Battery cell and battery pack

Abstract

The present application discloses a battery cell and a battery pack. The battery cell comprises: a casing and an insulating film. The casing comprises side surfaces and a bottom surface. The side surfaces are arranged around the edges of the bottom surface. The insulating film covers the side surfaces. The bottom surface is in direct contact with an adhesive.

Description

Single battery and battery pack

[0001] The present application claims priority to the Chinese patent application No. 2024219978481 filed on August 16, 2024 with the China Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a single battery and a battery pack. BACKGROUND

[0003] New energy is accepted by more and more people as clean energy and is popularized on a large scale in various industries. The most widely used new energy is lithium battery, which is applied to various electric products. TECHNICAL PROBLEM

[0004] The lithium battery moves with the electric product during use, so if it is not firmly fixed, it is easy to be misaligned and cause the conductivity to decrease. TECHNICAL SOLUTION

[0005] In a first aspect, the present application provides a single battery, which comprises a shell and an insulating film; the shell comprises a side surface and a bottom surface, the side surface is annularly arranged at the edge of the bottom surface to form a containing cavity together, and the side surface surrounds to form an opening communicating with the containing cavity, and the containing cavity is used for containing a battery core assembly; the insulating film is coated on the side surface, and the bottom surface is not provided with the insulating film and is used for directly contacting with glue.

[0006] In a second aspect, the present application provides a battery pack, which comprises a box, glue and a plurality of single batteries of any one of the above, the plurality of single batteries are placed in the box, and the box and the bottom surface are fixed by the glue to form a glue layer. ADVANTAGEOUS EFFECT

[0007] The present application has the following advantageous effects: the single battery of the present application comprises a shell and an insulating film; the shell comprises a side surface and a bottom surface, the side surface is annularly arranged at the edge of the bottom surface; the insulating film is coated on the side surface, and the bottom surface is used for directly contacting with glue. The bottom surface of the shell is in a bare state, and the bottom surface of the shell is not coated with the insulating film. In the assembly process of the single battery and the box, the box is filled with glue, the glue is interposed between the bottom surface of the shell and the box, and after the glue is solidified, the bottom surface of the shell and the box are directly bonded together. Compared with the bottom surface of the shell being coated with the insulating film, there is no medium constraint between the insulating film and the bottom surface of the shell, so there is no direct constraint relationship between the shell and the box. The bottom surface of the shell of the present application and the box increase the medium constraint and are directly bonded together, thereby improving the bonding strength between the single battery and the box. In addition, compared with the scheme of the insulating film being opened or not, the present application also reduces the film coating cost of the single battery. BRIEF DESCRIPTION OF DRAWINGS

[0008] Fig. 1 is a structural schematic diagram of a battery pack according to an embodiment of the present application;

[0009] Fig. 2 is a cross-sectional structural schematic diagram of the battery pack according to an embodiment of the present application;

[0010] Fig. 3 is a partial enlarged schematic diagram of region A in Fig. 2 according to an embodiment of the present application;

[0011] Fig. 4 is a structural schematic diagram of a single battery according to an embodiment of the present application.

[0012] In the drawings:

[0013] box 20, glue 30, single battery 10, shell 12

[0014] side surface 121, bottom surface 122, opening 123, insulating film 14, escape hole 142.

[0015] Embodiments of the present application

[0016] Please refer to Figs. 1-4, Fig. 1 is a structural schematic diagram of a battery pack according to an embodiment of the present application, Fig. 2 is a cross-sectional structural schematic diagram of the battery pack according to an embodiment of the present application, Fig. 3 is a partial enlarged schematic diagram of region A in Fig. 2 according to an embodiment of the present application, and Fig. 4 is a structural schematic diagram of a single battery 10 according to an embodiment of the present application.

[0017] The present application provides a battery pack, which comprises a box 20, glue 30 and a plurality of single batteries 10, the plurality of single batteries 10 are placed in the box 20, and the glue 30 is connected with the box 20 and the plurality of single batteries 10 respectively. The glue 30 has viscosity and can bond the plurality of single batteries 10 in the box 20.

