Solar cell and photovoltaic module

Abstract

A solar cell includes a cell substrate, a plurality of collector electrodes, a plurality of bus electrode segments, and a plurality of columns of interconnects. The battery substrate has a target surface. The current collection electrodes are arranged on the target surface, extend in the first direction and are distributed at intervals in the second direction intersecting with the first direction. The bus electrode section is located on the target surface and extends in the second direction. And each row of interconnection parts extend along a second direction, and the interconnection parts are arranged on the current collection electrodes. The bus electrode section extends in the second direction and is located in the upper end edge area and / or the lower end edge area of the target surface. On the target surface, the number of the bus electrode sections is smaller than two times of the column number of the interconnection parts, and / or the length of at least one bus electrode section is smaller than or equal to 5.3 mm, and / or the weighted average width of at least one bus electrode section is smaller than or equal to 0.29 mm. And by reducing the number of the bus electrode sections, the current collection electrode can collect current carriers to the maximum extent, and the conversion efficiency of the battery is improved. The utility model also provides a photovoltaic module comprising the solar cell.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and more specifically, to a solar cell and a photovoltaic module including the solar cell. Background Art

[0002] During the production process of solar cells, it is necessary to print a plurality of fine grids arranged along a first direction on the cell substrate, so as to collect the current generated on the surface of the cell through the plurality of fine grids. In addition, the cell substrate is provided with a plurality of main grids along a second direction intersecting the first direction, so as to collect the current collected by the fine grids through the main grids. Existing solar cells with main grids are provided with N fine grid lines and P fine grid lines to collect current, and the N main grid is provided to collect the current (electrons) collected by the N fine grid lines, and the P main grid is provided to collect the current (holes) collected by the P fine grid lines. For back-contact solar cells, the N fine grid lines need to be disconnected at the position where the P main grid extends to avoid the P main grid, and the P fine grid lines need to be disconnected at the position where the N main grid extends to avoid the N main grid, so that the disconnected part carriers of the P fine grid lines and the N fine grid lines cannot be collected, thereby limiting the conversion efficiency of the battery. Utility Model Content

[0003] In view of this, the present application provides a solar cell, which retains part of the main grid (bus electrode segment) at the end of the cell substrate, so as to maximize the collection of carriers and improve the conversion efficiency of the cell.

[0004] A solar cell comprises a cell substrate, a plurality of collector electrodes, a plurality of busbar electrode segments and a plurality of interconnection columns.

[0005] The battery substrate comprises a first surface and a second surface opposite to each other, wherein at least one of the first surface and the second surface is a target surface; a plurality of collector electrodes are located on the target surface and extend along a first direction, the plurality of collector electrodes are spaced apart and distributed along a second direction, and the first direction intersects the second direction; each column of interconnection portions extends along the second direction and comprises a plurality of interconnection portions spaced apart from each other, and the interconnection portions are arranged on the collector electrodes;

[0006] Along the second direction, the upper end of the battery substrate has an upper edge region, and the lower end has a lower edge region, and the upper edge region is spaced from the lower edge region; the bus electrode segment extends along the second direction and is aligned with a row of interconnection portions, and is located in the upper edge region and / or the lower edge region of the target surface;

[0007] On each target surface, the number of busbar segments is less than twice the number of columns of the interconnection portions; and / or,

[0008] The length of at least one of the bus electrode segments along the second direction is less than or equal to 5.3 mm, and / or

[0009] A weighted average width of at least one of the bus electrode segments along the first direction is less than or equal to 0.29 mm.

[0010] The present application arranges and designs the electrode patterns on the surface of the solar cell. Compared with the related art in which the number of busbar segments is twice that of the interconnection portion, the length is longer, and the width is larger, the number of busbar segments in the present application is smaller, and / or the length of the busbar segments is shorter, and / or the width of the busbar segments is narrower, thereby reducing the power loss caused by the current passing through the busbar segments; reducing the area of ​​the cell covered by the metal (busbar segments), and improving the open circuit voltage of the cell; and reducing the amount of conductive paste required for the busbar segments, thereby reducing the manufacturing cost of the cell. In addition, since the number and / or length of the busbar segments are reduced, more collector electrodes do not need to be disconnected to avoid the busbar segments, so that the collector electrodes can collect more carriers and improve the conversion efficiency of the cell.

[0011] In the embodiment of the present application, the volume of at least one of the busbar segments is less than 0.0081 cubic millimeters. At this time, the volume of the busbar segment can be controlled to flexibly adjust one or more variables of length, width, and thickness to achieve the purpose of reducing power loss, material loss, and improving open circuit voltage and battery efficiency.

