Solar cell, conductive back sheet and photovoltaic module

Abstract

The present application discloses a solar cell, a conductive backplane and a photovoltaic module, which relate to the technical field of solar cells, and aim to solve the problem that the size of the joint on the battery body is set unreasonably, resulting in a low connection strength between the battery cell and the interconnect or the conductive layer, which affects the quality of the solar cell. The solar cell includes a collector electrode formed on the battery body, and a plurality of collector electrodes extend along a first direction and are distributed at intervals along a second direction. A plurality of joints are arranged at intervals on the battery body, and the joints include a first joint and a second joint, and the size of the second joint is larger than the size of the first joint. The collector electrode includes a first collector electrode and a second collector electrode, the first collector electrode is electrically connected to the first joint, and the second collector electrode is electrically connected to the second joint, and the extension length of a single first collector electrode along the first direction is larger than the extension length of a single second collector electrode along the first direction.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a solar cell, a conductive backplane and a photovoltaic module. Background Art

[0002] 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.

[0003] In the prior art, the size of the joint on the battery body is not set reasonably, resulting in a low connection strength between the battery cell (ie, solar cell) and the interconnector or the conductive layer, which affects the quality of the solar cell. Summary of the invention

[0004] The purpose of the present application is to provide a solar cell, a conductive back sheet and a photovoltaic module, which are used to improve the connection strength between a cell sheet and an interconnector or a conductive layer to ensure the quality of the solar cell.

[0005] In order to achieve the above-mentioned objectives, in a first aspect, the present application provides a solar cell, the solar cell comprising: a battery body, a collecting electrode and a joint. The collecting electrode is formed on the battery body, and a plurality of collecting electrodes extend along a first direction and are spaced apart along a second direction, and the first direction is different from the second direction. A plurality of joints are spaced apart on the battery body, and each joint is electrically connected to at least one collecting electrode. The joint comprises a first joint and a second joint, and the size of the second joint is larger than the size of the first joint. The collecting electrode comprises a first collecting electrode and a second collecting electrode, the first collecting electrode is electrically connected to the first joint, the second collecting electrode is electrically connected to the second joint, and the extension length of a single first collecting electrode along the first direction is larger than the extension length of a single second collecting electrode along the first direction.

[0006] Compared with the prior art, in the solar cell provided by the present application, the size of the second joint is larger than the size of the first joint, and the second collector electrode is electrically connected to the second joint. At this time, the second joint can be used to increase the connection strength between the cell and the interconnection member (such as a welding strip) or the conductive layer. Because the size of the second joint is relatively large, the connection between the interconnection member or the conductive layer and the second joint is more firmly connected to ensure the quality of the solar cell. Further, it can also reduce or eliminate the situation that the interconnection member or the conductive layer is offset due to the small size of the second joint, improve the connection quality between the interconnection member or the conductive layer and the second collector electrode, and further improve the quality of the solar cell. Furthermore, the above-mentioned collector electrode can collect the carriers generated in the corresponding area of ​​the battery body, and the above-mentioned joint can be used to collect the carriers collected by the collector electrode and transmit them to the interconnection member or the conductive layer. Specifically, compared with the second joint, the first joint mainly bears the role of collecting carriers. When the extension length of the single first collector electrode electrically connected to the first joint along the first direction is greater than the extension length of the single second collector electrode along the first direction, the collection reliability of the first collector electrode can be enhanced.

[0007] In one implementation, along the second direction, the battery body has a first edge and a second edge opposite to each other, and the distance between the first edge and the second edge is L1. For a single second joint portion, along the second direction, the minimum distance between the first edge or the second edge of the battery body closest to the single second joint portion and the second joint portion is L2, and the ratio of L2 to L1 is greater than or equal to 1% and less than or equal to 50%.

[0008] In the case of adopting the above technical solution, combined with the above description, since the second joint is used to increase the connection strength between the battery cell and the interconnection or conductive layer, the position of the second joint cannot be too close to the middle position of the battery body, so as to ensure that when forming a component, at least part of the adjacent second joints are arranged in adjacent solar cells along the second direction. There is a certain distance between the two adjacent second joints, so as to avoid the connection effect between the second collector electrode and the interconnection or conductive layer being affected by the small force point caused by the close distance, so as to further ensure the quality of the solar cell. Furthermore, the position of the second joint cannot be too close to the first edge or the second edge of the battery body, so as to ensure the connection strength between the battery cell and the interconnection or conductive layer and reduce the impact on the current collection in the edge area of ​​the battery body, so as to ensure the efficiency of the solar cell.

[0009] In one implementation, along the second direction, the distance between any two second joining portions located on the same straight line is greater than 1 / 5 L1.

[0010] When the above technical solution is adopted, when the distance between the two relatively distributed second joints is greater than 1 / 5L1, it can not only ensure the connection strength between the battery cell and the interconnector or the conductive layer, but also make the connection between the interconnector or the conductive layer and the battery cell more firmly, so as to ensure the quality of the solar cell; at the same time, it can also reduce the impact on the current collection in the edge area of ​​the battery body, so as to ensure the efficiency of the solar cell.

[0011] In one implementation, for a single second joint, along the second direction, the minimum distance between the edge of the battery body closest to the single second joint and the second joint is L2. Along the second direction, the spacing between two adjacent first collector electrodes is L3, and the ratio of L2 to L3 is greater than or equal to 1.

[0012] In the case of adopting the above technical solution, combined with the above description, since the second joint is used to increase the connection strength between the battery cell and the interconnection or conductive layer, the position of the second joint cannot be too close to the edge of the battery body, so as to avoid the distribution of two adjacent second joints along the second direction of two adjacent solar cells when forming a component. The distance is too close, resulting in the concentration of force points and the inability to effectively enhance the connection tension between the battery cell and the interconnection or conductive layer, thereby affecting the connection effect. In addition, if the second joint is too close to the edge, it will lead to poor edge carrier collection, and the second joint is large in size, the edge of the battery cell is brittle, and the second joint is too close to the edge of the battery cell. The stress between the two may cause problems such as battery cell fragmentation.

[0013] In one implementation, the second collector electrode includes a first polarity second collector electrode and a second polarity second collector electrode, the first polarity second collector electrode extends along the first direction and is located on the same straight line and is sequentially spaced and distributed, and the second polarity second collector electrode extends along the first direction and is located on the same straight line and is sequentially spaced and distributed. Along the first direction, the first polarity second collector electrode and the second polarity second collector electrode are alternately distributed and are not on the same straight line.

[0014] In one implementation, along the second direction, the projection of at least one first polarity second collector electrode on the second polarity second collector electrode adjacent thereto is located within the second polarity second collector electrode. And / or, along the second direction, the projection of at least one first polarity second collector electrode on the second polarity second collector electrode adjacent thereto is tangent to an end of at least one second polarity second collector electrode close to the first polarity second collector electrode.

[0015] In the case of adopting the above technical solution, the first polarity second collector electrode and the second polarity second collector electrode can cover more areas on the battery body, so that the second collector electrode can collect more carriers, thereby improving the efficiency of the solar cell. Further, by adopting the above design, when the distance between two adjacent second joints along the first direction decreases, more second joints can be accommodated on the battery body. At this time, not only can the connection strength between the battery cell and the interconnect or the conductive layer be further improved, but also a denser carrier collection structure can be constructed, further improving the efficiency of the solar cell. In addition, since along the second direction, the projection of at least one first polarity second collector electrode on the second polarity second collector electrode adjacent to it is located within the second polarity second collector electrode. At this time, the carrier collection areas of the two polarities are butted together to avoid the appearance of dead zones caused by the same polarity carrier collection area being too large, so as to reduce the carrier collection loss of the other polarity.

[0016] In one implementation, when the solar cell includes at least two electrode units spaced apart along the second direction, there is a separation region extending along the first direction between two adjacent electrode units. Along the second direction, a plurality of second bonding portions located on one side of the separation region are located on the same straight line, and the extension direction of the straight line is consistent with the first direction.

[0017] In one implementation, along the second direction, the battery body has a first edge and a second edge opposite to each other, and the distance between the first edge and the second edge is L1; the distance between two second joining portions located on both sides of the same partition and opposite to each other is greater than 1 / 5L1.

[0018] When the above technical solution is adopted, when the distance between the two relatively distributed second joints is greater than 1 / 5L1, it can not only ensure the connection strength between the battery cell and the interconnector or the conductive layer, but also make the connection between the interconnector or the conductive layer and the battery cell more firmly, so as to ensure the quality of the solar cell; at the same time, it can also reduce the impact on the current collection in the edge area of ​​the battery body, so as to ensure the efficiency of the solar cell.

[0019] In one implementation, the first engaging portion includes at least two first engaging portions of different sizes.

[0020] In one implementation, the solar cell includes at least two electrode units spaced apart along the second direction, and a separation zone extending along the first direction is provided between two adjacent electrode units, wherein the first joint portion with the smallest size is located on at least one side of the separation zone, and the first joint portion with the smallest size is arranged adjacent to the separation zone. And / or, along the second direction, the battery body includes two opposite edges and a middle area between the two edges, and the first joint portion with the smallest size is arranged adjacent to at least one edge.

[0021] When the above technical solution is adopted, the solar cell includes three sizes of joints. With the cooperation of large and small joints, the connection tension can be adjusted, thereby adjusting the connection strength between different positions of the battery cell and the interconnection parts (such as welding strips) or the conductive layer; at the same time, it can also reduce the impact on the current collection of the battery body and meet the carrier collection requirements.

[0022] In a second aspect, the present application further provides a conductive backplane. The conductive backplane includes an insulating material layer, a plurality of windows are provided on the insulating material layer, a group of windows on the insulating material layer are arranged at intervals along a third direction, a group of windows includes a first window and a second window, and the size of the second window is larger than the size of the first window. The first window corresponds to the first joint portion in the solar cell described in the above technical solution, and the second window corresponds to the second joint portion in the solar cell described in the above technical solution.

[0023] When the above technical solution is adopted, in actual use, the solar cell is electrically connected to the metal conductive layer through the insulating material layer with a window. Since the size of the second window is larger than the size of the first window, the second window corresponds to the second joint of the solar cell, and the first window corresponds to the first joint of the solar cell. Since the size of the second joint is larger than the size of the first joint, the second collector electrode is the collector electrode electrically connected to the second joint. At this time, the second joint can be used to increase the connection strength between the second collector electrode and the interconnection member (such as a welding strip) or the conductive layer, so that the interconnection member or the conductive layer is more firmly connected to the second collector electrode, so as to ensure the quality of the solar cell.

[0024] In one implementation, the first window includes at least two first windows of different sizes.

