Square lithium battery Mylar membrane and lithium battery

Abstract

The utility model provides a square lithium battery Mylar film and a lithium battery. The Mylar film is divided into a bottom surface, two large surfaces and four side surfaces by indentation lines; the bottom face is arranged between the two large faces, the four side faces are arranged on the two sides of the two large faces respectively, notches are formed in the long edges of the sides, away from the bottom face, of the large faces, and wrapping faces are connected to the positions, except the notches, of the long edges of the sides, away from the bottom face, of the large faces through indentation lines. The protrusions on the top support penetrate through the avoiding holes in the Mylar film and then are positioned to the limiting holes in the bottom of the top cover plate, the upper end of the Mylar film is fixed through cooperation of the protrusions and the limiting holes, and therefore hot melting between lower plastic and the Mylar film is omitted, the height of the lower plastic can be reduced, the utilization rate of a battery is increased, and the service life of the battery is prolonged. And the problem of poor welding caused by welding is also avoided.

Description

Technical Field

[0001] The utility model relates to the field of lithium ion batteries, in particular to a square lithium battery Mylar film and a lithium battery. Background Art

[0002] At present, large-capacity aluminum-shell batteries on the market are usually wrapped with a layer of mylar film around the core and then placed in the shell. The Mylar film is wrapped around the core to protect the core and ensure insulation between the core and the aluminum shell.

[0003] After wrapping, the Mylar film is then welded to the plastic under the cover by heat-melt welding. To meet the requirements of this hot-melt welding, the height of the lower plastic is generally around 4-7.5mm, which makes the lower plastic occupy a large space in the vertical space. When the Mylar film is welded to the lower plastic, the Mylar film is prone to explosion points and poor welding.

[0004] To this end, we propose a square lithium battery Mylar film and a lithium battery to solve the problems of low space utilization and low welding quality rate. Utility Model Content

[0005] The purpose of the utility model is to solve the shortcomings of the prior art. In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A square lithium battery Mylar film is used to wrap a battery cell. The Mylar film is divided into a bottom surface, two large surfaces and four side surfaces by indentation lines; the bottom surface is arranged between the two large surfaces, the four side surfaces are respectively arranged on both sides of the two large surfaces, a notch is provided on the long side of the large surface away from the bottom surface, and the long side of the large surface away from the bottom surface, except for the notch, is connected to a covering surface by indentation lines.

[0007] The two sides of the notch are covered with covering surfaces to completely cover the upper end of the bare battery cell except for the concave part. The notch of the Mylar film just avoids the overlap of the Mylar film and the lower plastic, thereby eliminating the hot melt between the lower plastic and the Mylar film. It can not only reduce the height of the lower plastic and improve the utilization rate of the battery, but also avoid poor welding problems caused by welding.

[0008] Further preferably, avoidance holes are provided on the covering surface.

[0009] Further preferably, the notch is located in the middle of the long side of the large surface.

[0010] Further preferably, the avoidance hole is any one of circular, square or elliptical.

[0011] A lithium battery comprises an outer shell, a bare cell, side adhesive, a top support, a top cover plate and the Mylar film described in any one of the above, wherein the bare cell and the outer shell are provided with recesses corresponding to the Mylar film, the Mylar film is wrapped around the remaining parts except the recesses of the bare cell, the side surfaces of the Mylar film are fixed to the bare cell by the side adhesive, the top support is attached to the upper end of the bare cell except the recesses, the top support is located on the inner side of the Mylar film, a protrusion is provided on the top support, the protrusion passes through an avoidance hole and is positioned at the bottom of the top cover plate, and the outer shell and the top cover plate enclose a containing space for accommodating the bare cell.

[0012] Further preferably, a limiting hole matching with the protrusion is formed on the bottom surface of the top cover plate.

[0013] Further preferably, the top cover plate includes a pole terminal and a lower plastic, the lower plastic is fixedly mounted on the bottom of the top cover plate, and the pole terminal passes through a pole mounting hole on the top cover plate and is connected to a pole ear on the bare cell.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] The utility model positions the protrusion on the top support through the avoidance hole on the Mylar film and then to the limiting hole at the bottom of the top cover plate, and fixes the upper end of the Mylar film through the cooperation between the protrusion and the limiting hole, thereby eliminating the hot melting between the lower plastic and the Mylar film, which can not only reduce the height of the lower plastic and improve the utilization rate of the battery, but also avoid the problem of poor welding caused by welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the unfolding of the Mylar film;

[0017] Figure 2 This is a schematic diagram of Mylar film packaging;

[0018] Figure 3 Schematic diagram of the explosion structure of a lithium battery.

[0019] In the figure: bottom surface 1, large surface 2, side surface 3, notch 4, covering surface 5, avoidance hole 6, shell 7, Mylar film 10, bare battery cell 8, side adhesive 9, top support 11, protrusion 111, top cover plate 12. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] Reference Figure 1-Figure 3A square lithium battery Mylar film is used to wrap a battery cell. The Mylar film 10 is divided into a bottom surface 1, two large surfaces 2 and four side surfaces 3 by an indentation line; the bottom surface 1 is arranged between the two large surfaces 2, and the four side surfaces 3 are respectively arranged on both sides of the two large surfaces 2. A notch 4 is provided on the long side of the large surface 2 away from the bottom surface 1. Except for the notch 4, the long side of the large surface 2 away from the bottom surface 1 is connected to a covering surface 5 by an indentation line.