[0012] As a possible implementation manner, on the target surface, the number of the busbar segments is equal to the number of columns of the interconnection portions;

[0013] As a possible implementation manner, the number of the bus electrode segments is 16-32.

[0014] As a possible implementation, at least one column of interconnection portions extends from one end of the bus electrode segment away from the first edge of the battery substrate to the outermost collector electrode close to the second edge of the battery substrate; the first edge and the second edge are opposite to each other along the second direction.

[0015] As a possible implementation manner, two ends of at least one column of interconnection portions are respectively connected to the bus electrode segments.

[0016] As a possible implementation manner, along the first direction, the plurality of bus electrode segments are alternately located in the upper edge region and the lower edge region of the same target surface.

[0017] As a possible implementation manner, the plurality of bus electrode segments are located at the upper edge region of one target surface and the lower edge region of another target surface, and each of the bus electrode segments is electrically connected to the collector electrode of the same polarity.

[0018] For back-contact cells, the target surface is single-sided, and the bus electrode segments are alternately located in the upper edge area and the lower edge area of ​​the same target surface. For double-sided electrode cells, the target surface is double-sided, and multiple bus electrode segments are located in the upper edge area of ​​one target surface and the lower edge area of ​​another target surface.

[0019] As a possible implementation manner, the interconnection portion is a thickened section provided on the collector electrode; or the interconnection portion is a portion on the collector electrode used for electrical connection with an interconnection member.

[0020] In the embodiment of the present application, along the second direction, the length of at least one of the bus electrode segments is less than or equal to 4 mm; as a possible implementation manner,

[0021] Along the second direction, a ratio between the length of at least one of the bus electrode segments and the length of the battery substrate is less than or equal to 5.5%;

[0022] As a possible implementation manner, along the first direction, a weighted average width of at least one of the bus electrode segments is less than or equal to 200 μm;

[0023] As a possible implementation manner, the thickness of at least one of the bus electrode segments is less than or equal to 8.5 μm;

[0024] Along the direction close to the edge of the battery substrate, the width of at least one bus electrode segment gradually decreases;

[0025] As a possible implementation, the bus electrode segment has a shape of a trapezoid, a triangle, a rectangle, a line or a U-shape;

[0026] As a possible implementation, the lengths of the busbar segments are the same or different.

[0027] As a possible implementation, the widths of the busbar segments are the same or different.

[0028] As a possible implementation method, the thickness of each busbar electrode segment is consistent.

[0029] As a possible implementation, one end of the bus electrode segment is electrically connected to an interconnection portion, and the bus electrode segment extends from the interconnection portion along the second direction to an upper edge or a lower edge of the battery substrate; the interconnection portion is wider than the bus electrode segment.

[0030] As a possible implementation manner, the collector electrode located between the upper edge region and the lower edge region is a continuous collector electrode;

[0031] As a possible implementation manner, the target surface is a single surface, and at least part of the collector electrodes located in the upper edge region and the lower edge region are continuous collector electrodes;

[0032] As a possible implementation manner, the target surface is double-sided, and at least a part of the collector electrode located in one of the upper edge region and the lower edge region is a continuous collector electrode.

[0033] In a second aspect, the present application provides a photovoltaic assembly, comprising at least two solar cells as described above, wherein the at least two solar cells are connected in series via an interconnection member, and each of the interconnection members is electrically connected to a column of the interconnection portions.

[0034] As a possible implementation, the interconnection member extends beyond a corresponding column of the interconnection portions.

[0035] As a possible implementation manner, an end portion of the interconnection member at least partially overlaps with the bus electrode segment.

[0036] The provision of the interconnector not only realizes the electrical connection of adjacent battery substrates, but also realizes the physical connection of adjacent battery substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of a cell substrate of a solar cell according to Embodiment 1 of the present application.

[0038] Figure 2 A graphical representation of the target surface of a solar cell.

[0039] Figure 3 is a graphical representation of a photovoltaic module comprising two solar cells.

[0040] Figure 4 is a graphical representation of a photovoltaic module comprising three solar cells.

[0041] Figure 5 This is a graphical schematic diagram of a target surface of a solar cell according to the second embodiment of the present application.

[0042] Figure 6 for Figure 5 Graphical schematic of another target surface of a solar cell.

[0043] Description of main component symbols:

[0044] Solar cell 100, 400

[0045] Battery substrate 10

[0046] First cell substrates 10A, 10C

[0047] Second cell substrates 10B, 10D

[0048] Collecting electrode 20

[0049] Busbar segment 30

[0050] First surface 11

[0051] Second surface 13

[0052] Interconnect 50

[0053] Photovoltaic modules 200, 300

[0054] The first type of current collecting electrode 20A

[0055] The second type of current collecting electrode 20B

[0056] The first type of busbar segment 30A

[0057] The second type of busbar segment 30B

[0058] Internet Department 23 DETAILED DESCRIPTION

[0059] The present application provides a solar cell that is beneficial to improving conversion efficiency. Figure 1 and Figure 2 The solar cell 100 of the embodiment of the present application includes a cell substrate 10 , a plurality of collector electrodes 20 disposed on the cell substrate 10 , a plurality of bus electrode segments 30 , and a plurality of columns of interconnection portions 23 .