[0025] In a third aspect, the present application also provides a photovoltaic module. The photovoltaic module includes: a conductive backplane and a solar cell group arranged on the conductive backplane; wherein the conductive backplane includes a metal conductive layer and an insulating material layer stacked in sequence, and the solar cell group includes a plurality of solar cells as described in the above technical solution; or, the solar cell group includes a plurality of sliced ​​cells divided from the solar cells described in the above technical solution. A plurality of windows are provided on the insulating material layer, and a plurality of solar cells as described in the above technical solution or the sliced ​​cells divided from the solar cells described in the above technical solution are electrically connected to the metal conductive layer through the insulating material layer with windows.

[0026] Compared with the prior art, the beneficial effects of the photovoltaic module provided in the present application are the same as the beneficial effects of the solar cell described in the first aspect, and will not be elaborated here.

[0027] In one implementation, the length of the window is greater than or equal to the length of the corresponding joint, and the length direction of the window and the length direction of the joint are both consistent with the first direction. And / or, the width of the window is greater than or equal to the width of the corresponding joint, and the width direction of the window and the width direction of the joint are both consistent with the second direction.

[0028] When the above technical solution is adopted, it is ensured that the joint portion can be smoothly electrically connected to the metal conductive layer through the window, thereby reducing the difficulty of assembly and the assembly error.

[0029] In one implementation, the photovoltaic module further includes: an insulating portion, the insulating portion covers at least a portion of the first collector electrode. Along the first direction, the insulating portion and the joint portion are alternately and spaced apart. And / or, along the second direction, the insulating portion and the joint portion are alternately and spaced apart.

[0030] When the above technical solution is adopted, during the actual assembly process, when the joint is connected to the metal conductive layer through the adhesive material, the insulating part can reduce or avoid the situation where the adhesive material covers two adjacent collector electrodes of different polarities at the same time, thereby reducing or eliminating the probability of short circuit of the solar cell.

[0031] In one implementation, the length of the insulating portion is greater than the length of any window adjacent to the insulating portion, and the length direction of the insulating portion and the length direction of the window are both consistent with the first direction.

[0032] When the above technical solution is adopted, the adhesive material used to connect the joint and the metal conductive layer can be prevented from overflowing the window and covering two adjacent collector electrodes of different polarities at the same time, thereby further reducing or eliminating the probability of short circuit of the solar cell.

[0033] In one implementation, the length of the insulating portion is greater than the length of any of the joining portions, and the length direction of the insulating portion and the length direction of the joining portion are both consistent with the first direction.

[0034] When adopting the above technical solution, generally, the length of the adhesive material used to connect a joint and the metal conductive layer is less than or equal to the length of the joint. Therefore, when the length of the insulating part is greater than the length of any joint, the insulation barrier capacity of the insulating part can be improved, further reducing or eliminating the probability of short circuit of the solar cell.

[0035] In one implementation, there is a first difference between the length of the insulating portion and the length of the window, and there is a second difference between the length of the window and the length of the joint portion. The first difference and the second difference are both positive numbers, and the first difference is greater than the second difference. The length direction of the insulating portion, the length direction of the window, and the length direction of the joint portion are all consistent with the first direction.

[0036] In one implementation, a solar cell group includes a plurality of cell strings; each cell string includes a plurality of solar cells as described in the above technical solution, or each cell string includes a plurality of sliced ​​cells divided from the solar cells described in the above technical solution. Among at least 1 / 3 of the number of solar cells or sliced ​​cells included in a single cell string, the distance between any two adjacent second junctions disposed in two solar cells or two sliced ​​cells is greater than 1 / 10 of the maximum distance between two opposite edges of the solar cells or sliced ​​cells where the two second junctions are located in a fifth direction; the fifth direction is consistent with the arrangement direction of the plurality of solar cells or the plurality of sliced ​​cells in the same cell string.

[0037] In the case of adopting the above technical solution, ensuring that a certain number of second joints in a single battery string are located between two solar cells or two slice cells and are adjacent to each other and maintain a certain distance can improve the connection strength between the solar cell or slice cell and the metal conductive layer, making the solar cell or slice cell and the metal conductive layer more firmly connected, thereby ensuring the quality of the photovoltaic module. Furthermore, the larger the proportion of adjacent second joints with larger distances, the more points that can withstand greater tension, and the more dispersed the distribution, so that the second joints are more evenly stressed and the photovoltaic module is more stable. Further, as long as the above conditions are met, the effect of making the solar cell or slice cell and the metal conductive layer more firmly connected can be achieved, and there is no need to strictly control the distance between other second joints that are located between two solar cells or two slice cells and are adjacent, which increases the selectivity of the photovoltaic module and expands the scope of application of the photovoltaic module.

[0038] In one implementation, a solar cell group includes a plurality of cell strings; each cell string includes a plurality of solar cells as described in the above technical solution, or each cell string includes a plurality of sliced ​​cells divided from the solar cells described in the above technical solution. In the same cell string, the distance between two adjacent second joints disposed in two solar cells or two sliced ​​cells is evenly distributed along the fifth direction; and / or, in the same cell string, the distance between two adjacent second joints disposed in two solar cells or two sliced ​​cells is alternately distributed along the fifth direction in long and short order; the fifth direction is consistent with the arrangement direction of the plurality of solar cells or the plurality of sliced ​​cells in the same cell string. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 1 A top view of a solar cell in an embodiment of the present application;

[0041] Figure 2 A schematic diagram of a part of the structure of a solar cell in an embodiment of the present application Figure 1 ;

[0042] Figure 3 A schematic diagram of a part of the structure of a solar cell in an embodiment of the present application Figure 2 ;

[0043] Figure 4 A top view of the insulating material layer in an embodiment of the present application;

[0044] Figure 5 In the embodiment of this application Figure 4 The enlarged schematic diagram of the N position in the middle;

[0045] Figure 6 This is an enlarged schematic diagram of a portion of the structure of the same line window in the embodiment of the present application. Figure 1 ;

[0046] Figure 7 This is an enlarged schematic diagram of a portion of the structure of the same line window in the embodiment of the present application. Figure 2 ;

[0047] Figure 8 This is a schematic diagram of the structure of the conductive backplane in the embodiment of the present application;

[0048] Fig. 9 A top view of the metal conductive layer in an embodiment of the present application;

[0049] Fig.10 This is a schematic diagram of the structure of the solar cell, the insulating portion and the conductive adhesive material layer after being combined in the embodiment of the present application;

[0050] Fig.11 This is a schematic diagram of the structure of a solar cell, an insulating portion, a conductive adhesive material layer, and an insulating material layer after being combined in an embodiment of the present application;

[0051] Fig.12 This is a schematic diagram of the structure of the first battery string in the embodiment of the present application;

[0052] Fig.13 This is a schematic diagram of the structure of the second battery string in the embodiment of the present application.

[0053] Reference numerals:

[0054] 1-battery body, 10-first edge, 11-second edge; 2-collecting electrode, 20-first collecting electrode, 21-second collecting electrode, 22-first polarity second collecting electrode, 23-second polarity second collecting electrode, 24-first polarity first collecting electrode, 25-second polarity first collecting electrode; 3-joining part, 30-first joining part, 31-second joining part; 6-separation area, 7-conductive back plate, 70-insulating material layer, 71-window, 72-first window, 73-second window, 74-metal conductive layer, 740-lead-out hole, 75-back plate, 76-adhesive layer; 8-insulating part, 9-conductive adhesive material layer, 90-sliced ​​battery cell, 91-edge, 92-third joining part, 93-fourth joining part, 94-edge, 95-third window, 96-fourth window, 97-spacer area. DETAILED DESCRIPTION

[0055] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application 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 application and are not used to limit the present application.

[0056] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0057] 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 technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0058] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0059] In the description of this application, 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 this application can be understood according to specific circumstances.

[0060] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the comparison of parameters such as size, length, width, etc. between the two is a comparison of a single quantity of targets.

[0061] Unless there are technical obstacles or contradictions, the various technical features disclosed in this application can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of this application.

[0062] In order to solve the above technical problems, in the first aspect, the present application provides a solar cell. Specifically, the solar cell provided in the embodiments of the present application can be any solar cell that can convert solar light energy into electrical energy.

[0063] In terms of the location of the positive electrode and the negative electrode, the solar cell can 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 light-facing side of the solar cell, and the other is arranged on the backlight side. Alternatively, the solar cell can also be a back-contact cell, that is, the positive electrode and the negative electrode of the solar cell are both arranged on the backlight side of the solar cell, and the front of the back-contact cell is not blocked by the grid line, which effectively reduces the optical loss and improves the power generation efficiency of the solar cell. In the embodiment of the present application, the solar cell can also be a back-contact solar cell.

[0064] In terms of the specific electrode structure of the positive electrode and the negative electrode, the solar cell can be a "busbarless solar cell"; in this case, the electrode structure in the solar cell only includes the collector electrode. Alternatively, the solar cell can also be a "busbar-equipped solar cell"; in this case, the solar cell includes not only the collector electrode, but also the busbar electrode, which can be a continuous structure extending from one side of the cell to the other side of the cell, or a discontinuous structure extending from one side of the cell to the other side of the cell, or a local residual segment located between two opposite edges of the cell. In the embodiment of the present application, the solar cell is a busbarless solar cell.

[0065] See also Figure 1The solar cell includes: a battery body 1, a collecting electrode 2 and a joint 3. The collecting electrode 2 is formed on the battery body 1, and a plurality of collecting electrodes 2 extend along a first direction A and are spaced apart along a second direction B, wherein the first direction A is different from the second direction B. A plurality of joints 3 are spaced apart on the battery body 1, and each joint 3 is electrically connected to at least one collecting electrode 2. The joint 3 includes a first joint 30 and a second joint 31, and the size of the second joint 31 is larger than the size of the first joint 30. The collecting electrode 2 includes a first collecting electrode 20 and a second collecting electrode 21, the first collecting electrode 20 is electrically connected to the first joint 30, the second collecting electrode 21 is electrically connected to the second joint 31, and the extension length of a single first collecting electrode 20 along the first direction A is larger than the extension length of a single second collecting electrode 21 along the first direction A. The number of collecting electrodes 2 is counted as one continuous collecting electrode structure extending along the first direction A or a continuous collecting electrode structure realized by the joint 3, and as one continuous collecting electrode structure. Figure 1 For example, in the figure, one second joint portion 31 corresponds to one second collector electrode 21 , and one first collector electrode 20 is distributed with four first joint portions 30 .

