Battery cell and battery cell module

Abstract

The utility model provides a battery cell and a battery cell module, and belongs to the field of new energy batteries. The battery cell comprises a shell, a cover plate and a core package, an opening is formed in the top of the shell, the core package is installed in the shell, the cover plate covers the opening, the cover plate comprises an upper convex surface and lower concave surfaces connected to the two sides of the upper convex surface, the upper convex surface and the lower concave surfaces are arranged in parallel at intervals in the opening direction of the opening, pole columns are arranged on the two lower concave surfaces respectively, and the pole columns are connected with the core package. The distance between the top of the pole and the lower concave surface is smaller than that between the upper convex surface and the lower concave surface; and the core bag is in overcurrent connection with the pole. The problem that in the prior art, space is wasted due to the fact that pole columns on the tops of battery cells in a module are welded to busbars can be solved.

Description

Technical Field

[0001] The utility model relates to the field of new energy batteries, and in particular to a battery cell and a battery cell module. Background Art

[0002] As one of the current mainstream energy storage devices, lithium-ion batteries are widely used in new energy vehicles, various portable electronic devices and communication equipment. With the continuous progress in the field of lithium-ion batteries, especially the explosive development of the new energy vehicle industry, in order to improve the utilization rate of the vehicle space, people have put forward higher requirements on the overall space occupied by lithium-ion batteries.

[0003] In the relevant technology, during the development of new energy vehicle structures, traditional models generally have a battery pack box structure, which is usually an aluminum profile or sheet metal structure, arranged under the lower body structure and fixed to the door sill side beam by screw connection. Multiple single cells are stacked in the battery pack box, and a busbar structure is welded on the top of the single cell to form a cell module.

[0004] When the battery cell module in the related art is formed, the pole on the single battery cell used for welding with the bus is usually arranged on the top cover plate of the battery cell shell. After the module is formed, the bus bar bridged on the pole and the pole protruding on the cover plate are both at a certain height. A certain top space needs to be provided in the battery pack box to accommodate both, which leads to an increase in the overall occupied space and causes space waste. Utility Model Content

[0005] The embodiment of the utility model provides a battery cell and a battery cell module, which can solve the problem of space waste caused by welding the top pole of the battery cell and the busbar in the module in the prior art. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the utility model provides a battery cell, comprising: a shell, a cover plate and a core package,

[0007] The shell is provided with an opening at the top, the core package is installed inside the shell, the cover plate is provided at the opening, the cover plate includes an upper convex surface and lower concave surfaces connected to both sides of the upper convex surface, the upper convex surface and the lower concave surfaces are arranged parallel and spaced along the opening direction of the opening, the spacing between the upper convex surface and the lower concave surface ranges from 1 to 5 mm, poles are respectively provided on the two lower concave surfaces, and the core package is connected to the poles in a current-carrying manner.

[0008] Optionally, the distance between the top of the pole and the lower concave surface is smaller than the distance between the upper convex surface and the lower concave surface.

[0009] Optionally, the shell is in the form of a rectangular parallelepiped, and welding protrusions matching the upper convex surface are provided on the tops of the two opposite side walls of the opening.

[0010] Optionally, a circular chamfer is provided at a connection between the upper convex surface and the lower concave surface.

[0011] Optionally, a current-passing sheet is further included, and a pole ear is protruding from the top of the core package. The pole ear is located below the upper convex surface and is connected to the pole through the current-passing sheet.

[0012] Optionally, an explosion-proof valve and a liquid injection hole are provided on the upper convex surface.

[0013] Optionally, a countersunk hole matching the explosion-proof valve is provided on the upper convex surface.

[0014] In the second aspect, an embodiment of the utility model further provides a battery cell module, comprising a plurality of battery cells as described in the first aspect, and a plurality of bus bars, wherein the plurality of battery cells are stacked and the poles of two adjacent battery cells are connected in series via the bus bars.