[0060] In the embodiment of the present application, the battery substrate 10 is a silicon substrate, and some functional layers are formed on the surface of the silicon substrate. Figure 1 As shown, the battery substrate 10 is in the shape of a thin plate, including a first surface 11 and a second surface (not shown) opposite to each other, one of the first surface 11 and the second surface is a light-facing surface, and the other is a backlight surface. At least one of the first surface 11 and the second surface is a target surface. For a back-contact battery, the target surface is a single surface, and for a bifacial battery, the target surface is a double surface and includes the first surface 11 and the second surface. The collector electrode 20 and the bus electrode segment 30 are arranged on the target surface.

[0061] like Figure 2 As shown, the collector electrode 20 extends in a linear shape along the first direction, and a plurality of collector electrodes 20 are spaced apart along the second direction. The first direction intersects the second direction. Preferably, the first direction is perpendicular to the second direction. The collector electrode 20 can collect the current generated by the battery substrate 10 after being illuminated. Each column of interconnection portions 23 extends along the second direction and includes a plurality of interconnection portions 23 spaced apart from each other, and the interconnection portions 23 are provided on the collector electrode 20. The bus electrode segment 30 can collect the current collected by the collector electrode 20.

[0062] The battery substrate 10 has an upper edge region at the upper end along the second direction and a lower edge region at the lower end, and the upper edge region is spaced from the lower edge region. The bus electrode segment 30 extends along the second direction and is electrically connected to the collector electrode of the same polarity. The bus electrode segment 30 is located in the upper edge region and / or the lower edge region of the target surface. In some embodiments, the bus electrode segment 30 is located in the upper edge region and the lower edge region of the same target surface. In other embodiments, a portion of the bus electrode segment 30 is located in the upper edge region of one target surface, and another portion of the bus electrode segment 30 is located in the lower edge region of another target surface. The bus electrode segment 30 located in the upper edge region is of the same polarity. The bus electrode segment 30 located in the lower edge region is of the same polarity, and has an opposite polarity to the bus electrode segment 30 located in the upper edge region.

[0063] In some embodiments, on the target surface, the number of bus electrode segments 30 is less than twice the number of columns of interconnection portions 23. For example, if the number of columns of interconnection portions 23 is N, the number of bus electrode segments 30 is less than 2N. That is, in the present application, not both ends of each column of interconnection portions 23 are connected to bus electrode segments 30, and at least one end of at least some interconnection portions 23 is connected to a bus electrode segment.

[0064] In some embodiments, the length of at least one bus electrode segment 30 is less than or equal to 5.3 mm. In the present application, the length of the bus electrode segment 30 refers to the length of the bus electrode segment 30 extending along the second direction. For example, the length of the bus electrode segment 30 can be 5.3 mm, 5.2 mm, 5.0 mm, 4.5 mm, 4.2 mm, 4.0 mm, 3.8 mm, 3.5 mm, 3.3 mm, 3.0 mm, 2.8 mm, 2.5 mm, 2.0 mm, 1.8 mm, 1.6 mm, 1.3 mm, 1 mm, etc.

[0065] In some embodiments, the weighted average width of at least one bus electrode segment 30 is less than or equal to 0.29 mm. In the present application, the width of the bus electrode segment 30 refers to the width of the bus electrode segment 30 extending along the first direction. Along the first direction, when the width of the bus electrode segment 30 is variable, the weighted average width of the bus electrode segment 30 is the weighted average of the multiple widths of the bus electrode segment 30 measured at multiple positions along the second direction. For example, the weighted average width of the bus electrode segment 30 can be 0.29 mm, 0.28 mm, 0.27 mm, 0.25 mm, 0.23 mm, 0.20 mm, 0.18 mm, 0.15 mm, etc.

[0066] By laying out and designing the electrode patterns on the surface of the solar cell, compared with the situation in the related art where the number of busbar segments is twice that of the interconnection portion, the length is longer, and the width is larger, the number of busbar segments 30 in the present application is smaller, and / or the length of the busbar segments 30 is shorter, and / or the width of the busbar segments 30 is narrower, thereby reducing the power loss caused by the current passing through the busbar segments 30; reducing the area of ​​the metal (busbar segment) covering the battery sheet, and improving the open circuit voltage of the battery; and reducing the amount of conductive paste required for the busbar segments 30, thereby reducing the manufacturing cost of the battery. In addition, since the number and / or length of the busbar segments 30 are reduced, more collector electrodes 20 do not need to be disconnected to avoid the busbar segments 30, so that the collector electrodes 20 can collect more carriers and improve the conversion efficiency of the battery.

