Photovoltaic module

Abstract

The invention provides a photovoltaic module, which comprises a plurality of battery bodies, and each battery body comprises a first side edge and a second side edge; the battery body is provided with an electrode structure, the electrode structure comprises a plurality of auxiliary grids, the auxiliary grids are at least partially parallel to the first side edge, and two auxiliary grids with opposite polarities are alternately arranged along the extension direction of the second side edge; the auxiliary grid comprises a plurality of second notches and a plurality of connecting parts in the extending direction of the first side edge, the second notches and the connecting parts are adjacently arranged, the auxiliary grid is divided into a plurality of sections by the second notches, and the second notch parts are of vacant disconnected structures; the plurality of interconnection strips are arranged along the extension direction of the second side edge and are connected in series with the adjacent battery bodies; any interconnection strip is electrically connected with the connecting part of the auxiliary grid with one polarity, and at least part of the interconnection strip is in contact with the surface of the battery body at the second notch part of the auxiliary grid with the other polarity. According to the invention, more insulating glue can be saved, the insulating glue cost is reduced, and a part of process time is saved.

Description

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on May 28, 2024, with application number 202410676883.1 and invention name “A solar cell, photovoltaic module and method for preparing photovoltaic module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of photovoltaic cells, and in particular to a photovoltaic module. Background Art

[0003] In the photovoltaic cell industry, when interconnecting bars are used to string two adjacent cells together, in order to ensure reliable insulation between the interconnecting bars and the auxiliary grids with opposite polarity, insulating glue (commonly known as green glue) is usually printed on the surface of the cell body to insulate the interconnecting bars from the auxiliary grids.

[0004] However, the current design of the electrode structure on the surface of the cell requires the use of a large amount of insulating glue when achieving insulation between the interconnection strips and the secondary grid with opposite polarity, which leads to an increase in the material cost of the photovoltaic module and an increase in the manufacturing process time. Summary of the Invention

[0005] The present application provides a photovoltaic module, which aims to solve the problem that traditional photovoltaic modules consume a lot of insulating glue.

[0006] A photovoltaic module, comprising:

[0007] A plurality of battery bodies, each comprising a first side and a second side; each battery body being provided with an electrode structure, each electrode structure comprising a plurality of auxiliary grids, each auxiliary grid being at least partially parallel to the first side, and two types of auxiliary grids having opposite polarities being alternately arranged along an extension direction of the second side;

[0008] Along the extension direction of the first side, the auxiliary grid includes a plurality of second notches and a plurality of connecting portions, the second notches and the connecting portions being adjacently arranged, and the plurality of second notches dividing the auxiliary grid into multiple sections, wherein the second notches are vacant and disconnected structures; along the extension direction of the first side and the second side, the second notches and the connecting portions are adjacently arranged;

[0009] A plurality of interconnecting bars are provided, each of which is arranged along the extension direction of the second side edge and connects the adjacent battery bodies in series; any one of the interconnecting bars is electrically connected to the connecting portion of the auxiliary grid of one polarity, and at the second notch portion of the auxiliary grid of the other polarity, the interconnecting bar is at least partially in contact with the surface of the battery body.

[0010] In the embodiments of the present application, by designing a second notch in the secondary grid on the surface of the cell, a portion of the insulating adhesive can be eliminated in this area. This saves more insulating adhesive from the perspective of the entire cell and photovoltaic module, helping to reduce insulating adhesive costs. Furthermore, by not applying a large amount of insulating adhesive in the second notch, a portion of the process time can be saved, shortening the processing and manufacturing time of the photovoltaic module, which is conducive to increasing the shipment volume of the photovoltaic module. Furthermore, removing a portion of the insulating adhesive in the second notch also helps to reduce the height difference between the top of the interconnecting strip and the top of the secondary grid, which helps to reduce the internal stress of the laminate and improve the product quality of the photovoltaic module.

[0011] Furthermore, when interconnecting bars are laid out for string welding, they can be welded to the corresponding polarity auxiliary grids through the connecting portions. Compared to the welding design of the interconnecting bars and auxiliary grids, the connecting portions can provide a larger welding area than the auxiliary grids, providing greater adhesion force for the interconnecting bars and making the connection between the interconnecting bars and the cell more reliable. Furthermore, the larger welding area helps reduce welding resistance, thereby reducing the power loss of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 The structure of the solar cell in the embodiment of the present application is shown Figure 1 ;

[0014] Figure 2 A schematic diagram showing the position of the connection portion of a solar cell in an embodiment of the present application;

[0015] Figure 3 A schematic diagram showing the connection between solar cells and interconnecting strips in an embodiment of the present application is shown;

[0016] Figure 4 A schematic diagram showing a gap formed between the interconnection strip and the insulating adhesive in an embodiment of the present application is shown;

[0017] Figure 5 A schematic diagram showing an embodiment of the present application in which no gap is formed between the interconnection strip and the insulating adhesive;

[0018] Figure 6 A schematic diagram showing the stacking of interconnection strips and insulating adhesive in an embodiment of the present application is shown;

[0019] Figure 7A schematic diagram showing a structure in which the auxiliary grid at the connecting portion in an embodiment of the present application is continuously connected is shown;

[0020] Figure 8 A schematic diagram showing an embodiment of the present application in which the width of the interconnection bar at the connection portion is greater than the width of the interconnection bar at the second notch;

[0021] Figure 9 The local structure of the solar cell in the embodiment of the present application is shown Figure 1 ;

[0022] Figure 10 The local structure of the solar cell in the embodiment of the present application is shown Figure 2 ;

[0023] Figure 11 The local structure of the solar cell in the embodiment of the present application is shown Figure 3 ;

[0024] Figure 12 A schematic diagram showing the complete arrangement of the electrode structure on the surface of a battery cell in an embodiment of the present application is shown;

[0025] Figure 13 In the embodiment of this application Figure 12 A partial enlarged diagram of the I position in the middle;

[0026] Figure 14 The structure of the solar cell in the embodiment of the present application is shown Figure 2 ;

[0027] Figure 15 The structure of the solar cell in the embodiment of the present application is shown Figure 3 ;

[0028] Figure 16 The structure of the solar cell in the embodiment of the present application is shown Figure 4 ;

[0029] Figure 17 The shape of the connecting portion in the embodiment of the present application is shown Figure 1 ;

[0030] Figure 18 The shape of the connecting portion in the embodiment of the present application is shown Figure 2 ;

[0031] Figure 19 The shape of the connecting portion in the embodiment of the present application is shown Figure 3 .

[0032] Description of the accompanying figures:

[0033] Battery body-10, first side-10a, second side-10b, electrode structure-101, first notch-102b, second notch-102a, interconnection bar-103, connection part-104, first monopolar unit-105, auxiliary grid-1011, positive auxiliary grid-1011a, negative auxiliary grid-1011b, end main grid-1012, middle main grid-1013, edge main grid-1014, insulating glue-1015, first connection part-1016, second connection part-1017, edge interconnection bar-1031 on the left edge, edge interconnection bar-1032 on the right edge. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] In the photovoltaic modules of the present application, by optimizing and improving the electrode structure on the surface of the cells that make up the cell strings, during string soldering, the interconnecting strips do not need to be extensively coated with insulating adhesive for insulation when passing through certain locations on the cell surfaces, thereby reducing the consumption of insulating adhesive. Compared to traditional photovoltaic modules, since a large amount of insulating adhesive is no longer required on certain locations on the cell surfaces, the cost of insulating adhesive is naturally reduced, and the time previously spent on adhesive application is also saved, which helps to improve the manufacturing efficiency of photovoltaic modules.

