Photovoltaic module

Abstract

The utility model discloses a photovoltaic assembly, which is used for solving the problems of complex insulation structure and poor insulation stability, the photovoltaic assembly comprises a battery string, a solder strip and a bus bar, the battery string comprises a plurality of battery pieces, and the plurality of battery pieces comprise a string head battery piece located at the string head and a string tail battery piece located at the string tail; an insulating material layer is arranged on one edge, far away from the string tail battery piece, of the string head battery piece and / or one edge, far away from the string head battery piece, of the string tail battery piece; the bus bar is arranged on one surface, back to the battery piece, of the insulating material layer; the bus bar is conductively connected with the welding strip with the first polarity, and a gap is formed between the bus bar and the welding strip with the second polarity; the welding strip with the first polarity is electrically connected with the electrode with the first polarity on the battery piece, and the welding strip with the second polarity is electrically connected with the electrode with the second polarity on the battery piece; and the bus bar is insulated from the electrode with the second polarity through an insulating material layer.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic technology field especially relates to a photovoltaic module. BACKGROUND

[0002] The photovoltaic module is composed of a plurality of cell strings, each cell string is composed of a plurality of cell pieces in series through welding strips, and the welding strips on each cell string and the welding strips between adjacent cell strings are usually conductively connected through bus bars.

[0003] In order to reduce the invalid area occupied by the bus bar in the photovoltaic module, the bus bar is placed on the back of the cell piece, so that the bus bar needs to be insulated from the electrode on the cell piece and the welding strip conductively dissimilar to the bus bar, and the current insulation structure for the bus bar on the photovoltaic module is relatively complex, and the insulation stability needs to be further improved. SUMMARY

[0004] The utility model aims at providing a photovoltaic module to simplify the insulation structure and improve the insulation stability.

[0005] The utility model provides a photovoltaic module, including cell string and bus bar, cell string includes a plurality of cell pieces that the welding strip is connected in series, a plurality of cell pieces includes the string head cell piece at the string head and the string tail cell piece at the string tail;

[0006] The edge of the string head cell piece away from the string tail cell piece and / or the edge of the string tail cell piece away from the string head cell piece is provided with an insulating material layer;

[0007] On a cell piece, the bus bar is arranged on the side of the insulating material layer away from the cell piece;

[0008] The bus bar is conductively connected with the welding strip of the first polarity, and the bus bar has a spacing between the welding strip of the second polarity, the welding strip of the first polarity is electrically connected with the electrode of the first polarity on the cell piece, and the welding strip of the second polarity is electrically connected with the electrode of the second polarity on the cell piece;

[0009] The bus bar and the electrode of the second polarity are insulated by the insulating material layer.

[0010] In the technical solution, for the case that the bus bar is arranged on the back surface of the battery piece, the bus bar is arranged on the edge of the back surface of the first battery piece and / or the last battery piece, an insulating material layer is arranged on the edge of the first battery piece away from the last battery piece and / or the edge of the last battery piece away from the first battery piece, the bus bar is arranged on the side of the insulating material layer away from the battery piece, the bus bar is electrically connected with the welding band of the first polarity, there is a space between the bus bar and the welding band of the second polarity, the welding band of the first polarity is electrically connected with the electrode of the first polarity on the battery piece, the welding band of the second polarity is electrically connected with the electrode of the second polarity on the battery piece, the bus bar is electrically isolated from the electrode of the second polarity on the battery piece by the insulating material layer, and the bus bar and the welding band of the second polarity are electrically isolated by the space.

[0011] Firstly, the bus bar is arranged on the edge of the first battery piece and the last battery piece in the application, which is compatible with the existing process of first manufacturing the battery string and then welding the battery string with the battery string. At this time, the structure of each battery string and the manufacturing process are basically the same, and the same equipment and process can be used. In the battery string welding process, the main changes are the placement position of the bus bar, the heating method, and the transportation of the battery string, which are compatible with the existing equipment. Compared with the battery string manufacturing process and the battery string welding process in the prior art, the process difficulty is lower, which can greatly save the process cost, improve the component manufacturing efficiency, and improve the component yield based on the reduction of the process difficulty. Secondly, the printing scheme of the insulating material layer on the battery piece is changed in the application to realize the insulation of the bus bar without increasing the process, such as the insulating tape and other insulating parts, which can reduce the process steps and improve the component manufacturing efficiency. Compared with the additional insulating parts, the insulating material layer of the application only completely adheres to the edge surface of the battery piece at the position corresponding to the bus bar, which can reduce the space occupation of the insulating material layer in the thickness direction of the battery piece, simplify the insulation structure, make the structure more compact, and realize stable electrical isolation and insulation.

[0012] In some possible implementation schemes, the distance between the bus bar and the welding band of the second polarity is 0.5mm-6mm. The distance can meet the electrical isolation requirement between the bus bar and the welding band of different electrical properties, avoid short circuit connection, and increase the length of the welding band of different electrical properties as much as possible to improve the current collection capability and the welding reliability of the end of the welding band.

[0013] In some possible implementation schemes, the distance between the bus bar and the electrode of the second polarity on the battery piece in the thickness direction of the battery piece is 10μm-200μm. That is, the electrode of different electrical properties on the battery piece and the bus bar are arranged apart by the insulating material layer in the thickness direction of the battery piece. The distance can meet the insulation requirement, save the material of the insulating material layer, and prevent the insulating material layer from warping due to excessive thickness.

[0014] In some possible implementation manners, the bus bar includes an edge bus bar, wherein the insulating material layer located on the outermost cell of the photovoltaic module and close to the edge is an edge insulating material layer, the length of the edge insulating material layer is less than or equal to the length of the edge where the edge insulating material layer is located minus 0.5 mm to 5 mm, and greater than the length of the edge bus bar; and / or, the width of the edge insulating material layer is 0.8 to 1.4 times the width of the edge bus bar; and / or, the projection of the edge bus bar on the cell is located in the edge insulating material layer, and the width of the edge bus bar is 3.8 mm to 5.5 mm.

[0015] In the case of the above technical solution, the bus bar arranged at the edge position of the photovoltaic module is an edge bus bar, and correspondingly, the edge bus bar is arranged on the insulating material layer (i.e., the edge insulating material layer) of the string head cell and / or the string tail cell close to the edge position of the photovoltaic module. The size range of the edge insulating material layer and the size relationship with the edge bus bar can meet the insulation requirement, and at the same time, the material of the edge insulating material layer can be saved, and the edge insulating material layer can be prevented from being warped due to the size being too large relative to the edge bus bar. The edge bus bar located in the edge insulating material layer can achieve more reliable insulation effect between the edge bus bar and the electrode of the second polarity. The width of the edge bus bar can achieve the current collection effect and save the material. When the width of the edge insulating material layer is 0.8 to 1.4 times the width of the edge bus bar, the width of the edge bus bar covered on the cell can be determined according to the width of the edge bus bar and the width of the distance between the end of the solder strip of the second polarity and the edge of the cell. If the distance is large, a wider edge insulating material layer can be designed to arrange the entire edge bus bar at the edge of the cell; if the distance is small, a narrower edge insulating material layer can be designed to arrange part of the edge bus bar at the edge of the cell, and the remaining part is arranged outside the cell, so as to avoid the edge bus bar being too close to the end of the solder strip of the second polarity.

[0016] In some possible implementation manners, the bus bar includes an intermediate bus bar, the intermediate bus bar is located at the middle of the photovoltaic module, and is arranged on the side of the insulating material layer of the string head cell and / or the string tail cell of the previous cell string and / or the string head cell and / or the string tail cell of the next cell string away from the cell; wherein the length of the insulating material layer of the string head cell and the string tail cell is less than or equal to the length of the edge where the insulating area is located minus 0.5 mm to 1.5 mm, and greater than the length of the intermediate bus bar; and / or, the width of the insulating material layer of the string head cell and the string tail cell is 0.5 to 1.2 times the width of the intermediate bus bar; and / or, the width of the area covered by the intermediate bus bar on the string head cell is 2 mm to 5 mm, the width of the area covered by the intermediate bus bar on the string tail cell is 2 mm to 5 mm, and the spacing between the two series cell strings is 0 to 2 mm; and / or, the width of the intermediate bus bar is 6 mm to 8.5 mm.

[0017] In the technical solution, the intermediate busbar is located in the middle of the photovoltaic module, and can be arranged on the insulating material layer of the tail cell of the upper cell string, or on the insulating material layer of the head cell of the lower cell string, or at the gap between the two series-connected cell strings. Correspondingly, the intermediate busbar spans the insulating material layers of the adjacent head cell and tail cell of the two series-connected cell strings, and is located in the area surrounded by the two insulating material layers. The size of the insulating material layer corresponding to the intermediate busbar can meet the insulation requirement and save the material of the insulating material layer. The intermediate busbar needs to transmit more current than the edge busbar. In order to ensure the current transmission efficiency and avoid the hidden crack of the cell caused by excessive thickness, the intermediate busbar is designed to be thin and wide. At this time, the intermediate busbar spans the gap between the two cells and the upper and lower cell strings, which can avoid the hidden crack or short circuit risk caused by excessive stress due to being arranged on a certain cell, and can disperse the stress of the stacked intermediate busbar, thereby improving the yield of the module.