[0067] In some embodiments, the volume of at least one busbar segment 30 is less than or equal to 0.0081 cubic millimeters. For example, the volume of the busbar segment 30 may be 0.0081 mm 3 、0.0078mm 3 、0.0075mm 3 、0.007mm 3 、0.0065mm 3 、0.006mm 3 、0.0055mm 3 、0.005mm 3 、0.0045mm 3 、0.004mm 3 、0.0035mm 3 、0.003mm 3 , 0.0025mm 3 The volume of the busbar electrode segment 30 can be controlled to flexibly adjust one or more variables of length, width, thickness to achieve the purpose of reducing power loss, material loss, and improving open circuit voltage and battery efficiency.

[0068] In some embodiments, such as Figure 2 As shown, on the target surface, one column of interconnection 23 is provided corresponding to one bus electrode segment 30, and the number of bus electrode segments 30 is equal to the number of columns of interconnection 23. At this time, the number of bus electrode segments 30 is minimal, which can further improve the conversion efficiency and open circuit voltage of the solar cell and reduce the cost.

[0069] In order to ensure the better performance of the solar cell, combined with the comprehensive consideration of factors such as the collection of carriers, the blocking of light, and the amount of slurry used, on a target surface, the interconnection 23 can be set to 16-32 columns, and the number of corresponding busbar segments 30 can be set to 16-32. For example, the interconnection 23 can be set to 16 columns, 17 columns, 18 columns, 19 columns, 20 columns, 21 columns, 22 columns, 23 columns, 24 columns, 25 columns, 26 columns, 27 columns, 28 columns, 29 columns, 30 columns, 31 columns, and 32 columns. In this way, by selecting the appropriate number of columns of the interconnection 23, the solar cell can have better comprehensive performance.

[0070] In some embodiments, such as Figure 2 As shown, at least one column of interconnection parts 23 extends from one end of the bus electrode segment 30 away from the first edge of the battery substrate 10 to the outermost collector electrode 20 close to the second edge of the battery substrate 10; the first edge and the second edge are opposite to each other along the second direction, and are the upper edge and the lower edge of each other in the second direction. For example, the interconnection part 23 extends from the bus electrode segment 30 located in the upper edge area to the outermost collector electrode 20 at the lower edge of the battery substrate 10, or the interconnection part 23 extends from the bus electrode segment 30 located in the lower edge area of ​​the battery substrate 10 to the outermost collector electrode 20 at the upper edge of the battery substrate 10. In this case, the interconnection part is provided with a bus electrode segment only at one end and no bus electrode segment at the other end, which can reduce the interruption of the opposite collector electrode, thereby improving the current collection, solar cell efficiency and open circuit voltage and reducing the cost.

[0071] In some embodiments, both ends of at least one column of interconnection 23 are respectively connected to the bus electrode segment 30. It can be that both ends of some columns of interconnection 23 are respectively connected to the bus electrode segment 30. Both ends of some columns of interconnection 23 are connected to the bus electrode segment 30, and only one end of other columns of interconnection 23 is connected to the bus electrode segment 30; in this case, the length and width of the bus electrode segment 30 are not limited. It can also be that both ends of all columns of interconnection 23 are connected to the bus electrode segment 30, in which case the length of the bus electrode segment 30 is less than or equal to 5.3 mm, and / or the width of the bus electrode segment 30 is less than or equal to 0.29 mm. In this way, although the number of bus electrode segments 30 is not the least, the conversion efficiency and open circuit voltage of the solar cell can be controlled and the cost can be reduced by controlling the length and width of the bus electrode segment 30.

[0072] In some embodiments, along the first direction, a plurality of busbar segments 30 are alternately located at the upper edge region and the lower edge region of the same target surface. In this way, the number of busbar segments 30 is minimized, which can further improve the battery efficiency. Figures 2 to 4As shown, at this time, the solar cell 100 is a back contact cell, the target surface is a single surface, and is the backlight surface. For example, six busbar segments 30 are arranged on the solar cell 100, and along the first direction from left to right, the first, third, and fifth busbar segments 30 are located in the upper edge region and are all N-type busbar segments, and the second, fourth, and sixth busbar segments 30 are located in the lower edge region and are all P-type busbar segments.