[0015] The beneficial effects brought by the technical solution provided by the embodiment of the utility model include at least:

[0016] Compared with the conventional method of adding a welded busbar structure to the pole protruding from the horizontal cover plate, the battery cell provided by the embodiment of the utility model has a rational and special-shaped arrangement of the cover plate structure, and the convex upper surface in the middle of the cover plate and the concave lower surfaces with poles on both sides are arranged in layers along the height direction, so that the pole and the busbar structure to be welded later share the height space, thereby achieving the effect of reducing the space occupied in the vertical direction, saving the battery cell and the external height after the module is formed, and effectively solving the problem of space waste caused by welding the pole and the busbar at the top of the battery cell in the module in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 It is a structural schematic diagram of a battery cell provided by an embodiment of the utility model;

[0019] Figure 2 It is a structural cross-sectional view of a battery cell provided by an embodiment of the utility model;

[0020] Figure 3 yes Figure 2A magnified schematic diagram of the local structure;

[0021] Figure 4 It is a structural schematic diagram of a battery cell module provided by an embodiment of the utility model.

[0022] In the figure: 1-shell; 2-cover plate; 3-core package; 4-current-passing plate; 5-bus; 11-opening; 21-upper convex surface; 22-lower concave surface; 23-pole; 24-arc chamfer; 25-explosion-proof valve; 26-liquid injection hole; 31-pole ear; 111-welding protrusion; 211-countersunk hole. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] In the relevant technology, during the development of new energy vehicle structures, traditional models generally have a battery pack box structure, which is usually an aluminum profile or sheet metal structure, arranged under the lower body structure and fixed to the door sill side beam by screw connection. Multiple single cells are stacked in the battery pack box, and a busbar structure is welded on the top of the single cell to form a cell module.

[0025] When the battery cell module in the related art is formed, the pole on the single battery cell used for welding with the bus is usually arranged on the top cover plate of the battery cell shell. After the module is formed, the bus bar bridged on the pole and the pole protruding on the cover plate are both at a certain height. A certain top space needs to be provided in the battery pack box to accommodate both, which leads to an increase in the overall occupied space and causes space waste.

[0026] Figure 1 It is a structural schematic diagram of a battery cell provided by an embodiment of the utility model; Figure 2 It is a structural cross-sectional view of a battery cell provided by an embodiment of the utility model; Figure 3 yes Figure 2 A magnified schematic diagram of the local structure. Figures 1 to 3 A battery cell shown includes a shell 1, a cover plate 2 and a core package 3.

[0027] The shell 1 is provided with an opening 11 at the top, the core package 3 is installed inside the shell 1, and the cover plate 2 is provided at the opening 11. The cover plate 2 includes an upper convex surface 21 and lower concave surfaces 22 connected to both sides of the upper convex surface 21. The upper convex surface 21 and the lower concave surface 22 are arranged parallel to and spaced apart from each other along the direction of the opening 11 of the opening 11, and poles 23 are respectively provided on the two lower concave surfaces 22. The spacing between the top of the pole 23 and the lower concave surface 22 is smaller than the spacing between the upper convex surface 21 and the lower concave surface 22, and the core package 3 is connected to the pole 23 through current.