[0066] See also Figure 1 In the solar cell provided in the embodiment of the present application, the size of the second joint part 31 is larger than the size of the first joint part 30, and the second collector electrode is electrically connected to the second joint part 31. At this time, the second joint part 31 can be used to increase the connection strength between the battery cell and the interconnection part (such as a welding strip) or the conductive layer. Since the size of the second joint part 31 is relatively large, the connection between the interconnection part or the conductive layer and the second joint part 31 is more firmly connected to ensure the quality of the solar cell. Furthermore, it is also possible to reduce or eliminate the situation where the interconnection part or the conductive layer is offset due to the small size of the second joint part 31, improve the connection quality between the interconnection part or the conductive layer and the second collector electrode, and further improve the quality of the solar cell. Furthermore, the above-mentioned collector electrode can collect the carriers generated in the corresponding area of ​​the battery body 1, and the above-mentioned joint part can be used to collect the carriers collected by the collector electrode and transmit them to the interconnection part or the conductive layer. Specifically, compared with the second joint portion 31, the first joint portion 30 mainly assumes the role of collecting carriers. When the extension length of the single first collecting electrode 20 electrically connected to the first joint portion 30 along the first direction A is greater than the extension length of the single second collecting electrode 21 along the first direction A, the collection reliability of the first collecting electrode 20 can be enhanced.

[0067] In actual application, the embodiments of the present application 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 in the embodiments of the present application.

[0068] For example, when the solar cell provided in the embodiment of the present application 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 light-facing side, and the other is formed on a side of the semiconductor substrate corresponding to the backlight side. Moreover, the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types.

[0069] 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, etc. The conductivity type of the semiconductor substrate may be N-type, P-type or intrinsic type.

[0070] For the 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.

[0071] Exemplarily, in the case where the solar cell is a back contact cell, the above-mentioned 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 the side of the semiconductor substrate corresponding to the backlight surface. At least a portion of the first doped semiconductor layer is separated from at least a portion of the second doped semiconductor layer. Among them, the 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 the previous text and will not be repeated here.

[0072] The first direction and the second direction may be any two directions parallel to the surface of the battery body and different from each other. Figure 1 , the first direction A and the second direction B are orthogonal.

[0073] The following is an explanation of "the size of the second joining portion is larger than the size of the first joining portion" from two angles. It should be understood that the following description is only for understanding and is not used for specific limitation. In actual application, the angle for convenient measurement of size can be selected according to actual conditions.

[0074] The first angle: The size of the joint can be the distance between two points on the edge of the joint along the first direction or the second direction or any other direction parallel to the surface of the battery body. This method may not limit the shapes of the first joint and the second joint, and may also be applicable to joints with regular geometric shapes. For example, "the size of the second joint is greater than the size of the first joint" may mean that along at least one of the first direction or the second direction or any other direction, the distance between two points on the edge of the second joint is greater than the distance between two points on the edge of the first joint, that is, the size of the second joint is greater than the size of the first joint. Alternatively, along the first direction and the second direction, the distance between two points on the edge of the second joint is greater than the distance between two points on the edge of the first joint, that is, the size of the second joint is greater than the size of the first joint.

[0075] The second angle: The size of the joint can be the distance between two specific points on the edge of the joint section parallel to the surface of the battery body. This is particularly applicable to the case where the joint section parallel to the surface of the battery body has a regular geometric shape. For example, when the joint section parallel to the surface of the battery body is a rectangle or a square, the size of the joint can be the length or width of the joint section parallel to the surface of the battery body, or the diagonal length; when the joint section parallel to the surface of the battery body is a circle, the size of the joint can be the diameter of the joint section parallel to the surface of the battery body; when the joint section parallel to the surface of the battery body is an ellipse, the size of the joint can be the long axis or short axis of the joint section parallel to the surface of the battery body. For example, (1) when the cross-sections of the first joint and the second joint parallel to the surface of the battery body are both rectangular, "the size of the second joint is larger than the size of the first joint" can mean that the size of the second joint is larger than the size of the first joint along the length direction (i.e., the first direction) or the width direction (i.e., the second direction) or the diagonal direction. (2) When the cross-sections of the first joint and the second joint parallel to the surface of the battery body are both circular, “the size of the second joint is larger than the size of the first joint” may mean that the size of the second joint is larger than the size of the first joint in any direction. (3) When the cross-sections of the first joint and the second joint parallel to the surface of the battery body are both elliptical, “the size of the second joint is larger than the size of the first joint” may mean that the size of the second joint is larger than the size of the first joint in the major axis direction (i.e., the first direction) or the minor axis direction (i.e., the second direction) or other directions. It should be noted that the shape of the cross-sections of the first joint and the second joint parallel to the surface of the battery body is not limited to rectangle, circle and ellipse, but may also be other shapes that meet actual needs, such as trapezoid, pentagon, etc., and here only the shape of the cross-section partially parallel to the surface of the battery body is used as an example for description. Usually, the side length, diagonal length, height, diameter, or axis length of a geometric figure are selected as the size of the joint.

[0076] It should be noted that when comparing the sizes of the first joint portion and the second joint portion, the sizes in the same direction should be selected for comparison. Generally, as long as there is a direction in which the size of the first joint portion is larger than the size of the second joint portion, it can be determined that the size of the second joint portion is larger than the size of the first joint portion.

[0077] In the embodiment of the present application, the joining portion may be a pad, a thickened section of the electrode, or a local area of ​​the electrode, as long as the connection between the battery cell and the interconnect or the conductive layer can be achieved.

[0078] As a possible implementation, the length of the first joint is greater than or equal to 0.4 mm and less than or equal to 3 mm; the length of the second joint is greater than or equal to 0.4 mm and less than or equal to 3 mm; the length direction of the first joint and the length direction of the second joint are both consistent with the first direction. Exemplarily, the length of the first joint or the length of the second joint can be 0.4 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, etc. The width of the first joint is greater than or equal to 0.1 mm and less than or equal to 1 mm; the width of the second joint is greater than or equal to 0.5 mm and less than or equal to 5 mm; the width direction of the first joint and the width direction of the second joint are both consistent with the second direction. Exemplarily, the width of the first joint can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1 mm, etc. The width of the second joining portion may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc.

[0079] In the case of adopting the above technical solution, when the length and width of the first joint part and the second joint part meet the above value range, not only can the first joint part (and the second joint part) and the interconnection part or the conductive layer be prevented from being offset, but more first joint parts and second joint parts can also be arranged on the battery body to construct a denser carrier collection structure, thereby improving the efficiency of the solar cell. Furthermore, the connection strength requirements between the battery cell and the interconnection part or the conductive layer can be met, so that the connection between the interconnection part or the conductive layer and the battery cell is more firmly connected to ensure the quality of the solar cell.

[0080] Two or more sizes of the first joint part can be provided according to the requirements. If the sizes of the first joint parts at different positions are different, four possible situations are described below as examples. It should be understood that the following description is only for understanding and is not used for specific limitation.

[0081] The first case: See Figure 1, when the solar cell includes at least two electrode units spaced apart along the second direction B, there is a separation area 6 extending along the first direction A between two adjacent electrode units. The first joint 30 includes at least two first joints of different sizes; wherein the first joint with the smallest size is located at least on one side of the separation area 6, and the joint is adjacent to the separation area 6. Specifically, a row of first joints with the smallest size (i.e., along the first direction A) may be arranged on one side of the separation area 6, or a row of first joints with the smallest size may be arranged on both sides of the separation area 6, or two or even more rows of first joints with the smallest size spaced apart along the second direction B may be arranged on one side of the separation area 6; or two or even more rows of first joints with the smallest size spaced apart along the second direction B may be arranged on both sides of the separation area 6; the number of rows of first joints with the smallest size arranged on both sides of the separation area 6 may be equal or unequal; the adjacent separation area 6 includes the case of being adjacent to the separation area 6.

[0082] The second case: See Figure 1 , along the second direction B, the battery body 1 includes two opposite edges 91 and a middle area between the two edges 91. The first joint 30 includes at least two first joints of different sizes; wherein the first joint 30 of the smallest size is arranged adjacent to at least one edge 91. Specifically, a row of first joints 30 of the smallest size (i.e., along the first direction A) may be arranged on the side adjacent to one of the edges 91, or two or more rows of first joints 30 of the smallest size may be arranged on the side adjacent to one of the edges 91 at intervals along the second direction B; a row of first joints 30 of the smallest size (i.e., along the first direction A) may be arranged on the side adjacent to the two edges 91, or two or more rows of first joints 30 of the smallest size may be arranged on the side adjacent to the two edges 91 at intervals along the second direction B; the number of rows of first joints 30 of the smallest size arranged on the side adjacent to the edge 91 may be equal or unequal; adjacent to the edge includes the case of being adjacent to the edge. It should be noted that at this time, the solar cell may be a whole solar cell or a sliced ​​solar cell.

[0083] The third case: See Figure 1, the first joining portion 30 with the smallest size is arranged on at least one side adjacent to the second joining portion 31. Specifically, a row of the first joining portions 30 with the smallest size (i.e., along the first direction A) may be arranged on one side adjacent to the second joining portion 31, or a row of the first joining portions 30 with the smallest size may be arranged on both sides adjacent to the second joining portion 31, or two or even more rows of the first joining portions 30 with the smallest size spaced apart along the second direction B may be arranged on one side adjacent to the second joining portion 31; or two or even more rows of the first joining portions 30 with the smallest size spaced apart along the second direction B may be arranged on both sides adjacent to the second joining portion 31; the number of rows of the first joining portions 30 with the smallest size arranged on both sides adjacent to the second joining portion 31 may be equal or unequal; adjacent to the second joining portion 31 includes the case of being adjacent to the second joining portion 31.

[0084] Fourth situation: the junction is a combination of any two or three of the above three situations. It should be noted that if a separation region exists, the middle region of the solar cell includes the separation region.

[0085] Because the area adjacent to the edge of the battery body or adjacent to the separation area or adjacent to the second joint portion generally has lower requirements on carrier collection and tensile force bearing capacity, the size of the joint portion can be appropriately reduced.

[0086] Solar cells include three sizes of joints. With the cooperation of large and small joints, the connection tension can be adjusted, thereby adjusting the connection strength between different positions of the battery cell and the interconnection parts (such as welding strips) or conductive layers; at the same time, it can also reduce the impact on the current collection of the battery body and meet the carrier collection requirements.

[0087] For example, see Figure 1 In the present application, the first joint part 30 includes two first joint parts 30 of different sizes. For the convenience of description, the first joint part 30 with the smallest size is named as the third joint part 92, and the first joint part 30 with the larger size is named as the fourth joint part 93. In the present application, the solar cell is a whole solar cell having a partition area 6 and two edges 91, wherein a row of third joint parts 92 is arranged on both sides of the partition area 6, and a row of third joint parts 92 is arranged on one side of the two edges 91, and the fourth joint part 93 is located between the second joint part 31 and the third joint part 92 close to the partition area 6.