[0073] Combined with reference Figure 2 and Figure 3 , the plurality of collector electrodes 20 include a plurality of first-type collector electrodes 20A and a plurality of second-type collector electrodes 20B with opposite polarities, and the first-type collector electrodes 20A and the second-type collector electrodes 20B are electrically insulated. The first-type collector electrodes 20A and the second-type collector electrodes 20B are mutually N-type fine grid lines and P-type fine grid lines. That is, when the first-type collector electrode 20A is an N-type fine grid line, the second-type collector electrode 20B is a P-type fine grid line; when the first-type collector electrode 20A is a P-type fine grid line, the second-type collector electrode 20B is an N-type fine grid line. In the embodiment of the present application, the plurality of first-type collector electrodes 20A and the plurality of second-type collector electrodes 20B are alternately arranged along the second direction. Correspondingly, the plurality of bus electrode segments 30 include a first-type bus electrode segment 30A and a second-type bus electrode segment 30B. Along the first direction, the first-type bus electrode segment 30A and the second-type bus electrode segment 30B are alternately located in the upper edge region and the lower edge region. Each bus electrode segment 30 is electrically connected to a corresponding collector electrode 20 of the same polarity along its extension path, and is electrically insulated from a collector electrode 20 of the opposite polarity. The first type of bus electrode segment 30A is electrically connected to the first type of collector electrode 20A to collect the current collected by the first type of collector electrode 20A. The second type of bus electrode segment 30B is electrically connected to the second type of collector electrode 20B to collect the current collected by the second type of collector electrode 20B.

[0074] like Figure 2 As shown, in the upper edge region of the first battery substrate 10A, the region where the first type bus electrode segment 30A passes through, the second type collector electrode 20B is intermittently disconnected to avoid the first type bus electrode segment 30A, and the second type collector electrode 20B in other regions is a continuous collector electrode. In the lower edge region of the first battery substrate 10A, the region where the second type bus electrode segment 30B passes through, the first type collector electrode 20A is intermittently disconnected to avoid the second type bus electrode segment 30B, and the first type collector electrode 20A in other regions is a continuous collector electrode.

[0075] In the upper edge region of the first battery substrate 10A, the first type of collector electrode 20A electrically connected to the first type of bus electrode segment 30A is a continuous collector electrode; in the lower edge region of the first battery substrate 10A, the second type of collector electrode 20B electrically connected to the second type of bus electrode segment 30B is a continuous collector electrode. In this way, the collector electrode 20 between the upper edge region and the lower edge region is a continuous collector electrode. Part of the collector electrode 20 located in the upper edge region is a continuous collector electrode, and part of the collector electrode 20 located in the lower edge region is a continuous collector electrode. With such a design, the number and proportion of continuous collector electrodes in the upper edge region and the lower edge region can be increased, thereby improving current collection and improving battery efficiency.

[0076] In some embodiments, a plurality of busbar segments are located at the upper edge region of one target surface and the lower edge region of another target surface, and each busbar segment is electrically connected to a collector electrode of the same polarity. In this way, the number of busbar segments can be reduced as much as possible, thereby improving battery efficiency. Figure 5 and Figure 6 , the solar cell 400 is a double-sided electrode cell, and the target surface includes a first surface 11 and a second surface 13 opposite to each other, and the first surface 11 and the second surface 13 are mutually light-facing and backlight-facing. In the solar cell 400, the collector electrodes 20 with opposite polarities are respectively located on the first surface 11 and the second surface 13 opposite to each other, and the corresponding bus electrode segments 30 with opposite polarities are respectively located on the first surface 11 and the second surface 13 opposite to each other. The bus electrode segments 30 on the first surface 11 are located at the upper edge region of the solar cell 400, and the bus electrode segments 30 on the second surface 13 are located at the lower edge region of the solar cell 400. Figure 5 and Figure 6 As shown, the bus electrode segment 30 is U-shaped.

[0077] like Figure 5 and Figure 6 As shown, the multiple collector electrodes 20 on each target surface (each of the first surface 11 and the second surface 13) extend in the first direction in the shape of thin lines, and the multiple collector electrodes 20 are spaced apart along the second direction. The collector electrode 20 located in one of the upper edge region and the lower edge region is at least partially a continuous collector electrode. Figure 5 and Figure 6 As shown, on the first surface 11, the collecting electrodes 20 located in the upper edge area are all discontinuous collecting electrodes, and the collecting electrodes 20 in the lower edge area and the middle area are all continuous collecting electrodes; on the second surface 13, the collecting electrodes 20 located in the lower edge area are all discontinuous collecting electrodes, and the collecting electrodes 20 in the upper edge area and the middle area are all continuous collecting electrodes.

