Series group connecting film structure and battery assembly

Abstract

The utility model provides a string group connecting film structure which comprises a metal sheet and covering films wrapping the two sides of the metal sheet in the length direction, the peripheries of the end faces of the upper side and the lower side of the metal sheet are covered with the covering films, and a connecting film is integrally formed. The string group connecting film structure is simple in structure and easy to produce, replaces an existing long string welding strip, and is convenient to coat conductive adhesive or welding flux so as to perform lamination connection on battery pieces; and meanwhile, the shading area can be reduced to the maximum extent, and the technical problem of alignment deviation of series welding is solved. The utility model further provides a battery assembly connected through the connecting film.

Description

Technical Field

[0001] The present application belongs to the technical field of battery assembly production, and in particular, relates to a series connection membrane structure and a battery assembly connected by the connection membrane. Background Art

[0002] The existing shingled modules are connected by long strips of welding tape, but the alignment during welding cannot ensure that the traditional string welding rods are completely in contact with the grid lines on the cells, resulting in cold welding. This will have a great impact on the power output of the module and the reliability of the overall module quality. Summary of the invention

[0003] The present application provides a series connection membrane structure, which particularly solves the technical problem of easy deviation of the series welding alignment in the prior art.

[0004] In order to solve at least one of the above technical problems, the technical solution adopted in this application is:

[0005] A series connection membrane structure comprises a metal sheet and a covering membrane wrapped around both sides of the length of the metal sheet. The upper and lower end surface peripheries of the metal sheet are covered by the covering membrane to form a connection membrane as a whole.

[0006] Furthermore, the metal sheet is constructed as a long strip with a rectangular cross section.

[0007] Furthermore, the thickness of the metal sheet is in the range of 20-100 μm, and the horizontal width is in the range of 1.5-5 mm.

[0008] Furthermore, the vertical length of the covering film is not less than the vertical length of the metal sheet, wherein the length of the metal sheet is 50-250 mm.

[0009] Furthermore, the vertical length and horizontal width of the connection film are adapted to the size of the battery cell, and the thickness of the connection film is in the range of 60-250 μm.

[0010] Furthermore, gap sections on which conductive adhesive can be coated are provided on the upper and lower sides of the metal sheet, and the gap sections in the upper and lower end surfaces of the metal sheet are staggered.

[0011] Furthermore, in the gap sections on the upper and lower sides of the metal sheet, the horizontal widths thereof may be the same or different.

[0012] Furthermore, the horizontal width of the gap segment is 1000-3000 μm.

[0013] A battery assembly uses the above-mentioned connecting film to stack and connect battery sheets to form a battery string.

[0014] Furthermore, when two adjacent battery cells are stacked and connected,

[0015] The cover film completely covers the back of the front battery cell and the front of the rear battery cell; and one end of the metal sheet is placed above the bus bar on the front of the rear battery cell, and the other end is placed below the bus bar on the back of the front battery cell;

[0016] In each battery string, the front side of the first battery cell and the back side of the last battery cell are covered with a separate covering film.

[0017] The present invention adopts a series connection membrane structure designed by the present invention. The present invention adopts a series connection membrane structure, which has a simple structure and is easy to produce. It replaces the existing long series welding belt and is convenient for coating conductive glue or solder to stack the battery cells. At the same time, it can also minimize the shading area and solve the technical problem of series welding alignment deviation.

[0018] The connecting film structure can be used for battery cell alignment, serial welding and packaging, and can quickly and accurately align and overlap, making the serial welding connection more solid, thereby reducing the contact resistance and light shielding area of ​​the connecting film to the battery assembly, and improving the output power of the battery assembly. The present application also proposes a battery assembly connected by the connecting film. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a connecting membrane structure in this application;

[0020] Figure 2 is a top view of the connecting membrane in the present application;

[0021] Figure 3 It is a schematic diagram of the alignment and stacking of the string connection membrane and the battery cell busbar area in this application.

[0022] In the figure:

[0023] 10. Connecting film 11. Metal sheet 12. Covering film

[0024] 13. Gap segment 14. Conductive adhesive 20. Battery cell

[0025] 21, front 22, back 30, bus bar

[0026] 40, battery string 50, welding strip DETAILED DESCRIPTION

[0027] The present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment proposes a structure of a series connection membrane 10, such as Figure 1As shown, it includes a metal sheet 11 and a covering film 12 wrapped on both sides of the length of the metal sheet 11. The upper and lower end surfaces of the metal sheet 11 are covered by the covering film 12 to form a connecting film 10. Specifically, part of the width of the upper and lower end surfaces of the metal sheet 11 is covered and wrapped by the covering film 12. The metal sheet 11 is a conductive material and can be made of metal materials such as copper or tin-copper or composite metal materials. It is a long strip structure with a rectangular cross section, and the thickness H1 of the metal sheet 11 is in the range of 20-100μm, and the horizontal width W1 is in the range of 1.5-5mm.

[0029] The covering film 12 is formed by injection molding of insulating polymer materials, including but not limited to PI, TOP and POE, etc. The thickness H2 of the covering film 12 ranges from 5 to 200 μm, and the polymer materials used therein can be used as polymer materials for packaging of subsequent photovoltaic cell modules.