[0036] like Figure 1 FIG. 1 is a schematic diagram of the structure of a cell used in a photovoltaic module according to an embodiment of the present application. The cell body 10 may be a silicon wafer made of monocrystalline or polycrystalline silicon. The cell body 10 may be in the shape of a rectangle having a first side 10a and a second side 10b. The first side 10a and the second side 10b may be two mutually perpendicular sides of the rectangular silicon wafer. For example, the first side 10a may be the long side of the rectangle, and the second side 10b may be the short side of the rectangle. The first side 10a extends in the X direction shown in the figure, and the second side 10b extends in the Y direction shown in the figure.

[0037] An electrode structure 101 is provided on the surface of the battery body 10. For example, the electrode structure 101 can be prepared by screen printing or electroplating. The electrode structure 101 includes a plurality of auxiliary grids 1011 distributed on the battery body 10. The auxiliary grids 1011 are generally thin and can also be called fine grids. These auxiliary grids 1011 can include two auxiliary grids with opposite polarities, one is a positive auxiliary grid 1011a, and the other is a negative auxiliary grid 1011b.Figure 1 As shown in FIG. 1 , all the sub-grids 1011 may be partially or completely parallel to the first side 10 a , and the positive sub-grids 1011 a and the negative sub-grids 1011 b may be alternately arranged along the extension direction Y of the second side 10 b .

[0038] like Figure 1 and Figure 2 The hint, Figure 2 For Figure 1 In the embodiment of the present application, whether it is the positive electrode sub-grid 1011a or the negative electrode sub-grid 1011b, along the extension direction X of the first side 10a, the sub-grid 1011 includes a plurality of second notches 102a and a plurality of connecting portions 104 (see the connecting portion 104 for details). Figure 2 (See the schematic diagram for details). The second notch 102a is a vacant, disconnected structure. No conductive medium exists at the location of the second notch 102a, thus breaking the secondary grid 1011 into multiple sections. However, at the location of the connecting portion 104, the secondary grid 1011 remains conductive. For example, the connecting portion 104 may be a solder pad. Along the first side 10a, the second notch 102a and the connecting portion 104 are adjacently positioned on the same secondary grid 1011. The second notch 102a and the connecting portion 104 may each be located at opposite ends of the same segment of the secondary grid 1011. Furthermore, along the extension direction of the second side 10b, the second notch 102a and the connecting portion 104 on two adjacent secondary grids 1011 are adjacently positioned.

[0039] In conjunction with the above-described embodiments, it should be noted that, in the present embodiment, when counting the number of auxiliary grids 1011, grid lines that overlap along the X-direction are considered to be the same auxiliary grid 1011. Portions of the same auxiliary grid 1011 separated by the second notch 102a are considered to be different segments of the auxiliary grid 1011.

[0040] Combine Figure 2 As shown in the schematic diagram, it can be understood that along the X direction, the auxiliary grid 1011 forms a structure of "grid line-connection portion-grid line-second notch-grid line-connection portion-grid line-second notch-grid line-connection portion-grid line". When actually processing and manufacturing such a solar cell, the connection portion 104 and the auxiliary grid 1011 can be printed in the same process or in separate processes.

[0041] Figure 3 The figure also shows a schematic diagram of interconnection bars 103 laid on the surface of one of the battery cells when using multiple interconnection bars 103 for series welding. The interconnection bars 103 are all arranged along the extension direction of the second side 10b, connecting the battery bodies 10 arranged adjacent to each other in the Y direction in series.

[0042] Combine Figure 3As shown in the schematic, when any one interconnection strip 103 is laid along the Y direction, the connection portions 104 of the sub-ridges 1011 of one polarity are electrically connected together, and the interconnection strip 103 is insulated from the sub-ridges 1011 of the other polarity at the positions of the second gaps 102a. Along the extension direction of the second side edge 10b (i.e. the Y direction), i.e. the extension direction of the interconnection strip 103, the connection portions 104 on at least one sub-ridge 1011 and the second gaps 102a on another sub-ridge 1011 are arranged alternately. For example, in Figure 2 the Y direction, the connection portions 104 on the positive sub-ridges 1011a and the second gaps 102a on the negative sub-ridges 1011b are arranged alternately. Thus, a shape feature of "connection portion-second gap-connection portion-second gap-connection portion-second gap" is formed in the Y direction.

[0043] Because the second gaps 102a have been designed to make the interconnection strip 103 insulated from the sub-ridges 1011 of the other polarity, at the positions of the second gaps 102a, the interconnection strip 103 is at least partially in contact with the surface of the battery body 10, i.e. at the positions of the second gaps 102a, a large amount of insulating glue can not be applied, and the interconnection strip 103 can be at least partially in direct contact with the battery body 10. The interconnection strip 103 can include a core material and a peripheral soldering layer such as a tin alloy layer. At the positions of the second gaps 102a, the interconnection strip 103 is in contact with the passivation layer (e.g. silicon nitride layer, aluminum oxide layer, etc.) and the TCO layer of the battery body 10, and the interconnection strip 103 and the battery body 10 can have a structure without electrodes and insulating glue.

[0044] Therefore, in the embodiments of the present application, by designing the second gaps in the sub-ridges on the surface of the battery piece, a part of the insulating glue can be saved at the positions of the second gaps. From the perspective of the entire battery piece and photovoltaic module, more insulating glue can be saved, which helps to reduce the cost of the insulating glue. At the same time, because a large amount of insulating glue is not applied at the positions of the second gaps, a part of the process time can be saved, which helps to shorten the processing and manufacturing time of the photovoltaic module, and is conducive to improving the shipment volume of the photovoltaic module. In addition, the removal of a part of the insulating glue at the positions of the second gaps also helps to reduce the height difference between the top of the interconnection strip and the top of the sub-ridge, which is conducive to reducing the internal stress of the laminated piece and improving the product quality of the photovoltaic module.

[0045] In addition, when the interconnection strip is laid along the Y direction for series welding, the interconnection strip can be welded and connected to the sub-ridge of the corresponding polarity through the connection portion. Compared with the welding design of the interconnection strip and the sub-ridge, the connection portion can provide more welding area than the sub-ridge, which provides greater adhesion force for the interconnection strip, and makes the connection of the interconnection strip and the battery piece more reliable. In addition, the greater welding area is also conducive to reducing the welding resistance, thereby reducing the power loss of the battery piece.

[0046] Optionally, in one embodiment, when laying the interconnection bar 103, in order to prevent the interconnection bar 103 from shifting and causing an accidental short circuit with the auxiliary grid 1011 adjacent to the second notch 102a, a small amount of insulating glue 1015 may be applied to the second notch 102a to further improve insulation reliability. Specifically, within the allowable process error range, when the degree of shift of the interconnection bar 103 varies, the interconnection bar 103 and the insulating glue 1015 in the photovoltaic module may form different positional relationships as follows:

[0047] a) If Figure 4 As shown, along the extension direction of the first side 10a (i.e., the X direction in the figure), when the interconnecting bar 103 is slightly offset, a certain gap can still be maintained between the interconnecting bar 103 and the insulating adhesive 1015. In this case, along the thickness direction Z of the battery body 10, there is no insulating adhesive 1015 between the interconnecting bar 103 and the battery body 10, and the interconnecting bar 103 is in full direct contact with the battery body 10. In this case, the physical insulation distance between the interconnecting bar 103 and the oppositely polarized auxiliary grid 1011 is large, resulting in better insulation performance.

[0048] b) If Figure 5 As shown, when the interconnecting bar 103 deviates significantly along the extension direction of the first side 10a (i.e., the X direction in the figure), the interconnecting bar 103 just barely contacts the edge of the insulating adhesive 1015. Along the X direction, there is no gap between the interconnecting bar 103 and the insulating adhesive 1015. At this point, along the thickness direction Z of the battery body 10, there is still no insulating adhesive 1015 between the interconnecting bar 103 and the battery body 10, and the interconnecting bar 103 and the battery body 10 are in direct contact. In this case, even if the interconnecting bar 103 deviates, the insulating and isolating effect of the insulating adhesive 1015 ensures good insulation between the interconnecting bar 103 and the oppositely polarized secondary grid 1011.

