CN219066884U

CN219066884U - Lithium battery

Info

Publication number: CN219066884U
Application number: CN202223250488.2U
Authority: CN
Inventors: 夏天军; 何畅
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-05-23
Anticipated expiration: 2032-12-05

Abstract

The utility model relates to the technical field of batteries, in particular to a lithium battery, which comprises a winding core, a negative electrode lug, a shell and a negative electrode cover plate, wherein the negative electrode lug is connected to one end of the winding core; the shell is sleeved outside the winding core; one end of the shell along the axis direction is a negative electrode end, and the other end is a positive electrode end; the negative electrode cover plate is in penetration welding with the negative electrode lug, and the periphery of the negative electrode cover plate is in sealing arrangement with the negative electrode end of the shell. According to the lithium battery, the negative electrode lug and the negative electrode cover plate are directly penetrated and welded, the periphery of the negative electrode cover plate and the negative electrode end of the shell are sealed, the structural form of the lithium battery is simplified, and the assembly production of the lithium battery is simplified.

Description

Lithium battery

Technical Field

The utility model relates to the technical field of batteries, in particular to a lithium battery.

Background

With the continuous development of new energy technology, lithium batteries are widely used as power batteries in the field of electric automobiles. The power battery can be a cylindrical battery, a square battery or a soft package battery, and the cylindrical battery is more and more favored by people because the cylindrical battery has the advantages of high production efficiency, high equipment automation degree, good product performance consistency and the like.

The conventional cylindrical battery generally comprises a shell, a winding core, a connecting sheet and a negative electrode cover plate, wherein the winding core is arranged in the shell, a negative electrode tab at one end of the winding core is welded with one side of the connecting sheet, the other side of the connecting sheet is welded with the negative electrode cover plate, and the negative electrode cover plate is welded with the periphery of the shell. The internal structure of the battery is redundant, the assembly is complex, and the production efficiency of the battery is low due to a plurality of welding operations.

Disclosure of Invention

Therefore, the technical problem to be solved by the utility model is to overcome the defects of the prior art that the internal structure of the battery is redundant and the assembly production efficiency is low, thereby providing the lithium battery which simplifies the internal structure and is convenient to assemble.

In order to solve the technical problems, the lithium battery provided by the utility model comprises a winding core, a negative electrode tab, a shell and a negative electrode cover plate, wherein the negative electrode tab is connected to one end of the winding core; the shell is sleeved outside the winding core; one end of the shell along the axis direction is a negative electrode end, and the other end is a positive electrode end; the negative electrode cover plate is in penetration welding with the negative electrode lug, and the periphery of the negative electrode cover plate is in sealing arrangement with the negative electrode end of the shell.

The lithium battery provided by the utility model comprises a cover plate body, wherein the cover plate body is provided with a pressure relief area and a welding area wound on the periphery of the pressure relief area, the pressure relief area is provided with an explosion-proof valve, and the welding area and the negative electrode lug are in penetration welding.

According to the lithium battery provided by the utility model, the explosion-proof valve is of a groove-shaped structure formed by punching and grooving in the direction away from the negative electrode lug.

The lithium battery provided by the utility model further comprises a connecting edge, wherein the connecting edge protrudes towards the direction opposite to the negative electrode lug, is wound on the periphery of the cover plate body in a winding manner, and is connected with the negative electrode end of the shell in a sealing manner.

According to the lithium battery provided by the utility model, the connecting edge is inwards Zhou Fanshe to form a first curled edge, the negative electrode end of the shell is inwards Zhou Fanshe to form a second curled edge, and the second curled edge is wrapped outside the first curled edge.

The lithium battery provided by the utility model further comprises an elastic sealing piece which is clamped between the first curled edge and the second curled edge.

According to the lithium battery provided by the utility model, gaps are arranged between the tail ends of the first curled edge and the second curled edge and the cover plate body.

According to the lithium battery provided by the utility model, the first curled edge and the second curled edge are obliquely arranged inwards, and an inverted frustum-shaped structure is formed on one side of the cover plate body, which is opposite to the negative electrode lug.

According to the lithium battery provided by the utility model, the through hole is formed in the positive electrode end of the shell; the lithium battery further comprises a positive electrode terminal, a positive electrode lug and an insulating assembly, wherein the positive electrode lug is connected to the other end of the winding core, one end of the positive electrode terminal is connected with the positive electrode lug, and the other end of the positive electrode terminal extends to the outside of the shell through the through hole; the positive terminal is connected with the shell in an insulating way through the insulating component.

