Connecting mechanism for connecting photovoltaic module cells and photovoltaic module

Abstract

The utility model discloses a connecting mechanism for connecting photovoltaic module cells and a photovoltaic module, the connecting mechanism comprises a metal sheet for connecting adjacent cells, one side surface of the metal sheet is overlapped with the front surfaces of the cells and is electrically connected with bus bars on the front surfaces of the cells; and the other side surface of the metal sheet is overlapped with the back surface of the other battery piece and is electrically connected with the bus bar on the back surface of the other battery piece. The adjacent battery pieces are connected through the metal sheets, the metal sheets are massively produced and used in the industry, and raw materials are easy to obtain. The adjacent battery pieces are connected through the metal sheets, a welding strip does not need to be used on the light receiving faces of the battery pieces, the problems of series welding alignment deviation and shading are solved, higher output power and better reliability can be obtained through a smaller shading area, and finally the purposes of improving efficiency and reducing cost are achieved. The distance between the battery pieces is reduced, and the CTM (Cell To Module) loss is reduced on the whole.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, and in particular to a connection mechanism for connecting photovoltaic module cells and a photovoltaic module. Background Art

[0002] A popular and feasible method to improve the efficiency and reduce the cost of photovoltaic cells is to reduce the CTM loss process from the module packaging. One of the representative methods is the stacking shingles / sheets process, but it has been patented by foreign companies. Another is to replace the long-standing solar cell main grid with 0BB (Busbar) technology. Because the conductivity of silver paste is poor, the number of BBs of photovoltaic cells has developed from the original 3BB to 20BB. Although it can effectively improve the conversion efficiency output and reduce the consumption of silver paste, it is still impossible to completely remove the silver. Therefore, in recent years, the industry has also introduced the electroplating copper process, combined with the yellow light patterning process, so that the overall fine grid line width is less than 20μm or even finer. Such a thorough removal of silver also has the advantages of reducing the shading rate and contact resistance. However, the thinning of the grid line also brings problems to the module packaging. That is, the alignment during welding cannot ensure that the traditional string welding rod can completely fit the grid line on the solar cell and cause a cold solder joint. This will reduce the power output of the module and the overall module reliability. Utility Model Content

[0003] The purpose of the utility model is to provide a connection mechanism for connecting photovoltaic module cells and a photovoltaic module to solve the above technical problems.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is: a connecting mechanism for connecting photovoltaic module cells, including a metal sheet connecting adjacent cells, one side of the metal sheet overlaps with the front side of the cell and is electrically connected to the bus bar on the front side of the cell; the other side of the metal sheet overlaps with the back side of another cell and is electrically connected to the bus bar on the back side of another cell.

[0005] Due to the thinness of the metal sheet itself, it can be naturally stacked with the battery cells without the need for fine processing in advance to form a thickness that matches the battery cells. It is a time-saving, convenient and universal production material. It is also reflected in the improvement of the preparation of modules and battery cell series connection. In the past, when the string welding rod was connected to the battery cells in series, the string welding required a pressurization step, which was the main cause of the battery cells to break or cause hidden cracks. This will cause concerns about the reliability of the module. Because the metal sheet replaces the traditional string welding rod, it only needs to be superimposed and bonded with the bus bar on the edge of the battery cell, which greatly reduces the shading rate and ultimately minimizes the CTM loss.

[0006] Furthermore, the thickness of the metal sheet is 50 μm to 150 μm. Exemplarily, the thickness of the metal sheet is 50 μm, 70 μm, 90 μm, 100 μm, 110 μm, 130 μm, or 150 μm.

[0007] Furthermore, the length of the metal sheet is 150 mm to 250 mm. Exemplarily, the length of the metal sheet is 150 mm, 170 mm, 190 mm, 200 mm, 210 mm, 230 mm, or 250 mm.

[0008] Furthermore, the edge of the metal sheet in the length direction is straight or circular wave-shaped.

[0009] Further, the width of the metal sheet at the contact and overlapped portion with the battery cell is in the range of 0.5 mm to 3.5 mm, and the length is in the range of 50 mm to 250 mm. Exemplarily, the width of the metal sheet at the contact and overlapped portion with the battery cell is in the range of 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, and the length is in the range of 50 mm, 100 mm, 150 mm, 200 mm, 250 mm.

[0010] Furthermore, a connection layer is provided between the metal sheet and the busbar, and the thickness of the connection layer is 5 μm to 50 μm, and the width is 0.1 mm to 2.5 mm. Exemplarily, the thickness of the connection layer is 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, and the width is 0.1 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm.

[0011] Furthermore, the connection layer is a linear structure arranged along the length direction of the metal sheet.