[0049] It should be understood that there will inevitably be certain process errors in actual production. At this time, the main part of the interconnection bar 103 is in direct contact with the battery body 10, and the edge of the interconnection bar 103 will partially overlap with the insulating glue 1015 (such as Figure 6 ), it can be understood that this overlapping structure can still ensure insulation performance within the range allowed by process errors.

[0050] Optionally, in one embodiment, Figure 1 and Figure 2As shown, in the solar cell of the embodiment of the present application, along the extension direction X of the first side 10a, the auxiliary grid 1011 also includes multiple first notches 102b. Similar to the second notches 102a of the aforementioned embodiment, the auxiliary grid 1011 can also be a disconnected and non-continuous structure at the location of the first notches 102b. However, since the interconnection bar 103 needs to be electrically connected to the auxiliary grid 1011 of the same polarity at the location when passing through the location of the first notches 102b, the aforementioned connecting portion 104 is provided at the location of the first notches 102b. The connecting portion 104 can connect and conduct the separated auxiliary grids 1011. Therefore, when the interconnection bar 103 is welded to the connecting portion 104, an electrical connection can be established with the auxiliary grid 1011 at that location.

[0051] In a solar cell of this shape and structure, the design of the first notch 102 b can further reduce the consumption of the paste for printing the secondary grid 1011 , thereby saving the cost of the paste for the secondary grid 1011 .

[0052] Optionally, in one embodiment, Figure 7 As shown, in order to prevent the failure of effectively conducting the auxiliary grid 1011 at the first notch 102b due to the setting of the first notch 102b and then printing the connecting portion 104 at the position of the first notch 102b, in the embodiment of the present application, the auxiliary grid 1011 at the position of the connecting portion 104 can also be designed as a continuous through structure, that is, the grid line at this position is not separated by the first notch 102b, and the connecting portion 104 is directly printed and covered on top of the continuous grid line. In this case, the electrical contact area between the connecting portion 104 and the auxiliary grid 1011 is larger, which is more conducive to the transmission of current from the auxiliary grid 1011 to the connecting portion 104. It should be noted that the structure of the auxiliary grid 1011 continuously connected in the embodiment of the present application refers to a design structure opposite to that with the first notch 102b, which means that the grid line of the auxiliary grid 1011 at the position where the first notch 102b was originally provided remains continuously connected, and does not mean that a complete auxiliary grid 1011 is continuously connected along the X direction shown in the figure.

[0053] Optionally, in one embodiment, when the interconnection strip 103 is laid through the connecting portion 104, the interconnection strip 103 and the connecting portion 104 can be directly connected in electrical contact without using materials such as solder paste to weld the interconnection strip 103 and the connecting portion 104. The interconnection strip 103 includes a core material and a welding layer coated on the surface of the core material. For example, when a tinned copper solder strip is used as the interconnection strip 103, the tinned layer on the surface of the interconnection strip 103 can be melted to weld and fix the interconnection strip 103 and the connecting portion 104 together. The photovoltaic module of the embodiment of the present application can reduce the use and consumption of welding materials such as solder paste and reduce the process cost of series welding. It can be understood that the fixation between the interconnection strip 103 and the connecting portion 104 does not rely on other welding materials, and of course the residual components of the pretreatment such as surface cleaning agent are not considered as the welding materials between the interconnection strip 103 and the connecting portion 104. At this time, the interconnection strip 103 directly contacts the connecting portion 104 and the battery body 10 at the position of the second gap 102a, which can simultaneously save the insulating glue and the welding material, reduce the height of the interconnection strip 103 relative to the battery body 10, and enhance the bonding strength of the interconnection strip 103 and the battery body 10.

[0054] As can be seen from the above two embodiments, the sub-grid 1011 at the position of the connecting portion 104 can be continuous or disconnected, which can be selected according to different functional requirements.

[0055] Optionally, in one embodiment, when the interconnecting bar 103 is laid along the extension direction of the second side 10b (i.e., the Y direction shown in the figure), the interconnecting bar 103 has a first bottom at the position of the connecting portion 104, the interconnecting bar 103 has a second bottom at the position of the second notch 102a, and the interconnecting bar 103 has a third bottom at the position outside the connecting portion 104 and the second notch 102a. The bottom of the interconnecting bar 103 refers to the position adjacent to the battery body 10 along the thickness direction of the battery body 10. In the same interconnecting bar 103, along the thickness direction of the battery body 10, the height difference between any two bottoms of the first bottom, the second bottom, and the third bottom is less than or equal to 0.5 mm. Exemplarily, the height difference between any two bottoms can be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm. Thus, when the interconnecting bars 103 are laid along the Y direction shown in the figure, the various parts of the interconnecting bars 103 can be controlled to be in the same horizontal plane as much as possible, so as to prevent the interconnecting bars 103 from forming large bending deformations in the thickness direction of the battery body 10, and improve the problem of cold welding caused by this. In some embodiments, the above-mentioned height difference is less than or equal to 50μm, which can make the photovoltaic modules have higher quality. For example, the height difference between any two bottoms can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm. Furthermore, the height difference between the bottoms of adjacent interconnecting bars 103 is less than or equal to 90μm. It can make the welding height and welding performance differences between multiple interconnecting bars 103 smaller in the same process and under the same process conditions. For example, the height difference between the bottoms of adjacent interconnection bars 103 may be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or 90 μm.

[0056] Optionally, in one embodiment, Figure 8 As shown, in the same interconnection bar 103, along the extension direction of the first side 10a (i.e., the X direction shown in the figure), the interconnection bar 103 has a first width W1 at the position of the connecting portion 104, and the interconnection bar 103 has a second width W2 at the position of the second notch 102a, and the first width W1 is greater than the second width W2. With such a design, the portion of the interconnection bar 103 with a larger width has a larger contact area with the connecting portion 104, and the connection strength is better. In some embodiments, the first width W1 is at least 1.3 times the second width W2. The first width and the second width here include the welding layer of the interconnection bar 103. Furthermore, the first width located in the edge area of ​​the battery body 10 is greater than the first width located in the middle area of ​​the battery body 10.

[0057] Optionally, in one embodiment, along the extension direction of the first side 10a (i.e., the X direction in the figure), the first notch 102b has a first length, and the second notch 102a has a second length, where the second length is greater than the first length. Such differentiated dimensional design helps ensure that the interconnection bar 103 maintains sufficient clearance from the grid lines on both sides of the second notch 102a, and the distance between the electrically connected interconnection bar 103, the connecting portion 104, and the auxiliary grid 1011 is small, thereby reducing electrical loss. For example, the second length of each section of the battery body 10 can be greater than the first length, or the second length of the end region of the battery cell can be greater than the first length, while the second length of the remaining region is approximately equal to the first length.

[0058] Optionally, in one embodiment, the second notch 102a has a second length along the extension direction of the first side 10a (i.e., the X direction in the figure). When the interconnection bar 103 used in the embodiment of the present application is a round wire interconnection bar with a circular cross-section, the second length is at least twice the diameter of the round wire interconnection bar.

[0059] When the interconnecting bar 103 used in the embodiment of the present application is a flat wire interconnecting bar with a rectangular cross-section, the second length is at least 1.5 times the width of the flat wire interconnecting bar. Compared to flat wire interconnecting bars, round wire interconnecting bars typically have a smaller diameter and a smaller contact area with the battery body 10, making them more susceptible to rolling and offsetting. Therefore, when using round wire interconnecting bars, a larger gap can be designed between the round wire interconnecting bar and the secondary grid 1011 of the second notch 102a. Flat wire interconnecting bars typically have a relatively large contact area with the battery body 10, and rectangular interconnecting bars 103 have a smaller relative offset and are less prone to rolling. Designing a relatively small gap between them and the adjacent secondary grid 1011 of opposite polarity can increase the current collection effect of the secondary grid 1011. In this case, the ends of the secondary grids 1011 of opposite polarity on both sides of the interconnecting bar 103 can be provided with insulating glue in the form of dots or blocks, or no insulating glue can be provided.