[0088] See also Figure 1 The first collector electrode 20 is a continuous collector electrode, and a plurality of first joints 30 are disposed on one first collector electrode 20 along the first direction A. The first collector electrode 20 includes a first polarity first collector electrode 24 and a second polarity first collector electrode 25 .

[0089] See also Figure 1The second collector electrode 21 is a discontinuous collector electrode, and the discontinuous collector electrode is disconnected at the second joint portion 31 electrically connected to the second collector electrode 21 of opposite polarity.

[0090] The extension length of a single first collecting electrode 20 along the first direction is greater than the extension length of a single second collecting electrode 21 along the first direction, which means that on the battery body 1, the length of a single first collecting electrode 20 along the first direction is greater than the length of a single second collecting electrode 21 along the first direction.

[0091] Applicable sizes of solar cells include 166mm, 182mm, 192mm, 210mm or 260mm, etc. The above solar cells of different specifications can meet different needs and expand the scope of application.

[0092] As a possible implementation, see Figure 1 , along the second direction B, the battery body 1 has a first edge 10 and a second edge 11 opposite to each other, and the distance between the first edge 10 and the second edge 11 is L1. For a single second bonding portion 31, along the second direction B, the minimum distance between the first edge 10 or the second edge 11 of the battery body 1 closest to the second bonding portion 31 and the second bonding portion 31 is L2, and the ratio of L2 to L1 is greater than or equal to 1% and less than or equal to 50%. Exemplarily, the ratio of L2 to L1 can be 1%, 3%, 5%, 7%, 10%, 13%, 15%, 17%, 20%, 23%, 25%, 27%, 30%, 43%, 45%, 47% or 50%, etc. It should be noted that when a solar cell includes a plurality of second bonding portions 31, each of the plurality of second bonding portions 31 may satisfy the above relationship, or one or part of the second bonding portions 31 may satisfy the above relationship. Further, the edge 91 of the battery body described above includes a first edge 10 and a second edge 11.

[0093] Combined with the above description, since the second joint part 31 is used to increase the connection strength between the battery cell and the interconnection part or the conductive layer, the position of the second joint part 31 cannot be too close to the middle position of the battery body 1, so as to ensure that when forming a component, at least part of the adjacent second joint parts 31 are arranged in the adjacent solar cells along the second direction B with a certain distance, so as to avoid the connection effect between the second collector electrode 21 and the interconnection part or the conductive layer being affected by the small force point caused by the close distance, so as to further ensure the quality of the solar cell. Furthermore, the position of the second joint part 31 cannot be too close to the first edge 10 or the second edge 11 of the battery body 1, so as to ensure the connection strength between the battery cell and the interconnection part or the conductive layer and reduce the influence on the current collection in the edge area of ​​the battery body, so as to ensure the efficiency of the solar cell.

[0094] Figure 1 For the exemplary cell, the difference between the side length along the first direction A and the side length along the second direction B is small, and in some other cases, the two can even be approximately equal. The cell can be used in whole or in pieces. The ratio of L2 to L1 can be greater than or equal to 1% and less than or equal to 50%; a more preferred solution is that the ratio of L2 to L1 can be greater than or equal to 10% and less than or equal to 50%, or the ratio of L2 to L1 can be greater than or equal to 1% and less than or equal to 30%; a more preferred solution is that the ratio of L2 to L1 can be greater than or equal to 10% and less than or equal to 30%. The ratio of L2 to L1 is greater than or equal to 10%, which further avoids the position of the second joint 31 being too close to the first edge 10 or the second edge 11 of the battery body 1, on the one hand, reducing the influence on the current collection of the edge area of ​​the battery body and the connection strength of the battery edge, and on the other hand, ensuring that there is a certain distance between the two adjacent second joints 31 in the second direction B in the adjacent solar cells when forming the assembly, avoiding the connection effect between the second collector electrode 21 and the interconnector or the conductive layer caused by the small force point due to the close distance. The ratio of L2 to L1 is less than or equal to 30%, which can prevent the second joint portion 31 from being too close to the first edge 10 or the second edge 11 of the battery body 1 after slicing. The specific effect description can be found in the above text.

[0095] Fig.12 In the exemplary cell sheet given in the figure, the difference between the side length along the first direction A and the side length along the second direction B is relatively large. In some other cases, the ratio of the side length in the first direction A to the side length in the second direction B can even be close to 2:1. The ratio of L2 to L1 can be greater than or equal to 1% and less than or equal to 50%; a more preferred solution is that the ratio of L2 to L1 can be greater than or equal to 10% and less than or equal to 50%. At this time, it is possible to further avoid the position of the second joint 31 being too close to the first edge 10 and the second edge 11 of the battery body 1, on the one hand, reducing the impact on the current collection in the edge area of ​​the battery body and the connection strength of the battery edge, and on the other hand, ensuring that at least part of the adjacent second joints 31 in the adjacent solar cells along the second direction B have a certain distance when forming the component, so as to avoid the connection effect between the second collector electrode 21 and the interconnect or conductive layer caused by the small force point due to the close distance.

[0096] As a possible implementation manner, along the second direction, the distance between any two second joining portions 31 located on the same straight line is greater than 1 / 5 L1.

[0097] When the above technical solution is adopted, when the distance between the two relatively distributed second joints 31 is greater than 1 / 5L1, it can not only ensure the connection strength between the battery cell and the interconnector or the conductive layer, but also make the connection between the interconnector or the conductive layer and the battery cell more firmly to ensure the quality of the solar cell; it can also reduce the impact on the current collection in the edge area of ​​the battery body to ensure the efficiency of the solar cell.

[0098] As a possible implementation, see Figure 1 , for a single second joint portion 31, along the second direction B, the minimum distance between the edge of the battery body 1 closest to the single second joint portion 31 and the second joint portion 31 is L2. Along the second direction B, the spacing between two adjacent first collector electrodes 20 is L3, and the ratio of L2 to L3 is greater than or equal to 1. Exemplarily, the ratio of L2 to L3 can be 1, 1.1, 1.2, 1.3, 1.5 or 1.8, etc.

[0099] When the above technical solution is adopted, combined with the previous description, since the second bonding portion 31 is used to increase the connection strength between the battery cell and the interconnection member or the conductive layer, the position of the second bonding portion 31 cannot be too close to the edge position of the battery body 1, so as to avoid the two adjacent second bonding portions 31 distributed on two adjacent solar cells along the second direction being too close when forming a component, resulting in the concentration of force points and the inability to effectively enhance the connection tension between the battery cell and the interconnection member or the conductive layer, thereby affecting the connection effect. In addition, if the second bonding portion 31 is too close to the edge, it will lead to poor edge carrier collection, and the second bonding portion 31 is large in size, and the edge of the battery cell is brittle. If the second bonding portion 31 is too close to the edge of the battery cell, the stress between the two may cause problems such as battery cell fragmentation.

[0100] As a possible implementation, see Figure 1 The second collector electrode 21 includes a first polarity second collector electrode 22 and a second polarity second collector electrode 23. The first polarity second collector electrode 22 extends along the first direction A and is located on the same straight line and is distributed in sequence and at intervals. The second polarity second collector electrode 23 extends along the first direction A and is located on the same straight line and is distributed in sequence and at intervals. Along the first direction A, the first polarity second collector electrode 22 and the second polarity second collector electrode 23 are alternately distributed and are not on the same straight line.

[0101] See also Figure 2 , along the second direction B, the projection of at least one first polarity second collector electrode 22 on the second polarity second collector electrode 23 adjacent thereto is located within the second polarity second collector electrode 23. And / or, see Figure 3, along the second direction B, a projection of at least one first polarity second collecting electrode 22 on the second polarity second collecting electrode 23 adjacent thereto is tangent to an end of at least one second polarity second collecting electrode 23 close to the first polarity second collecting electrode 22 .

[0102] At this time, the first polarity second collector electrode 22 and the second polarity second collector electrode 23 can cover more areas on the battery body 1, so that the second collector electrode 21 collects more carriers, thereby improving the efficiency of the solar cell. Further, with the above design, when the distance between two adjacent second joints 31 along the first direction A decreases, more second joints 31 can be accommodated on the battery body 1. At this time, not only can the connection strength between the battery cell and the interconnect or the conductive layer be further improved, but also a denser carrier collection structure can be constructed, further improving the efficiency of the solar cell. In addition, along the second direction B, the projection of at least one first polarity second collector electrode 22 on the second polarity second collector electrode 23 adjacent to it is located within the second polarity second collector electrode 23. At this time, the carrier collection areas of the two polarities are butted together to avoid the appearance of dead zones caused by the same polarity carrier collection area being too large, so as to reduce the carrier collection loss of the other polarity.

[0103] In an optional manner, along the second direction, the projection of at least one first polarity second collecting electrode 22 on the second polarity second collecting electrode 23 adjacent to it is not located within the second polarity second collecting electrode 23; and, along the second direction, the projection of at least one first polarity second collecting electrode 22 on the second polarity second collecting electrode 23 adjacent to it is spaced apart from one end of at least one second polarity second collecting electrode 23 close to the first polarity second collecting electrode 22.

[0104] In an alternative approach, see Figure 2 , along the second direction B, when the projection of at least one first polarity second collector electrode 22 on the adjacent second polarity second collector electrode 23 is located within the second polarity second collector electrode 23, along the first direction A, the minimum distance L4 between the free end of the first polarity second collector electrode 22 and the second junction 31 where the adjacent second polarity second collector electrode 23 is located is greater than or equal to 0.2 mm and less than or equal to 0.8 mm; and / or, along the first direction A, the minimum distance L5 between the free end of the second polarity second collector electrode 23 and the second junction 31 where the adjacent first polarity second collector electrode 22 is located is greater than or equal to 0.2 mm and less than or equal to 0.8 mm. For example, the minimum distance L4 or the minimum distance L5 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm or 0.8 mm, etc. The above minimum distance L4 and the minimum distance L5 can be equal or unequal.

[0105] When the above technical solution is adopted, it is avoided that when the second collector electrode is connected to the interconnector or the conductive layer, the same interconnector or the conductive layer is connected to the second collector electrodes of two polarities at the same time, so as to prevent the solar cell from short-circuiting.

[0106] As a possible implementation, see Figure 1 , along the second direction B, a plurality of joints 3 arranged on the collector electrode 2 of the first polarity are located on the first straight line O, and a plurality of joints 3 arranged on the collector electrode 2 of the second polarity are located on the second straight line P; the first straight line O and the second straight line P are alternately and spaced apart along the first direction A.

[0107] When the above technical solution is adopted, it is avoided that when the collector electrode is connected to the interconnection member or the conductive layer, the same interconnection member or the conductive layer is connected to collector electrodes of two polarities at the same time, so as to prevent the solar cell from short-circuiting.

