Bare battery cell with folding tabs

Abstract

The utility model provides a naked battery cell with folding tabs, which relates to the technical field of lithium batteries and comprises a battery cell body, a plurality of pole piece tabs are cut at the top end of the battery cell body, the pole piece tabs and the pole piece tabs are laminated to form a pole piece tab group, the tail end of the pole piece tab group is bent, and the bent position is horizontal to the battery cell body; the tab is arranged above the pole piece tab group, one end, close to the pole piece tab group, of the tab is bent at a right angle, the bent position is horizontal to the bent position of the pole piece tab group, the surfaces of the bent position of the tab and the bent position of the pole piece tab group are respectively provided with a welding part I and a welding part II, the folding area is folded at the top of the battery cell body, only the tab extends out, and the welding part II extends out of the top of the battery cell body. And the distance from the lug root part of the pole piece to the tail end of the lug can be reduced, the width of a material-free area is reduced, and higher energy density is achieved in the same-proportion battery cell size.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and more specifically, to a bare battery cell with foldable tabs. Background Art

[0002] A bare cell refers to a structure consisting of a positive electrode sheet, a negative electrode sheet and a separator. An insulating separator is sandwiched between the positive electrode sheet and the negative electrode sheet to form a bare cell. The positive electrode sheet and the negative electrode sheet are made by coating electrode slurry on substrates such as aluminum foil and copper foil and then roller-pressing and drying them.

[0003] The length of the battery cell includes the battery cell body, the width of the top seal and the height of the tab. The above three constitute the battery cell size. If the energy density of the battery cell needs to be further improved, it is necessary to study from the perspective of optimizing the battery cell structure. Firstly, the tab is the external carrier of the battery cell. It needs to be connected to the busbar when grouping. Its outward extension requires a long length. Therefore, in traditional battery cells (such as Figure 5-Figure 6 As shown in the figure, the distance from the base of the pole piece ear to the end of the pole piece ear cut out of the bare battery cell is long, which will result in a wider welding area between the two. This area is a material-free area and only serves as a connection, wasting battery cell space. The energy density of the battery cell cannot be effectively improved. Therefore, it is necessary to propose a bare battery cell with foldable pole ear to solve the above problems. Utility Model Content

[0004] The technical problem to be solved by the present invention is that the distance from the base of the pole ear to the end of the pole ear cut out of the bare battery cell is long, which wastes the battery cell space. In view of the problems existing in the prior art, a bare battery cell with foldable pole ears is provided.

[0005] The purpose and effect of this utility model are achieved by the following specific technical means:

[0006] A bare battery cell with foldable tabs, comprising:

[0007] The battery cell body has a plurality of pole tabs cut out of the top of the battery cell body, and the pole tabs are stacked together to form a pole tab group. The ends of the pole tab group are bent, and the bending position is horizontal to the battery cell body.

[0008] The pole ear is arranged above the pole ear group, and one end of the pole ear close to the pole ear group is bent at a right angle, the bending position is horizontal to the bending position of the pole ear group, and the bending position of the pole ear and the bending position of the pole ear group are respectively provided with a welding portion 1 and a welding portion 2, and the welding portion 1 and the welding portion 2 are welded to each other, and the bending position of the pole ear and the bending position of the pole ear group form a folding area;

[0009] A glue fixing structure is provided on the outer side of the folding area.

[0010] A further preferred solution: the battery cell body is composed of a positive electrode sheet, a negative electrode sheet and a separator wound or stacked, and the separator is located between the positive electrode sheet and the negative electrode sheet;

[0011] The tops of the positive electrode sheet and the negative electrode sheet are both cut with electrode ears.

[0012] A further preferred solution is that a plurality of pits are punched out on the surface between the first welding part and the second welding part after welding.

[0013] A further preferred solution is that the folding area is level with the battery cell body, and after being fixed by the adhesive fixing structure, the bottom surface is close to the top of the battery cell body.

[0014] A further preferred solution: the adhesive fixing structure includes two groups of protective adhesive and fixing adhesive;

[0015] The two groups of protective adhesives are respectively adhered to the two surfaces of the welding part 1 and the welding part 2 after welding;

[0016] One of the fixing adhesives is adhered to the bent position of the root of the electrode ear group and extends to the outer wall of the battery cell body;

[0017] The other fixing adhesive is adhered to the bent position of the tab and extends to the outer wall of the battery cell body.