[0060] Optionally, in one embodiment, at the position of the second notch 102a, along the extension direction of the first side 10a (i.e., the X direction in the figure), the spacing between the ends of the interconnection bar 103 and the auxiliary grids 1011 on both sides can be the same or different, and the sum of the spacings on both sides is 200μm-600μm. For example, it can be 200μm, 300μm, 400μm, 500μm or 600μm. Here, the "auxiliary grids on both sides" can be auxiliary grids 1011 on both sides of the interconnection bar 103, with opposite polarity to the interconnection bar 103 or requiring insulation. When the specific shape of the interconnection bar 103 is uncertain, a certain safety distance can be reserved between the interconnection bar 103 and the auxiliary grid 1011 to ensure the insulation effect.

[0061] Optionally, in one embodiment, the second notch 102a has a second length along the extension direction of the first side 10a (i.e., the X direction shown in the figure). Along the extension direction of the second side 10b (i.e., the Y direction shown in the figure), the second length of the second notch 102a near the edge of the battery body 10 is greater than the second length of the second notch 102a located in the middle of the battery body 10. The offset at the ends of the interconnecting bar 103 is often greater than that in the middle. The second notch 102a near the edge of the battery body 10 corresponds to the truncated end of the interconnecting bar 103. Designing the second length of the second notch 102a in this area to be greater than the second length of the second notch 102a in the middle of the battery body 10 improves the tolerance during installation of the ends of the interconnecting bar 103 and reduces the risk of short circuits at the ends of the interconnecting bar 103.

[0062] Optionally, in one embodiment, Figure 4 As shown in FIG. 1 , an insulating glue 1015 is provided at the end of the auxiliary grid 1011 forming the second notch 102a. The minimum spacing between the two insulating glues 1015 corresponding to the second notch 102a can be 1.8 mm and the maximum spacing does not exceed 5 mm. For example, the spacing can be 1.8 mm, 1.9 mm, 2 mm, 3 mm, 4 mm, or 5 mm. The spacing between the two insulating glues 1015 can be the shortest gap between the edges of the two insulating glues 1015. When the gap is 1.8 mm, the spacing is small, and the second width corresponding to the second notch 102a is also narrow, that is, the ends of the auxiliary grid 1011 on both sides of the second notch 102a are closer, which is conducive to the collection of current by the auxiliary grid 1011. When the gap is 5 mm, the spacing is larger, and the second width corresponding to the second notch 102 a is also wider, that is, the ends of the auxiliary grids 1011 on both sides of the second notch 102 a are farther apart, and there is enough space between the two insulating glues 1015 to place the interconnection bar 103, and the interconnection bar 103 can be completely in direct contact with the battery body 10.

[0063] Optionally, in one embodiment, in the embodiment of the present application, the slurry used when printing the auxiliary grid 1011 may be a burn-through type slurry, and the slurry used when printing the connecting portion 104 may be a non-burn-through type slurry. The connecting portion 104 cannot pass through the passivation layer on the surface of the battery body 10. Therefore, at the location of the first notch 102b, the end of the auxiliary grid 1011 overlaps and conducts with the connecting portion 104, and the end of the auxiliary grid 1011 is at least partially located on the side of the connecting portion 104 facing away from the battery body 10. That is, the end of the auxiliary grid 1011 overlaps the upper layer of the connecting portion 104. On the one hand, it can ensure that the auxiliary grid 1011 is in full contact with the connecting portion 104 to improve the electrical connection performance. On the other hand, the protruding ends of the auxiliary grid 1011 at both ends can play the role of limiting the interconnection strip 103.

[0064] In some embodiments, at the connection portion 104 , the auxiliary grid 1011 may be pressed against the surface of the connection portion 104 and protrude from the surface of the connection portion 104 , or the connection portion 104 may cover the auxiliary grid 1011 and a portion of the connection portion 104 may be lifted up by the auxiliary grid 1011 .

[0065] Optionally, in one embodiment, Figure 3 As shown in FIG. 1 , along the extension direction of the first side 10a (i.e., the X direction in the figure), the interconnection bars 103 include a central interconnection bar 103, an edge interconnection bar 1031 on the left edge, and an edge interconnection bar 1032 on the right edge. Wherever an edge interconnection bar passes, a secondary grid 1011 of opposite polarity to that of the edge interconnection bar continuously passes through, and insulating adhesive 1015 is disposed between the edge interconnection bar and the secondary grid 1011 of opposite polarity.

[0066] Combine Figure 3 As shown in the figure, the edge interconnection bar 1032 on the right side is taken as an example. The edge interconnection bar 1032 on the right side is laid along the Y direction shown in the figure, and the positive electrode sub-grids 1011a are electrically connected together through the corresponding multiple connection parts 104. The negative electrode sub-grid 1011b between two adjacent positive electrode sub-grids 1011a is a continuous through structure at the part where the edge interconnection bar 1032 passes. In order to avoid short circuit between these negative electrode sub-grids 1011b and the edge interconnection bar 1032, an insulating glue 1015 is provided on the continuous negative electrode sub-grid 1011b below the edge interconnection bar 1032. It should be understood that the battery body 10 can be entirely made of Figure 3 The design shown can also be partially adopted Figure 3 design.

[0067] Optionally, in one embodiment, when the edge interconnection strip is connected to the connection portion 104, solder paste or the like may be coated on a portion of the upper layer of the connection portion 104 to form a conductive layer. The welding effect of the conductive layer may make the edge interconnection strip and the connection portion 104 more reliably fixed.

[0068] Optionally, in one embodiment, Figure 3 As shown in FIG. 1 , along the extension direction of the first side 10a (ie, the X direction in the figure), the interconnection bar 103 includes a middle interconnection bar 103, an edge interconnection bar 1031 on the left edge, and an edge interconnection bar 1032 on the right edge. Figure 9 As shown in FIG. 1 , the electrode structure 101 further includes an edge main grid 1014 close to the edge of the battery body 10; the edge main grid 1014 is closer to the edge of the battery body 10 than the edge interconnection bar. Figure 9 , that is, the edge main grid 1014 is closer to the outside of the battery body 10 than the edge interconnection bar.

[0069] like Figure 9As shown in FIG. 1 , a portion of the secondary grids 1011 connected to the edge busbar 1014 is continuously connected. These continuously connected secondary grids 1011 electrically connect the edge busbar 1014 to the connecting portion 104 of the same polarity located inside the edge busbar 1014. The current collected by the edge busbar 1014 can be transmitted to the left through the continuously connected secondary grids 1011 to another adjacent interconnection bar 103 from right to left.

[0070] At the same time, the edge interconnection strip 1031 on the left edge and the edge interconnection strip 1032 on the right edge are each arranged along the extension direction of the second side 10b (i.e., the Y direction in the figure). Taking an edge interconnection strip laid on the left side of the edge main grid 1014 as an example, the edge interconnection strip at this position is electrically connected to the positive electrode sub-grid 1011a, and the negative electrode sub-grid 1011b is electrically connected to the edge main grid 1014. At this time, it can be understood that the continuous through-grid structure can be designed on part of the negative electrode sub-grid 1011b. In order to avoid a short circuit between the edge interconnection strip and the part that is continuously through-grid when passing through the negative electrode sub-grid 1011b, an insulating glue 1015 is provided between the continuously through-grid negative electrode sub-grid 1011b and the edge interconnection strip.