[0030] In the actual processing, the copper metal sheet 11 needs to be placed in a preset position in the injection mold cavity. Then, an insulating polymer material is injected into the mold cavity to wrap the two sides of the metal sheet 11 in the width direction to form a counter-positioned covering film 12. After the covering film 12 is injected, a connecting film 10 formed by the metal sheet 11 and the covering films 12 on both sides is formed in the mold cavity, wherein the covering films on both sides are formed in one piece. Finally, the mold is demolded to obtain the connecting film 10 in which the metal sheet 11 and the covering film 12 are placed in one piece.

[0031] like Figure 3 As shown, the vertical length L2 of the connecting film 10 needs to be compatible with the vertical length of the battery cell, and its horizontal width W3 is compatible with the horizontal width of the battery cell; in addition, the thickness H2 of the connecting film 10 ranges from 60 to 250 μm. The thickness of the covering film 12 in the connecting film 10 is the same, and the vertical length of the covering film 12 is not less than the vertical length of the metal sheet 11; preferably, the vertical length L1 of the metal sheet 11 ranges from 50 to 250 mm.

[0032] Furthermore, the covering film 12 covers the periphery of the metal sheet 11 and is diffusely disposed along the length direction and the width direction of the metal sheet 11 .

[0033] like Figure 2 As shown, in the cross section of the connecting film 10 , the thickness of the covering film 12 is half wrapped around the metal sheet 11 , and on the opposite side elevations of the covering film 12 on both sides of the metal sheet 11 , the side elevations are wrapped around the length side edges of the metal sheet 11 .

[0034] The vertical length of the covering film 12 may be the same as the vertical length of the metal sheet 11. Of course, the vertical length of the covering film 12 may be greater than the vertical length of the metal sheet 11, so that the covering film completely covers the width and length periphery of the metal sheet 11 and wraps it. Regardless of how the covering film 12 and the metal sheet 11 are covered, the final vertical length of the covering film 12 is the vertical length of the connecting film 10, which is compatible with the vertical length of the battery cell.

[0035] like Figure 2 As shown, the metal sheet 11 is embedded in the middle position of the side elevation of the covering film 12, that is, the film thickness of the upper and lower end surfaces of the metal sheet 11 is the same, and each upper and lower end surfaces of the metal sheet 11 are provided with a gap section 13 for coating the conductive adhesive 14. In the gap section 13 on the same side, the overlapping widths of the covering film 12 and the metal sheet 11 on both sides are not equal, that is, the width of the upper and lower side surfaces in the connecting film 10 is asymmetric, so that the side elevation ends of the covering film 12 on both sides of the metal sheet 11 have a small overlapping width above / below, and correspondingly, a large overlapping width below / above. That is, in the covering film 12, in the upper and lower side surfaces covered by the metal sheet 11, the horizontal lateral width of the overlapping end surface on one side is smaller than the horizontal width of the overlapping end surface on the other side.

[0036] Correspondingly, the covering films 12 on both sides of the metal sheet 11 in the width direction are relatively arranged, covering the periphery of the metal sheet 11 and enclosing the metal sheet therein to form a stable and integrated connecting film 10 structure, and the width of the covering film 12 wrapped around the length side of the metal sheet 11 is uneven.

[0037] In each connecting film 10, there is a metal sheet 11, and in the horizontal width direction of the metal sheet 11, gap sections 14 for coating conductive adhesive 14 are provided in the upper and lower end faces, namely the gap section 13 on the upper end face and the gap section 13 on the lower end face, and the gap sections on the upper and lower end faces are staggered; they are mainly used for interactive connection with two parallel arranged battery cells.

[0038] Furthermore, the width W2 of the gap segment 13 may be the same or different in the upper and lower end surfaces of the metal sheet 11. Preferably, the width W2 of the gap segment 13 is in the range of 1000-3000 μm.

[0039] When the gap section 13 at the upper end surface has the same width as the gap section 13 at the lower end surface, the covering films 12 at both sides are staggered relative to the width center line of the metal sheet 11 .

[0040] When the width of the gap section 13 on the upper end surface is different from that of the gap section 13 on the lower end surface, that is, the width of the gap section 13 on one side is greater than that of the gap section 13 on the other side. Accordingly, when the stack is connected, the side surface with the longer gap section 13 is directly connected to the back surface 22 of one of the battery cells 20. Since a sealing frame is provided on the back surface 22 of the battery cell 20, the position where it is welded to the back surface of the battery cell will shrink by 0.5-1.5mm, and thus a wider width is required to cooperate with the back surface 22 of the battery cell when welding, so as to ensure the strength and stability of welding when the stack is connected.

[0041] A battery assembly, using the above-mentioned connecting film 10 structure to stack and connect battery cells 20, forming a battery assembly as shown in FIG. Figure 3 The battery string 40 shown can be connected in series to form a desired battery assembly.