[0078] like Figure 2As shown, optionally, the interconnection portion 23 is a thickened section provided on the collector electrode 20. Figure 3 As shown, the subsequent interconnection member 50 is electrically connected to the collector electrode through the interconnection portion 23. The interconnection portion 23 is thicker than the collector electrode 20, which can improve the welding reliability between the interconnection member and the interconnection portion.

[0079] Optionally, the interconnection portion 23 is a portion on the collector electrode 20 for electrical connection with the interconnection member, and is not thickened relative to the collector electrode 20 .

[0080] Furthermore, in some embodiments, along the second direction, the length of at least one bus electrode segment 30 is less than or equal to 4 mm. For example, the length of the bus electrode segment 30 may be 4.0 mm, 3.7 mm, 3.5 mm, 3.3 mm, 3.0 mm, 2.7 mm, 2.5 mm, 2.2 mm, 2.0 mm, 1.8 mm, 1.6 mm, 1.3 mm, 1.0 mm, 0.8 mm, etc.

[0081] In some embodiments, along the second direction, the ratio between the length of at least one bus electrode segment 30 and the length of the battery substrate 10 is less than or equal to 5.5%. At this time, the length of the bus electrode segment 30 is relatively small, which can further reduce the power loss caused by the current passing through the bus electrode segment 30, further reduce the amount of conductive paste required for the bus electrode segment 30, and further reduce the disconnection of the collector electrodes 20 of opposite polarity. In some embodiments, along the first direction, the width of at least one bus electrode segment 30 is less than or equal to 200μm. For example, the length of the bus electrode segment 30 can be 200μm, 180μm, 165μm, 150μm, 145μm, 130μm, 100μm, 90μm, 80μm, 75μm, 70μm, 65μm, 60μm, etc.

[0082] Along the first direction, the weighted average width of at least one bus electrode segment 30 is less than or equal to 200 μm. At this time, the width of the bus electrode segment 30 is further reduced, which can further reduce current loss, reduce costs, and improve battery efficiency. Exemplarily, the weighted average width of the bus electrode segment is 200 μm, 190 μm, 180 μm, 170 μm, 160 μm, 150 μm, 140 μm, 130 μm, 120 μm, 110 μm, 100 μm, 90 μm, 80 μm, etc.

[0083] In some embodiments, at least one bus electrode segment 30 has a thickness less than or equal to 8.5 μm. For example, the bus electrode segment 30 may have a thickness of 8.5 μm, 8.0 μm, 7.5 μm, 7.0 μm, 6.5 μm, 6.0 μm, 5.5 μm, 4.0 μm, 3.5 μm, 3.0 μm, 3.5 μm, etc.

[0084] In some embodiments, the width of at least one of the bus electrode segments gradually decreases along the direction close to the edge of the battery substrate. For example, whether it is the upper edge region or the lower edge region, the width of one or more bus electrode segments 30 gradually decreases. It should be understood that for the bus electrode segments in the upper edge region, the closer to the upper edge, the smaller the width. For the bus electrode segments in the lower edge region, the closer to the lower edge, the smaller the width. In this way, the relative constant width of the bus electrode segment 30 can save more conductive paste and meet the needs of converging current.

[0085] In some embodiments, the bus electrode segment 30 may be in a trapezoidal, triangular, rectangular, linear, or U-shaped shape.

[0086] In some embodiments, the lengths of the bus electrode segments 30 are the same or different; thus, the lengths of the bus electrode segments 30 can be flexibly adjusted as needed, for example, less than or equal to 5.3 mm, thereby reducing power loss, material loss, and improving open circuit voltage and battery efficiency.

[0087] In some embodiments, the widths of the bus electrode segments 30 are the same or different; thus, the widths of the bus electrode segments 30 can be flexibly adjusted as needed, for example, the weighted average width can be less than or equal to 0.29 mm, thereby reducing power loss, material loss, and improving open circuit voltage and battery efficiency.

[0088] In some embodiments, the thickness of each bus electrode segment 30 is consistent. In this way, the thickness of each bus electrode segment 30 is substantially uniform, for example, the thickness is less than or equal to 8.5 μm, thereby achieving the purpose of reducing power loss, material loss, and improving open circuit voltage and battery efficiency.

[0089] In some embodiments, one end of the bus electrode segment 30 is electrically connected to the interconnection portion 23, and the bus electrode segment 30 extends from the interconnection portion 23 along the second direction to the upper edge or the lower edge of the battery substrate 10; the interconnection portion 23 is wider than the bus electrode segment 30 and is used to electrically connect to the interconnection member. Since the interconnection portion 23 is relatively wide, it has a larger contact area with the interconnection member, thereby improving the welding pull-out force and improving the welding reliability; in addition, it can also reduce the solder bypassing the interconnection portion to enter the silicon substrate and corrode the silicon substrate.