[0071] exist Figure 9 In FIG, the arrow next to the auxiliary grid 1011 shows the path of current transmission from the end portion close to the second side 10b through the edge main grid 1014 and the continuous auxiliary grid 1011. Figure 9 As shown in the schematic, it is easy to understand that the edge main grid 1014 can be electrically connected to multiple continuous sub-grids 1011, forming multiple parallel current transmission paths at different locations of the cell near the second side 10b. The current transmission path direction is generally along the X direction, with current transmitted between the edge interconnect bar 1032 on the right edge and another interconnect bar 103 adjacent to the edge interconnect bar 1032. The current transmission direction flows from the edge interconnect bar 1032 to the other interconnect bar 103 adjacent to the edge interconnect bar 1032. The current transmission path direction can include one, two, or more, and each current transmission path is independent of each other, thereby allowing the current to be fully collected from different areas of the cell edge, reducing power loss. In this case, at the edge interconnect bar, some sub-grids 1011 are disconnected and some are continuously connected, which can further reduce the loss of insulating adhesive and conductive layer material in the edge area. Furthermore, the fewer continuous sub-grids 1011 used for the edge main grid 1014 to transmit current, the more insulating adhesive and conductive layer material can be saved. Preferably, one or two continuous through-going auxiliary grids 1011 are provided at both ends of the edge main grid 1014 .

[0072] Optionally, in one embodiment, Figure 10As shown, an insulating adhesive 1015 is provided between the continuous through-grid 1011 and the edge interconnection strip. When the edge interconnection strip extends along the Y direction shown in the figure and electrically connects to at least one of the secondary grids 1011 adjacent to the continuous through-grid 1011, poor contact is more likely to occur due to height differences. Therefore, in the embodiment of the present application, the electrode structure 101 also includes a first connecting portion 1016. The function of the first connecting portion 1016 is similar to that of the main grid in a traditional solar cell. At least one of the secondary grids 1011 adjacent to the continuous through-grid 1011 is electrically connected to the adjacent connecting portion 104 via the first connecting portion 1016, forming a first monopolar unit 105. The provision of the first connecting portion 1016 can ensure that even if the welding reliability of the secondary grid 1011 adjacent to the continuous through-grid 1011 and the interconnection strip 103 is weak, the current can be transmitted through the first connecting portion 1016 to the adjacent connecting portion 104, and then conducted to the corresponding edge interconnection strip.

[0073] Furthermore, when the edge interconnection strip is electrically connected to at least one sub-grid 1011 adjacent to the continuously penetrating sub-grid 1011, the other sub-grids 1011 adjacent to the continuously penetrating sub-grid 1011 may be continuously penetrating without the connecting portion 104, or may be provided with the connecting portion 104 and the connecting portion 104 is in direct contact with the edge interconnection strip without a conductive layer. Figure 10 For example, the continuous through-type auxiliary gate 1011 can be Figure 10 The schematic negative electrode sub-grid 1011b and the sub-grid 1011 close to it can be Figure 10 When the positive electrode sub-grid 1011a is continuously connected, it may not be provided with a connecting portion 104, or it may be provided with a connecting portion 104. When the connecting portion 104 is provided, the edge interconnection strip is in direct contact with the connecting portion 104 on the positive electrode sub-grid 1011a without a conductive layer. Figure 10 As shown in the figure, when the first connecting portion 1016 is longer, multiple sub-grids 1011 can be connected. At both ends of the first connecting portion 1016 in the length direction, a continuous negative sub-grid 1011b is provided. Multiple positive sub-grids 1011a are distributed between the two continuous negative sub-grids 1011b. The first connecting portion 1016 can connect these positive sub-grids 1011a to form a first monopolar unit 105.

[0074] It is understood that when the continuously connected auxiliary grid 1011 is the positive auxiliary grid 1011a, the opposite auxiliary grid can be the negative auxiliary grid 1011b, and vice versa. In this case, the first connecting portion 1016 connects multiple opposite auxiliary grids together to form a first monopolar unit 105. The first monopolar unit 105 can all be positive electrodes or negative electrodes. The current is collected by the multiple auxiliary grids 1011 extending in the X direction, and then can be collected to the interconnection bar at that location through the first connecting portion 1016. This can avoid the risk of damaging the auxiliary grid 1011 when the interconnection bar is directly welded to each auxiliary grid 1011. At the same time, the first connecting portion 1016 can also form a redundant backup protection structure with the interconnection bar, avoiding local failure of the interconnection bar to collect current when the interconnection bar is used alone, which helps to improve the operating stability and reliability of the battery cell.

[0075] Optionally, in one embodiment, Figure 10 As shown, in the auxiliary grid 1011 electrically connected to the edge interconnection strip, at least one connecting portion 104 is provided, and the edge interconnection strip is electrically connected to the auxiliary grid 1011 via the connecting portion 104. Figure 10 As shown in the schematic diagram, it can be understood that in the aforementioned first monopolar unit 105, at least one connecting portion 104 is provided to keep the corresponding auxiliary grid 1011 conductive and to achieve reliable connection between the corresponding auxiliary grid 1011 and the edge interconnection strip. Figure 11 As shown, the embodiment of the present application further shows a schematic diagram of three connecting parts 104 provided in the first monopolar unit 105. With the increase of the connecting parts 104, it is more conducive to improving the connection reliability between the edge interconnection strip and the corresponding auxiliary grid 1011 in the first monopolar unit 105. In addition, in order to more intuitively show a battery cell used in the embodiment of the present application, Figure 12 A schematic diagram of the complete arrangement of the electrode structure 101 on the surface of the battery cell of the embodiment of the present application is also shown. Figure 13 for Figure 12 A partial enlargement of the I position in the middle shows that Figure 13 At least the second side 10b, the second notch 102a, the connecting portion 104, the positive electrode sub-grid 1011a, the negative electrode sub-grid 1011b, the first connecting portion 1016 and the second connecting portion 1017 in the embodiment of the present application are shown, as well as the positions and connection relationships of these structures introduced in the aforementioned embodiments.

[0076] Optionally, in one embodiment, for any of the edge interconnection strips 1031 on the left edge and the edge interconnection strip 1032 on the right edge, when connecting to the connecting portion 104, solder paste or other materials may not be used to solder the interconnection strip 103 to the connecting portion 104, so that the interconnection strip 103 and the connecting portion 104 are in direct contact and electrically connected. In this case, the conductive layer material in the edge region can be further saved. Furthermore, the ends of the sub-grids 1011 of opposite polarity on both sides of the edge interconnection strips can be provided with dot-shaped or block-shaped insulating adhesive, or no insulating adhesive can be provided at all, and the edge interconnection strips and the ends of the sub-grid 1011 can be insulated by a gap.

[0077] Optionally, in one embodiment, along the extension direction of the first side 10a (ie, the X direction in the figure), the spacing between a group of edge interconnecting strips and the edge main grid 1014 close to the same side of the cell is 2 mm to 6 mm. Figure 3 and Figure 9 As shown in the figure, the spacing between the edge interconnection bar 1032 on the right edge and the edge main grid 1014 can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, or 6mm. It can be understood that if the spacing is too small, it is not conducive to the laying and arrangement of the edge interconnection bar 1032 on the right edge, and it is easy to contact and be close to the edge main grid 1014. When the spacing is too large, it is easy to affect the overall arrangement density of the interconnection bar 103 in the battery string. Therefore, the specific value of the above spacing can be determined according to the specifications of the battery cell and the arrangement density of the interconnection bar 103 in the battery string.

[0078] Optionally, in one embodiment, Figure 9 As shown, in the auxiliary grid 1011 insulated from the edge interconnection strip, part of the auxiliary grid 1011 is provided with a second notch 102 a , and another part of the auxiliary grid 1011 is a continuous through auxiliary grid.