[0018] In some possible implementation manners, in the length direction of the busbar, the distance from the end of the busbar to the outermost solder strip is greater than or equal to 1 mm; and / or in the width direction of the busbar, the distance from the edge of the busbar to the edge of the insulating material layer is greater than or equal to 1 mm. In this way, the length of the busbar can span all the solder strips of the first polarity welded thereto, and can be fully welded with the outermost solder strip and leave sufficient welding process window. The excess length facilitates the connection of the busbar with other leads of the photovoltaic module. Moreover, the busbar is located in the insulating material layer, thereby improving the insulation effect of the busbar and the electrode of the second polarity.

[0019] In some possible implementation manners, the insulating material layer is composed of a plurality of first insulating adhesive strips arranged in parallel and at intervals, the first insulating adhesive strips continuously extend along the length direction of the cell edge, and the first insulating adhesive strips cover the fine grid electrodes of the second polarity of the cell;

[0020] Alternatively, the insulating material layer is an insulating adhesive layer covering the cell edge as a whole;

[0021] Alternatively, the insulating material layer is a plurality of second insulating adhesive strips arranged in parallel and at intervals, part of the second insulating adhesive strips cover the fine grid electrodes of the second polarity, and / or part of the second insulating adhesive strips cover the fine grid electrodes of the first polarity, and / or part of the second insulating adhesive strips are located between the fine grid electrodes of the first polarity and the fine grid electrodes of the second polarity.

[0022] In the above technical solution, the insulating material layer has three forms. The first form is composed of a plurality of first insulating adhesive strips arranged in parallel and at intervals. The first insulating adhesive strips continuously extend along the length direction of the edges. The total area between the two first insulating adhesive strips located at the outermost side has a width greater than that of the bus bar. The plurality of first insulating adhesive strips can support the bus bar, so that a space is formed between the bus bar and the fine grid electrode of the second polarity of the battery piece, thereby achieving electrical isolation. At the same time, the plurality of first insulating adhesive strips do not cover the edge area of the battery piece, thereby saving the material of the insulating material layer and reducing the warping of the battery piece caused by the insulating adhesive strips. The second form is an insulating adhesive layer covering the edges of the battery piece as a whole. The insulating adhesive layer can support the entire surface of the bus bar and achieve electrical isolation between the bus bar and the fine grid electrode of the second polarity of the battery piece. In this case, the insulating effect of the bus bar is good, and the fine grid of the battery piece can be well protected, thereby reducing the adverse effects of the welding heat of the fine grid silver bus bar on the fine grid. The third form is a plurality of second insulating adhesive strips arranged in parallel and at intervals. The second insulating adhesive strips cover the fine grid electrode of the second polarity and / or part of the second insulating adhesive strips cover the fine grid electrode of the first polarity and / or part of the second insulating adhesive strips are located between the fine grid electrode of the first polarity and the fine grid electrode of the second polarity. The second insulating adhesive strips locally support the bus bar and can electrically isolate the bus bar from the fine grid electrode of the second polarity on the battery piece in space. The insulating material layer can save the material of the insulating material layer, and can greatly disperse and shorten the length of the second insulating adhesive strips, thereby further reducing the warping of the battery piece caused by the second insulating adhesive strips and reducing the hidden cracking of the battery piece.

[0023] In some possible implementations, the battery piece has a pad. The distance between the bus bar and the closest pad in the extension direction of the solder strip is 0.5 mm to 4 mm. The pad can be used for welding the solder strip of the first polarity or the solder strip of the second polarity. The distance can ensure that the bus bar and the pad have sufficient distance at the welding position of the solder strip, thereby avoiding the disturbance of the bus bar to the solder strip when the bus bar is arranged between the solder strip and the battery piece, and affecting the welding reliability of the solder strip. The distance can reduce the influence of the welding heat of the bus bar on the adjacent pad, thereby avoiding the occurrence of overwelding. In addition, the distance can meet the electrical isolation requirement of the bus bar and the pad with different electrical conductivity, thereby avoiding short circuit connection, and at the same time, the length of the solder strip with different electrical conductivity can be increased as much as possible, so as to improve the current collection capacity and the welding reliability.

[0024] In some possible implementation manners, the end of the solder strip of the second polarity protrudes from the solder pad connected with the solder strip by a distance of -0.5 mm to 0.2 mm. That is, the end of the solder strip of the second polarity can be located in the solder pad or protrude from the solder pad, to ensure reliable connection between the solder strip and the solder pad, while taking into account the space for arranging the bus bar, that is, the solder strip protrudes relatively less from the solder pad, so as to leave sufficient space on the battery piece for arranging the bus bar, to avoid the problem of insufficient space for designing the bus bar due to excessive protrusion of the solder strip. In addition, it can also ensure a large insulation distance between the bus bar and the solder strip, to ensure insulation safety.

[0025] In some possible implementation manners, the solder strip of the first polarity is located between the bus bar and the insulating material layer. That is, the solder strip of the first polarity is sandwiched between the bus bar and the insulating material layer, and the bus bar covers the solder strip of the first polarity. This structure can facilitate welding of the solder strip of the first polarity to the battery piece, and facilitate welding of the bus bar to the solder strip of the first polarity, to improve the welding strength. Since the layering structure of the solder strip and the bus bar is simple, the solder strip and the bus bar do not need to be bent at the welding position, so that the solder strip of the first polarity can be in flat contact with the battery piece, to reduce the risk of hidden cracks on the battery piece caused by the solder strip of the first polarity under pressure. Alternatively, the bus bar can be located between the solder strip of the first polarity and the insulating material layer. Of course, the bus bar can also be located between the solder strip of the first polarity and the insulating material layer.

[0026] In some possible implementation manners, the bus bar includes an intermediate bus bar, the intermediate bus bar is located at the middle of the photovoltaic module, and electrically connects a tail cell of an upper cell string and a head cell of a lower cell string; the solder strip on the head cell is aligned with or connected to the solder strip on the tail cell on the intermediate bus bar. The alignment of the solder strip on the head cell with the solder strip on the tail cell on the intermediate bus bar can reduce the difference in the creepage distance between the upper part and the lower part of the module, reduce the side length of the photovoltaic module, and reduce the blank area of the photovoltaic module. The connection of the solder strip on the head cell to the solder strip on the adjacent tail cell on the intermediate bus bar can reduce current loss.

[0027] In some possible implementation manners, the photovoltaic module includes m columns of battery pieces, and each column of battery pieces includes 2 or more cell strings; the distance between adjacent battery pieces in one column of battery pieces is 0 to 2 mm, the distance between adjacent columns of battery pieces is 0.3 mm to 3.3 mm, and the distance between the two cell strings in the first column or the last column of battery pieces and the edge of the photovoltaic module is less than or equal to 0.2 mm. Based on the design of the bus bar, the distance between the battery pieces, the distance between the cell strings, and the distance between the battery piece and the edge of the photovoltaic module are all reduced in this version of the photovoltaic module, to improve the unit power of the photovoltaic module.

[0028] Alternatively, the plurality of cell pieces in the battery string are arranged in a shingle manner, the width of the overlapping area of adjacent cell pieces in each battery string is 0.3mm-2mm, and the spacing between adjacent rows of cell pieces is 0.3mm-3.3mm. The inter-string spacing and the cell piece and photovoltaic module edge spacing of the photovoltaic module of this version are reduced, which can improve the unit power of the photovoltaic module.

[0029] In some possible implementations, a connecting line is provided between the edge of the cell piece and the pad at the head and / or tail of the solder strip along the length direction of the solder strip, and the connecting line electrically connects the fine grid electrode of the cell piece and the pad; the bus bar covers part of the connecting line. Through the connecting line, the current of the fine grid electrode of the cell piece covered by the bus bar can be conveniently collected and then collected to the bus bar, thereby improving the current collection efficiency. In particular, the solder strip of the second polarity cannot extend to or cover the edge portion of the cell piece to directly collect the current on the fine grid in the case of maintaining an insulating distance from the bus bar, and needs to collect the current through the connecting line and the pad.

[0030] In some possible implementations, the cell piece has an end pad, the end pad is close to the edge of the cell piece along the extension direction of the solder strip, and the end pad is a rectangular pad having adjacent first and second edges, the length of the first edge is 0.5mm-1.5mm, and the length of the second edge is 0.5mm-1.5mm. After the solder strip is electrically connected with the end pad and extends to the position of the bus bar, the end of the solder strip is welded with the bus bar. Due to the presence of the bus bar, the solder strip will be affected by the force and welding heat of the bus bar, and there may also be bending, which affects the welding effect of the solder strip and the end pad. Therefore, the end pad is set to a larger size, which can improve the electrical connection performance of the end pad and the solder strip.

