Battery with improved tab bending structure

Abstract

The utility model discloses a battery with an improved tab bending structure. The battery comprises a roll core main body and tabs, the roll core body has a body end face. The tab comprises a first tab section and a second tab section which are bent and overlapped; the first tab section is arranged between the second tab section and the end surface of the main body; the first tab section is provided with a leading-out end and a first bent end which are opposite in the length direction, the leading-out end is connected with the main body end face, and the first bent end is arranged on the side of the leading-out end deviating from the center of the main body end face. According to the battery with the improved tab bending structure, the tab bending structure is reasonable, the first bending end is arranged on the side, deviating from the center of the end face of the main body, of the leading-out end, and the first tab section is arranged to be shorter, so that the flattening length of the tab is reduced, the wind resistance of tab movement during high-speed production is reduced, and the probability of irregular collapse and deformation of the tab is effectively reduced; the pole lug positioning difficulty in subsequent production is reduced, and the production efficiency of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production, in particular to a battery with an improved pole ear bending structure. Background Art

[0002] The upper limit of cylindrical battery design production capacity is usually greater than 100 PPM (100 cells per minute). The main factors affecting the upper limit of design production capacity include winding speed and the flow speed of battery assembly between different workstations.

[0003] In order to meet the bending requirements, the tabs drawn from the winding core must have a predetermined length. During the circulation of battery assemblies, the longer the tabs are, the greater the wind resistance they will experience, making them more prone to irregular collapse and deformation, which in turn increases the difficulty of tab positioning in subsequent assembly steps.

[0004] The improved technical solution is mainly to reduce the length of the electrode tab. After the high-speed winding support core is wound, the tab is welded to the electrode connecting sheet to form a combination of the tab and the electrode connecting sheet. The existing assembly bending structure is mostly Z-shaped, and the first tab section close to the core extends from the eccentric lead-out position through the center area of ​​the core end face to the opposite side of the lead-out position (such as Figure 1 ), so the flattened length of the assembly of the electrode tab and the electrode connecting sheet is longer when it is not bent, and the probability of deformation is greater when the winding core flows at high speed between workstations. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects in the prior art and provide a battery with an improved tab bending structure, which reduces the flattened length of the tab and reduces the deformation probability of the tab by changing the extension direction of the first tab segment and the bending mode of the tab.

[0006] In order to achieve the above technical effects, the technical solution of the utility model is: a battery with an improved tab bending structure, comprising:

[0007] The winding core body has a main body end surface;

[0008] The pole lug comprises a first pole lug segment and a second pole lug segment which are bent and overlapped;

[0009] The first pole lug segment is arranged between the second pole lug segment and the end face of the main body; the first pole lug segment has a lead end and a first bent end opposite to each other along the length direction, the lead end is eccentrically connected to the end face of the main body, and the first bent end is arranged on the side of the lead end away from the center of the end face of the main body.

[0010] A preferred technical solution is that the second pole lug segment is connected to an electrode connecting piece, and the electrode connecting piece has a pole connecting portion.

[0011] A preferred technical solution is that the second pole lug segment is eccentrically disposed on the orthographic projection of the end face of the main body.

[0012] A preferred technical solution is that the number of bends in the tab is one.

[0013] A preferred technical solution is that the electrode connecting sheet and at least a portion of the second pole lug segment are overlapped and welded, and the overlapping area of ​​the electrode connecting sheet and the second pole lug segment and the pole column connecting portion are spaced apart from each other.

[0014] A preferred technical solution is that the electrode tab is arranged between the electrode connecting sheet and the end surface of the main body.

[0015] A preferred technical solution is that the electrode connecting sheet is a flat structure.

[0016] A preferred technical solution is that the overlapped area is projected on the main body end face as a first area, the pole connection portion is projected on the main body end face as a second area, and the first area and the second area are arranged on opposite sides of the center of the main body end face.

[0017] The preferred technical solution is to further include an insulating gasket, which has a gasket body abutting against the end face of the main body, a side stopper protruding from the gasket body, the first pole ear segment passing through the through hole of the gasket body, and the side stopper being blocked on the side of the first bent end away from the center of the end face of the main body.

[0018] A preferred technical solution is that the side stopper is continuously arranged to surround the edge of the gasket body.