[0028] In the embodiment of the utility model, the cell structure adopts the traditional vertical square shell single cell structure, and the core package 3 is accommodated by the shell 1 with an opening 11 on the top. After the over-current welding between the pole ear 31 on the top of the core package 3 and the two poles 23 on the cover plate 2 is completed, the cover plate 2 is covered on the opening 11 and welded and sealed, and finally the electrolyte is injected into the interior through the injection hole 26 on the cover plate 2 to complete the preliminary preparation. In the structure of the cover plate 2, it is set to be convex in the middle, flush with the top surface of the traditional cover plate, and the sections with poles 23 on both sides are concave, so as to form a structure in which the middle section of the cover plate 2 in the length direction has a certain height difference with the two sides, and there is still a certain distance between the top of the pole 23 and the upper convex surface 21. The distance between the top of the pole 23 and the lower concave surface 22 is smaller than the distance between the upper convex surface 21 and the lower concave surface 22. For example, in the embodiment of the utility model, the distance between the lower concave surface of the pole 23 and the middle upper convex surface 21 is H2, and the length of the pole 23 protruding from the lower concave surface 22, that is, the distance between the top of the pole 23 and the lower concave surface 22 is H, and the distance between the top of the pole 23 and the upper convex surface 21 is H1. The three distances satisfy H2≥H+H1, wherein the distance H2 between the upper convex surface 21 and the lower concave surface 22 ranges from 1 to 5 mm to ensure compatibility with the sum of the heights of the conventional specifications of the cell bus 5 and the pole 23 in the existing lithium-ion new energy battery. After the cover is sealed, the top height of the pole 23 is lower than the height of the upper convex surface 21 of the cover plate 2, and there is still a certain distance between the two. When the modules are subsequently stacked and the busbar 5 is welded on the top of the pole 23 for series arrangement, by controlling the spacing H1 and selecting the busbar 5 with a thickness less than or equal to H1, the overall height of the battery module can be controlled on the horizontal plane of the cover plate 2 with the upper convex surface 21 as the reference. Compared with the traditional method of adding a welded busbar structure to the pole protruding from the horizontal cover plate, the pole 23 and the busbar 5 structure to be welded later share the height space through the rational special-shaped arrangement of the cover plate 2 structure, achieving the effect of reducing the space occupied in the vertical direction, saving the battery cell and the external height after the module is formed, and effectively solving the space waste problem caused by the welding of the pole and the busbar at the top of the battery cell in the module in the prior art.

[0029] Optionally, the shell 1 is a rectangular parallelepiped, and the tops of the two opposite side walls of the opening 11 are provided with welding protrusions 111 matching the upper convex surface 21. Exemplarily, in the embodiment of the utility model, at the opening 11 of the shell 1, a preset welding protrusion 111 structure is protruding on the tops of its two opposite long sides, and its outer contour matches the two side edges of the upper convex surface 21 of the cover plate 2 in the length direction. After the cover plate 2 is covered at the opening 11, the side edges of the upper convex surface 21 and the lower concave surface 22 of the cover plate 2 are directly and tightly spliced ​​with the opposite side edges of the opening 11. When preparing the cover plate 2, it is only necessary to perform one-way bending or casting of the metal plate body, and there is no need to form the cavity between the upper convex surface 21 and the lower concave surface 22, which reduces the processing difficulty and improves the overall processing efficiency.

[0030] Optionally, a circular chamfer 24 is provided at the connection between the upper convex surface 21 and the lower concave surface 22. For example, in the embodiment of the utility model, a circular chamfer is performed at the bending connection between the upper convex surface 21 and the lower concave surface 22 to make the transition smooth, thereby avoiding scratches and damages caused by possible contact and collision during transportation, installation of the cover plate 2, and stacking to form a module, thereby improving the overall service life.

[0031] Optionally, a current-passing sheet 4 is further included, and a pole ear 31 is protruding from the top of the core package 3, the pole ear 31 is located below the upper convex surface, and is connected to the pole 23 through the current-passing sheet 4. Exemplarily, in the embodiment of the utility model, corresponding to the structural change of the cover plate 2, the lead-out position of the pole ear at the top of the core package 3 in the battery cell is also adjusted accordingly, and the pole ear 31 corresponding to the positive and negative poles 23 after being led out is located as a whole in the internal gap space of the shell between the upper convex surface 21 and the lower concave surface 22, and the current connection is performed by setting a bending structure current-passing sheet 4 with the same height difference, and the staggered welding arrangement between the pole ear 31 and the pole 23 is realized in the vertical direction, and the longitudinal projections thereof do not overlap, so as to realize the structural arrangement of the pole 23, the bus bar 5 and the internal pole ear 31 sharing the height space, so as to achieve the purpose of saving the external height of the battery cell, improve the internal space utilization of the battery cell, and increase the energy density of the battery cell.