[0031] In some possible implementations, the photovoltaic module further includes a strip-shaped adhesive film covering the bus bar away from the cell piece, and a projection of the bus bar on the strip-shaped adhesive film is located in the strip-shaped adhesive film. In the case of adopting the above technical solution, the strip-shaped adhesive film covers the bus bar, so that when the bus bar is pressed, the strip-shaped adhesive film buffers the position of the bus bar, thereby reducing the risk of cell piece cracking.

[0032] In some possible implementations, the thickness of the strip-shaped adhesive film is 200μm-1000μm, and / or the width of the strip-shaped adhesive film is 0-100mm wider than the width of the bus bar, and / or the length of the strip-shaped adhesive film is 0-5mm longer than the length of the bus bar, and / or the material of the strip-shaped adhesive film is POE, EPE or EVA. At this time, the selection of the material can ensure that the bus bar has a good buffering effect; through the design of the thickness of the strip-shaped adhesive film, the buffering effect and the laminated thickness can be considered, and the problem of lamination bubbles caused by excessive thickness can be avoided; through the design of the width and thickness of the strip-shaped adhesive film, it can be ensured that the strip-shaped adhesive film covers the entire bus bar, and the problem of uneven stress in the local part can be reduced.

[0033] In some possible implementation manners, the solder strip is a flat solder strip; and / or the insulating material layer is a printed insulating glue. In this way, the flat solder strip is thinner and wider, and after being welded with the battery piece, the contact area can be increased and the pressure can be reduced, and when the solder strip is pressed, the risk of hidden cracks caused to the battery piece can be reduced. The printed insulating glue can ensure the reliability of the combination of the insulating material layer and the battery piece, and reduce the thickness of the photovoltaic module. Moreover, the printed insulating glue can be made synchronously and of the same material as the insulating glue for insulating different polarity electrodes of the battery piece, thereby reducing the process improvement cost and improving the module manufacturing efficiency.

[0034] In some possible implementation manners, the insulating material layer is arranged on two edges of the vertical solder strip on each battery piece of the photovoltaic module. At this time, the design of each battery piece structure and the insulating material layer of the module is the same, and there is no need to distinguish the first and last battery pieces and the middle battery pieces of the battery string when the battery string is manufactured, which can further reduce the process difficulty and improve the module manufacturing efficiency.

[0035] The melting temperature of the insulating material layer located below the bus bar is higher than the fusion temperature of the adhesive film protective layer located above the bus bar, so that the heating temperature of the photovoltaic module in the laminating process can make the adhesive film protective layer fuse to fix, package and protect the bus bar, the battery piece and the solder strip, and the heating temperature in the laminating process cannot melt the insulating material layer, and the photovoltaic module with a complete structure and reliable insulating effect can be obtained.

[0036] In some possible implementation manners, the angle between the bus bar and / or the solder strip and the surface of the battery piece is less than 80° at the position where the solder strip is connected with the bus bar, so that the solder strip and / or the bus bar are more flat, the bending angle of the solder strip is smaller, and when the solder strip is pressed, the stress of the bending part of the solder strip is larger and is easy to cause hidden cracks of the battery piece. When the bending angle of the solder strip is smaller, the risk of hidden cracks caused to the battery piece is reduced, and the adverse effect of excessive bending of the solder strip on the reliability of the connection between the solder strip and the solder pad can be reduced.

[0037] In some possible implementation manners, the thickness of the battery piece is 100 μm to 160 μm; the thickness of the electrode on the battery piece is 10 μm to 20 μm; the thickness of the solder strip is 0.18 mm to 0.8 mm; and the thickness of the bus bar is 0.07 mm to 0.2 mm. In this way, the height of the protruding battery piece can be reduced, and the risk of hidden cracks caused to the battery piece can be reduced. In the thickness direction of the photovoltaic module, the sum of the thicknesses of the battery piece, the electrode, the solder strip and the bus bar accounts for less than 85% of the distance between the cover plate and the back plate of the photovoltaic module, so as to provide sufficient thickness space for the adhesive film layer having a buffering and fixing effect, improve the buffering and fixing effect, and reduce the risk of hidden cracks of the battery piece.

[0038] In some embodiments, the corner of the battery piece has a chamfer, and the minimum distance between the bus bar and the chamfer is greater than 1mm. In this way, the insulation effect can be improved, and the chamfer position is a stress concentration area. During the lamination process, the overlap of the bus bar and the chamfer can be reduced, and hidden cracks in the battery piece at the chamfer position can be avoided. BRIEF DESCRIPTION OF DRAWINGS

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

[0040] Figure 1 A structure schematic diagram of an insulating material layer in a photovoltaic module is provided for the embodiments of the present application;

[0041] Figure 2 Another structure schematic diagram of an insulating material layer is provided for the embodiments of the present application;

[0042] Figure 3 Another structure schematic diagram of an insulating material layer is provided for the embodiments of the present application;

[0043] Figure 4 A layout structure schematic diagram of an edge bus bar in a photovoltaic module is provided for the embodiments of the present application;

[0044] Figure 5 A layout structure schematic diagram of an edge bus bar in a photovoltaic module is provided for the embodiments of the present application; Figure 4 A cross-sectional view of section A-A;

[0045] Figure 6 Another layout structure schematic diagram of an edge bus bar in a photovoltaic module is provided for the embodiments of the present application;

[0046] Figure 7 A layout structure schematic diagram of a middle bus bar in a photovoltaic module is provided for the embodiments of the present application; Figure 6 A cross-sectional view of section B-B;

[0047] Figure 8 Another layout structure schematic diagram of a middle bus bar in a photovoltaic module is provided for the embodiments of the present application;

[0048] Figure 9 Another layout structure schematic diagram of a middle bus bar in a photovoltaic module is provided for the embodiments of the present application; Figure 8 A cross-sectional view of section C-C;

[0049] Figure 10 Another layout structure schematic diagram of a middle bus bar in a photovoltaic module is provided for the embodiments of the present application;

[0050] Figure 11 Another layout structure schematic diagram of a middle bus bar in a photovoltaic module is provided for the embodiments of the present application; Figure 10 A cross-sectional view of section D-D.

[0051] The reference signs: 1 is a battery piece, 11 is an end pad, 2 is an insulating material layer, 21 is a first insulating adhesive strip, 22 is an insulating adhesive layer, 23 is a second insulating adhesive strip, 3 is a solder strip insulating piece, 4 is a solder strip, 41 is a first solder strip, 42 is a second solder strip, 5 is a bus bar. DETAILED DESCRIPTION

[0052] In order to make the technical problems, technical solutions and beneficial effects of the utility model clearer and more apparent, the utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0053] 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.

[0054] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise explicitly specified. The meaning of "several" is one or more than one, unless otherwise explicitly specified.

[0055] In the description of the utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0056] In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0057] As Figures 1-11The utility model provides a kind of photovoltaic module, including cell string, solder strip 4 and busbar 5, wherein the quantity of cell string is multiple, multiple cell string is connected in series and parallel, cell string includes multiple stringing cell piece 1, multiple cell piece 1 includes string head cell piece located at string head and string tail cell piece located at string tail and remaining cell piece between string head and string tail, when cell string is connected in series, the cell piece of one cell string is connected with the cell piece of another cell string;Cell piece 1 has electrode, electrode includes grid line electrode and solder pad connected with grid line electrode, for back contact cell, the anode and cathode of electrode are located at the back of cell piece 1, then correspondingly, grid line electrode includes positive grid line electrode and negative grid line electrode, positive grid line electrode and negative grid line electrode are connected with different solder strip 4 respectively through solder pad, and different solder strip 4 is connected with corresponding busbar 5. Wherein, in the same cell string, the edge of string head cell piece away from string tail cell piece and / or the edge of string tail cell piece away from string head cell piece is provided with insulating material layer 2, i.e. at least one edge of the outermost side of one cell string is provided with insulating material layer 2, and busbar 5 is arranged on the side of insulating material layer 2 away from cell piece 1;Busbar 5 is electrically connected with solder strip 4 of first polarity, and there is interval between busbar 5 and solder strip 4 of second polarity. Insulating material layer 2 extends along the length direction of cell piece edge as a whole. Solder strip 4 of first polarity is electrically connected with electrode of first polarity on cell piece 1, and solder strip 4 of second polarity is electrically connected with electrode of second polarity on cell piece 1;Busbar 5 is insulated from electrode of second polarity through insulating material layer 2;The melting temperature of insulating material layer 2 located below busbar 5 is higher than the fusion temperature of adhesive film protective layer located above busbar 5. Wherein, the first polarity and the second polarity are different.

[0058] For example, the cell string is connected with multiple half cell pieces, and the insulating material layer is arranged on one long edge of the half cell piece away from the string tail cell piece at the string head, and / or the insulating material layer is arranged on one long edge of the half cell piece away from the string head cell piece at the string tail, and the busbar extends along the length direction of the long edge. Figure 4 As shown in the figure, the solder strip of first polarity is first solder strip 41, and the solder strip of second polarity is second solder strip 42. One busbar 5 is electrically connected with first solder strip 41 of first polarity, and there is interval between the second solder strip 42 of second polarity, first solder strip 41 is electrically connected with one of positive grid line electrode and negative grid line electrode, and second solder strip 42 is electrically connected with the other of positive grid line electrode and negative grid line electrode. The solder strip in the application is not limited to the metal wire for welding, as long as the fixation and electrical connection of cell piece and solder strip can be realized. The solder pad described below can be understood as the point on the cell piece fixed and electrically connected with the solder strip.