[0019] The advantages and beneficial effects of the utility model are:

[0020] The battery pole ear bending structure with improved pole ear bending structure is reasonable, the first bending end is arranged on the side of the lead-out end away from the center of the main body end face, and the first pole ear section is arranged to be shorter, which is beneficial to reducing the flattened length of the pole ear, reducing the wind resistance of the pole ear movement during high-speed production, effectively reducing the probability of irregular collapse and deformation of the pole ear, reducing the difficulty of positioning the pole ear in subsequent production, and helping to improve the production efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of a battery cell in the prior art;

[0022] Figure 2 is an exploded view of a battery with an improved tab bending structure according to an embodiment;

[0023] Figure 3 is an exploded view of a battery with an improved tab bending structure according to another embodiment;

[0024] Figure 4 yes Figure 3 Schematic diagram of the battery structure with the middle tab in an unbent state;

[0025] Figure 5 yes Figure 3 Schematic diagram of the battery structure with the middle tab in a bent state;

[0026] Figure 6 is a schematic diagram of the structure of the electrode tab and the electrode connecting piece in the battery of another second embodiment;

[0027] In the figure: 1, winding core body; 2, pole ear; 21, first pole ear segment; 211, lead end; 212, first bending end; 22, second pole ear segment; 3, electrode connecting piece; 4, insulating gasket; 41, gasket body; 42, side stop;

[0028] 201, fixed end; 202, bent end. DETAILED DESCRIPTION

[0029] The following examples are used to further describe the specific implementation of the present invention. The following examples are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0030] In the description of the present application, it should be noted that, unless otherwise specified, “plurality” means more than two; the terms “upper”, “lower”, “left”, “right”, “inside”, “outside”, etc., indicating directions or positional relationships, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application.

[0031] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0032] In the description of the present invention, "first", "second" and the like are used to distinguish different objects rather than to describe a specific order or a primary-secondary relationship.

[0033] The battery structure in the prior art is as follows Figure 1As shown, it includes a core body 1 and a pole lug 2, the core body 1 has a main end face; the pole lug 2 includes a first pole lug segment 21, a fixed end 201 of the first pole lug segment 21 is connected to the core body 1, and the other end opposite to the fixed end is a bent end 202, and the bent end 202 is arranged on the side of the fixed end 201 toward the center of the core end face.

[0034] Example

[0035] like Figure 2-6 As shown, the battery with an improved tab bending structure in the embodiment includes a winding core body 1 and a tab 2; the winding core body 1 has a main body end face; the tab 2 includes a first tab segment 21 and a second tab segment 22 that are bent and stacked; the first tab segment 21 is arranged between the second tab segment 22 and the main body end face; the first tab segment 21 has a lead-out end 211 and a first bent end 212 that are opposite to each other along the length direction, the lead-out end 211 is eccentrically connected to the main body end face, and the first bent end 212 is arranged on the side of the lead-out end 211 away from the center of the main body end face.

[0036] According to the shape of the winding core, the battery can be selected as a cylindrical battery or an elliptical cylindrical battery. According to the structure of the tab 2, the battery can be selected as a single-pole tab battery or a multi-pole tab battery. The winding core body 1 is a straight column in which the positive electrode sheet, the negative electrode sheet and the diaphragm are wound, and the tab is eccentrically led out from the center of the end face of the main body.

[0037] It is understandable that, in addition to the winding core body and the tabs, the battery also includes known components such as a cover plate, a shell, and an insulating gasket.

[0038] The tab 2 may be a positive tab and / or a negative tab. In the present embodiment, the battery is a multi-tab battery, and the tab 2 is a negative tab.

[0039] The process steps of bending the pole ear include: the winding core is arranged in the shell, the main end face of the winding core is provided with an insulating gasket, the pole ear 2 passes through the through hole of the insulating gasket and extends along the axial direction of the winding core to the outside of the shell opening; the free end of the pole ear 2 away from the winding core is welded and connected to the cover plate, and while the bending knife folds the pole ear 2, the grasping mechanism grasps the cover plate and flips it according to a predetermined covering path until the cover plate is covered and connected to the shell opening, and the bent pole ear is clamped between the cover plate and the main end face.

[0040] Taking the round core end face as an example, the bending orientation of the first pole lug segment 21 includes the following two modes: first, when the first bending end 212 is arranged on the side of the lead end 211 facing the center of the main body end face, the first pole lug segment 21 covers the central area of ​​the core end face, and its length is usually greater than the radius of the core end face; second, when the first bending end 212 is arranged on the side of the lead end 211 away from the center of the main body end face, the first pole lug segment 21 does not cover the central area of ​​the core end face, and its length is less than the radius of the core end face. Based on the same length of the second pole lug segment 22 and the bending method, the total length of the pole lug before bending in the second method is less than the total length of the pole lug before bending in the first method.

[0041] The second pole lug segment 22 can be optionally directly connected to the pole, and the pole lug bending structure including the first pole lug segment 21 and the second pole lug segment 22 is a "7"-shaped bend; or the second pole lug segment 22 is connected to the third pole lug segment 2 through a bend, and the third pole lug segment 2 is directly connected to the pole, and the pole lug bending structure including the first pole lug segment 21, the second pole lug segment 22 and the third pole lug segment 2 is a "Z"-shaped bend.