[0012] Furthermore, a plurality of the connection layers are provided, and the plurality of the connection layers are arranged at intervals along the length direction of the metal sheet, and the connection layers are circular or rectangular.

[0013] Furthermore, the connecting layer is an anisotropic conductive adhesive film, a conductive adhesive layer or a solder layer.

[0014] A photovoltaic module comprises the connection mechanism as described above.

[0015] The beneficial effects of the utility model are:

[0016] 1) Adjacent cells are connected by metal sheets. No soldering tape is required on the light-receiving surface of the cell, and there is no problem of string soldering alignment deviation. This allows for faster and more accurate alignment and stacking, and reduces the light-shielding area of ​​the cell, resulting in higher output power and better reliability, ultimately achieving the goal of improving efficiency and reducing costs.

[0017] 2) Connect adjacent cells through metal sheets to reduce the distance between adjacent cells and reduce the overall CTM (Cell to Module) loss.

[0018] 3) Due to the thinness of the metal sheet itself, it can be naturally stacked with the battery cell without the need for fine processing in advance. It is an excellent material for time-saving and convenient battery cell serial connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and the description thereof are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a top view schematic diagram of the connection between the metal sheet and the battery cell according to an embodiment of the utility model;

[0022] Figure 2 This is a schematic front view of the connection between the metal sheet and the battery sheet before lamination according to an embodiment of the utility model;

[0023] Figure 3 for Figure 2 A partial enlarged view of

[0024] Figure 4 This is a schematic front view of the connection between the metal sheet and the battery sheet after lamination according to an embodiment of the utility model;

[0025] Figure 5 for Figure 4 A partial enlarged view of

[0026] Figure 6 This is a front view of a metal sheet covered with a connecting layer according to an embodiment of the utility model;

[0027] Figure 7 It is a schematic top view of a metal sheet covered with a connection layer according to an embodiment of the present invention, wherein the dotted line frame represents that the connection layer is coated on the other side of the metal sheet;

[0028] In the figure: 1. Metal sheet; 2. Connection layer; 3. Battery cell; 31. Bus bar; 32. Metal grid line. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0030] See attached Figure 1 As shown, a photovoltaic module in this embodiment includes a plurality of cells 3, a plurality of metal grid lines 32 are provided on the front and back of the cells 3, and a bus bar 31 connected to the metal grid lines 32 is also provided on the cells 3, and the metal grid lines 32 guide the carriers generated by the photoelectric effect to the bus bar 31. A connecting mechanism for connecting the cells 3 is provided between adjacent cells 3, and the connecting mechanism connects two adjacent cells 3 to form a current loop to guide the carriers generated by the photoelectric effect.

[0031] See attached Figure 1-5 As shown, in some embodiments, the connection mechanism includes a metal sheet 1 connecting adjacent battery cells 3, wherein one side of the metal sheet 1 in the thickness direction overlaps with the front side of the battery cell 3 and is electrically connected to the bus bar 31 on the front side of the battery cell 3; the other side of the metal sheet 1 in the thickness direction overlaps with the back side of another battery cell 3 and is electrically connected to the bus bar 31 on the back side of the other battery cell 3. The adjacent battery cells 3 are connected by the metal sheet 1. When pressure is applied up and down on the metal sheet 1 and the bus bar 31 of the battery cell 3, a current loop that is conductive up and down but not conductive laterally can be formed to conduct the carriers generated after the photoelectric effect. The metal sheet 1 has been mass-produced and used in the industry, and the raw materials are easy to obtain. Since the metal sheet 1 is easily deformed, in the process of connecting adjacent battery cells 3, it is not necessary to pre-process the shape of the metal sheet 1, and it is in the original flat structure (see the attached Figure 2 and attached Figure 3 After the battery cell 3 and the metal sheet 1 are pressed up and down, the metal sheet 1 will deform (see the attached Figure 4 and attached Figure 5 ), which is beneficial to the later packaging of photovoltaic modules.

[0032] In some embodiments, the thickness of the metal sheet 1 is 50 μm to 150 μm. If the metal sheet 1 is too thin, the resistance of the metal sheet 1 will increase; if the metal sheet 1 is too thick, it will be unfavorable for the metal sheet 1 to deform during the extrusion process and cause waste of the raw material of the metal sheet 1. In this application, the thickness of the metal sheet 1 is limited to 50 μm to 150 μm as a suitable thickness.

[0033] In some embodiments, the length of the metal sheet 1 is 150 mm to 250 mm. The length of the metal sheet 1 is determined according to the length of the battery cell 3 and does not exceed the length of the battery cell 3 at most.