[0059] In the above technical solution, in order to reduce the invalid area occupied by the busbar in the photovoltaic module, the busbar is arranged on the back surface of the cell sheet. For this case, the busbar is arranged on the edge of the front cell sheet away from the rear cell sheet and / or the edge of the rear cell sheet away from the front cell sheet. The insulating material layer 2 is arranged at the position corresponding to the busbar 5, that is, on the edge of the front cell sheet away from the rear cell sheet and / or on the edge of the rear cell sheet away from the front cell sheet. The busbar 5 is arranged on the side of the insulating material layer 2 away from the cell sheet 1. The busbar 5 is electrically connected with the solder strip 4 of the first polarity. There is a gap between the busbar 5 and the solder strip 4 of the second polarity. The solder strip 4 of the first polarity is electrically connected with the electrode of the first polarity on the cell sheet 1. The solder strip 4 of the second polarity is electrically connected with the electrode of the second polarity on the cell sheet 1. The busbar 5 is electrically isolated from the electrode of the second polarity on the cell sheet 1 by the insulating material layer 2. The busbar 5 and the solder strip 4 of the second polarity are electrically isolated by the gap. First, the busbar 5 is arranged on the edge of the front cell sheet and the rear cell sheet in the present application. On the one hand, it is compatible with the existing process of first manufacturing the cell string and then welding the cell string with the cell string. At this time, the structure of each cell string and the manufacturing process are basically the same, and the same equipment and process can be used. In the cell string welding process, the main changes are the placement position of the busbar, the heating method, and the transportation of the cell string, which are compatible with the existing equipment. Compared with the cell string manufacturing process and the cell string welding process in the prior art, the process difficulty is lower, which can greatly save the process cost, improve the module manufacturing efficiency, and improve the yield of the module based on the reduction of the process difficulty. Second, the printing scheme of the insulating material layer on the cell sheet is changed in the present application to realize the insulation of the busbar without increasing the process, such as the insulating tape and other insulating parts, which can reduce the process steps and improve the module manufacturing efficiency. Compared with the additional insulating parts, the insulating material layer of the present application is only completely attached to the edge surface of the cell sheet 1 at the position corresponding to the busbar 5, which can reduce the space occupation of the insulating material layer 2 in the thickness direction of the cell sheet 1, simplify the insulation structure, make the structure more compact, and realize stable electrical isolation and insulation. At the same time, the melting temperature of the insulating material layer 2 located below the busbar 5 is higher than the fusion temperature of the protective film layer located above the busbar 5, so that the heating temperature of the photovoltaic module in the laminating process can make the protective film layer fuse to fix, package and protect the busbar 5, the cell sheet 1 and the solder strip 4. The heating temperature in the laminating process will not melt the insulating material layer 2, and a photovoltaic module with a complete structure and reliable insulation effect can be obtained.

[0060] Exemplarily, the insulating material layer 2 can be an insulating glue printed on the edge of the cell sheet or an insulating adhesive tape adhered on the edge of the cell sheet. The printed insulating glue can ensure the reliability of the combination of the insulating material layer and the cell sheet, thereby improving the insulation reliability and reducing the thickness of the photovoltaic module. It should be understood that the insulating material layer 2 is used to insulate the bus bar 5 and the electrode of the second polarity, which can be located between the end pad and the edge of the cell sheet, i.e., the edge of the cell sheet.

[0061] In some embodiments, the spacing distance between the bus bar 5 and the solder tape 4 of the second polarity is 0.5 mm to 6 mm, and specifically, the spacing distance can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, etc., for example, as shown in Figure 4 、 Figure 6 、 Figure 8 and Figure 10 shown, the spacing distance between the bus bar 5 and the end of the second solder tape 42 is 0.5 mm to 4 mm. This distance can meet the electrical isolation requirement between the bus bar 5 and the second solder tape 42 of the second polarity, avoid short-circuit connection, and at the same time, can increase the length of the second solder tape 42 as much as possible to improve the current collection capability and the welding reliability of the end of the solder tape.

[0062] In some possible implementations, in the thickness direction of the cell sheet 1, the spacing between the bus bar 5 and the electrode of the second polarity on the cell sheet 1 is 10 μm to 200 μm, and specifically, can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 150 μm, 170 μm, 190 μm, 200 μm, etc. The electrode of the second polarity is an electrode different from the bus bar 5 in electrical conductivity, for example, the bus bar 5 is electrically connected with the positive grid line electrode through the first solder tape 41, and the negative grid line electrode is the electrode of the second polarity, the negative grid line electrode is connected with the second solder tape 42, and there is a spacing between the second solder tape 42 and the bus bar 5. In the thickness direction of the cell sheet 1, the electrode of the second polarity on the cell sheet 1 and the bus bar 5 are spaced apart by the insulating material layer 2, and therefore, the spacing between the bus bar 5 and the electrode of the second polarity on the cell sheet 1 can represent the thickness of the insulating material layer 2, which can meet the insulation requirement, and at the same time, can save the material of the insulating material layer and prevent the insulating material layer from warping due to excessive thickness. Of course, the spacing between the bus bar 5 and the electrode of the second polarity on the cell sheet 1 can also represent the physical space spacing dimension therebetween.

[0063] As Figures 4-7As shown, in some embodiments, the busbar 5 comprises an edge busbar, wherein the insulating material layer 2 located on the outermost cell 1 of the photovoltaic module and on the outer side is an edge insulating material layer, which can be the insulating material layer 2 on the head cell of the string or the insulating material layer 2 on the tail cell. The head and tail of the string herein can be understood as the head and tail of a cell string in the module layout. The length of the edge insulating material layer is less than or equal to the length of the edge of the cell on which the edge insulating material layer is located minus 0.5mm-5mm, and greater than the length of the edge busbar; specifically, the length of the edge of the cell can be reduced by 0.5mm, 1mm, 1.5mm, 2mm, 3mm, 4mm, 5mm, etc. The width of the edge insulating material layer is 0.8-1.4 times the width of the edge busbar, and can specifically be 0.8 times, 0.9 times, 1 times, 1.1 times, 1.2 times, 1.3 times, 1.4 times, etc. For example, the width of the edge insulating material layer can be 2mm-7mm, and can specifically be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, etc. The edge busbar is arranged on the side of the edge insulating material layer away from the cell 1, and the projection of the edge busbar on the cell 1 is located within the edge insulating material layer, for example, the edge busbar can be located within the edge insulating material layer near the outer side of the cell 1, near the inner side of the cell 1, or in the middle of the edge insulating material layer, and is preferably located near the outer side of the cell 1, so as to further increase the distance between the busbar 5 and the second solder strip 42 having different conductivity, further improve the insulation effect, or in the case of meeting the insulation requirements, further lengthen the second solder strip 42, and improve the current collection effect. The width of the edge busbar is 3.8mm-5.5mm, and can specifically be 3.8mm, 4mm, 4.5mm, 5mm, 5.5mm, etc.

[0064] In the technical scheme, the busbar 5 arranged at the edge of the photovoltaic module is an edge busbar, and the edge busbar is arranged on the insulating material layer 2 (i.e., an edge insulating material layer) of the first cell and / or the last cell close to the edge of the photovoltaic module. The size of the edge insulating material layer and the size of the edge busbar can meet the insulation requirement, and the material of the edge insulating material layer can be saved, and the edge insulating material layer is prevented from being too large to be pressed and covered by the edge busbar and easily warped. The edge busbar is arranged in the edge insulating material layer, and the insulation effect between the edge busbar and the electrode of the second polarity is more reliable. The width of the edge busbar can realize the current collection and save the material. When the width of the edge insulating material layer is 0.8-1.4 times the width of the edge busbar, the width of the edge busbar on the cell 1 can be determined according to the width of the edge busbar and the distance between the end of the solder strip 4 of the second polarity and the edge of the cell 1. If the distance is large, a wider edge insulating material layer can be designed to arrange the entire edge busbar on the edge of the cell 1. If the distance is small, a narrower edge insulating material layer can be designed to arrange part of the edge busbar on the edge of the cell 1, and the remaining part is arranged outside the cell 1 to avoid the edge busbar being too close to the end of the solder strip 4 of the second polarity.