[0108] As a possible implementation, see Figure 1 In the case where the solar cell includes at least two electrode units spaced apart along the second direction B, a separation region 6 extending along the first direction A is provided between two adjacent electrode units.

[0109] See also Figure 1 , along the second direction B, the plurality of second joining portions 31 located on one side of the separation area are located on the same straight line M, and the extension direction of the straight line M is consistent with the first direction A.

[0110] See also Figure 1 , along the second direction, the battery body 1 has a first edge 10 and a second edge 11 opposite to each other, and the distance between the first edge 10 and the second edge 11 is L1; the distance L6 between the two second joints 31 located on both sides of the same partition 6 and opposite to each other is greater than or equal to 1 / 5L1. In the case of adopting the above technical solution, when the distance between the two second joints 31 opposite to each other is greater than or equal to 1 / 5L1, it can not only ensure the connection strength between the battery cell and the interconnection member or the conductive layer, but also make the connection between the interconnection member or the conductive layer and the battery cell more firmly, so as to ensure the quality of the solar cell; at the same time, it can also reduce the influence on the current collection in the edge area of ​​the battery body 1, so as to ensure the efficiency of the solar cell.

[0111] As a possible implementation, the solar cell may be a whole solar cell or a half solar cell. If the solar cell needs to be sliced ​​later to obtain a half solar cell, the cutting line may be located in the separation area. That is, when the solar cell is a half solar cell, the whole solar cell may be cut along the cutting line located in the separation area.

[0112] In a second aspect, the present application also provides a conductive backplane. Figure 4 and Figure 5 The conductive backplane includes an insulating material layer 70, on which a plurality of windows 71 are formed. A group of windows 71 on the insulating material layer 70 (see Figure 5 E) is arranged at intervals along the third direction C, a group of windows includes a first window 72 and a second window 73, and the size of the second window 73 is larger than that of the first window 72.

[0113] In actual use, the window opened on the insulating material layer corresponds to the joint in the solar cell. It should be noted that the conductive backplane provided in the embodiment of the present application is not limited to being applicable only to the solar cell described in the first aspect, but can also be applicable to solar cells that are different from the description in the first aspect (for example, the size of the joint is different, the arrangement of the joint is different, the length of the collector electrode is different, etc.), as long as the window can correspond to the joint in the solar cell and the joint and the metal conductive layer are electrically connected. Exemplarily, when the solar cell is the solar cell described in the first aspect, the first window corresponds to the first joint in the solar cell described in the above technical solution, and the second window corresponds to the second joint in the solar cell described in the above technical solution.

[0114] See also Figure 1 , Figure 4 and Figure 5 In actual use, the solar cell is electrically connected to the metal conductive layer 74 through the insulating material layer 70 with the window 71. Since the size of the second window 73 is larger than the size of the first window 72, the second window 73 corresponds to the second joint 31 of the solar cell, and the first window 72 corresponds to the first joint 30 of the solar cell. Since the size of the second joint 31 is larger than the size of the first joint 30, the second collector electrode 21 is the collector electrode electrically connected to the second joint 31. At this time, the second joint 31 can be used to increase the connection strength between the second collector electrode 21 and the interconnection member (such as a welding strip) or the conductive layer, so that the interconnection member or the conductive layer is more firmly connected to the second collector electrode 21, so as to ensure the quality of the solar cell.

[0115] As a possible implementation, the number of second windows 73 accounts for 1%-50% of the total number of windows 71; the proportion of the second windows 73 needs to be controlled to avoid excessive proportion of connection points with large contact areas (i.e., the second joints described above), which may lead to excessive stress and damage to the battery cell. The ratio of the number of second windows 73 to the total number of windows 71 can also be set to 1%-30%, 4%-20%, 10%-20%, etc.

[0116] As a possible implementation, along the width direction of the insulating material layer 70 (ie, along the direction perpendicular to the third direction C), multiple rows of windows (see Figure 4Furthermore, along the width direction of the insulating material layer 70, the total number of windows included in each row of windows in two adjacent rows of windows is different, and the total number of windows included in the multiple rows of windows is alternately distributed with more in one row and less in another.

[0117] Along the length direction of the insulating material layer 70 (ie, along the third direction C), a row of windows 71 is divided into a plurality of window sub-units (see Figure 4 The G in , i.e., a "group of windows" described in this application). Figure 6 , the distance between two adjacent second windows 73 in the same window 71 which are arranged in two window subunits G (see attached Figure 6 L11 in FIG. 7 is evenly distributed along the length direction of the insulating material layer 70. And / or, see Figure 7 The distance between two adjacent second windows 73 in the same window 71, which are arranged in two window subunits G, is alternately distributed along the length direction of the insulating material layer 70 to ensure that there is a connection point with a large contact area every certain distance, so that the distribution of the force points is relatively uniform. Figure 7 L11 and L12 in the figure represent the distance between two adjacent second windows 73 in the same window 71 which are arranged in two window sub-units G. L11 and L12 are of different lengths. L11 and L12 are alternately distributed in length direction of the insulating material layer 70 .

[0118] As a possible implementation manner, the first window includes at least two first windows of different sizes.

[0119] First windows of different sizes may be arranged according to needs. For example, first windows at different positions may have different sizes. Four possible situations are described below as examples. It should be understood that the following description is only for understanding and is not intended to be a specific limitation.

[0120] The first case: See Figure 4 and Figure 5, along the length direction of the insulating material layer 70 (i.e., along the third direction C), a row of windows 71 is divided into a plurality of groups of windows, and there is a spacing area 97 between two adjacent groups of windows; wherein, the first windows 72 of the smallest size are arranged adjacent to at least one side of the spacing area 97. Specifically, one side of the adjacent spacing area 97 may be provided with a row of the first windows 72 of the smallest size (i.e., arranged along the direction perpendicular to the third direction C), or one side of the adjacent spacing area 97 may be provided with a row of the first windows 72 of the smallest size, or two sides of the adjacent spacing area 97 may be provided with two or more rows of the first windows 72 of the smallest size spaced along the third direction C, or two sides of the adjacent spacing area 97 may be provided with two or more rows of the first windows 72 of the smallest size spaced along the third direction C; the number of rows of the first windows 72 of the smallest size arranged on both sides of the adjacent spacing area 97 may be equal or unequal; the adjacent spacing area 97 includes the case of the adjacent spacing area 97.

[0121] The second case: See Figure 4 and Figure 5 The insulating material layer 70 includes two opposite edges 94 along the length direction (i.e., along the third direction C), and an inner area between the two edges 94. The first windows 72 include at least two first windows 72 of different sizes, wherein the first window 72 of the smallest size is arranged adjacent to at least one edge 94. Specifically, a row of first windows 72 of the smallest size (i.e., arranged along a direction perpendicular to the third direction C) may be arranged on a side adjacent to one of the edges 94, or two or more rows of first windows 72 of the smallest size spaced along the third direction C may be arranged on a side adjacent to one of the edges 94; one row of first windows 72 of the smallest size (i.e., arranged along a direction perpendicular to the third direction C) may be arranged on a side adjacent to two edges 94, or two or more rows of first windows 72 of the smallest size spaced along the third direction C may be arranged on a side adjacent to two edges 94; the number of rows of first windows 72 of the smallest size arranged on a side adjacent to an edge 94 may be equal or unequal; and the adjacent edge 94 includes the case of being adjacent to the adjacent edge 94.

[0122] The third case: See Figure 4 and Figure 5, the first window 72 with the smallest size is arranged on at least one side adjacent to the second window 73. Specifically, a row of the first windows 72 with the smallest size (i.e., along the third direction C) may be arranged on one side adjacent to the second window 73, or a row of the first windows 72 with the smallest size may be arranged on both sides adjacent to the second window 73, or two or more rows of the first windows 72 with the smallest size spaced apart along the third direction C may be arranged on one side adjacent to the second window 73; or two or more rows of the first windows 72 with the smallest size spaced apart along the third direction C may be arranged on both sides adjacent to the second window 73; the number of rows of the first windows 72 with the smallest size arranged on both sides adjacent to the second window 73 may be equal or unequal; being adjacent to the second window 73 includes being adjacent to the second window 73.

[0123] Fourth situation: the window is a combination of any two or three of the above three situations. It should be noted that if there is a spacing area, the inner area of ​​the insulating material layer includes the spacing area.

[0124] Because the area adjacent to the edge of the battery body or adjacent to the separation area or adjacent to the second joint portion generally has lower requirements for carrier collection and tensile bearing capacity, the size of the joint portion can be appropriately reduced. Therefore, the size of the first window adjacent to the edge of the insulating material layer or adjacent to the separation area or adjacent to the second window can be correspondingly reduced.

[0125] For example, see Figure 5 In the present application, the first window 72 includes two first windows 72 of different sizes. For the convenience of description, the first window 72 with the smallest size is named as the third window 95, and the first window 72 with the larger size is named as the fourth window 96. The third window 95 is arranged on one side close to the two edges 94 of the insulating material layer, and a row of third windows 95 is arranged on both sides close to the spacing area 97, and the fourth window 96 and the second window 73 are located in the inner area.

[0126] As a possible implementation manner, the material of the above-mentioned insulating material layer can be IEP material, EPE (polyethylene foam board) material or PI (polyimide) material, etc.

[0127] In the actual window opening process, laser can be used to open multiple windows on the insulating material layer.

[0128] As a possible implementation, see Figure 4 and Figure 5 , the plurality of groups of windows 71 are arranged at intervals in the fourth direction D, two adjacent groups of windows 71 in the fourth direction D include different numbers of openings, and the third direction C is different from the fourth direction D.

[0129] When the above technical solution is adopted, in the fourth direction, the numbers of joints corresponding to two adjacent groups of windows are different, which enhances the connection firmness between the solar cell and the conductive backplane compared to the case where the numbers of joints corresponding to two adjacent groups of windows are the same.

[0130] The third direction and the fourth direction can be any two directions parallel to the surface of the insulating material layer and different from each other. Figure 4 , the third direction C and the fourth direction D are orthogonal.

[0131] As a possible implementation, see Figure 4 and Figure 5 , the plurality of groups of windows are arranged at intervals in the third direction C, and two adjacent groups of windows in the third direction C are axially symmetrical or centrally symmetrical.

[0132] The following is an explanation of "the size of the second window is larger than the size of the first window" from two perspectives. It should be understood that the following description is only for understanding and is not used for specific limitation. In actual application, the angle for convenient measurement of size can be selected according to actual conditions.