[0018] Specifically, the single battery 10 comprises a shell 12 and an insulating film 14, the insulating film 14 is wrapped on the outer surface of the shell 12, the material of the shell 12 can be steel or aluminum, the shell 12 comprises a side surface 121 and a bottom surface 122, the side surface 121 is annularly arranged at the edge of the bottom surface 122 to form a containing cavity together, the containing cavity can be square, circular or the like, the side surface 121 forms an opening 123 in communication with the containing cavity, the opening 123 can be square, circular or the like, the opening 123 is opposite to the bottom surface 122, the containing cavity is used for containing a cell assembly, and the containing cavity is also filled with electrolyte. The insulating film 14 is wrapped on the side surface 121, the insulating film 14 is located on the outer surface of the side surface 121, the bottom surface 122 is not provided with the insulating film 14 and is in a bare state, the bottom surface 122 is used for coating the glue 30, and the glue 30 directly bonds the bottom surface 122 and the box 20 together.

[0019] In the embodiment, the bottom surface 122 of the shell 12 is in a bare state, the bottom surface 122 of the shell 12 is not covered by the insulating film 14, and the bottom surface 122 of the shell 12 is directly in contact with the glue. During the assembly of the single battery 10 and the box 20, the glue is filled in the box 20 and is between the bottom surface 122 of the shell 12 and the box 20. After the glue is solidified, the bottom surface 122 of the shell 12 and the box 20 are directly bonded together, and the bonding strength is high. Compared with the bottom surface 122 of the shell 12 covered by the insulating film 14, there is no medium constraint between the insulating film 14 and the bottom surface 122 of the shell 12, and there is no direct constraint relationship between the shell 12 and the box 20. In the application, the bottom surface 122 of the shell 12 and the box 20 are directly bonded together by increasing the medium constraint, and the bonding strength between the single battery 10 and the box 20 is improved. In addition, compared with the scheme of the insulating film 14 being opened or not, the application also reduces the film coating cost of the single battery 10.

[0020] In an embodiment, the insulating film 14 is provided with a relief hole 142, the side surface 121 corresponding to the position of the relief hole 142 is used to contact the glue, and the relief hole 142 allows part of the side surface 121 to be covered by the insulating film 14. The relief hole 142 can be circular, square or other shapes. The number of relief holes 142 can be one or multiple and spaced from each other. By setting the relief hole 142 on the insulating film 14, the area of the side surface 121 exposed is increased to ensure that the glue and the side surface 121 are directly bonded together, thereby further improving the stability of the single battery 10. In the embodiment, the glue 30 is also coated on the side surface 121, thereby increasing the constraint in the horizontal direction of the single battery 10, and the glue 30 on the bottom surface 122 vertically constrains the single battery 10 together to improve the stability of the single battery 10.

[0021] In an embodiment, the relief hole 142 can be located at the connection between the side surface 121 and the bottom surface 122, and the insulating film 14 and the bottom surface 122 are spaced apart from each other in appearance. The side surface 121 located between the insulating film 14 and the bottom surface 122 is not covered by the insulating film 14, and the position of the side surface 121 where the insulating film 14 is not provided is used to coat the glue 30. The bottom surface 122 of the shell 12 is also coated with the glue 30, so that the glue on the side surface 121 and the glue 30 on the bottom surface 122 form an integral whole and support each other to directly bond the shell 12 and the box 20 together.

[0022] As shown in FIG. 4, the distance between the insulating film 14 and the bottom surface 122 is L1, and the height of the side surface 121 is H1, 0 < L1 / H1 ≤ 0.95. For example, 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, etc. Understandably, the larger the value of L1 / H1, the larger the area of the side surface 121 without the insulating film 14, and the more the area of the glue 30, thereby further improving the bonding strength. In addition, the glue 30 itself also has the characteristic of insulation, so such a setting will not reduce the insulation effect of the single battery 10.

[0023] Optionally, the plurality of single batteries 10 are arranged at intervals, and the interval space between the single batteries 10 allows the glue 30 to enter normally and smoothly, and the insulating film 14 and the bottom surface 122 are arranged at intervals, and the glue 30 is filled between the side surfaces 121 of adjacent single batteries 10. The side surfaces 121 of adjacent single batteries 10 are connected into a whole through the glue 30. In this embodiment, the glue 30 is also coated on the side surface 121, and the single batteries 10 in the middle of the plurality of single batteries 10 are directly bonded together through the glue 30, thereby improving the bonding strength between each other, thereby increasing the constraint in the horizontal direction between the plurality of single batteries 10, and together with the vertical constraint of the glue 30 on the bottom surface 122, the fixation of the single battery 10 is completed, preventing the single battery 10 from shaking.