[0065] As Figures 8-11As shown, in some embodiments, the busbar 5 includes a middle busbar, which is located in the middle of the photovoltaic module (i.e. a non-edge position) and is arranged on the side of the insulating material layer 2 of the tail cell of the upper cell string and / or the head cell of the lower cell string, i.e. the side away from the cell 1. That is, the middle busbar is located between the upper and lower cell strings on the photovoltaic module. The middle busbar can be arranged on the insulating material layer 2 of the tail cell of the upper cell string; or, the middle busbar is arranged on the insulating material layer 2 of the head cell of the lower cell string; or, the middle busbar is arranged across the insulating material layers 2 of the tail cell of the upper cell string and the head cell of the lower cell string, i.e. at the inter-string gap of the two series-connected cell strings, and the middle busbar is located in the area enclosed by the two insulating material layers 2. Wherein, the length of the insulating material layer 2 of the head and tail cells is less than or equal to the length of the cell edge where the insulating material layer 2 is located minus 0.5mm-1.5mm, and greater than the length of the middle busbar; specifically, the length of the cell edge can be reduced by 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, etc. The width of the insulating material layer 2 of the head and tail cells is 0.5-1.2 times the width of the middle busbar, specifically 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1 times, 1.1 times, 1.2 times, etc. For example, the width of the insulating material layer 2 is 4mm-7mm, specifically 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, etc. The size of the insulating material layer 2 corresponding to the middle busbar can meet the insulation requirements, while saving the material of the insulating material layer.

[0066] In some embodiments, when the intermediate busbar is arranged at the inter-string gap of the two series-connected battery strings, the width of the region where the intermediate busbar covers on the battery tab at the head of the string is 2 mm to 5 mm, and can be 2 mm, 3 mm, 4 mm, 5 mm, etc. The width of the region where the intermediate busbar covers on the battery tab at the tail of the string is 2 mm to 5 mm, and can be 2 mm, 3 mm, 4 mm, 5 mm, etc. The width of the region where the intermediate busbar covers on the battery tab at the head of the string can be the same as or different from the width of the region where the intermediate busbar covers on the battery tab at the tail of the string. The spacing between the two series-connected battery strings is 0 to 2 mm, i.e. the spacing between the strings covered by the intermediate busbar is 0 to 2 mm, and can be 0 mm, 1 mm, 2 mm, etc. The width of the intermediate busbar is 6 mm to 8.5 mm, and can be 6 mm, 6.5 mm, 7 mm, 7.2 mm, 7.5 mm, 7.8 mm, 8 mm, 8.5 mm, etc. The current to be transmitted by the intermediate busbar is larger than that by the edge busbar. In order to ensure the current transmission efficiency and avoid the battery tab cracking caused by excessive thickness, the intermediate busbar is designed to be thin and wide. At this time, the intermediate busbar spans two battery tabs and the gap between the upper and lower battery strings, which can avoid the risk of cracking or short circuit caused by excessive stress on a certain battery tab, thereby dispersing the stress of the stacked intermediate busbar and improving the yield of the module.

[0067] In some embodiments, in the length direction of the busbar 5, the distance between the end of the busbar 5 and the outermost solder strip 4 is 1 mm or more, and can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc. For example, as shown in FIG. 5, the length direction of the busbar 5 is perpendicular to the length direction of the first solder strip 41. The plurality of first solder strips 41 are arranged at intervals in the length direction of the busbar 5. The busbar 5 is connected to one end of the plurality of first solder strips 41. In the length direction of the busbar 5, the distance between the end of the busbar 5 and the outermost first solder strip 41 is 1 mm or more. In this way, the length of the busbar 5 can span all the solder strips 4 welded thereto, and can be fully welded with the two outermost solder strips 4 and leave enough welding process window. The excess length facilitates the connection of the busbar 5 to other leads of the photovoltaic module. Figure 4

[0068] In the width direction of the busbar 5, the distance between the edge of the busbar 5 and the edge of the insulating material layer 2 is greater than or equal to 1 mm, i.e. the distance by which the edge of the busbar 5 is recessed relative to the edge of the insulating material layer 2 is greater than or equal to 1 mm, and can be 1 mm, 1.5 mm, 2 mm, etc. This can make the busbar 5 located within the insulating material layer 2, and improve the insulation effect of the busbar 5 and the electrode of the second polarity.

[0069] For example, as shown in FIG. 6, the length direction of the busbar 5 is perpendicular to the length direction of the first solder strip 41. The plurality of first solder strips 41 are arranged at intervals in the length direction of the busbar 5. The busbar 5 is connected to one end of the plurality of first solder strips 41. In the length direction of the busbar 5, the distance between the end of the busbar 5 and the outermost first solder strip 41 is 1 mm or more. In this way, the length of the busbar 5 can span all the solder strips 4 welded thereto, and can be fully welded with the two outermost solder strips 4 and leave enough welding process window. The excess length facilitates the connection of the busbar 5 to other leads of the photovoltaic module. Figure 1 ​As shown, the embodiment provides a specific form of the insulating material layer 2, that is, the insulating material layer 2 is composed of a plurality of first insulating adhesive strips 21 arranged in parallel and at intervals, the first insulating adhesive strips 21 continuously extend along the length direction of the cell tab edge, and the first insulating adhesive strips 21 cover the fine grid electrodes of the second polarity of the cell tab 1. The fine grid electrodes have a plurality of strips parallel to the length direction of the bus bar 5, the plurality of fine grid electrodes are arranged at intervals along the width direction of the bus bar 5, the fine grid electrodes include positive fine grid electrodes and negative fine grid electrodes arranged alternately, the same polarity fine grid electrodes (such as one of the positive fine grid electrodes and the negative fine grid electrodes) are connected by the solder strip 4, the solder strip 4 is electrically isolated from the conductive fine grid electrodes of the opposite polarity (such as the other of the positive fine grid electrodes and the negative fine grid electrodes) by the solder strip insulating member 3, the solder strip insulating member 3 can be printed on the cell tab 1 together with the insulating material layer 2, and the solder strip insulating member 3 is used to cover the conductive fine grid electrodes near the solder strip 4, so that the solder strip 4 is electrically isolated from the conductive fine grid electrodes below. The total area width between the two outermost first insulating adhesive strips 21 in the insulating material layer 2 is greater than the width of the bus bar 5, the plurality of first insulating adhesive strips 21 can support the bus bar 5, so that a gap is formed between the bus bar 5 and the fine grid electrodes of the second polarity of the cell tab 1, and the first insulating adhesive strips 21 cover the fine grid electrodes of the second polarity, which can realize the electrical isolation of the bus bar 5 and the fine grid electrodes of the second polarity. At the same time, the plurality of first insulating adhesive strips 21 do not cover the edge of the cell tab 1, so that the material of the insulating material layer can be saved, and the cell tab warping caused by the setting of the insulating adhesive strip can be reduced. The first insulating adhesive strip 21 can be specifically an insulating adhesive (such as green, black, transparent, etc.) printed on the edge of the cell tab, or a plurality of insulating adhesive tapes bonded to the edge of the cell tab. The first insulating adhesive strip 21 is prepared by a printing process, which can simplify the process, improve the preparation efficiency, and has good adhesion to the edge of the cell tab and high insulation stability.

[0070] Further, the length of the first insulating adhesive strip 21 is 0.5mm-1mm less than the length of the edge of the cell tab 1, and can be specifically 0.5mm, 0.7mm, 0.8mm, 1mm, etc. The width of the first insulating adhesive strip 21 can be 0.2mm-1mm, and can be specifically 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, etc. The thickness of the first insulating adhesive strip 21 can be 10μm-100μm, and can be specifically 10μm, 30μm, 50μm, 70μm, 90μm, 100μm, etc. The size of the first insulating adhesive strip 21 can meet the insulation requirements, and at the same time, the material of the insulating adhesive strip can be saved.

[0071] As shown, Figure 2As shown, this embodiment provides a second form of insulating material layer 2, namely, insulating material layer 2 is an insulating adhesive layer 22 that is entirely covered on the edge of the battery cell 1. The insulating adhesive layer 22 completely covers the edge of the battery cell 1, the width of the insulating adhesive layer 22 is greater than the width of the busbar 5, and the thickness of the insulating adhesive layer 22 can be 10μm to 100μm, specifically 10μm, 30μm, 50μm, 70μm, 90μm, 100μm, etc. The insulating adhesive layer 22 can be insulating adhesive printed on the edge of the battery cell or a whole piece of insulating tape adhered to the edge of the battery cell. Preparing the insulating adhesive layer 22 through a printing process simplifies the process, improves the preparation efficiency, and provides good adhesion to the edge of the battery cell and high insulation stability. The insulating adhesive layer 22 can support the entire surface of the busbar 5 and achieve electrical isolation between the busbar 5 and the fine grid electrode of the second polarity on the cell 1. At this time, not only is the insulation effect of the busbar 5 better, but it can also play a better role in protecting the fine grid electrode on the cell 1 and reducing the adverse effects of the welding heat of the fine grid silver busbar on the fine grid.