[0090] The present application also provides a photovoltaic module, which includes at least two photovoltaic modules of the above-mentioned solar cells 100, at least two solar cells are connected in series through an interconnection member, and each of the interconnection members is electrically connected to a column of the interconnection parts. The interconnection members and the interconnection parts can be electrically connected by infrared welding process, or by conductive adhesive bonding, or by low temperature welding process.

[0091] In some embodiments, the interconnection member extends beyond the corresponding column of interconnection portions, thereby ensuring effective welding between the interconnection member and the interconnection portions, and avoiding reliability problems caused by less overlap between the interconnection member and the interconnection portions of the terminal.

[0092] In some embodiments, the end of the interconnection member at least partially overlaps with the busbar electrode segment, so that a certain clamping position can be reserved for the end of the interconnection member to facilitate processing.

[0093] like Figure 3 As shown, the two bus electrode segments 30 at the upper edge region of the first solar cell 10A and the lower edge region of the second solar cell 10B are aligned with each other along the second direction and have opposite polarities, and the two bus electrode segments 30 located at the lower edge region of the first cell substrate 10A and the upper edge region of the second cell substrate 10B are aligned with each other along the second direction and have opposite polarities. The interconnector 50 connects the two bus electrode segments 30 located at the upper edge region of the first cell substrate 10A and the lower edge region of the second cell substrate 10B.

[0094] In the first battery 10A, the first type of bus electrode segment 30A is located at the upper edge region of the first battery substrate 10A, and the second type of bus electrode segment 30B is located at the lower edge region of the first battery substrate 10A. In the second battery substrate 10B, the second type of bus electrode segment 30B is located at the lower edge region of the second battery substrate 10B, and the first type of bus electrode segment 30A is located at the upper edge region of the first battery substrate 10A.

[0095] like Figure 3 As shown, the interconnector 50 is connected between the first cell 10A and the second cell 10B, specifically connecting the first type of busbar segment 30A of the first cell substrate 10A and the second type of busbar segment 30B of the second cell substrate 10B. In this way, in the two solar cells 100 arranged in sequence along the second direction, the first cell substrate 10A and the second cell substrate 10B are physically connected and electrically connected in series through the interconnector 50.

[0096] In addition, on the same battery substrate 10, on the extension path of the interconnection member 50 along the second direction, in order to avoid the interconnection member 50 being electrically connected to the collector electrode 20 of the opposite polarity of the bus electrode segment 30 connected to it, an insulating layer (not shown) can be provided on the collector electrode 20 of the opposite polarity of the bus electrode segment 30 connected to it on the extension path of the interconnection member 50, so that the interconnection member 50 is electrically insulated from the collector electrode 20 of the opposite polarity through the insulating layer.

[0097] The present application also provides a photovoltaic module including at least two of the above-mentioned solar cells 400 . Figure 5 and Figure 6Taking a photovoltaic module including two solar cells 400 spliced ​​along the second direction as an example, the photovoltaic module includes two cells 10, which are two cell substrates spliced ​​along the second direction, namely a first cell substrate 10C and a second cell substrate 10D. The two solar cells 100 are connected in series.

[0098] In the photovoltaic module, although not shown in the figure, at least part of the interconnection member (not shown in the figure) is connected between the bus electrode segment 30 (located in the upper edge region) of the first surface 11 of the first cell substrate 10C and the bus electrode segment 30 (located in the lower edge region) of the second surface 13 of the second cell substrate 10D. That is, the interconnection member connects the bus electrode segment 30 in the upper edge region of the first surface 11 of the first cell substrate 10C, then extends along the second direction on the first surface 11 to the lower edge of the first surface 11, then goes around to the second surface 13 of the second cell substrate 10D and continues to extend along the second direction, and finally connects the bus electrode segment 30 in the lower edge region of the second surface 13 of the second cell substrate 10D. And on the first cell substrate 10C, the interconnection member connects the collector electrode 20 on the first cell substrate 10C, and on the second cell substrate 10D, the interconnection member connects the collector electrode 20 of the same polarity as that on the second cell substrate 10D.

[0099] The present application is laid out and designed through the electrode pattern on the surface of the battery cell, so as to control the number of bus electrode segments 30 as small as possible, and / or the length of the bus electrode segment 30 is short, and / or the width of the bus electrode segment 30 is narrow, thereby reducing the power loss caused by the current passing through the bus electrode segment 30; reducing the area of ​​the battery cell covered by the metal (bus electrode segment 30), improving the open circuit voltage of the battery; and reducing the amount of conductive paste required for the bus electrode segment 30, reducing the manufacturing cost of the battery. In addition, since the number and / or length of the bus electrode segment 30 are reduced, more collector electrodes 20 do not need to be disconnected to avoid the bus electrode segment 30, so that the collector electrode 20 can maximize the collection of carriers and improve the conversion efficiency of the battery.

