collecting electrode and the second collecting electrode are alternately spaced along the second direction, at least a portion of the first collecting electrode in the middle area is in direct contact with the first interconnection structure, and at least a portion of the second collecting electrode in the middle area is in direct contact with the first interconnection structure.

7. The solar cell according to claim 5, characterized in that: The solar cell further comprises a second interconnect structure arranged on the target surface; each of the second interconnect structures is electrically connected to at least one of the collector electrodes, and the size of the second interconnect structure is smaller than the size of the first interconnect structure; At least a portion of the second interconnection structure is located on the same straight line and is collinear with the connection line; Among all the collector electrodes located on the same target surface, some of the collector electrodes are in contact with the first interconnection structure, and the remaining collector electrodes are in contact with the second interconnection structure; wherein the collector electrodes in contact with the first interconnection structure are connection electrodes; Along the second direction, the distance between two adjacent connecting electrodes is D1; ​​at least one connecting electrode located in the middle area is in contact with multiple first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced apart along the first direction; the geometric center distance between two adjacent first interconnect structures in contact with the same connecting electrode is D2; D2 corresponding to at least one pair of the first interconnect structures is not equal to D1, and each pair of the first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode.

8. The solar cell according to claim 1, characterized in that The solar cell also includes a bus electrode arranged on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode with the same polarity as itself and is in contact with at least one of the first interconnection structures; different bus electrodes correspond one-to-one to different connecting lines.

9. The solar cell according to claim 8, characterized in that The bus electrode is a connecting electrode; wherein, Along the first direction, the distance between two adjacent connecting electrodes is D1; At least one of the connecting electrodes is in contact with a plurality of the first interconnect structures, and different first interconnect structures in contact with the same connecting electrode are spaced apart along the second direction; the distance between the geometric centers of two adjacent first interconnect structures in contact with the same connecting electrode is D2; D2 corresponding to at least one pair of the first interconnect structures is not equal to D1, and each pair of the first interconnect structures is two adjacent first interconnect structures in contact with the same connecting electrode.

10. The solar cell according to claim 8, characterized in that The collector electrode comprises a first collector electrode and a second collector electrode with opposite polarities, and the first collector electrode and the second collector electrode are alternately spaced and distributed along the second direction; the bus electrode comprises a first bus electrode and a second bus electrode with opposite polarities, and the first bus electrode and the second bus electrode are alternately spaced and distributed along the first direction; The bus electrode and the collector electrode having opposite polarities are insulated from each other.

11. The solar cell according to claim 9, characterized in that: A ratio of D2 to D1 corresponding to at least one pair of the first interconnect structures is greater than or equal to 1.06 and less than or equal to 1.

16.

12. A solar cell, characterized in that: include: A battery body, the battery body having a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; A collector electrode is arranged on the target surface; different collector electrodes located on the same target surface all extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; first interconnect structures, forming an array on the target surface; each of the first interconnect structures is electrically connected to at least one of the collector electrodes; at least partial areas of different first interconnect structures spaced apart along the second direction are located on the same connection line, and different connection lines are spaced apart along the first direction; The number of the connecting lines located in the same target surface is N1, the number of the first interconnecting structures intersecting with the target line segments located in the target surface is N2, N1>N2, the target line segments are diagonals of the target surface, and intersect with each of the connecting lines.

13. The solar cell according to claim 12, characterized in that: The solar cell comprises at least two slice battery units spaced apart and distributed along the second direction, and a cutting path is provided between two adjacent slice battery units; Wherein, the collector electrodes with opposite polarities in two adjacent slice battery units are symmetrically arranged about the cutting path; And / or, the first interconnection structures with opposite polarities in two adjacent sliced ​​battery units are symmetrically arranged about the cutting path; And / or, the solar cell also includes a bus electrode arranged on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode with the same polarity as itself and is in contact with at least one of the first interconnection structures; different bus electrodes correspond one-to-one to different connecting lines; the bus electrodes with opposite polarities in two adjacent slice battery units are symmetrically arranged about the cutting path.

14. The solar cell according to claim 12, characterized in that: The solar cell includes M slice battery units spaced apart along the second direction, where M is a positive integer greater than or equal to 1; in the same slice battery unit, the geometric centers of the two first interconnect structures located at the edge along the second direction are respectively equal to the number of pairs of the collecting electrodes between the edges of the slice battery unit; each pair of the collecting electrodes includes two collecting electrodes having the same polarity as the corresponding first interconnect structures and adjacent to each other along the second direction.

15. The solar cell according to claim 12, characterized in that: The solar cell further comprises a bus electrode disposed on the target surface; different bus electrodes located on the same target surface extend along the second direction and are spaced apart along the first direction; each bus electrode is electrically connected to the collector electrode having the same polarity as itself and is in contact with at least one of the first interconnection structures; different bus electrodes correspond to different connection lines one by one; The collecting electrode includes a first collecting electrode and a second collecting electrode with opposite polarities, and the first collecting electrode and the second collecting electrode are alternately spaced along the second direction; the bus electrode includes a first bus electrode and a second bus electrode with opposite polarities, and the first bus electrode and the second bus electrode are alternately spaced along the first direction; the bus electrode and the collecting electrode with opposite polarities are insulated from each other.

16. The solar cell according to claim 15, characterized in that: When the polarities of the two bus electrodes located outside along the first direction are opposite, among all the first interconnect structures intersecting the target line segment, at least two of the first interconnect structures are equidistant from the midline of the target surface along the second direction and have the same polarity.

17. The solar cell according to claim 15, characterized in that In the case where the solar cell includes two slice battery units spaced apart along the second direction, N2 corresponding to the two slice battery units are equal; in the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are opposite; the polarities of the two oppositely arranged bus electrodes located on the outside along the first direction and belonging to different slice battery units are opposite; Or, in the case where the solar cell includes two slice battery units spaced apart along the second direction, N2 corresponding to the two slice battery units are not equal; in the same slice battery unit, the polarities of the two bus electrodes located on the outside along the first direction are the same; the polarities of the two bus electrodes located on the outside along the first direction that belong to different slice battery units are opposite.

18. A photovoltaic module, characterized in that: include: A solar cell as claimed in any one of claims 1 to 11; or a solar cell as claimed in any one of claims 12 to 17.

19. A photovoltaic module, characterized in that: The photovoltaic module comprises: a solar cell, and an intra-string interconnector for connecting two adjacent solar cells in series; The solar cell comprises: a cell body, a collector electrode and a first interconnection structure; the cell body has a first surface and a second surface opposite to each other; at least one of the first surface and the second surface is a target surface; the collector electrode is arranged on the target surface; different collector electrodes located on the same target surface extend along a first direction and are spaced apart along a second direction; the first direction is perpendicular to the second direction; each first interconnection structure is electrically connected to at least one collector electrode; each intra-string interconnection member is electrically in contact with a corresponding first interconnection structure; the number of the first interconnection structures intersecting with a target line segment located in the target surface is N2, the target line segment being a line segment connecting a midpoint of the longer one of two edges of the target surface extending along the first direction and being relatively distributed and a vertex end point corresponding to the smaller one of the two edges; the number of intra-string interconnections located on the same target surface is N5; the number of the first interconnection structures intersecting with a vector line segment with an inclination angle of 45° is N4; the number of intra-string interconnections intersecting with the same vector line segment with an inclination angle of 45° is N6; Among them, N2<1 / 2N5; or, N6>N4.

20. The photovoltaic module according to claim 19, characterized in that: N2 corresponding to at least two solar cells in the same photovoltaic module is equal.

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