[0072] like Figure 3 As shown, this embodiment provides a third form of insulating material layer 2, namely, insulating material layer 2 is a multi-row, multi-column arrangement of parallel and spaced second insulating strips 23. Part of the second insulating strips 23 cover the fine grid electrode of the second polarity, and / or, part of the second insulating strips 23 cover the fine grid electrode of the first polarity, and / or, part of the second insulating strips 23 are located between the fine grid electrode of the first polarity and the fine grid electrode of the second polarity. The arrangement of the fine grid electrode can refer to the arrangement described in the first type of insulating material layer 2, and will not be repeated here. The third type of insulating material layer 2 does not require the second insulating strips 23 to cover the fine grid electrode of the second polarity. This insulating material layer 2 can partially support the busbar 5 and can electrically isolate the busbar 5 from the fine grid electrode of the second polarity on the battery cell 1 through spatial spacing. This insulating material layer 2 can save material and can disperse the second insulating strips 23 to a large extent, shorten the length of the second insulating strips 23, further reduce battery cell warping caused by the second insulating strips 23, and reduce microcracks in the battery cell. The second insulating strip 23 can be insulating adhesive printed on the edge of the battery cell or multiple short insulating tapes adhered to the edge of the battery cell. Preparing the second insulating strip 23 through a printing process simplifies the process, improves preparation efficiency, and provides good adhesion to the edge of the battery cell, resulting in high insulation stability.

[0073] Furthermore, the width of the second insulating strip 23 is 0.2mm to 1mm, the length of the second insulating strip 23 can be 0.5mm to 10mm, and the thickness of the second insulating strip 23 is 10μm to 100μm. This size can meet the electrical isolation requirements between the busbar 5 and the fine grid electrode of the second polarity on the battery cell 1, and can save material of the insulating material layer.

[0074] The above three types of insulation material layers can be used as edge insulation material layers for corresponding edge busbars or as insulation material layers for corresponding middle busbars, and are all applicable.

[0075] In some embodiments, the battery cell 1 has pads connected to the grid line electrodes. Along the extension direction of the solder strip 4, the spacing between the busbar 5 and the nearest pad is 0.5mm to 4mm, specifically 0.5mm, 0.8mm, 1mm, 2mm, 3mm, 4mm, etc. For example, each fine grid electrode has several pads, with positive and negative fine grid electrodes arranged alternately. A solder strip 4 of one polarity connects to the pads of multiple positive fine grid electrodes, and a solder strip 4 of another polarity connects to the pads of multiple negative fine grid electrodes. The busbar 5 is connected to the solder strip 4 of the first polarity, and there is a spacing between the busbar 5 and the solder strip 4 of the second polarity. The connection between the solder strip 4 and the pad can be soldered, or the solder strip 4 and the pad can be alloyed together by the lamination temperature during the lamination process. For example... Figure 4 The pads welded to the ends of the second solder strip 42 of the second polarity or the end pads 11 connected to the solder strip 4 of the first polarity, with a spacing of 0.5mm to 4mm between the pads and the busbar 5, ensure sufficient distance between the welding positions of the busbar 5 and the solder strip 4, i.e., between the pads. This prevents disturbance to the solder strip 4 caused by the busbar 5 being positioned between the solder strip 4 and the battery cell 1, thus affecting the welding reliability of the solder strip 4. This distance reduces the impact of the welding heat from the busbar 5 on adjacent pads, preventing over-soldering. In addition, this spacing meets the electrical isolation requirements between the busbar 5 and pads with different conductivity, preventing short-circuit connections, while maximizing the length of the solder strips 4 with different electrical properties to improve current collection capacity and welding reliability.

[0076] Furthermore, the distance by which the end of the second polarity solder ribbon 4 protrudes from the pad connected to it is -0.5mm to 0.2mm, specifically -0.5mm, -0.3mm, 0mm, 0.1mm, 0.2mm, etc. When the protrusion distance is negative, it indicates that the end of the solder ribbon 4 is inside the pad; when the protrusion distance is positive, it indicates that the end of the solder ribbon 4 protrudes outside the pad; when the protrusion distance is zero, it indicates that the end of the solder ribbon 4 is flush with the boundary of the pad. Taking the pad welded to the end of the second solder ribbon 42 as an example, the end of the second solder ribbon 42 can be inside the pad or protrude outside the pad along the direction close to the busbar 5. This ensures a reliable connection between the solder ribbon 4 and the pad while also taking into account the space for the busbar 5. In other words, the solder ribbon 4 protrudes relatively little or not at all from the pad, leaving enough space on the battery cell 1 to place the busbar 5, avoiding the problem of insufficient space for the busbar 5 due to the solder ribbon 4 protruding too much. In addition, this ensures a large insulation distance between the busbar 5 and the solder strip 4, guaranteeing insulation safety. Figure 4As shown, the end of the second solder strip 42 protrudes beyond the solder pad.

[0077] like Figure 4 and Figure 5 As shown, the first polarity solder strip 4 is located between the busbar 5 and the insulating material layer 2. Taking the connection between the first solder strip 41 and the busbar 5 as an example, the first solder strip 41 is sandwiched between the busbar 5 and the insulating material layer 2, and the busbar 5 covers the first solder strip 41, as shown. Figure 5 As shown, in this area, the battery cell 1, the insulating material layer 2, the first solder strip 41, and the busbar 5 are arranged in sequence. This structure facilitates the welding of the solder strip 4 to the battery cell 1 and the welding of the busbar 5 to the solder strip 4, improving welding strength and efficiency. Due to the simple stacked structure of the solder strip 4 and the busbar 5, the welding joint between the solder strip 4 and the busbar 5 does not require bending, allowing the solder strip 4 to make flat contact with the battery cell 1, which reduces the risk of microcracks in the battery cell 1 caused by the pressure on the solder strip 4.

[0078] Of course, the busbar 5 can also be located between the insulating material layer 2 and the first solder strip 41, such as... Figure 6 and Figure 7 As shown, in this area, the battery cell 1, the insulating material layer 2, the busbar 5, and the first solder strip 41 are stacked sequentially. At this time, the first solder strip 41 is located on top, and the welding effect of the busbar 5 can be easily and quickly determined by the naked eye.

[0079] like Figure 8 As shown, in some embodiments, the intermediate busbar electrically connects the tail cell of the previous battery string and the head cell of the next battery string. The intermediate busbar spans the insulating material layer 2 connecting adjacent head and tail cells in two series-connected battery strings, or is located within the insulating material layer of a single cell. The solder strip 4 on the head cell and the solder strip 4 on the tail cell are aligned or connected on the intermediate busbar. For example, taking the connection of the first solder strip 41 to the busbar 5 as an example, the tail cell (… Figure 8 The first solder strip 41 on the left-hand cell (middle left) and the first cell in the string ( Figure 8 The first solder strip 41 on the right-hand cell (in the middle section) is aligned or connected horizontally on the middle busbar. Aligning the solder strip 41 on the tail cell and the first cell of the string with the first solder strip 41 on the middle busbar reduces the creepage distance difference between the upper and lower parts of the module, reduces the side length of the photovoltaic module (this side is parallel to the length direction of the first solder strip 41), and reduces the blank area of ​​the photovoltaic module. Connecting the first solder strip 41 on the first cell of the string with the first solder strip 41 on the adjacent tail cell of the string on the middle busbar reduces current loss. It should be understood that the first solder strip 41 of the previous string and the first solder strip 41 of the next string can also be staggered on the middle busbar.

[0080] In some possible implementations, for a photovoltaic module with a cell gap, the photovoltaic module includes m rows of cell pieces, m is an integer greater than or equal to 2, and one row of cell pieces includes 2 or more cell strings; the distance between adjacent cell pieces 1 in one row of cell pieces is 0-2 mm, specifically, 0 mm, 0.5 mm, 1 mm, 2 mm, etc., the distance between adjacent rows of cell pieces is 0.3-3.3 mm, specifically, 0.3 mm, 1 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm, 3.3 mm, etc., and the difference between the distances of two cell strings in the first row or the last row from the edge of the photovoltaic module is less than or equal to 0.2 mm. Taking the first row as an example, one row of cell pieces is arranged along the long side of the photovoltaic module, and the difference between the distance of the upper cell string in the first row from the long side edge of the photovoltaic module and the distance of the lower cell string from the long side edge of the photovoltaic module is less than or equal to 0.2 mm, so that the creeping distance between the two cell strings in the first row from the long side edge of the photovoltaic module is similar, and the length of the photovoltaic module in the short side direction can be reduced. The last row is the same as the first row, and will not be described again. The distance between the nearest cell pieces 1 in the long side direction of the photovoltaic module is 11-15 mm, specifically, 11 mm, 13 mm, 15 mm, etc., and the distance between the nearest cell pieces 1 in the short side direction of the photovoltaic module is 11-17 mm, specifically, 11 mm, 12 mm, 14 mm, 16 mm, 17 mm, etc. The cell gap, the string gap, and the distance between the cell piece 1 and the edge of the photovoltaic module of the photovoltaic module of this version are all reduced, which can improve the unit power of the photovoltaic module.