According to the lithium battery provided by the utility model, the periphery of the positive electrode terminal is provided with the annular limiting groove, the through hole is sleeved on the periphery of the groove bottom of the annular limiting groove, the groove wall positioned in the shell is a first groove wall, and the groove wall positioned outside the shell is a second groove wall; the insulation assembly includes:

a first insulating portion provided between the first groove wall and the housing;

the second insulating part is sleeved on the second groove wall and is positioned between the second groove wall and the shell;

the sealing ring is arranged in the annular limiting groove and is clamped between the groove bottom of the annular limiting groove and the through hole.

The technical scheme of the utility model has the following advantages:

1. the lithium battery provided by the utility model comprises a winding core, a negative electrode lug, a shell and a negative electrode cover plate, wherein the negative electrode lug is connected to one end of the winding core; the shell is sleeved outside the winding core; one end of the shell along the axis direction is a negative electrode end, and the other end is a positive electrode end; the negative electrode cover plate and the negative electrode lug are welded in a penetrating way, and the periphery of the negative electrode cover plate and the negative electrode end of the shell along the axial direction are arranged in a sealing way. Through directly penetrating the welding with negative pole tab and negative pole apron, will the periphery of negative pole apron with the casing sets up along the negative pole end seal of axis direction, has cancelled current negative pole connection piece, and on the function integration of negative pole connection piece was to the negative pole apron, still realized with the sealed encapsulation of casing through the negative pole apron, simplified the structural style of lithium cell, simplified the assembly production of lithium cell, improved production efficiency. The lithium battery overcomes the defects of multiple redundancy of the internal structure of the battery and low assembly production efficiency of the finished battery in the prior art, thereby simplifying the internal structure and facilitating assembly.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is an exploded view of the installation of a lithium battery provided by the present utility model;

fig. 2 is a cross-sectional view of a lithium battery provided by the present utility model;

fig. 3 is an enlarged view of a portion a of fig. 2;

fig. 4 is a schematic diagram of a curling process of a first curl and a second curl of a lithium battery provided by the utility model;

fig. 5 is an enlarged view of a portion B of fig. 2;

fig. 6 is an enlarged view of a portion C of fig. 2;

fig. 7 is a schematic view of a lithium battery provided by the present utility model;

fig. 8 is a bottom view of a lithium battery provided by the present utility model;

fig. 9 is a top view of a lithium battery provided by the present utility model;

fig. 10 is a schematic view of a negative electrode cover plate provided by the utility model;

FIG. 11 is a cross-sectional view of a negative electrode cover plate provided by the utility model;

fig. 12 is an oblique schematic view of a first curl and a second curl of a lithium battery provided by the present utility model.

Reference numerals illustrate:

1. a winding core; 2. a housing; 21. a second crimp; 22. a through hole; 3. a negative electrode cover plate; 31. a cover plate body; 311. the pressure relief area; 312. a welding area; 32. a connecting edge; 33. a first crimp; 4. a seal; 5. a gap; 6. a positive electrode terminal; 61. an annular limit groove; 7. an insulating assembly; 71. a first insulating portion; 72. a second insulating portion; 73. a seal ring; 8. a plastic nail; 9. sealing nails; 10. a central tube; 11. a frustum-shaped structure.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

As shown in fig. 1 to 12, a lithium battery is disclosed in this embodiment, which includes a winding core 1, a negative electrode tab, a case 2, and a negative electrode cover 3, the negative electrode tab being connected to one end of the winding core 1; the shell 2 is sleeved outside the winding core 1; one end of the shell 2 along the axis direction is a negative electrode end, and the other end is a positive electrode end; the negative electrode cover plate 3 is in penetration welding with the negative electrode tab, and the periphery of the negative electrode cover plate 3 is in sealing arrangement with the negative electrode end of the shell 2 along the axial direction.

Through directly penetrating the welding with negative pole tab and negative pole apron 3, will the periphery of negative pole apron 3 with the negative pole end seal arrangement of casing 2 along the axis direction has cancelled current negative pole connection piece, and on the function integration of negative pole connection piece was to negative pole apron 3, still realized with the sealed encapsulation of casing 2 through negative pole apron 3, simplified the structural style of lithium cell, simplified the assembly production of lithium cell, improved production efficiency. The lithium battery overcomes the defects of multiple redundancy of the internal structure of the battery and low assembly production efficiency of the finished battery in the prior art, thereby simplifying the internal structure and facilitating assembly. In a specific embodiment, the lithium battery may be a cylindrical battery, or may be a power battery such as a prismatic battery, and in this embodiment, a cylindrical battery is preferable.