[0079] by Figure 3 and Figure 9 For example, the edge interconnection bar 1032 on the right edge is insulated from the negative electrode sub-grid 1011b. Specifically, when achieving insulation, two different methods can be used to achieve insulation according to the location of the negative electrode sub-grid 1011b. A portion of these negative electrode sub-grids 1011b is provided with a second notch 102a, which is used to maintain insulation from the edge interconnection bar 1032 on the right edge. The other portion of the negative electrode sub-grid 1011b is a continuous through structure. At this time, insulating glue 1015 can be applied to the intersection of the continuous through negative electrode sub-grid 1011b and the interconnection bar 103. Preferably, insulating glue 1015 is provided only on the continuous through sub-grid 1011, that is, on the sub-grid 1011 that generates current for the edge main grid 1014, so that the continuous through sub-grid 1011 is not interrupted. For example, Figure 9In the embodiment, the continuously penetrating auxiliary grid 1011 is the negative auxiliary grid 1011b. It is understood that in other embodiments, the continuously penetrating auxiliary grid 1011 may also be the positive auxiliary grid 1011a.

[0080] Optionally, in one embodiment, in the auxiliary grid 1011 insulated from the edge interconnection strip, the more auxiliary grids 1011 that are continuously connected, the more insulating glue that needs to be consumed. The fewer auxiliary grids 1011 that are continuously connected, the less conducive it is to collect current. Therefore, in an embodiment of the present application, the number of auxiliary grids 1011 that are continuously connected can be 1 to 10, for example, the number of auxiliary grids 1011 that are continuously connected can be 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. In some embodiments, the number of auxiliary grids 1011 that are continuously connected can be 1 to 3. It should be understood that the number of auxiliary grids 1011 that are continuously connected here is the number of auxiliary grids 1011 that are continuously connected in the auxiliary grid 1011 that is insulated from the edge interconnection strip in the edge area of ​​the battery cell adjacent to a second side 10b, that is, the number of auxiliary grids 1011 that are continuously connected to an edge main grid 1014.

[0081] Optionally, in one embodiment, Figure 3 and Figure 9 As shown in the figure, in the auxiliary gate 1011 insulated from the edge interconnection strip, the through auxiliary gate 1011 is connected to another interconnection strip. Therefore, the width of the through auxiliary gate 1011 is greater than the width of the remaining auxiliary gates 1011, which can ensure that the through auxiliary gate 1011 has stronger overcurrent performance and reduce the risk of gate line burnout and disconnection when transmitting large current.

[0082] Alternatively, in one embodiment, the aforementioned through-grid 1011 having a greater width may be composed of two layers of grid lines: one layer being a bottom grid line printed on the surface of the battery body 10, and the other layer being a top grid line printed on the side of the bottom grid line facing away from the battery body 10, i.e., the top grid line is printed and stacked over the bottom grid line. The width of the top grid line is greater than the width of the bottom grid line or the remaining sub-grids, thereby enabling the through-grid 1011 to have a greater width.

[0083] It should also be noted that when printing the bottom grid lines and the top grid lines separately, the pastes used can be the same or different. For example, when printing the bottom grid lines of conventional width, the paste of the auxiliary grid is used, and it is the same width and printed synchronously with the auxiliary grid 1011. Then, when printing the wider top grid lines, it can be replaced with the paste of the connecting part 104 and printed synchronously with the connecting part 104.

[0084] Optionally, in one embodiment, Figure 10As shown, the electrode structure 101 in the embodiment of the present application also includes a second connecting portion 1017, which can be connected to the interconnecting bar 103 in the middle of the battery cell. The second connecting portion 1017 can be located between two adjacent middle interconnecting bars 103. The function of the second connecting portion 1017 is similar to the main grid line in a traditional battery cell. The second connecting portion 1017 is extended along the Y direction and can electrically connect multiple sub-grids with the same polarity together to form multiple second monopolar units.

[0085] by Figure 10 Taking the illustrated structure as an example, the second connecting portion 1017 is arranged along the extension direction of the second side 10b. The second connecting portion 1017 electrically connects the through-grid 1011 to the connecting portion 104 of the same polarity to form a second monopolar unit. It should be noted that the through-grid 1011 comes from the sub-grid 1011 that is insulated from the edge interconnection bar, that is, from the sub-grid 1011 that is electrically connected to the edge main grid 1014. In other embodiments, the second connecting portion 1017 has a similar function to the first connecting portion 1016, and the second monopolar unit and the first monopolar unit 105 can be the same. In the present application, the second connecting portion 1017 can avoid the risk of damaging the sub-grid 1011 when the interconnection bar is directly welded to each sub-grid 1011. At the same time, the second connecting portion 1017 can also form a redundant backup protection structure with the interconnection bar to avoid local failure of the interconnection bar when used alone, which helps to improve the operating stability and reliability of the battery cell.

[0086] Optionally, in one embodiment, a spacer region is provided between two adjacent sub-grids 1011 of opposite polarity. This spacer region is commonly referred to as a gap region, i.e., the isolation region between the PN regions on the battery. Along the thickness direction of the battery body 10, insulating adhesive 1015 is provided between the edge interconnecting strips and the through-going sub-grids 1011. The insulating adhesive 1015 at least partially covers the aforementioned spacer region. In this configuration, when the same amount of insulating adhesive 1015 is used, the area covered by the insulating adhesive 1015 is larger, and its thickness is reduced, which helps to reduce the height difference between the insulating adhesive 1015 and the connecting portions 104 on both sides, thereby improving the welding effect between the interconnecting strips 103 and the connecting portions 104 on both sides of the insulating adhesive 1015.

[0087] Optionally, refer to Figure 14 and Figure 15 The electrode structure 101 also includes a plurality of end main grids 1012; along the extension direction of the second side 10b, the end main grid 1012 of a preset length is arranged near the first side 10a of the solar cell, and the end main grid 1012 is connected to at least two of the connecting portions 104.

[0088] Specifically, if Figure 14 and Figure 15As shown, to ensure accurate and reliable electrical connections between adjacent cells during string welding, the cell of the embodiment of the present application includes a plurality of end main grids 1012 in the electrode structure 1011. The end main grids 1012 may at least include: grid lines located near the first side 10a of the cell, extending from the first side 10a along the Y direction toward the inside of the cell, and connecting to a portion of the auxiliary grid 1011. The end main grids 1012 may be shorter, but slightly thicker than the auxiliary grid 1011.

[0089] Combine Figure 14 As shown in FIG. 1 , along the extension direction Y of the second side 10b, both sides close to the battery cell (i.e., the upper and lower first sides 10a) are provided with end main grids 1012. Figure 14 The upper end busbar 1012 can extend downward through the connection portions 104 on multiple sub-grids 1011 of the same polarity. For example, when the end busbar 1012 is shorter, it can be connected to two connection portions 104. When the end busbar 1012 is longer, it can be connected to more than two connection portions 104.

[0090] Therefore, by providing an end main grid 1012 near the first side 10a of the solar cell, accurate and reliable welding of the interconnection bar and the solar cell can be ensured, and local failure of the interconnection bar in collecting current when the interconnection bar is used alone can be avoided, which helps to improve the working stability and reliability of the cell; in addition, the end main grid 1012 can be welded to two or more small-sized connecting parts 104, which can appropriately save the connecting part slurry compared to the larger area connecting part structure in traditional solar cells, and the electrode structure cost is lower.

[0091] Combine Figure 13 As shown in the figure, an end main grid 1012 is provided at one end of the first side 10a of the cell along the extension direction Y of the second side 10b. When performing string welding, one end of the interconnection bar used to connect two cell slices (for example, the first cell slice and the second cell slice) in series is connected to the end main grid 1012 on the first cell slice, and then along the Y direction, passes through the battery body 10 and the other end of the first cell slice, and then crosses the inter-cell gap between the first cell slice and the second cell slice until it extends to the end main grid 1012 position of the second cell slice. Therefore, in Figure 14 On this basis, the interconnection bar is not cut when passing through the gap between the first battery cell and the second battery cell, the risk of deviation in the arrangement and welding of the interconnection bar is small, and the end main grid 1012 near the gap between the cells can be omitted, which can further save the electrode slurry of the end main grid 1012 and further reduce the slurry cost.