[0100] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A solar cell, characterized in that: It includes a battery substrate, a plurality of current collecting electrodes, a plurality of busbar electrode segments and a plurality of interconnection columns. The battery substrate comprises a first surface and a second surface opposite to each other, wherein at least one of the first surface and the second surface is a target surface; a plurality of collector electrodes are located on the target surface and extend along a first direction, the plurality of collector electrodes are spaced apart along a second direction, and the first direction intersects the second direction; each column of interconnection portions extends along the second direction and comprises a plurality of interconnection portions spaced apart from each other, and the interconnection portions are arranged on the collector electrodes; Along the second direction, the upper end of the battery substrate has an upper edge region, and the lower end has a lower edge region, and the upper edge region is spaced apart from the lower edge region; the bus electrode segment extends along the second direction and is electrically connected to a collector electrode of the same polarity, and is located in the upper edge region and / or the lower edge region of the target surface; On the target surface, the number of the busbar segments is less than twice the number of columns of the interconnection portions; and / or, The length of at least one of the bus electrode segments along the second direction is less than or equal to 5.3 mm, and / or A weighted average width of at least one of the bus electrode segments along the first direction is less than or equal to 0.29 mm.

2. The solar cell according to claim 1, characterized in that The volume of at least one of the bus electrode segments is less than or equal to 0.0081 cubic millimeters.

3. The solar cell according to claim 1, characterized in that On the target surface, the number of busbar segments is equal to the number of columns of the interconnection portions; and / or, On the target surface, the number of the busbar electrode segments is 16-32.

4. The solar cell according to claim 1, characterized in that At least one column of interconnection portions extends from one end of the busbar electrode segment away from a first edge of the battery substrate to an outermost collector electrode close to a second edge of the battery substrate; the first edge and the second edge are opposite to each other along the second direction.

5. The solar cell according to claim 1, characterized in that: Two ends of at least one column of interconnection parts are respectively connected to the bus electrode segments.

6. The solar cell according to claim 1, characterized in that Along the first direction, the plurality of bus electrode segments are alternately located in the upper edge region and the lower edge region of the same target surface. or, The plurality of bus electrode segments are located at the upper edge region of one target surface and the lower edge region of another target surface, and each of the bus electrode segments is electrically connected to the collector electrode of the same polarity.

7. The solar cell according to any one of claims 1 to 6, characterized in that The interconnection portion is a thickened section provided on the collector electrode, or the interconnection portion is a portion on the collector electrode used for electrical connection with an interconnection member.

8. The solar cell according to any one of claims 1 to 6, characterized in that Along the second direction, the length of at least one of the bus electrode segments is less than or equal to 4 mm; and / or, Along the second direction, the ratio between the length of at least one of the bus electrode segments and the length of the battery substrate is less than or equal to 5.5%; and / or, Along the first direction, the weighted average width of at least one of the bus electrode segments is less than or equal to 200 μm; and / or the thickness of at least one of the bus electrode segments is less than or equal to 8.5 μm; The width of at least one of the bus electrode segments gradually decreases along the direction close to the edge of the battery substrate; and / or the bus electrode segment is in a trapezoidal, triangular, rectangular, linear or U-shaped shape; and / or, The lengths of the busbar segments are the same or different, and / or, The widths of the busbar segments are the same or different, and / or, The thickness of each busbar segment is consistent; and / or, One end of the bus electrode segment is electrically connected to the interconnection portion, and the bus electrode segment extends from the interconnection portion along the second direction to the upper edge or the lower edge of the battery substrate; the interconnection portion is wider than the bus electrode segment.

9. The solar cell according to any one of claims 1 to 6, characterized in that: The current collecting electrode located between the upper edge region and the lower edge region is a continuous current collecting electrode; And / or, the target surface is a single surface, and the parts of the collector electrodes located in the upper edge region and the lower edge region are continuous collector electrodes; And / or, the target surface is double-sided, and at least part of the collector electrode located in one of the upper edge region and the lower edge region is a continuous collector electrode.

10. A photovoltaic module, characterized in that: The method comprises at least two solar cells according to any one of claims 1 to 9, wherein the at least two solar cells are connected in series via an interconnection member, and each of the interconnection members is electrically connected to a column of the interconnection portions.

11. The photovoltaic module according to claim 10, characterized in that: The interconnection member extends beyond a corresponding column of the interconnection portions, and / or An end portion of the interconnection member at least partially overlaps with the bus electrode segment.

Images