[0018] A further preferred solution is that the top of the tab is upright in the Y-axis direction.

[0019] Beneficial effects of the utility model:

[0020] 1. Bend the end of the pole ear group to be horizontal with the battery body. Bend the end of the pole ear close to the pole ear group at a right angle of 90 degrees, and weld the two to each other. After welding, a folding area is formed, and then the folding area is fixed by a glue fixing structure. The folding area is horizontal with the battery body. The folding area is folded on the top of the battery body, and only the pole ear extends. This can shorten the distance from the base of the pole ear to the end of the pole ear, reduce the width of the material-free area, make the conductive transmission performance better, avoid high resistance, and effectively reduce the total size of the battery cell, thereby achieving a higher energy density in the same proportion of battery cell size;

[0021] The adhesive fixing structure is made of insulating material, and the protective glue at the bottom can protect the electrode ear group from direct contact with the electrode inside the battery cell, avoiding short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0024] Figure 2This is a schematic diagram of the connection between the pole piece ear and the pole ear structure of the utility model;

[0025] Figure 3 This is a schematic diagram of the connection between the fixing glue and the folding area structure of the utility model;

[0026] Figure 4 For this utility model Figure 1 A local enlarged structural diagram in FIG.

[0027] Figure 5 This is a schematic diagram of the welding structure of traditional bare battery cells and tabs;

[0028] Figure 6 Schematic diagram of the welding structure of traditional bare battery cells and tabs.

[0029] Figures 1-6 Middle: battery cell body 1, pole piece ear group 101, welding part 102, pole ear 2, welding part 201, protective glue 3, folding area 4, fixing glue 5. DETAILED DESCRIPTION

[0030] To more clearly understand the above-mentioned objectives, features, and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely examples of implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. On the contrary, modifications and improvements made without departing from the scope of the present invention are within the scope of patent protection of the present invention.

[0031] See also Figures 1-4 , a bare battery cell with foldable tabs, comprising:

[0032] The battery cell body 1 is composed of a positive electrode sheet, a negative electrode sheet and a separator wound or stacked. It is a wound or stacked bare battery cell, and the separator is located between the positive electrode sheet and the negative electrode sheet to prevent short circuit between the positive and negative electrodes. A plurality of electrode ears are cut from the top of the battery cell body 1. The electrode ears protrude from the bare battery cell, and the tops of the positive and negative electrode sheets are both cut with electrode ears, and the electrode ears of the same electrode are stacked to form a electrode ear group 101 (such as Figure 1 and Figure 4 ), the positive electrode tab group 101 and the negative electrode tab group 101 do not touch each other, which also avoids short circuit between the positive and negative electrodes and facilitates the subsequent connection of the two to the positive and negative bus bars respectively;

[0033] First, bend the end of the electrode ear group 101 to be horizontal with the battery body 1 (as shown in the figure). Figure 2), then pick up the pole ear 2, and bend the end of the pole ear 2 close to the pole ear group 101 at a right angle of 90°. At this time, the bending position of the pole ear 2 is horizontal to the bending position of the pole ear group 101. The bending position of the pole ear 2 and the bending position of the pole ear group 101 are respectively provided with a welding part 102 and a welding part 2 201 on the surface. Align the welding part 102 and the welding part 2 201, and weld the two to each other. After welding, the two are formed into a folding area 4, and then the folding area 4 is fixed by a glue fixing structure.