[0092] Optionally, refer to Figure 14The electrode structure 101 includes a plurality of intermediate main grids 1013 ; along the extension direction Y of the second side 10b , the intermediate main grids 1013 are electrically connected to the plurality of connecting portions 104 .

[0093] Specifically, in the present application, the intermediate busbar 1013 at least refers to: a grid line between the edge interconnecting bars 1031 and 1032 and connecting at least two connecting portions 104. Accordingly, when preparing the solar cell of the embodiment of the present application, the aforementioned auxiliary grid 1011, second notch 102b, intermediate busbar 1013, and connecting portion 104 can be formed by screen printing. The width of the intermediate busbar 1013 can be slightly thicker than the auxiliary grid 1011, while being thinner than a conventional busbar. Pre-printing the intermediate busbar 1013 and electrically connecting it to the connecting portion 104 of the auxiliary grid 1011 of the same polarity can avoid local failure of the interconnecting bar to collect current when using only the interconnecting bar for connection, thus helping to improve the operating stability and reliability of the solar cell. It can also avoid the auxiliary grid 1011 fusing defect caused by the small size of the connecting portion 104 in a completely busbar-free solution, and can appropriately improve the string soldering yield.

[0094] Of course, in some embodiments, along the extension direction Y of the second side 10b, the battery cell may include at least two connecting portions 104 that are not connected to the grid line. Specifically, when preparing the battery cell of the embodiment of the present application, the aforementioned auxiliary grid 1011, the second notch 102a and the connecting portion 104 can be formed by screen printing. When performing string soldering, the interconnecting bar is connected to the auxiliary grid 1011 of the same polarity through the connecting portion 104. The battery cell may include at least two connecting portions 104 that are not connected to the grid line, that is, the above-mentioned end main grid and / or intermediate main grid may not be required. In this way, the interconnecting bar can be used instead of the main grid to collect the current from the auxiliary grid 1011 and output the current. Therefore, this battery cell is a solar cell cell with less main grid or no main grid that can reduce the cost of the main grid slurry.

[0095] Optionally, refer to Figures 14 to 16 The electrode structure 101 further includes a main grid, which includes an end main grid 1012 and / or an intermediate main grid 1013. Insulating glue 1015 is provided at the intersection of the auxiliary grid 1011 and the interconnecting strips or the main grids with opposite polarities.

[0096] Specifically, refer to Figures 14 to 15As shown in the figure, the main grid includes an end main grid 1012. The polarity of the auxiliary grid 1011 connected to the end main grid 1012 or the interconnection bar is opposite to the polarity of other auxiliary grids 1011. Therefore, in order to avoid short circuit at the intersection of the interconnection bar 103 or the end main grid 1012 and the auxiliary grid 1011 when the interconnection bar 103 or the end main grid 1012 is laid out, an insulating glue 1015 is provided at the intersection of the auxiliary grid 1011 of the battery cell and the interconnection bar or the end main grid 1012 with opposite polarity.

[0097] Reference Figure 16 As shown in the figure, the main grid includes an intermediate main grid 1013. The continuous through portion of the auxiliary grid 1011 can be printed and formed into one piece with the other portions of the auxiliary grid 1011 using the same paste. The polarity of the auxiliary grid 1011 connected to the interconnection bar connected to the connecting portion 104 is opposite to the polarity of the continuous through auxiliary grid 1011. Therefore, in order to avoid the interconnection bar and the continuous through auxiliary grid 1011 from contacting and short-circuiting the intersection when laying the interconnection bar, as shown in the figure, Figure 16 As shown, when the middle main grid 1013 passes through the continuously penetrating auxiliary grid 1011, an insulating glue 1015 is provided at the intersection of the two.

[0098] Optionally, refer to Figures 17 to 19 , the battery cell of the embodiment of the present application is a back-contact battery cell; and / or, along the extension direction of the first side 10a, the maximum dimension of the connecting portion 104 is a, and a is not less than the width of the first notch 102b; along the extension direction of the second side 10b, the maximum dimension of the connecting portion 104 is b, and b is less than the spacing between two adjacent auxiliary grids 1011 with the same polarity.

[0099] Specifically, in the embodiment of the present application, the cell is a back-contact cell. Furthermore, for various shapes of the connecting portion 104, the maximum dimension of the connecting portion 104 along the X direction is a, and the maximum dimension of the connecting portion 104 along the Y direction is b. a and b satisfy the following conditions: a is not less than the width of the first notch 102b, thereby reliably connecting two segments of the same-polarity sub-grid 1011 on either side of the first notch 102b. Along the illustrated Y direction, b is less than the spacing between two adjacent segments of the same-polarity sub-grid 1011, thereby preventing a short circuit between the sub-grid 1011 connected by the connecting portion 104 and another adjacent segment of the opposite polarity in the Y direction. For example, 0.5 mm ≤ a ≤ 6 mm, and 0.05 mm ≤ b < 1 mm.

[0100] In some embodiments, the connecting portion 104 may be symmetrical with respect to the extension direction (which may be the X direction) of the auxiliary gate 1011. For example, when the connecting portion 104 is Figure 17When the connecting portion 104 is a rectangle, the maximum dimension a of the connecting portion 104 along the X direction is the length of the rectangle, and the maximum dimension b of the connecting portion 104 along the Y direction is the width of the rectangle, 0.5mm≤a≤6mm, 0.05mm≤b≤1mm. Figure 18 When the connecting portion 104 is a similar rhombus, the maximum dimension a of the connecting portion 104 along the X direction is the distance between the two short sides of the similar rhombus, 0.5mm≤a≤6mm, and the maximum dimension b of the connecting portion 104 along the Y direction is the distance from the highest point to the lowest point of the similar rhombus, and the middle width of the rhombus is b, 0.05mm≤b≤1mm, preferably, 0.1mm≤b≤0.5mm. Figure 19 The combination of the illustrated rectangle and trapezoid also satisfies the following conditions: 0.5 mm ≤ a ≤ 6 mm, 0.05 mm ≤ b ≤ 1 mm, and preferably, 0.1 mm ≤ b ≤ 0.5 mm.

[0101] The shape and size of the connection portion 104 in the embodiment of the present application can provide a larger welding contact area compared to the width of the auxiliary grid 1011. Compared with the traditional connection portion (soldering pad), the welding contact area is relatively small, which can avoid the problem of low open circuit voltage caused by the large composite area of ​​the large connection portion and the silicon substrate of the battery cell, and can reduce current transmission power consumption.

[0102] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0103] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are protected by this application.

Claims

1. A photovoltaic module, characterized in that: include: A plurality of battery bodies, each comprising a first side and a second side; each battery body being provided with an electrode structure, each electrode structure comprising a plurality of auxiliary grids, each auxiliary grid being at least partially parallel to the first side, and two types of auxiliary grids having opposite polarities being alternately arranged along an extension direction of the second side; Along the extension direction of the first side, the auxiliary grid includes a plurality of second notches and a plurality of connecting portions; the plurality of second notches divide the auxiliary grid into multiple sections, wherein the second notches are vacant and disconnected structures; along the extension direction of the first side and the second side, the second notches and the connecting portions are adjacently arranged; A plurality of interconnecting bars are provided, each of which is arranged along the extension direction of the second side edge and connects the adjacent battery bodies in series; any one of the interconnecting bars is electrically connected to the connecting portion of the auxiliary grid of one polarity, and at the second notch portion of the auxiliary grid of the other polarity, the interconnecting bar is at least partially in contact with the surface of the battery body.