[0024] In an embodiment, the position of the bottom surface 122 for contacting the glue is provided with an abrasive structure. The abrasive structure is a fine concave-convex structure, which can increase the contact area of the bottom surface 122 and the glue 30, and theoretically can increase the contact area of the bottom surface 122 and the glue 30 by more than one time, so as to at least increase the connection strength of the bottom surface 122 and the glue 30 by more than one time.

[0025] In an embodiment, the included angle between the side surface 121 and the bottom surface 122 is obtuse. That is, the side surface 121 gradually expands outward from the bottom surface 122 to the opening 123, and the opposite side surfaces 121 are away from each other, so that the side surface 121 and the solidified glue 30 form a reverse buckling structure, thereby improving the connection strength of the shell 12 and the glue 30.

[0026] The position of the side surface 121 corresponding to the avoiding hole 142 is provided with an abrasive structure, i.e., the position without the insulating film 14 is provided with an abrasive structure. The abrasive structure is a fine concave-convex structure, which can increase the contact area of the side surface 121 and the glue 30, and theoretically can increase the contact area of the side surface 121 and the glue 30 by more than one time, so as to at least increase the connection strength of the side surface 121 and the glue 30 by more than one time.

[0027] Optionally, the distance between the bottom surface 122 and the box 20 is L2mm, 1≤L2≤3, for example, 1, 1.5, 2, 2.5, 3, etc. It can be understood that the distance between the bottom surface 122 and the box 20 is used to fill the glue 30 to bond the bottom surface 122 and the box 20 together. Therefore, too little distance will result in too little glue 30 to bond the shell 12 and the box 20 together, and too much distance will result in too much glue 30, which will reduce its own strength and thus cannot bond the shell 12 and the box 20 together. Therefore, the distance within the above protection range can maximize the bonding strength between the shell 12 and the box 20.

[0028] Optionally, the depth of the box 20 is H2, and the thickness of the glue 30 is D, 0.1≤D / H2≤0.3, for example, 0.1, 0.15, 0.2, 0.25, 0.3, etc. The glue 30 within this range does not occupy too much space of the box 20, and can also vertically and horizontally bind the bottom surface 122 and the side surface 121 of the shell 12, improving the space utilization efficiency of the box 20.

[0029] In order to enable those skilled in the art to have a further understanding of the present application, the applicant will explain the specific assembly process of the battery pack.

[0030] Clean the box 20 and check the sealing of the bottom of the box 20. Coat the insulating film 14 on the side surface 121 of the shell 12, and expose the bottom surface 122 of the shell 12. Place multiple single batteries 10 in the box 20 at intervals and keep a distance of L2 from the bottom of the box 20. Introduce the glue 30 into the box 20, and after waiting for the glue 30 to solidify, bond the single battery 10 and the box 20 together.

Claims

1. A single battery, comprising: a housing including a side surface and a bottom surface, the side surface being provided around a periphery of the bottom surface; and an insulation film coated on the side surface, the bottom surface being configured to be directly contacted with a glue. The insulation film is provided with a relief hole, and the side surface is configured to be contacted with the glue at a position corresponding to the relief hole.

2. The single cell according to claim 1, wherein The bottom surface is provided with a frosted structure at a position configured to be contacted with the glue.

3. The cell according to claim 2, wherein The avoiding hole is located at the joint of the side surface and the bottom surface, the distance between the insulating film and the bottom surface is L1, the height of the side surface is H1, 0 ≤0.

95.

4. The cell according to claim 1, wherein An included angle between the side surface and the bottom surface is obtuse.

5. The cell according to claim 2, wherein The side surface is provided with the frosted structure at a position corresponding to the relief hole.

6. The cell according to claim 2, wherein A plurality of single batteries according to any one of claims 1 to 6 are placed in a box, and a glue layer is formed by curing the glue between the box and the bottom surface.

7. A battery pack comprising: The plurality of single batteries are spaced apart, the insulation film and the bottom surface are spaced apart, and the glue is filled between the side surfaces of adjacent single batteries.

8. The battery pack of claim 7, wherein, A distance between the bottom surface and the box is L2, and 1 mm≤L2≤3 mm.

9. The battery pack of claim 7, wherein, ​ 10. The battery pack of claim 7, wherein, The depth of the box is H2, the thickness displacement D of the glue, 0.1≤ ≤0.3.

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