[0032] Optionally, an explosion-proof valve 25 and a liquid injection hole 26 are provided on the upper convex surface 21. For example, in the embodiment of the utility model, by providing the explosion-proof valve 25 and the liquid injection hole 26 structure on the upper convex surface 21, the degassing and pressure relief of the battery cell during thermal runaway and the liquid injection function are realized, thereby ensuring its working safety and practicality.

[0033] Optionally, a countersunk hole 211 matching the explosion-proof valve 25 is provided on the upper convex surface 21. For example, in the embodiment of the utility model, the area where the explosion-proof valve 25 is installed can also be arranged concave based on the thickness of the upper convex surface 21 of the cover plate 2, and by arranging the corresponding countersunk holes 211, the valve plate of the explosion-proof valve 25 is sunken as a whole, further reducing the overall height of the battery cell.

[0034] Figure 4 Schematic diagram of the structure of a battery module provided by an embodiment of the utility model. Figure 4 As shown, the present utility model embodiment also provides a battery module, including Figures 1 to 3The battery cell shown also includes a plurality of busbars 5, and the plurality of battery cells are stacked and arranged, and the poles 23 of two adjacent battery cells are connected in series through the busbars 5. By way of example, the battery cells provided by the utility model are connected in series to form a battery cell module. Compared with the traditional battery cell in which a welded busbar structure is added to the pole protruding from the horizontal cover plate, the battery cell has a reasonable and special-shaped arrangement of the cover plate 2 structure, so that the pole 23 and the busbar 5 structure to be welded later share the height space, thereby achieving the effect of reducing the space occupied in the vertical direction, saving the battery cell and the external height after the module is formed, and effectively solving the problem of space waste caused by welding the pole and busbar at the top of the battery cell in the module in the prior art.

[0035] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the utility model belongs. The words "first", "second" and similar words used in the specification and claims of the utility model patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0036] The above description is only an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery cell, characterized in that: include: Shell (1), cover plate (2) and core package (3), The shell (1) is provided with an opening (11) at the top, the core package (3) is installed inside the shell (1), the cover plate (2) is provided to cover the opening (11), the cover plate (2) comprises an upper convex surface (21) and lower concave surfaces (22) connected to both sides of the upper convex surface (21), the upper convex surface (21) and the lower concave surfaces (22) are arranged parallel to each other along the opening (11) direction of the opening (11), the spacing between the upper convex surface (21) and the lower concave surface (22) ranges from 1 to 5 mm, poles (23) are respectively provided on the two lower concave surfaces (22), and the core package (3) is connected to the poles (23) in a current-carrying manner.

2. The battery cell according to claim 1, characterized in that: The distance between the top of the pole (23) and the lower concave surface (22) is smaller than the distance between the upper convex surface (21) and the lower concave surface (22).

3. The battery cell according to claim 1, characterized in that: The housing (1) is in the form of a rectangular parallelepiped, and welding protrusions (111) matching the upper convex surface (21) are provided on the tops of the two opposite side walls of the opening (11).

4. The battery cell according to claim 1, characterized in that: A circular chamfer (24) is provided at the connection between the upper convex surface (21) and the lower concave surface (22).

5. The battery cell according to claim 1, characterized in that: It also comprises a current-passing sheet (4), a pole ear (31) protruding from the top of the core package (3), the pole ear (31) being located below the upper convex surface (21) and being current-passingly connected to the pole (23) via the current-passing sheet (4).

6. The battery cell according to any one of claims 1 to 5, characterized in that: An explosion-proof valve (25) and a liquid injection hole (26) are provided on the upper convex surface (21).

7. The battery cell according to claim 6, characterized in that: The upper convex surface (21) is provided with a countersunk hole (211) matching the explosion-proof valve (25).

8. A battery cell module, comprising a plurality of battery cells according to any one of claims 1 to 7, characterized in that: It also includes a plurality of bus bars (5), wherein the plurality of battery cells are stacked and arranged, and the poles (23) of two adjacent battery cells are connected in series via the bus bars (5).

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