[0133] The first angle: the size of the window can be the distance between two points on the edge of the window along the third direction or the fourth direction or any other direction parallel to the surface of the battery body. This method may not limit the shapes of the first window and the second window, and may also be applicable to windows of specific regular geometric shapes. For example, "the size of the second window is larger than the size of the first window" may mean that along at least one of the third direction or the fourth direction or any other direction, the distance between two points on the edge of the second window is larger than the distance between two points on the edge of the first window, that is, the size of the second window is larger than the size of the first window. Alternatively, along the third direction and the fourth direction, the distance between two points on the edge of the second window is larger than the distance between two points on the edge of the first window, that is, the size of the second window is larger than the size of the first window.

[0134] The second angle: The size of the window can be the distance between two specific points on the edge of the window section parallel to the battery body surface. This is particularly applicable to the case where the window section parallel to the battery body surface has a regular geometric shape, such as when the window section parallel to the battery body surface is a rectangle or a square, the size of the window can be the length or width of the window section parallel to the battery body surface, or the diagonal length; when the window section parallel to the battery body surface is a circle, the size of the window can be the diameter of the window section parallel to the battery body surface; when the window section parallel to the battery body surface is an ellipse, the size of the window can be the long axis or short axis of the window section parallel to the battery body surface. For example, (1) when the shapes of the first window and the second window (or when the first window and the second window section parallel to the battery body surface) are both rectangular, "the size of the second window is larger than the size of the first window" can mean that the size of the second window is larger than the size of the first window along the length direction (i.e., the fourth direction) or the width direction (i.e., the third direction) or the diagonal direction. (2) When the shapes of the first window and the second window (or when the cross-section of the first window and the second window is parallel to the surface of the battery body) are both circular, "the size of the second window is larger than the size of the first window" may mean that the size of the second window is larger than the size of the first window in any direction. (3) When the shapes of the first window and the second window (or when the cross-section of the first window and the second window is parallel to the surface of the battery body) are both elliptical, "the size of the second window is larger than the size of the first window" may mean that the size of the second window is larger than the size of the first window in the major axis direction (i.e., the fourth direction) or the minor axis direction (i.e., the third direction) or other directions. It should be noted that the shapes of the first window and the second window are not limited to rectangle, circle and ellipse, but may also be other shapes that meet actual needs, such as trapezoid, pentagon, etc., and only some shapes are used as examples for description. Usually, the side length, diagonal length, height, diameter, axis length, etc. of the geometric figure are selected as the size of the window.

[0135] It should be noted that when comparing the sizes of the first window and the second window, the sizes in the same direction should be selected for comparison. Generally, as long as there is a direction in which the size of the first window is larger than the size of the second window, it can be determined that the size of the second window is larger than the size of the first window.

[0136] Preferably, the shapes of the first window and the second window are both rectangular, that is, the shape of the window is rectangular. At this time, the length of the rectangular window is greater than or equal to 1mm and less than or equal to 5mm, and the width of the rectangular window is greater than or equal to 0.5mm and less than or equal to 3mm. Exemplarily, the length of the rectangular window can be 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm or 5mm, etc. The width of the rectangular window can be 0.5mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm or 3mm, etc. Preferably, the length of the rectangular window is 3mm, and the width of the rectangular window is 2mm. The conductive backplane of the present application can be used independently, or it can be used in conjunction with the battery cell of the present application to form a component, and it can also be applied to the component of the present application.

[0137] In a third aspect, the present application also provides a photovoltaic module. Figures 1 to 11 The photovoltaic module comprises: a conductive backplane 7 and a solar cell group arranged on the conductive backplane 7. The conductive backplane 7 comprises a metal conductive layer 74 and an insulating material layer 70 stacked in sequence, and the solar cell group comprises a plurality of solar cells as described in the above technical solution; or, the solar cell group comprises a plurality of cell slices divided from the solar cells as described in the above technical solution. A plurality of windows 71 are provided on the insulating material layer 70, and a plurality of solar cells as described in the above technical solution or cell slices divided from the solar cells as described in the above technical solution are electrically connected to the metal conductive layer 74 through the insulating material layer 70 with the windows 71.

[0138] The beneficial effects of the photovoltaic module provided in the embodiment of the present application are the same as the beneficial effects of the solar cell described in the first aspect, and are not described in detail here. Furthermore, compared with the photovoltaic module in the prior art, the power of the photovoltaic module provided in the embodiment of the present application is increased by 5W to 10W.

[0139] In an alternative approach, see Fig. 9The above-mentioned metal conductive layer 74 can be copper-aluminum foil, aluminum foil, copper foil aluminum-plated, copper foil nickel-plated, copper foil tin-plated, aluminum foil copper-plated, aluminum foil tin-plated, aluminum foil nickel-plated, etc., as long as it can be applied to the conductive backplane provided in the embodiment of the present application. Since the cost of aluminum material is relatively low, when the material of the metal conductive layer 74 is aluminum, it is beneficial to control the manufacturing cost of the photovoltaic module. In addition, the chemical properties of aluminum are relatively active. It can be oxidized at room temperature to form a dense oxide layer on its surface, which can prevent itself from being further oxidized. Based on this, when the material of the metal conductive layer 74 includes aluminum, the surface of the metal conductive layer 74 can be oxidized to form a dense oxide layer, which can not only prevent leakage through the oxide layer, but also prevent the metal conductive layer from continuing to be oxidized through the oxide layer, thereby improving the structural reliability of the photovoltaic module.

[0140] See also Fig. 9 , three lead-out holes 740 are provided in the middle of the metal conductive layer 74 to facilitate the busbar lead-out. One end of the busbar is electrically connected to the metal conductive layer 74, and the other end is electrically connected to the junction box. The shape of the lead-out hole 740 can be circular, elliptical, rectangular or other shapes. Preferably, the shape of the lead-out hole 740 is rectangular. At this time, the length of the lead-out hole is greater than or equal to 3mm and less than or equal to 15mm, and the width of the lead-out hole is greater than or equal to 3mm and less than or equal to 15mm. Exemplarily, the length of the lead-out hole 740 can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm or 15mm, etc. The width of the lead-out hole 740 can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm or 15mm, etc. Preferably, the length of the lead-out hole 740 is 5mm, and the width of the lead-out hole 740 is 5mm.

[0141] As a possible implementation, the length of the window is greater than or equal to the length of the corresponding joint, and the length direction of the window and the length direction of the joint are both consistent with the first direction. And / or, the width of the window is greater than or equal to the width of the corresponding joint, and the width direction of the window and the width direction of the joint are both consistent with the second direction. When the above technical solution is adopted, it is ensured that the joint can be smoothly electrically connected to the metal conductive layer through the window, reducing the difficulty of assembly and reducing assembly errors.

[0142] In the embodiment of the present application, the size of the above-mentioned window is relatively small, which reduces the time for laser opening of the insulating material layer and improves the production efficiency of the photovoltaic module.

[0143] In one implementation, the difference between the length of the window and the length of the joint is greater than 1 mm; the length direction of the window and the length direction of the joint are both consistent with the first direction; illustratively, the above difference can be 1 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2 mm, 2.1 mm, 2.3 mm, 2.5 mm, 2.7 mm or 2.9 mm, etc. And / or, the difference between the width of the window and the width of the joint is greater than 1 mm; the width direction of the window and the width direction of the joint are both consistent with the second direction. illustratively, the above difference can be 1 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2 mm, 2.1 mm, 2.3 mm, 2.5 mm, 2.7 mm or 2.9 mm, etc.

[0144] As a possible implementation, see Figure 1 and Fig.10 The photovoltaic module further comprises: an insulating portion 8, the insulating portion 8 covers at least a portion of the first collector electrode 2. Along the first direction A, the insulating portion 8 and the joint portion 3 are alternately and spaced apart. And / or, along the second direction B, the insulating portion 8 and the joint portion 3 are alternately and spaced apart.

[0145] In the actual assembly process, when the joint is connected to the metal conductive layer through the adhesive material, the insulating part can reduce or avoid the situation where the adhesive material covers two adjacent collector electrodes of different polarities at the same time, thereby reducing or eliminating the probability of short circuit of the solar cell. Specifically, because different solar cells in the solar cell group are electrically connected to each other through a conductive backplane, and the spacing between the two collector electrodes of different polarities included in the same solar cell is small, when the solar cell also includes an insulating part, the two collector electrodes of different polarities included in the same solar cell can be isolated by the insulating part, reducing or avoiding the situation where the adhesive material covers two adjacent collector electrodes of different polarities at the same time, reducing or preventing overlapping short circuits, and further improving the electrical reliability of the photovoltaic module. In addition, the above-mentioned insulating part can also play a buffering role, preventing the rigid contact between one side of the solar cell group and the conductive backplane during the lamination process of the photovoltaic module, resulting in problems such as damage to the solar cell, thereby improving the yield of the photovoltaic module.

[0146] For example, see Figure 1 and Fig.10 , along the first direction A, the insulating portions 8 and the joining portions 3 are distributed alternately and at intervals. Also, along the second direction B, the insulating portions 8 and the joining portions 3 are distributed alternately and at intervals.

[0147] In an optional manner, the length of the insulating portion is greater than the length of any window adjacent thereto, and the length direction of the insulating portion and the length direction of the window are consistent with the first direction. When the above technical solution is adopted, it is avoided that when the adhesive material used to connect the joint portion and the metal conductive layer overflows the window, the adhesive material simultaneously covers two adjacent collector electrodes of different polarities, further reducing or eliminating the probability of short circuit of the solar cell.

[0148] In an optional manner, the difference between the length of the insulating portion and the length of the window is greater than or equal to 0.5 mm. Exemplarily, the above difference may be 0.5 mm, 0.6 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 2.7 mm, 2.9 mm, 3 mm, 3.5 mm, 4 mm, 4.2 mm, 4.5 mm or 4.8 mm, etc. When the above difference satisfies the above value range, it can not only further improve the insulation barrier capability of the insulating portion, reduce or eliminate the probability of short circuit of the solar cell; at the same time, it can also reduce the raw materials for making the insulating portion and reduce the manufacturing cost of the insulating portion.

[0149] In an alternative approach, see Figure 1 and Fig.10, the length of the insulating portion 8 is greater than the length of any of the joining portions 3, and the length direction of the insulating portion 8 and the length direction of the joining portion 3 are both consistent with the first direction A. Generally, the length of the adhesive material used to connect one joining portion 3 and the metal conductive layer 74 is less than or equal to the length of the joining portion 3. Therefore, when the length of the insulating portion 8 is greater than the length of any of the joining portions 3, the insulation barrier capability of the insulating portion 8 can be improved, further reducing or eliminating the probability of short circuit of the solar cell.

[0150] In an optional manner, the difference between the length of the insulating portion and the length of the joint portion is greater than or equal to 1.5 mm. Exemplarily, the above difference may be 1.5 mm, 2 mm, 2.5 mm, 2.7 mm, 2.9 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 5.7 mm or 6 mm, etc. When the above difference satisfies the above value range, it can not only improve the insulation barrier capability of the insulating portion, but also reduce or eliminate the probability of short circuit of the solar cell; at the same time, it can also reduce the raw materials for making the insulating portion and reduce the manufacturing cost of the insulating portion.