[0022] In the embodiment: the Mylar film 10 can completely wrap the bare battery cell 8 except for the 4 notches. The 4 notches of the Mylar film 10 just prevent the Mylar film 10 from overlapping with the lower plastic, thereby eliminating the hot melt between the lower plastic and the Mylar film, which can not only reduce the height of the lower plastic and improve the battery utilization rate, but also avoid poor welding problems caused by welding. The two sides of the notch 4 completely cover the upper end of the bare battery cell 8 except for the concave part through the covering surface 5.

[0023] The covering surface 5 is provided with an avoidance hole 6 , and the avoidance hole 6 is any one of circular, square or elliptical.

[0024] In the embodiment, the protrusion 111 on the support 11 passes through the avoidance hole 6 and cooperates with the top cover plate 12 .

[0025] The notch 4 is located in the middle of the long side of the large surface 2 .

[0026] In the embodiment, the notch 4 on the large surface 2 just avoids the concave portion on the bare battery cell 8 .

[0027] A lithium battery comprises a shell 7, a bare cell 8, a side adhesive 9, a top support 11, a top cover plate 12 and the Mylar film 10 described in any one of the above, wherein the bare cell 8 and the shell 7 are provided with recesses corresponding to the Mylar film 10, and the Mylar film 10 is wrapped around the remaining parts except the recesses of the bare cell 8, and the side of the Mylar film 10 is fixed to the bare cell 8 through the side adhesive 9, and the top support 11 is attached to the upper end of the bare cell 8 except the recesses, and the top support 11 is located on the inner side of the Mylar film 10, and a protrusion 111 is provided on the top support 11, and the protrusion 111 is positioned at the bottom of the top cover plate 12 after passing through the avoidance hole 6, and the shell 7 and the top cover plate 12 enclose a containing space for accommodating the bare cell 8.

[0028] The bottom surface of the top cover plate 12 is provided with a limiting hole matched with the protrusion 111 .

[0029] In the embodiment: positioning is achieved by the cooperation between the protrusion 111 and the limiting hole.

[0030] The top cover plate 12 includes a pole terminal and a lower plastic, the lower plastic is fixedly mounted on the bottom of the top cover plate 12 , and the pole terminal passes through a pole mounting hole on the top cover plate 12 and is connected to a pole ear on the bare battery cell 8 .

[0031] In the embodiment: the top support 11 is located on the inner side of the Mylar film 10, the protrusion 111 on the top support 11 passes through the avoidance hole 6 on the Mylar film 10 and is positioned to the bottom of the top cover, the side of the Mylar film 10 is fixed to the bare battery cell 8 by the side adhesive 9, and a limiting hole matching the protrusion 111 is opened on the bottom surface of the top cover plate 12. The limiting hole on the top cover plate 12 not only realizes the limiting, but also saves space. The top cover plate 12 is located at the opening of the outer shell 7 and is welded to the outer shell 7. The pole ears on the bare battery cell 8 are welded to the bottom of the positive and negative terminals on the top cover plate 12, and the pole ears are located in the concave part of the bare battery cell 8. The Mylar film 10 wraps the rest of the parts except the concave part of the bare battery cell 8, and the pole ears and the top cover are isolated by the lower plastic.

[0032] The utility model positions the protrusion on the top support through the avoidance hole on the Mylar film and then to the limiting hole at the bottom of the top cover plate, and fixes the upper end of the Mylar film through the cooperation between the protrusion and the limiting hole, thereby eliminating the hot melting between the lower plastic and the Mylar film, which can not only reduce the height of the lower plastic and improve the utilization rate of the battery, but also avoid the problem of poor welding caused by welding.

Claims

1. A square lithium battery Mylar film, used for wrapping a battery cell, characterized in that: The Mylar film is divided into a bottom surface, two large surfaces and four side surfaces by indentation lines; the bottom surface is arranged between the two large surfaces, the four side surfaces are arranged on both sides of the two large surfaces respectively, a notch is provided on the long side of the large surface away from the bottom surface, and the long side of the large surface away from the bottom surface is connected to a covering surface by indentation lines except for the notch.

2. A square lithium battery Mylar film according to claim 1, characterized in that: The covering surface is provided with avoidance holes.

3. The square lithium battery Mylar film according to claim 1, characterized in that: The notch is located in the middle of the long side of the large surface.

4. The square lithium battery Mylar film according to claim 2, characterized in that: The avoidance hole is any one of circular, square or elliptical.

5. A lithium battery, characterized in that: The invention comprises a shell, a bare battery cell, side adhesives, a top support, a top cover plate and the Mylar film according to any one of claims 1 to 4, wherein the bare battery cell and the shell are provided with recesses corresponding to the Mylar film, the Mylar film is wrapped around the remaining parts except the recesses of the bare battery cell, the side surfaces of the Mylar film are fixed to the bare battery cell by the side adhesives, the top support is attached to the upper end of the bare battery cell except the recesses, the top support is located on the inner side of the Mylar film, a protrusion is provided on the top support, the protrusion passes through an avoidance hole and is positioned at the bottom of the top cover plate, and the shell and the top cover plate enclose a containing space for accommodating the bare battery cell.

6. A lithium battery according to claim 5, characterized in that: The bottom surface of the top cover plate is provided with a limiting hole matched with the protrusion.

7. A lithium battery according to claim 5, characterized in that: The top cover plate includes a pole terminal and a lower plastic, wherein the lower plastic is fixedly mounted on the bottom of the top cover plate, and the pole terminal passes through a pole mounting hole on the top cover plate and is connected to a pole ear on the bare cell.

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