[0034] See also Figure 1 、 Figure 3 and Figure 4 , glue fixing steps:

[0035] The adhesive fixing structure includes a protective adhesive 3 and a fixing adhesive 5, both of which are two groups. First, the protective adhesive 3 is pasted. The two groups of protective adhesive 3 are respectively adhered to the two surfaces after welding of the welding part 102 and the welding part 201 (such as Figure 3 ), the protective glue 3 can protect the welding position to prevent the bottom surface of the electrode ear group 101 from directly contacting the upper end of the battery body 1 and scratching the diaphragm;

[0036] Then paste the fixing glue 5, (such as Figure 3 and Figure 4 ) Adhere one of the fixing glues 5 to the bent position at the root of the electrode ear group 101 and extend it to the outer wall of the battery cell body 1, and adhere the other fixing glue 5 to the outer surface of the bent position of the electrode ear 2, and the end of the fixing glue 5 extends to the outer wall of the battery cell body 1. At this time, the folding area 4 can be fixed. After being fixed by the adhesive fixing structure, the bottom surface of the folding area 4 is close to the top of the battery cell body 1, and the folding area 4 is horizontal with the battery cell body 1. The folding area 4 is folded over the top of the battery cell body 1, and only the electrode ear 2 extends out. This can shorten the distance from the root of the electrode ear to the end of the electrode ear 2, reduce the width of the material-free area, make the conductive transmission performance better, avoid high resistance, and effectively reduce the total size of the battery cell, thereby having a higher energy density in the same proportion of battery cell size;

[0037] Furthermore, the adhesive fixing structure is made of insulating material, and the protective adhesive 3 at the bottom can protect the electrode ear group 101 from directly contacting the electrode inside the battery cell, thereby avoiding short circuit.

[0038] like Figure 3 As shown, preferably, a plurality of pits are punched out on the surface between the first welding part 102 and the second welding part 201 after welding. The pits can play a compacting role, further strengthening the tightness of the connection between the first welding part 102 and the second welding part 201 on the basis of welding, and improving the resistance of the welding area, thereby avoiding the situation where the two are broken during the later conduction;

[0039] like Figure 4As shown, preferably, the top of the tab 2 is upright in the Y-axis direction. This design allows the tab 2 to extend outward, making it easier to connect to the busbar when grouped.

Claims

1. A bare battery cell with foldable tabs, characterized in that: include: A battery cell body (1), wherein a plurality of pole piece ears are cut out of the top of the battery cell body (1), and the pole piece ears are stacked with the same electrode to form a pole piece ear group (101), and the end of the pole piece ear group (101) is bent, and the bending position is horizontal to the battery cell body (1); A pole ear (2) is arranged above the pole ear group (101), and one end of the pole ear (2) close to the pole ear group (101) is bent at a right angle, and the bending position is horizontal to the bending position of the pole ear group (101), and the bending position of the pole ear (2) and the bending position of the pole ear group (101) are respectively provided with a welding portion 1 (102) and a welding portion 2 (201), and the welding portion 1 (102) and the welding portion 2 (201) are welded to each other, and the bending position of the pole ear (2) and the bending position of the pole ear group (101) form a folding area (4); A glue fixing structure is provided on the outside of the folding area (4).

2. The bare battery cell with foldable tabs according to claim 1, characterized in that: The battery cell body (1) is composed of a positive electrode sheet, a negative electrode sheet and a separator which are wound or laminated, and the separator is located between the positive electrode sheet and the negative electrode sheet; The tops of the positive electrode sheet and the negative electrode sheet are both cut with electrode ears.

3. The bare battery cell with foldable tabs according to claim 1, characterized in that: A plurality of pits are punched out on the surface between the welding portion 1 (102) and the welding portion 2 (201) after welding.

4. The bare battery cell with foldable tabs according to claim 1, characterized in that: The folding area (4) is horizontal to the battery cell body (1), and after being fixed by the adhesive fixing structure, the bottom surface is close to the top of the battery cell body (1).

5. The bare battery cell with foldable tabs according to claim 4, characterized in that: The adhesive fixing structure includes protective adhesive (3) and fixing adhesive (5), both of which are in two groups; The two groups of protective glue (3) are respectively adhered to the two surfaces of the welding part 1 (102) and the welding part 2 (201) after welding; One of the fixing glues (5) is adhered to the bent position of the root of the pole piece ear group (101) and extends to the outer wall of the battery cell body (1); Another fixing glue (5) is adhered to the bent position of the tab (2) and extends to the outer wall of the battery cell body (1).

6. The bare battery cell with foldable tabs according to claim 1, characterized in that: The top end of the tab (2) is upright in the Y-axis direction.

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