[0042] like Figure 3-6 As shown, in another preferred embodiment, the second pole lug segment 22 is connected to an electrode connecting piece 3, and the electrode connecting piece 3 has a pole connecting portion.

[0043] After the winding of the core is completed, the pole tab 2 is connected to the electrode connecting sheet 3, and then the electrode connecting sheet 3 is connected to the pole of the cover plate. One of the functions of the electrode connecting sheet 3 is to increase the length of the pole tab 2. Compared with the direct connection of the pole tab 2 to the pole, the length of the pole tab of the winding core can be set to be smaller, meeting the shape retention requirements of the pole tab 2 during high-speed winding.

[0044] like Figure 5 As shown, in another preferred embodiment, the second pole lug segment 22 is eccentrically disposed on the orthographic projection of the main body end surface, so that the length of the second pole lug segment 22 is set to be shorter, meeting the production requirement of keeping the shape of the pole lug 2 during high-speed winding. In order to meet the predetermined length requirement of the assembly of the pole lug 2 and the electrode connecting sheet 3, the length of the electrode connecting sheet 3 is increased accordingly.

[0045] The first pole lug section 21 and the second pole lug section 22 are both shortened, which is beneficial to the supporting stability of the multi-pole lug stacking structure on the electrode connecting sheet 3 and reduces the influence of wind resistance on the deformation of the assembly of the pole lug 2 and the electrode connecting sheet 3 .

[0046] like Figure 2-6 As shown, in another preferred embodiment, the number of bends of the pole lug 2 is one, that is, the pole lug 2 only includes a first pole lug segment 21 and a second pole lug segment 22, which is conducive to simplifying the bending structure of the pole lug, reducing the axial space of the winding core occupied by the bent pole lug, and adjusting the axial dimensions of the winding core of components such as the stop frame according to changes in the bending structure of the pole lug to improve the utilization rate of the internal space of the shell.

[0047] like Figure 4 , 5 As shown, in another preferred embodiment, the electrode connecting piece 3 and the second pole lug segment 22 are at least partially overlapped and welded, and the overlapped area of ​​the electrode connecting piece 3 and the second pole lug segment 22 is spaced apart from the pole connecting portion. Figure 4 Middle shaded area.

[0048] The overall thickness of the overlapping area of ​​the electrode connecting sheet 3 and the second pole lug segment 22 is the sum of the thicknesses of the two components. The overlapping area is spaced apart from the pole connecting portion, which helps to reduce the difficulty of welding the pole and the electrode connecting sheet 3 and improve the welding yield.

[0049] Optionally, the orthographic projections of the overlapping area and the pole connection portion on the end face of the core body 1 are located on the same side of the center of the end face of the main body, or are arranged on opposite sides of the center of the end face of the main body; or the orthographic projection of the overlapping area on the end face of the core body 1 is located on the side of the center of the end face of the main body in a first direction, and the orthographic projection of the pole connection portion on the end face of the core body 1 is located on the side of the center of the end face of the main body in a second direction, and the first direction intersects the second direction.

[0050] like Figure 5 As shown, in another preferred embodiment, the electrode tab 2 is arranged between the electrode connecting sheet 3 and the end surface of the main body.

[0051] Taking the "7"-shaped bent pole ear as an example, when the electrode connecting sheet 3 is overlapped and connected with the surface of the second pole ear segment 22 facing the main end face, part of the electrode connecting sheet 3 is located between the second pole ear segment 22 and the main end face of the winding core, and the remaining part is located between the pole column and the main end face of the winding core; when the electrode connecting sheet 3 is overlapped and connected with the surface of the second pole ear segment 22 facing away from the main end face, the pole ear 2 composed of the first pole ear segment 21 and the second pole ear segment 22 is located between the electrode connecting sheet 3 and the main end face of the winding core. The electrode connecting sheet 3 has a predetermined thickness, and the latter scheme is more conducive to reducing the abutment wear of the electrode connecting sheet 3 on the pole ear 2; in addition, the folding direction of the pole ear punching knife is as follows: Figure 3 As shown by the leftward arrow in FIG. 1 , the electrode tab 2 is pushed and folded by utilizing the rigidity of the electrode connecting sheet 3 to avoid damaging the welding structure between the electrode tab 2 and the electrode connecting sheet 3 during the bending process.

[0052] The electrode connecting sheet 3 can be selected to have a bent structure or a flattened structure.