[0151] In an optional manner, there is a first difference between the length of the insulating portion and the length of the window, and there is a second difference between the length of the window and the length of the joint portion. The first difference and the second difference are both positive numbers, and the first difference is greater than the second difference. The length direction of the insulating portion, the length direction of the window, and the length direction of the joint portion are all consistent with the first direction.

[0152] The material of the insulating part can be various resins, organic silica gel, inorganic silica gel, various polymer film materials, and insulating media mixed with adhesive materials.

[0153] See also Fig.10 , the cross-sectional shape of the insulating portion 8 includes a rectangle, a circle or an ellipse, etc. The length of the insulating portion is greater than or equal to 1 mm and less than or equal to 5 mm, and the width of the insulating portion is greater than or equal to 0.5 mm and less than or equal to 2 mm. Exemplarily, the length of the insulating portion is 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm, etc. The width of the insulating portion is 0.5 mm, 0.6 mm, 0.9 mm, 1 mm, 1.5 mm or 2 mm, etc. Preferably, the length of the insulating portion is 4 mm, and the width of the insulating portion is 1 mm. The length direction of the insulating portion is consistent with the first direction A, and the width direction of the insulating portion is consistent with the second direction B.

[0154] When the insulating part is actually printed, the curing temperature of the material of the insulating part is greater than or equal to 160°C and less than or equal to 350°C. For example, the curing temperature of the material of the insulating part is 160°C, 190°C, 200°C, 220°C, 250°C, 270°C, 300°C, 320°C or 350°C. Preferably, the curing temperature of the material of the insulating part is 190°C. After printing the material of the insulating part, it is dried into a solid state in a high-temperature drying furnace. The temperature setting range of the drying furnace is greater than or equal to 160°C and less than or equal to 300°C. For example, the temperature of the drying furnace is 160°C, 190°C, 200°C, 220°C, 250°C, 270°C, 280°C, 290°C or 300°C.

[0155] As a possible implementation method, there can be a certain distance from the end of the second collecting electrode to the edge of the window 71 corresponding to the adjacent opposite-sex joint, such as greater than or equal to 1 mm, to ensure electrical isolation; when the distance from the end of the second collecting electrode to the edge of the window 71 corresponding to the adjacent opposite-sex joint is less than 1 mm or even extends to the window area, it can be used in conjunction with insulating glue to cover the end of the second collecting electrode to ensure the insulation effect.

[0156] As a possible implementation, see Figure 1 and Fig.10 The photovoltaic module also includes a conductive adhesive material layer 9, which is arranged on the joint portion 3 of the solar cell. The metal conductive layer 74 and the solar cell are bonded together through the conductive adhesive material layer 9 that penetrates the window.

[0157] When the above technical solution is adopted, the above conductive adhesive material layer can improve the bonding effect between the metal conductive layer and the solar cell, thereby improving the quality of the photovoltaic module. Furthermore, the above conductive adhesive material layer is not disposed as a whole layer between the solar cell and the metal conductive layer, thereby solving the problem that the photovoltaic module has poor fire resistance, complicated process and high cost due to the existing photovoltaic modules based on solar cells using a whole layer of packaging film to achieve composite bonding between the packaging backplane and the metal conductive circuit layer.

[0158] In an optional manner, the melting temperature of the conductive adhesive material layer is greater than or equal to 160° C. and less than or equal to 200° C. Exemplarily, the melting temperature of the conductive adhesive material layer is 160° C., 165° C., 170° C., 175° C., 180° C., 185° C., 190° C., 195° C. or 200° C., and any ranges between these values. Preferably, the melting temperature of the conductive adhesive material layer is 170° C.

[0159] The material of the conductive adhesive layer can be any commercially available conductive adhesive known in the art with a melting temperature greater than or equal to 160° C. and less than or equal to 200° C., such as Sn63Pb37, Sn60Pb40, Sn55Pb45, Sn99Ag0.3Cu0.7, Sn96.5Ag3.0Cu0.5, etc. It can also include conductive adhesives prepared by various known methods that can be used in photovoltaic modules and have a melting temperature greater than or equal to 160° C. and less than or equal to 200° C.

[0160] The shape of the conductive adhesive material layer is various regular and irregular shapes, such as a cube, an elliptical cylinder or a cylinder. The length of the conductive adhesive material layer is greater than or equal to 1mm and less than or equal to 3mm, the width of the conductive adhesive material layer is greater than or equal to 0.5mm and less than or equal to 2mm, and the height of the conductive adhesive material layer is greater than or equal to 0.1mm and less than or equal to 1mm. Exemplarily, the length of the conductive adhesive material layer is 1mm, 1.5mm, 2mm, 2.5mm or 3mm, etc.; the width of the conductive adhesive material layer is 0.5mm, 0.6mm, 0.9mm, 1mm, 1.5mm or 2mm, etc.; the height of the conductive adhesive material layer is 0.1mm, 0.3mm, 0.5mm, 0.6mm, 0.9mm or 1mm, etc. Preferably, the shape of the conductive adhesive material layer is a cube. The length of the cubic conductive adhesive material layer is 2mm, the width is 1mm, and the height is 0.3mm. The length direction of the above-mentioned conductive adhesive material layer is consistent with the first direction A, and the width direction of the conductive adhesive material layer is consistent with the second direction B.

[0161] After the conductive adhesive material layer is actually printed, it is dried into a solid state in a high-temperature drying oven, and the temperature setting range of the drying oven is greater than or equal to 160° C. and less than or equal to 250° C. Exemplarily, the temperature of the drying oven is 160° C., 165° C., 170° C., 175° C., 180° C., 185° C., 190° C., 195° C., 200° C., 220° C., or 250° C., and any ranges between these values.

[0162] In an alternative approach, see Figure 4 and Figure 5 , the length of the window 71 is greater than or equal to the length of the conductive adhesive material layer 9 on the corresponding joint, and the length direction of the window 71 and the length direction of the conductive adhesive material layer 9 on the joint are both consistent with the first direction A. And / or, the width of the window 71 is greater than or equal to the width of the conductive adhesive material layer 9 on the corresponding joint, and the width direction of the window 71 and the width direction of the conductive adhesive material layer 9 on the joint are both consistent with the second direction B.

[0163] When the above technical solution is adopted, it is ensured that the conductive adhesive material layer on the joint portion can be smoothly electrically connected to the metal conductive layer through the window, thereby reducing the difficulty of assembly and the assembly error.

[0164] In an alternative approach, see Fig.12 and Fig.13 The solar cell group includes a plurality of cell strings; each cell string includes a plurality of solar cells as described in the above technical solution, or each cell string includes a plurality of cell slices divided from the solar cells as described in the above technical solution. It should be noted that Fig.12 and Fig.13 It is only a schematic diagram of the arrangement of multiple segmented battery cells. The number of segmented battery cells shown in the figure does not fully represent the actual situation.

[0165] See also Fig.12 Among at least 1 / 3 of the solar cells or slice cells 90 included in a single battery string, the distance L7 between any two adjacent second joining portions 31 disposed on two solar cells or two slice cells 90 is greater than 1 / 10 of the maximum distance L9 between two opposite edges of the solar cell or slice cell 90 where the two second joining portions are located in the fifth direction F; the fifth direction is consistent with the arrangement direction of multiple solar cells or multiple slice cells in the same battery string.

[0166] Ensuring that a certain number of second joints 31 in a single battery string are located between two solar cells or two slice cells 90 and are adjacent to each other and maintain a certain distance can improve the connection strength between the solar cell or slice cell and the metal conductive layer, making the solar cell or slice cell and the metal conductive layer more firmly connected, thereby ensuring the quality of the photovoltaic module. Furthermore, the larger the proportion of adjacent second joints 31 with a larger distance (the proportion can be at least 1 / 3, at least 1 / 2, or even all), the more points that can withstand greater tension, and the more dispersed the distribution, so that the second joints are more evenly stressed and the photovoltaic module is more stable. Further, as long as the above conditions are met, the effect of making the solar cell or slice cell and the metal conductive layer more firmly connected can be achieved, and there is no need to strictly control the distance between other second joints located between two solar cells or two slice cells and adjacent to each other, which increases the selectivity of the photovoltaic module and expands the scope of application of the photovoltaic module.

[0167] The following three possible situations are used as examples to describe photovoltaic components. It should be understood that the following description is only for understanding and is not intended to be a specific limitation.

[0168] Example 1: The battery string includes 12 sub-cells, and each sub-cell 90 has a second joint 31. Among at least four adjacent sub-cells 90, the distance between any two adjacent second joints 31 disposed in two sub-cells (e.g. Fig.12 The middle distance L7 is greater than the maximum distance between two opposite edges of the split battery sheet 90 where the two second bonding portions 31 are located in the fifth direction F (for example Fig.12 The distance between two adjacent second joint portions of the remaining split battery sheets (e.g. Fig.12 The middle distance L8) is equal along the fifth direction F.

[0169] Example 2: The battery string includes 12 sliced ​​battery cells, of which 6 sliced ​​battery cells do not have the second joint portion, and the remaining 6 sliced ​​battery cells have the second joint portion. In at least two adjacent sliced ​​battery cells, the distance between the adjacent second joint portions is greater than 1 / 10 of the maximum distance between two opposite edges of the sliced ​​battery cells where the two second joint portions are located in the fifth direction.

[0170] Example 3: The battery string includes 14 sliced ​​battery cells, each of which has a second joint. Among at least 5 adjacent sliced ​​battery cells, the distance between any two adjacent second joints disposed in two sliced ​​battery cells is greater than 1 / 10 of the maximum distance between two opposite edges of the sliced ​​battery cells where the two second joints are located in the fifth direction. The distances between two adjacent second joints disposed in two sliced ​​battery cells in the remaining sliced ​​battery cells are equal along the fifth direction.

[0171] In an optional manner, the solar cell group includes a plurality of cell strings; each cell string includes a plurality of solar cells as described in the above technical solution, or each cell string includes a plurality of sliced ​​cell sheets divided from the solar cells described in the above technical solution.

[0172] See also Fig.13 In the same battery string, the distance between two adjacent second joint portions 31 disposed in two solar cells or two split battery cells 90 is evenly distributed along the fifth direction. Fig.13 Medium distance L10. And / or, see Fig.12 In the same battery string, the distance between two adjacent second joint portions 31 disposed in two solar cells or two segmented battery cells 90 is alternately long and short along the fifth direction F. For example, Fig.12The distance between the second joint portion on the first segmented cell and the second segmented cell is L7, the distance between the second segmented cell and the second joint portion on the third segmented cell is L8, and L7 is greater than L8. The fifth direction F is consistent with the arrangement direction of multiple solar cells or multiple segmented cells in the same battery string.