[0081] For another version of a photovoltaic module, the photovoltaic module also includes m rows of cell pieces, m is an integer greater than or equal to 2, and one row of cell pieces includes 2 or more cell strings; the plurality of cell pieces 1 in the cell string are arranged in a shingle arrangement, the width of the overlapping region of adjacent cell pieces 1 in each cell string is 0.3-2 mm, specifically, 0.3 mm, 0.5 mm, 1 mm, 1.3 mm, 1.6 mm, 2 mm, etc., the distance between adjacent rows of cell pieces is 0.3-3.3 mm, specifically, 0.3 mm, 1 mm, 1.5 mm, 1.8 mm, 2 mm, 2.5 mm, 3 mm, 3.3 mm, etc., the distance between the nearest cell pieces 1 in the long side direction of the photovoltaic module is 11-15 mm, specifically, 11 mm, 13 mm, 15 mm, etc., and the distance between the nearest cell pieces 1 in the short side direction of the photovoltaic module is 11-17 mm, specifically, 11 mm, 12 mm, 14 mm, 16 mm, 17 mm, etc. The string gap, the distance between the cell piece 1 and the edge of the photovoltaic module of the photovoltaic module of this version are all reduced, which can improve the unit power of the photovoltaic module.

[0082] In some embodiments, along the length direction of the solder strip 4 of the first polarity, a connecting line is provided between the pads at the beginning and / or end of the solder strip 4 of the first polarity and the edge of the solar cell 1. That is, along the length direction of the solder strip 4 of the first polarity, a connecting line is provided between the pad at the beginning of the solder strip 4 of the first polarity and the edge of the nearby solar cell 1; or, a connecting line is provided between the pad at the end of the solder strip 4 of the first polarity and the edge of the nearby solar cell 1; or, connecting lines are provided between the pads at the beginning and end of the solder strip 4 of the first polarity and the edges of the nearby solar cell 1, respectively. The connecting line electrically connects the fine grid electrode of the first polarity of the solar cell 1 to the pad; the busbar 5 covers part of the connecting line. The portion of the fine grid electrode of the first polarity located below the busbar 5 cannot directly contact the solder ribbon of the first polarity 4, resulting in poor current conduction in this area. Therefore, a connecting wire can be used to connect to this area of ​​the fine grid electrode of the first polarity, facilitating the collection of current from this area and channeling it to the solder ribbon of the first polarity 4, ultimately leading to the busbar 5, thus improving current collection efficiency. The solder ribbon of the second polarity 4, while maintaining an insulating distance from the busbar 5, cannot extend to or cover the edge of the cell 1 to directly collect current from the fine grid electrode; instead, current needs to be collected through connecting wires and solder pads.

[0083] In the case where the battery cell 1 has a main grid electrode of the first polarity, the extension direction of the main grid electrode is perpendicular to the extension direction of the busbar 5. The main grid electrode can be connected to multiple fine grid electrodes of the first polarity. The end of the main grid electrode extends into the area where the busbar 5 is located, and the busbar 5 covers part of the main grid electrode. The main grid electrode can be connected to the fine grid electrodes of the first polarity below the busbar 5, which facilitates the collection of current from the fine grid electrodes of the first polarity in this area and gathers it to the solder ribbon 4 of the first polarity, and finally leads it to the busbar 5, improving the current collection efficiency.

[0084] In some possible implementations, the battery cell 1 has an end pad 11 extending along the direction of the solder strip 4. The end pad 11 is located near the edge of the battery cell 1 and is a rectangular pad with adjacent first and second sides. The length of the first side is 0.5mm to 1.5mm, and the length of the second side is 0.5mm to 1.5mm. The lengths of the first and second sides can be the same or different. For example, as... Figure 4 As shown, after the first solder strip 41 is electrically connected to the end pad 11, it extends to the location of the busbar 5. The end of the first solder strip 41 is welded to the busbar 5. Due to the presence of the busbar 5, the first solder strip 41 will be affected by the force of the busbar 5, the welding heat, and may also be bent, which will affect the connection effect between the first solder strip 41 and the end pad 11. Therefore, setting the end pad 11 to a larger size can improve the electrical connection performance between the end pad 11 and the first solder strip 41.

[0085] In some embodiments, the photovoltaic module further comprises a strip-shaped adhesive film covering the side of the busbar 5 away from the cell, and the projection of the busbar 5 on the strip-shaped adhesive film is located within the strip-shaped adhesive film. With the above technical solution, the strip-shaped adhesive film covers the busbar 5, so that when the busbar 5 is pressed, the position of the busbar 5 is buffered by the strip-shaped adhesive film, reducing the risk of cell cracking.

[0086] For example, the thickness of the strip-shaped adhesive film is 200 μm to 1000 μm, and can be 200 μm, 400 μm, 600 μm, 800 μm, 1000 μm, etc. And / or, the width of the strip-shaped adhesive film is 0 to 100 mm wider than the width of the busbar 5, and can be 0 μm, 10 μm, 30 μm, 50 μm, 70 μm, 100 μm, etc. And / or, the length of the strip-shaped adhesive film is 0 to 5 mm longer than the length of the busbar 5, and can be 0 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc. And / or, the material of the strip-shaped adhesive film is a material with elasticity and resistance, such as POE (polyolefin elastomer), EPE (expandable polyethylene), or EVA (ethylene-vinyl acetate copolymer). At this time, the selection of the material can ensure better buffering effect on the busbar 5; through the design of the thickness of the strip-shaped adhesive film, the buffering effect and the laminated thickness can be considered, and the problem of laminated bubbles caused by excessive thickness can be avoided; through the design of the width and thickness of the strip-shaped adhesive film, the strip-shaped adhesive film can cover the entire busbar 5, and the problem of uneven stress in local areas can be reduced.

[0087] In some embodiments, an insulating material layer 2 is arranged on both edges of the vertical solder strip 4 of each cell of the photovoltaic module. At this time, the structure of each cell 1 of the module and the design of the insulating material layer 2 are the same, and there is no need to distinguish the first and last cells of the string and the middle cells of the string when making the cell string, which can further reduce the process difficulty and improve the module manufacturing efficiency.

[0088] In some embodiments, the solder strip 4 is a flat solder strip, and the thickness of the solder strip 4 is reduced from 0.25 mm to 0.18 mm to 0.22 mm, and the width of the solder strip 4 is increased to 0.6 mm to 1 mm. In this way, the flat solder strip is thinner and wider, and after being welded with the cell 1, the contact area can be increased and the pressure can be reduced, and when the solder strip 4 is pressed, the risk of cracking the cell 1 can be reduced.

[0089] In some embodiments, the angle between the position where the solder strip 4 is connected to the bus bar 5 and the surface of the battery sheet and / or the angle between the bus bar 5 and / or the solder strip 4 and the surface of the battery sheet is less than 80°, and the specific angle can be 0°, 10°, 30°, 45°, 60°, 70°, 79°, etc. This makes the solder strip 4 and / or the bus bar more flat, and the bending angle of the solder strip 4 is smaller. When under pressure, the stress of the bending part of the solder strip 4 is larger, which is easy to cause the battery sheet 1 to crack. When the bending angle of the solder strip 4 is smaller, the risk of causing the battery sheet 1 to crack is reduced, and the adverse effect of the solder strip 4 on the connection reliability of the solder strip 4 and the solder pad is also reduced.

[0090] In some possible implementations, the thickness of the battery sheet 1 is 100 μm-160 μm; the thickness of the electrode on the battery sheet 1 is 10 μm-20 μm; the thickness of the solder strip 4 is 0.18 mm-0.8 mm; and / or the thickness of the bus bar 5 is 0.07 mm-0.2 mm. In this way, the height of the protruding battery sheet 1 can be reduced, and the risk of causing the battery sheet 1 to crack is reduced.

[0091] In some embodiments, in the thickness direction of the photovoltaic module, the sum of the thicknesses of the battery sheet 1, the electrode, the solder strip 4, and the bus bar 5 between the cover plate and the back plate of the photovoltaic module accounts for less than 85% of the distance between the cover plate and the back plate. Since, between the cover plate and the back plate, in addition to the battery sheet 1, the electrode, the solder strip 4, and the bus bar 5, some adhesive film layers are also needed to fix and buffer the battery sheet 1, the solder strip 4, and the bus bar 5, in order to improve the fixing and buffering effect of the adhesive film layers and reduce the risk of causing the battery sheet to crack or misplace during the module lamination process, the adhesive film layers need to be provided with sufficient thickness space. Therefore, the sum of the thicknesses of the battery sheet 1, the electrode, the solder strip 4, and the bus bar 5 accounts for less than 85% of the distance between the cover plate and the back plate, and the remaining distance is left for the adhesive film layers.

[0092] In some embodiments, the corner of the battery sheet 1 has a chamfer, and the minimum distance between the bus bar and the chamfer is greater than 1 mm, and can be 1.2 mm, 1.5 mm, 2 mm, etc. In this way, the insulation effect is improved.

[0093] The main preparation process of the photovoltaic module provided in the embodiment is as follows:

[0094] Insulating glue printing: insulating glue is printed on the back of the battery sheet. The insulating glue can be printed on the edge of the back of the battery sheet to form an insulating material layer 2, and can be printed on the position corresponding to the solder strip to form a solder strip insulating piece 3. The insulating glue shields the part of the grid electrode with different conductivity from the solder strip and the bus bar, prevents the generation of conductive short circuit, protects the main grid electrode and the solder pad connection line position from overheat disconnection of series welding, and prevents short circuit caused by solder strip deviation and sliding through printing layout optimization, to form any one of the insulating forms in Figures 1-3 .