[0053] like Figure 4 As shown, in another preferred embodiment, the electrode connecting sheet 3 is a flat structure. Compared with the bending of the electrode connecting sheet 3 with greater rigidity, not only is the difficulty of bending the pole ear lower, but the thickness of the bending structure of the assembly of the pole ear 2 and the electrode connecting sheet 3 along the axial direction of the winding core is smaller.

[0054] like Figure 4As shown, the first bent end 212 is arranged flush with one end surface of the electrode connecting sheet 3, or as shown in Figure 6 As shown, the end edge of the first bent end 212 and the electrode connecting sheet 3 are spaced apart from each other in the length direction of the electrode tab.

[0055] In other embodiments, the orthographic projection of the overlapped area on the end face of the main body is the first area, and the orthographic projection of the pole connection portion on the end face of the main body is the second area. The first area and the second area are arranged on opposite sides of the center of the end face of the main body. Figure 4 The position of the second pole lug segment 22 is such that after closing the cover, the cover body and the end surface of the main body are arranged opposite to each other along the axial direction of the winding core.

[0056] The pole connection part is connected to the pole through the metal block of the cover plate. The welding surface of the metal block is circular or arc-shaped. The welding area between the pole connection part and the metal block is set to be larger, which is conducive to ensuring the stability of the welding structure.

[0057] like Figure 2-6 As shown, in another preferred embodiment, the battery also includes an insulating gasket 4, which has a gasket body 41 abutting against the end face of the main body, a side stopper 42 protruding from the gasket body 41, the first pole ear segment 21 is passed through the through hole of the gasket body 41, and the side stopper 42 is blocked on the side of the first bending end 212 away from the center of the end face of the main body.

[0058] Limited by the size of the main body end face and the folding direction of the first pole ear segment 21, the first bent end 212 is located close to the side wall of the battery housing, and the side stop 42 blocks the direct contact between the first bent end 212 and the battery housing to eliminate the risk of short circuit.

[0059] like Figure 2 As shown, in another preferred embodiment, the side stopper 42 is continuously arranged to surround the edge of the gasket body 41 .

[0060] The side stop 42 which is continuously enclosed is easy to install, and there is no need to rotate the insulating gasket 4 according to the position of the pole lug to adjust the side stop 42; the side stop 42 is arranged at the edge of the gasket body 41, so that the radial dimension of the pole lug accommodating space formed by the side stop 42 and the gasket body 41 is larger to adapt to the larger bending radius of the multi-pole lug stacking structure.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A battery with an improved tab bending structure, comprising: The winding core body has a main body end surface; The pole lug comprises a first pole lug segment and a second pole lug segment which are bent and overlapped; The first pole lug segment is arranged between the second pole lug segment and the end face of the main body; the first pole lug segment has a lead end and a first bent end opposite to each other along the length direction, the lead end is eccentrically connected to the end face of the main body, and is characterized in that the first bent end is arranged on the side of the lead end away from the center of the end face of the main body.

2. The battery with improved tab bending structure according to claim 1, characterized in that: The second pole lug segment is connected to an electrode connecting piece, and the electrode connecting piece has a pole connecting portion.

3. The battery with improved tab bending structure according to claim 1, characterized in that: The second pole lug segment is eccentrically disposed on the orthographic projection of the end surface of the main body.

4. The battery with an improved tab bending structure according to claim 1 or 2, characterized in that: The number of bends of the tab is one.

5. The battery with improved tab bending structure according to claim 2, characterized in that: The electrode connecting sheet and at least a portion of the second pole tab segment are overlapped and welded, and the overlapped region of the electrode connecting sheet and the second pole tab segment and the pole column connecting portion are spaced apart from each other.

6. The battery with improved tab bending structure according to claim 2, characterized in that: The electrode tab is arranged between the electrode connecting sheet and the end surface of the main body.

7. The battery with improved tab bending structure according to claim 2, characterized in that: The electrode connecting sheet is a flat structure.

8. The battery with improved tab bending structure according to claim 5, characterized in that: The orthographic projection of the overlapping area on the end surface of the main body is the first area, and the orthographic projection of the pole connecting portion on the end surface of the main body is the second area. The first area and the second area are respectively arranged on opposite sides of the center of the end surface of the main body.

9. The battery with an improved tab bending structure according to claim 1, characterized in that: It also includes an insulating gasket, which has a gasket body abutting against the end face of the main body, a side stopper protruding from the gasket body, the first pole ear segment is passed through the through hole of the gasket body, and the side stopper is blocked on the side of the first bent end away from the center of the end face of the main body.

10. The battery with improved tab bending structure according to claim 9, characterized in that: The side stopper is continuously arranged around the edge of the gasket body.

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