[0173] As a possible implementation, the photovoltaic assembly may further include a packaging film and a transparent cover plate sequentially disposed on the solar cell group.

[0174] For the above-mentioned encapsulation film and transparent cover plate, the thickness and material of the two can be determined according to actual needs, as long as they can be applied to the photovoltaic module provided in the embodiment of the present application. Exemplarily, the material of the encapsulation film may include at least one of polyolefin elastomer (POE), polyvinyl butyral (PVB) and ethylene-vinyl acetate copolymer (EVA).

[0175] Exemplarily, the material of the transparent cover plate may include at least one of tempered glass, high-transmittance plastic and silicone rubber.

[0176] As a possible implementation, see Figure 8 The conductive backplane 7 may further include a backplane 75 and an adhesive layer 76 , and a side of the metal conductive layer 74 facing away from the insulating material layer 70 is bonded to the backplane 75 via the adhesive layer 76 .

[0177] The backboard can be a TPC backboard, a PET backboard, a TPT backboard or a CPC backboard, etc. For example, a TPC backboard includes a PVF (polyvinyl fluoride) film, a PET substrate and a coating. A CPC backboard includes a coating + a PET substrate + a coating.

[0178] The back plate is provided with three holes in the middle position, and the shape of the back plate openings can be circular, oval, rectangular or other shapes. Preferably, the shape of the back plate openings is rectangular. At this time, the length of the back plate openings is greater than or equal to 3mm and less than or equal to 15mm, and the width of the back plate openings is greater than or equal to 3mm and less than or equal to 8mm. Exemplarily, the length of the back plate openings can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm or 15mm, etc. The width of the back plate openings can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm or 8mm, etc. Preferably, the length of the rectangular back plate opening is 6 mm, and the width of the rectangular back plate opening is 6 mm. The back plate opening corresponds to the position of the lead-out hole described above, and is used to lead out the busbar.

[0179] The material of the adhesive layer may include at least one of polyolefin elastomer (POE), polyvinyl butyral (PVB) and ethylene-vinyl acetate copolymer (EVA).

[0180] The adhesive layer is provided with three holes in the middle position, and the shape of the adhesive layer opening can be circular, oval, rectangular or other shapes. Preferably, the shape of the adhesive layer opening is rectangular. At this time, the length of the adhesive layer opening is greater than or equal to 3mm and less than or equal to 15mm, and the width of the adhesive layer opening is greater than or equal to 3mm and less than or equal to 10mm. Exemplary, the length of the adhesive layer opening can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm or 15mm, etc. The width of the adhesive layer opening can be 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc. Preferably, the length of the rectangular adhesive layer opening is 6mm, and the width of the rectangular adhesive layer opening is 6mm. The above-mentioned adhesive layer opening corresponds to the position of the lead-out hole described above, and is used to lead out the bus bar. Specifically, the above-mentioned bus bar is connected in the middle and at the ends of the metal conductive layer, and is led out through the above-mentioned lead-out hole, the adhesive layer opening and the back plate opening.

[0181] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0182] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A solar cell, characterized in that: The solar cell comprises: Battery body; A collector electrode is formed on the battery body; a plurality of the collector electrodes extend along a first direction and are spaced apart along a second direction, the first direction being different from the second direction; A plurality of joints are arranged at intervals on the battery body; each of the joints is electrically connected to at least one of the current collecting electrodes; The engaging portion comprises a first engaging portion and a second engaging portion, wherein the size of the second engaging portion is larger than the size of the first engaging portion; The collector electrode comprises a first collector electrode and a second collector electrode, the first collector electrode is electrically connected to the first joint portion, and the second collector electrode is electrically connected to the second joint portion; an extension length of a single first collector electrode along the first direction is greater than an extension length of a single second collector electrode along the first direction; The second collector electrode includes a first polarity second collector electrode and a second polarity second collector electrode; Second collector electrodes of the first polarity extend along the first direction and are located on the same straight line and are distributed in sequence at intervals; Second collector electrodes of second polarity extend along the first direction and are located on the same straight line and are distributed in sequence at intervals; Along the first direction, the first polarity second collecting electrodes and the second polarity second collecting electrodes are alternately distributed and are not on the same straight line.

2. The solar cell according to claim 1, characterized in that Along the second direction, the battery body has a first edge and a second edge opposite to each other, and a distance between the first edge and the second edge is L1; For a single second joint portion, along the second direction, a minimum distance between the first edge or the second edge of the battery body closest to the single second joint portion and the second joint portion is L2, and a ratio of L2 to L1 is greater than or equal to 1% and less than or equal to 50%; And / or, along the second direction, a distance between any two of the second joining portions located on the same straight line is greater than 1 / 5 L1.

3. The solar cell according to claim 1, characterized in that For a single second joint, along the second direction, the minimum distance between the edge of the battery body closest to the single second joint and the second joint is L2; ​​along the second direction, the spacing between two adjacent first collecting electrodes is L3, and the ratio of L2 to L3 is greater than or equal to 1.

4. The solar cell according to claim 1, characterized in that Along the second direction, a projection of at least one second collector electrode of the first polarity on the second collector electrode of the second polarity adjacent thereto is located within the second collector electrode of the second polarity; And / or, along the second direction, a projection of at least one first polarity second collecting electrode on the second polarity second collecting electrode adjacent thereto is tangent to an end of at least one second polarity second collecting electrode close to the first polarity second collecting electrode.

5. The solar cell according to any one of claims 1 to 4, characterized in that: When the solar cell comprises at least two electrode units spaced apart and distributed along the second direction, a separation region extending along the first direction is provided between two adjacent electrode units; Along the second direction, a plurality of the second joining portions located on one side of the separation area are located on the same straight line, and the extension direction of the straight line is consistent with the first direction; And / or, along the second direction, the battery body has a first edge and a second edge relative to each other, and the distance between the first edge and the second edge is L1; the distance between the two second joining portions located on both sides of the same separation area and relatively distributed is greater than 1 / 5L1.

6. The solar cell according to any one of claims 1 to 4, characterized in that: The first engaging portion includes at least two first engaging portions of different sizes.

7. The solar cell according to claim 6, characterized in that: The solar cell comprises at least two electrode units spaced apart along the second direction, a separation region extending along the first direction is provided between two adjacent electrode units, wherein the first joint portion with the smallest size is located at at least one side of the separation region, and the first joint portion with the smallest size is arranged adjacent to the separation region; And / or, along the second direction, the battery body includes two opposite edges and a middle area between the two edges, and the first joint portion with the smallest size is arranged adjacent to at least one of the edges.

8. A conductive backplane, characterized in that: The conductive backplane includes a layer of insulating material; A plurality of windows are provided on the insulating material layer, a group of the windows on the insulating material layer are arranged at intervals along the third direction, a group of the windows includes a first window and a second window, and the size of the second window is larger than the size of the first window; The first window corresponds to the first joining portion in the solar cell according to any one of claims 1 to 7; the second window corresponds to the second joining portion in the solar cell according to any one of claims 1 to 7.

9. The conductive backplane according to claim 8, characterized in that: The first windows include at least two first windows of different sizes.

10. A photovoltaic module, characterized in that: include: A conductive backplane and a solar cell group arranged on the conductive backplane; wherein the conductive backplane comprises a metal conductive layer and an insulating material layer stacked in sequence; The solar cell group comprises a plurality of solar cells according to any one of claims 1 to 7; or, the solar cell group comprises a plurality of sliced ​​cell sheets divided from the solar cell according to any one of claims 1 to 7; A plurality of windows are provided on the insulating material layer, and a plurality of solar cells according to any one of claims 1 to 7 or sliced ​​cells obtained by dividing the solar cell according to any one of claims 1 to 7 are electrically connected to the metal conductive layer through the insulating material layer having the windows.

11. The photovoltaic module according to claim 10, characterized in that: The length of the window is greater than or equal to the length of the corresponding joint portion, and the length direction of the window and the length direction of the joint portion are both consistent with the first direction; And / or, the width of the window is greater than or equal to the width of the corresponding joint portion, and the width direction of the window and the width direction of the joint portion are both consistent with the second direction.

12. The photovoltaic module according to claim 10 or 11, characterized in that: The photovoltaic module further includes: an insulating portion; the insulating portion covers at least a portion of the first collector electrode; Along the first direction, the insulating portions and the joining portions are distributed alternately and at intervals; and / or, along the second direction, the insulating portions and the joining portions are distributed alternately and at intervals.

13. The photovoltaic module according to claim 12, characterized in that: The length of the insulating portion is greater than the length of any of the windows adjacent thereto, and the length direction of the insulating portion and the length direction of the window are both consistent with the first direction; And / or, the length of the insulating portion is greater than the length of any of the joining portions; the length direction of the insulating portion and the length direction of the joining portion are both consistent with the first direction.

14. The photovoltaic module according to claim 12, characterized in that: There is a first difference between the length of the insulating part and the length of the window, and there is a second difference between the length of the window and the length of the joining part; the first difference and the second difference are both positive numbers, and the first difference is greater than the second difference; the length direction of the insulating part, the length direction of the window and the length direction of the joining part are all consistent with the first direction.

15. The photovoltaic module according to claim 10, characterized in that: The solar cell group comprises a plurality of cell strings; each of the cell strings comprises a plurality of solar cells according to any one of claims 1 to 7, or each of the cell strings comprises a plurality of cell slices divided from the solar cell according to any one of claims 1 to 7; Among at least 1 / 3 of the solar cells or the segmented cell sheets included in a single battery string, the distance between any two adjacent second joining portions which are located in two of the solar cells or two of the segmented cell sheets is greater than 1 / 10 of the maximum distance between two opposite edges of the solar cell or the segmented cell sheets where the two second joining portions are located in a fifth direction; the fifth direction is consistent with the arrangement direction of multiple solar cells or multiple segmented cell sheets in the same battery string.

16. The photovoltaic module according to claim 10, characterized in that: The solar cell group comprises a plurality of cell strings; each of the cell strings comprises a plurality of solar cells according to any one of claims 1 to 7, or each of the cell strings comprises a plurality of cell slices divided from the solar cell according to any one of claims 1 to 7; In the same battery string, the distance between two adjacent second joints which are respectively arranged at two of the solar cells or two of the segmented battery cells is evenly distributed along the fifth direction; and / or, in the same battery string, the distance between two adjacent second joints which are respectively arranged at two of the solar cells or two of the segmented battery cells is alternately distributed in long and short directions along the fifth direction; the fifth direction is consistent with the arrangement direction of multiple solar cells or multiple segmented battery cells in the same battery string.

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