[0034] In some embodiments, the edge of the metal sheet 1 in the length direction is straight or circular wave-shaped. When the edge is straight, the processing technology of the metal sheet 1 can be simplified, and when the edge of the metal sheet 1 is circular wave-shaped, the bonding strength between the metal sheet 1 and the battery cell 3 can be enhanced.

[0035] In some embodiments, the width of the metal sheet 1 and the battery cell 3 at the contact and overlapped portion is in the range of 0.5 mm to 3.5 mm, and the length is in the range of 50 mm to 250 mm.

[0036] See attached Figure 2-7 As shown, in some embodiments, a connection layer 2 is provided between the metal sheet 1 and the bus bar 31, and the thickness of the connection layer 2 is 5 μm to 50 μm and the width is 0.1 mm to 2.5 mm. The connection layer 2 is provided to connect the metal sheet 1 and the bus bar 31, thereby enhancing the stability of the connection between the metal sheet 1 and the battery cell 3.

[0037] In some embodiments, the connection layer 2 is an anisotropic conductive film (ACF), which mainly includes conductive particles and insulating adhesive materials, with a protective film on the top and bottom to protect the main components. When in use, first tear off the cover film, attach the anisotropic conductive film to the battery cell 3, and then tear off the other PET base film. After the metal sheet 1 is accurately aligned, the metal sheet 1 is pressed together with the battery cell 3, and the insulating adhesive is cured after heating and pressurizing for a period of time, and finally a stable structure with vertical conduction and lateral insulation is formed.

[0038] In some other embodiments, the connection layer 2 is a conductive adhesive layer or a solder layer, as long as it can connect and fix the metal sheet 1 and the battery cell 3, and make the bus bar 31 on the battery cell 3 and the metal sheet 1 conductive, the present application does not limit this.

[0039] In some embodiments, the connection layer 2 is a linear structure arranged along the length direction of the metal sheet 1. By setting the connection layer as a linear structure, the connection between the metal sheet and the battery cell is stable and the connection process is simple.

[0040] In some other embodiments, the connection layer 2 is provided in multiple shapes in a circular or rectangular structure and is arranged at intervals along the length direction of the metal sheet 1. Compared with the linear structure, this structure can save the coating material of the connection layer 2 and reduce the cost of raw materials.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0042] The above implementation modes are only for illustrating the technical concept and features of the utility model, and their purpose is to allow people familiar with this technology to understand the content of the utility model and implement it. It cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A connection mechanism for connecting photovoltaic module cells, characterized in that: It comprises a metal sheet (1) for connecting adjacent battery cells (3); one side of the metal sheet (1) overlaps with the front side of the battery cell (3) and is electrically connected to a bus bar (31) on the front side of the battery cell (3); the other side of the metal sheet (1) overlaps with the back side of another battery cell (3) and is electrically connected to the bus bar (31) on the back side of another battery cell (3).

2. The connection mechanism for connecting photovoltaic module cells according to claim 1, characterized in that: The thickness of the metal sheet (1) is 50 μm to 150 μm.

3. The connection mechanism for connecting photovoltaic module cells according to claim 1, characterized in that: The length of the metal sheet (1) is 150 mm to 250 mm.

4. The connection mechanism for connecting photovoltaic module cells according to claim 1, characterized in that: The edge of the metal sheet (1) in the length direction is straight or circular and wavy.

5. The connection mechanism for connecting photovoltaic module cells according to claim 1, characterized in that: The width of the metal sheet (1) and the battery sheet (3) at the contact and overlap portion is in the range of 0.5 mm to 3.5 mm, and the length is in the range of 50 mm to 250 mm.

6. The connection mechanism for connecting photovoltaic module cells according to any one of claims 1 to 5, characterized in that: A connection layer (2) is provided between the metal sheet (1) and the bus bar (31); the connection layer (2) has a thickness of 5 μm to 50 μm and a width of 0.1 mm to 2.5 mm.

7. The connection mechanism for connecting photovoltaic module cells according to claim 6, characterized in that: The connecting layer (2) is a linear structure arranged along the length direction of the metal sheet (1).

8. The connection mechanism for connecting photovoltaic module cells according to claim 6, characterized in that: A plurality of the connection layers (2) are provided, and the plurality of the connection layers (2) are arranged at intervals along the length direction of the metal sheet (1), and the connection layers (2) are circular or rectangular.

9. The connection mechanism for connecting photovoltaic module cells according to claim 6, characterized in that: The connecting layer (2) is an anisotropic conductive adhesive film, a conductive adhesive layer or a solder layer.

10. A photovoltaic module, characterized in that: It comprises the connecting mechanism described in any one of claims 1 to 9.

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