[0042] Conductive glue 14 is coated on the upper and lower end surfaces of the metal sheet 11. Of course, solder can also be used for welding. Two battery cells 20 are aligned and overlapped, so that the cover film 12 in the connection film 10 completely covers the back of the front battery cell and the front of the rear battery cell in the adjacent battery cells, and the conductive glue 14 under the metal sheet 11 in the connection film 10 is placed above the bus bar 30 on the front of the rear battery cell 20, and the conductive glue 14 above it is placed below the bus bar 30 on the back of the front battery cell 20. After welding, drying is performed to form a battery string 40.

[0043] The front sides of all battery cells 20 are positioned upwards, and a welding rod 50 is welded on the front side of the first battery cell 20 in the battery string 40 above its bus bar 30 to output current. At the same time, a welding rod 50 is welded on the back side of the tail battery cell 20 in the battery string 40 below its bus bar 30 to output current.

[0044] Preferably, the width of the gap segment 13 on the upper end surface and the gap segment 13 on the lower end surface may be the same or different. When the width of the gap segment 13 on the upper end surface and the gap segment 13 on the lower end surface are different, in the metal sheet 11, the side with a longer gap width of the covering film 12 is connected to the back side 22 of the battery cell 20. That is, when the stacking is connected, the side with the longer gap segment 13 is directly connected to the back side 22 of the battery cell 20 to stack the battery cells. The structure of the connecting film 10 can be quickly and accurately aligned and stacked on the battery cell 20 during alignment, series welding and packaging, so that the series welding connection is more firm, so as to reduce the contact resistance and shading area of ​​the connecting film 10 to the battery assembly, and improve the output power of the battery assembly.

[0045] Each battery string 40 includes a plurality of stacked and connected battery cells 20, including an independent covering film 12 covering the front side of the first battery cell and the back side of the tail battery cell. The covering film 12 is the same as the covering film in the connecting film 10, and the material used is one of PI, TOP and POE.

[0046] like Figure 3 As shown, the cover film 12 covering the front of the first battery cell and the back of the tail battery cell in the battery string is an independent film without metal sheet, made by injection molding, and is mainly used to protect the front and back of the battery cell and the implementation of the battery assembly. Whether it is the cover film 12 used to cover the surface of the first and last battery cells of the subsequent battery string alone, or the cover film 12 placed integrally with the metal sheet 11, the materials used are the same, all of which are polymer materials.

[0047] The present invention adopts a series connection membrane structure designed by the present invention. The present invention adopts a series connection membrane structure, which has a simple structure and is easy to produce. It replaces the existing long series welding belt and is convenient for coating conductive glue or solder to stack the battery cells. At the same time, it can also minimize the shading area and solve the technical problem of series welding alignment deviation.

[0048] The connecting film structure can be used for battery cell alignment, serial welding and packaging, and can quickly and accurately align and overlap, making the serial welding connection more solid, thereby reducing the contact resistance and light shielding area of ​​the connecting film to the battery assembly, and improving the output power of the battery assembly. The present application also proposes a battery assembly connected by the connecting film.

[0049] The above detailed description of the embodiments of the present application is only a preferred embodiment of the present application and cannot be considered to limit the scope of implementation of the present application. All equivalent changes and improvements made within the scope of the present application should still fall within the scope of the patent coverage of the present application.

Claims

1. A series connection membrane structure, characterized in that: It comprises a metal sheet and a covering film wrapped around both sides of the length of the metal sheet. The upper and lower side end surfaces of the metal sheet are covered by the covering film to form a connecting film as a whole.

2. A series connection membrane structure according to claim 1, characterized in that: The metal sheet is configured as a long strip with a rectangular cross section.

3. A series connection membrane structure according to claim 2, characterized in that: The thickness of the metal sheet is in the range of 20-100 μm; and the horizontal width thereof is in the range of 1.5-5 mm.

4. A series connection membrane structure according to any one of claims 1 to 3, characterized in that: The vertical length of the covering film is not less than the vertical length of the metal sheet, wherein the length of the metal sheet is 50-250 mm.

5. A series connection membrane structure according to claim 4, characterized in that: The vertical length and horizontal width of the connection film are adapted to the size of the battery cell, and the thickness of the connection film is in the range of 60-250 μm.

6. A series connection membrane structure according to any one of claims 1 to 3 and 5, characterized in that: Gap sections on which conductive adhesive can be coated are provided on the upper and lower sides of the metal sheet, and the gap sections in the upper and lower end surfaces of the metal sheet are staggered.

7. A series connection membrane structure according to claim 6, characterized in that: In the gap sections on the upper and lower sides of the metal sheet, the horizontal widths thereof may be the same or different.

8. A series connection membrane structure according to claim 7, characterized in that: The horizontal width of the gap segment is 1000-3000 μm.

9. A battery assembly, characterized in that: The connecting film as described in any one of claims 1 to 8 is used to stack and connect the battery cells to form a battery string.

10. A battery assembly according to claim 9, characterized in that: When two adjacent battery cells are stacked and connected, The cover film completely covers the back of the front battery cell and the front of the rear battery cell; and one end of the metal sheet is placed above the bus bar on the front of the rear battery cell, and the other end is placed below the bus bar on the back of the front battery cell; In each battery string, the front side of the first battery cell and the back side of the last battery cell are covered with a separate covering film.

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