2. The photovoltaic module according to claim 1, characterized in that Insulation glue is provided at the second notch, and the interconnection strip is in contact with the insulation glue along the extension direction of the first side.

3. The photovoltaic module according to claim 1, characterized in that Insulation glue is provided at the second notch, and a gap is provided between the interconnection strip and the insulation glue along the extension direction of the first side.

4. The photovoltaic module according to claim 1, characterized in that Along the extension direction of the first side, the auxiliary grid further includes a plurality of first notches, and the connecting parts are provided at the positions of the plurality of first notches, and the connecting parts connect the auxiliary grid at the positions of the first notches.

5. The photovoltaic module according to claim 1, characterized in that The auxiliary grid is designed to be continuous and through at the connection portion.

6. The photovoltaic module according to claim 1, characterized in that The interconnection bar is in direct contact and electrically connected with the connection portion.

7. The photovoltaic module according to claim 1, characterized in that The interconnection strip has a first bottom at the connecting portion, a second bottom at the second notch, and a third bottom outside the connecting portion and the second notch. In the same interconnection strip, along the thickness direction of the battery body, a height difference between any two bottoms among the first bottom, the second bottom and the third bottom is less than or equal to 0.5 mm.

8. The photovoltaic module according to claim 7, characterized in that: In the same interconnection strip, along the thickness direction of the battery body, a height difference between any two bottoms among the first bottom, the second bottom and the third bottom is less than or equal to 50 μm.

9. The photovoltaic module according to claim 1, characterized in that: In the same interconnection strip, along the extension direction of the first side, the interconnection strip has a first width at the connection portion, and has a second width at the second notch, and the first width is at least 1.3 times the second width.

10. The photovoltaic module according to claim 4, characterized in that: Along the extension direction of the first side, the first notch has a first length, the second notch has a second length, and the second length is greater than the first length.

11. The photovoltaic module according to claim 1, characterized in that: Along the extension direction of the first side, the second notch has a second length, the interconnection strip includes a round wire interconnection strip with a circular cross-section, and the second length is at least twice the diameter of the round wire interconnection strip; or, the interconnection strip includes a flat wire interconnection strip with a rectangular cross-section, and the second length is at least 1.5 times the width of the flat wire interconnection strip.

12. The photovoltaic module according to claim 1, characterized in that At the position of the second notch, along the extending direction of the first side, the sum of the distances between the interconnection strip and the ends of the auxiliary grids on both sides is in the range of 200 μm to 600 μm.

13. The photovoltaic module according to claim 1, characterized in that Along the extension direction of the first side, the second notch has a second length; Along the extension direction of the second side, a second length of the second notch close to the edge of the battery body is greater than a second length of the second notch located in the middle of the battery body.

14. The photovoltaic module according to claim 1, characterized in that Insulating glue is provided at the end of the auxiliary grid forming the second notch, and the distance between the two insulating glues corresponding to the second notch is 1.8 mm-5 mm.

15. The photovoltaic module according to claim 4, characterized in that: At the location of the first notch, the end of the auxiliary grid overlaps and conducts with the connecting portion, and at least a portion of the end of the auxiliary grid is located on a side of the connecting portion facing away from the battery body.

16. The photovoltaic module according to any one of claims 1 to 15, characterized in that: Along the extension direction of the first side, the interconnection bar includes an edge interconnection bar close to the edge of the battery body; At the portion where the edge interconnection strip passes, the auxiliary grid with the opposite polarity to the edge interconnection strip continuously passes through, and insulating glue is provided between the edge interconnection strip and the auxiliary grid with the opposite polarity.

17. The photovoltaic module according to claim 16, characterized in that: The edge interconnection strip is fixed and electrically connected to at least a portion of the connection portion via a conductive layer.

18. The photovoltaic module according to any one of claims 1 to 15, characterized in that: Along the extension direction of the first side, the interconnection bar includes an edge interconnection bar close to the edge of the battery body, and the electrode structure further includes an edge main grid close to the edge of the battery body; the edge main grid is closer to the edge of the battery body than the edge interconnection bar; The edge interconnection strip is arranged along the extension direction of the second side, the edge interconnection strip is electrically connected to the auxiliary grid of one polarity, and the auxiliary grid of the other polarity is electrically connected to the edge main grid, and the edge main grid is electrically connected to the connecting portion of the same polarity located on the inner side of the edge main grid through the continuously penetrating auxiliary grid; and insulating glue is provided between the edge interconnection strip and the continuously penetrating auxiliary grid.

19. The photovoltaic module according to claim 18, characterized in that: The electrode structure further includes a first connecting portion, and the first connecting portion is arranged along an extension direction of the second side; In the auxiliary grid electrically connected to the edge interconnection strip, along the extension direction of the second side, at least one auxiliary grid close to the continuous auxiliary grid is electrically connected to an adjacent connection portion through the first connection portion to form a first monopolar unit.

20. The photovoltaic module according to claim 18, characterized in that At least one connecting portion is provided in the auxiliary grid electrically connected to the edge interconnection bar, and the edge interconnection bar is electrically connected to the auxiliary grid via the connecting portion.

21. The photovoltaic module according to claim 20, characterized in that: The edge interconnection strip is in direct contact and electrically connected to the connection portion.

22. The photovoltaic module according to claim 18, characterized in that Along the extension direction of the first side, the distance between the edge interconnection strip and the edge main grid is 2 mm to 6 mm.

23. The photovoltaic module according to claim 18, characterized in that In the auxiliary grid insulated from the edge interconnection strip, part of the auxiliary grid is provided with the second notch, and another part of the auxiliary grid is a continuous through auxiliary grid.

24. The photovoltaic module according to claim 18, characterized in that In the auxiliary grid insulated from the edge interconnection strip, there are 1 to 10 auxiliary grids that are continuously passed through.

25. The photovoltaic module according to claim 18, characterized in that In the auxiliary grid insulated from the edge interconnection strip, there are 1 to 3 auxiliary grids that are continuously passed through.

26. The photovoltaic module according to claim 18, characterized in that The width of the continuously penetrating auxiliary grid is greater than the width of the remaining auxiliary grids.

27. The photovoltaic module according to claim 26, characterized in that The continuously penetrating auxiliary grid includes a bottom grid line and a top grid line arranged in layers, wherein the bottom grid line is arranged on the surface of the battery body, and the top grid line is arranged on the side of the bottom grid line away from the battery body, and the width of the top grid line is greater than the width of the bottom grid line or the rest of the auxiliary grid.

28. The photovoltaic module according to claim 18, characterized in that The electrode structure further includes a second connecting portion, and the second connecting portion is arranged along an extension direction of the second side; The second connecting portion electrically connects the continuously penetrating auxiliary grid and the connecting portion of the same polarity to form a second monopolar unit.

29. The photovoltaic module according to claim 18, characterized in that A spacing region is provided between two adjacent auxiliary grids with opposite polarities; Along the thickness direction of the battery body, insulating glue is provided between the edge interconnection strip and the continuously penetrating auxiliary grid, and the insulating glue at least partially covers the spacer area.

30. The photovoltaic module according to claim 1, characterized in that The electrode structure also includes a plurality of end main grids; along the extension direction of the second side, the end main grid with a preset length is arranged near the first side of the battery body, and the end main grid is connected to at least two of the connecting parts; and / or, the electrode structure also includes a plurality of intermediate main grids; along the extension direction of the second side, the intermediate main grid is electrically connected to the plurality of the connecting parts.

31. The photovoltaic module according to claim 30, characterized in that The electrode structure includes a main grid, which includes the end main grid and / or the middle main grid. Insulation glue is provided at the intersection of the auxiliary grid and the interconnection strip with opposite polarity or the main grid.

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