[0095] Conductive glue printing: printing conductive glue on the back pad of the battery piece to meet the welding requirements of the pad and the welding strip, and improve the welding performance and conductive performance.

[0096] String welding: the welding strip connects the negative electrode on the back of the previous battery piece with the positive electrode on the back of the next battery piece, and connects the positive electrode on the back of the previous battery piece with the negative electrode on the back of the next battery piece, forming a series circuit, wherein the first welding strip on both sides of the battery string extends to the edge of the battery piece, and a plurality of same battery strings are prepared in this way.

[0097] Layout: the device arranges the battery string welded by the welding machine on the glass adhesive film in an alternating positive and negative electrode manner, and controls the position and spacing between the strings according to requirements.

[0098] Battery string, bus bar laying and welding: the edge bus bar is placed above the first welding strip on the outermost side of the battery piece at the edge of the photovoltaic module or between the first welding strip and the insulating material layer, the edge bus bar is placed in the edge insulating material layer (such as printed insulating glue), the adjacent battery strings are connected, and then high-temperature welding (infrared heating or laser welding) is performed.

[0099] Intermediate bus bar laying and welding: the intermediate bus bar is placed across the first welding strip on both sides of the gap between adjacent battery strings and the insulating material layer, or placed above the first welding strip, and then high-temperature welding is performed.

[0100] Laminating: laying the back adhesive film and back plate above the battery string to form a laminated part.

[0101] The insulating material layer preparation process of the photovoltaic module preparation process is simple, and has good adhesion with the battery piece, which can simplify the structure and improve the insulation stability.

[0102] In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0103] 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 can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A photovoltaic module, characterized by, The battery string comprises a plurality of battery pieces connected in series by welding strips, and a busbar, wherein the plurality of battery pieces comprises a first battery piece at the head of the string and a last battery piece at the tail of the string; An edge of the first battery piece away from the last battery piece and / or an edge of the last battery piece away from the first battery piece is provided with a layer of insulating material; On one of the battery pieces, the busbar is arranged on a side of the layer of insulating material away from the battery piece; the busbar is electrically connected with the welding strips of the first polarity, and there is a gap between the busbar and the welding strips of the second polarity; the welding strips of the first polarity are electrically connected with the electrodes of the first polarity on the battery piece, and the welding strips of the second polarity are electrically connected with the electrodes of the second polarity on the battery piece; The busbar is insulated from the electrodes of the second polarity by the layer of insulating material.

2. The photovoltaic module of claim 1, wherein, The distance of the gap is 0.5mm-6mm.

3. The photovoltaic module of claim 1, wherein, In the thickness direction of the battery piece, the distance between the busbar and the electrodes of the second polarity on the battery piece is 10μm-200μm.

4. The photovoltaic module of claim 1, wherein, The busbar comprises an edge busbar, wherein the layer of insulating material on the battery piece at the outermost side of the photovoltaic module is an edge layer of insulating material, The length of the edge layer of insulating material is less than or equal to the length of the edge where the edge layer of insulating material is located minus 0.5mm-5mm, and is greater than the length of the edge busbar; and / or, the width of the edge layer of insulating material is 0.8-1.4 times the width of the edge busbar; And / or, the projection of the edge busbar on the battery piece is located within the edge layer of insulating material, and the width of the edge busbar is 3.8mm-5.5mm.

5. The photovoltaic module of claim 1, wherein, The busbar comprises a middle busbar, which is located in the middle of the photovoltaic module and is arranged on the side of the layer of insulating material away from the battery piece of the last battery piece of the upper battery string and / or the first battery piece of the lower battery string; wherein the length of the layer of insulating material of the first battery piece and the last battery piece is less than or equal to the length of the edge where the layer of insulating material is located minus 0.5mm-1.5mm, and is greater than the length of the middle busbar; and / or, the width of the layer of insulating material of the first battery piece and the last battery piece is 0.5-1.2 times the width of the middle busbar; And / or, the width of the region covered by the middle busbar on the first battery piece is 2mm-5mm, and the width of the region covered by the middle busbar on the last battery piece is 2mm-5mm, and the distance between the two series-connected battery strings is 0-2mm; And / or, the width of the middle busbar is 6mm-8.5mm.

6. The photovoltaic module of claim 1, wherein, In the length direction of the busbar, the distance between the end of the busbar and the outermost welding strip is greater than or equal to 1mm; And / or, in the width direction of the busbar, the distance between the edge of the busbar and the edge of the layer of insulating material is greater than or equal to 1mm.

7. The photovoltaic module of claim 1, wherein, The insulating material layer is composed of a plurality of first insulating adhesive strips arranged in parallel and at intervals, the first insulating adhesive strips continuously extend along the length direction of the edge, and the first insulating adhesive strips cover the fine grid electrodes of the second polarity of the battery piece; Or, the insulating material layer is an insulating adhesive layer covering the edge as a whole; Or, the insulating material layer is a plurality of rows and columns of second insulating adhesive strips arranged in parallel and at intervals, part of the second insulating adhesive strips cover the fine grid electrodes of the second polarity and / or part of the second insulating adhesive strips cover the fine grid electrodes of the first polarity and / or part of the second insulating adhesive strips are located between the fine grid electrodes of the first polarity and the fine grid electrodes of the second polarity.

8. The photovoltaic module of claim 1, wherein, The battery piece has a pad, and the distance between the bus bar and the closest pad in the extension direction of the solder strip is 0.5mm-4mm; And / or, the end of the solder strip of the second polarity protrudes from the pad connected with the solder strip by a distance of-0.5mm-0.2mm.

9. The photovoltaic module of claim 1, wherein, The solder strip of the first polarity is located between the bus bar and the insulating material layer; or the bus bar is located between the solder strip of the first polarity and the insulating material layer.

10. The photovoltaic module according to any of claims 1 to 9, characterized in that The bus bar includes a middle bus bar located in the middle of the photovoltaic module and electrically connected with the tail battery piece of the previous battery string and the head battery piece of the next battery string; the solder strip on the head battery piece is aligned with or connected with the solder strip on the tail battery piece on the middle bus bar.

11. The photovoltaic module according to any of claims 1 to 9, characterized in that The battery piece includes m columns, and each column includes 2 or more battery strings; the distance between adjacent battery pieces in a column is 0-2mm, and the distance between adjacent columns is 0.3mm-3.3mm; in the first or last column, the distance between the two battery strings and the edge of the photovoltaic module is less than or equal to 0.2mm; Or, the battery pieces in the battery string are arranged in a shingle manner, the width of the overlapping area between adjacent battery pieces in each battery string is 0.3mm-2mm, and the distance between adjacent columns is 0.3mm-3.3mm.

12. The photovoltaic module according to any of claims 1-9, wherein, In the length direction of the solder strip, a connecting line is arranged between the pad at the head and / or tail of the solder strip and the edge of the battery piece, and the connecting line electrically connects the fine grid electrode of the battery piece and the pad; The bus bar covers part of the connecting line.

13. The photovoltaic module according to any of claims 1-9, wherein, The battery piece has an end pad, and in the extension direction of the solder strip, the end pad is close to the edge of the battery piece; the end pad is a rectangular pad having adjacent first and second edges, the length of the first edge is 0.5mm-1.5mm, and the length of the second edge is 0.5mm-1.5mm.

14. The photovoltaic module according to any of claims 1-9, wherein, The photovoltaic module further includes a strip-shaped adhesive film covering the side of the bus bar away from the battery piece, and the projection of the bus bar on the strip-shaped adhesive film is located in the strip-shaped adhesive film.

15. The photovoltaic module of claim 14, wherein, The thickness of the strip-shaped adhesive film is 200-1000 μm, and / or the width of the strip-shaped adhesive film is 0-100 mm wider than the width of the bus bar, and / or the length of the strip-shaped adhesive film is 0-5 mm longer than the length of the bus bar, and / or the material of the strip-shaped adhesive film is POE, EPE or EVA.

16. The photovoltaic module according to any of claims 1-9, wherein, The solder strip is a flat solder strip; and / or the insulating material layer is a printed insulating adhesive; and / or an insulating material layer is arranged on each cell of the photovoltaic module perpendicularly to the two edges of the solder strip; and / or The melting temperature of the insulating material layer under the bus bar is higher than the melting temperature of the adhesive film protective layer above the bus bar.

17. The photovoltaic module according to any of claims 1-9, wherein, The angle between the solder strip and the bus bar and / or the solder strip and the surface of the cell is less than 80°.

18. The photovoltaic module of any of claims 1-9, wherein, The thickness of the cell is 100-160 μm; the thickness of the electrode on the cell is 10-20 μm; the thickness of the solder strip is 0.18-0.8 mm; the thickness of the bus bar is 0.07-0.2 mm; And / or in the thickness direction of the photovoltaic module, the sum of the thicknesses of the cell, the electrode, the solder strip and the bus bar accounts for less than 85% of the distance between the cover plate and the back plate of the photovoltaic module.

19. The photovoltaic module of any of claims 1-9, wherein, The corner of the cell has a chamfer, and the minimum distance between the bus bar and the chamfer is greater than 1 mm.

Images