In this embodiment, the negative electrode cover plate 3 includes a cover plate body 31, a pressure relief area 311 and a welding area 312 around the outer periphery of the pressure relief area 311 are provided on the cover plate body 31, the pressure relief area 311 is provided with an explosion-proof valve, and the welding area 312 and the negative electrode tab are welded in a penetrating manner. The explosion-proof valve can play a role in pressure relief when the lithium battery is expanded under overpressure. The welding area 312 is wound around the periphery of the pressure relief area 311, so that a good connection effect can be obtained, and the functions of welding and pressure relief can be realized separately, so that mutual interference is avoided.

In this embodiment, the explosion-proof valve is a groove-shaped structure formed by punching and grooving in a direction away from the negative electrode tab. The explosion-proof valve protrudes out of the plane where the welding area 312 is located, so that the strength of the pressure relief area 311 where the explosion-proof valve is located can be enhanced. The explosion-proof valve is an elliptic groove-shaped structure formed by stamping and grooving, and a plurality of welding beads and welding holes which penetrate through the welding are uniformly distributed on two sides of the elliptic groove-shaped structure in the length direction.

In the embodiment, a central tube 10 is arranged inside the winding core 1, a sealing groove protruding towards the winding core 1 is arranged at the bottom of the explosion-proof valve, a perforation is arranged on the bottom of the sealing groove, a plastic nail 8 is connected at the perforation in a sealing way and seals the central tube 10, and a sealing nail 9 is sleeved outside the plastic nail 8 and is connected in the sealing groove in a sealing way. The plastic nails 8 and the sealing nails 9 seal the lithium battery.

In this embodiment, the negative electrode cover plate 3 further includes a connection edge 32, where the connection edge 32 protrudes in a direction opposite to the negative electrode tab, is wound around the outer periphery of the cover plate body 31, and is in sealing connection with the negative electrode end of the housing 2. Through the setting of connection border 32, increase the cooperation junction surface between negative pole apron 3 and the casing 2, the steadiness of reinforcing connection, and reinforcing sealed effect.

In this embodiment, the connecting edge 32 forms a first bead 33 inwardly Zhou Fanshe, and the negative end of the can 2 forms a second bead 21 inwardly Zhou Fanshe, the second bead 21 being wrapped around the outside of the first bead 33. In the crimping process, the connecting edge 32 is tightly attached to the negative electrode end of the shell 2, so that a stable connecting effect is achieved, and mutual movement in the axial direction is avoided. The first curled edge 33 and the second curled edge 21 are both inward Zhou Fanshe and do not protrude towards the periphery of the shell 2, so that the aesthetic property of the shell of the lithium battery is guaranteed, and the interference of the protruding curled edges on the connection between the lithium battery and the power utilization structure can be avoided.

Specifically, the connecting edge 32 is firstly connected in the negative end of the shell 2, and then the negative end of the shell 2 and the connecting edge 32 are simultaneously inwards Zhou Fanshe through mechanical equipment; alternatively, the connecting edge 32 may be turned over by mechanical equipment, then the negative electrode cover plate 3 is connected to the negative electrode end of the casing 2, and then the negative electrode end of the casing 2 is turned over by mechanical equipment and wrapped outside the first curled edge 33.

As an alternative embodiment, the connecting edge 32 may be turned over to the outside to form a first bead 33, the negative end of the case 2 may be turned over to the outside to form a second bead 21, and the first bead 33 may be wrapped around the second bead 21.

The lithium battery of the present embodiment further comprises an elastic sealing member 4 interposed between the first bead 33 and the second bead 21. The elastic sealing element 4 can be attached to the outside of the connecting edge 32 before the negative electrode cover plate 3 is connected with the negative electrode end of the shell 2, and after the lithium battery is packaged, the elastic sealing element 4 is clamped between the connecting edge 32 and the shell 2, and the elastic sealing element 4 is compressed to play a sealing role. The elastic sealing element 4 is clamped between the first curled edge 33 and the second curled edge 21, and the position of the elastic sealing element 4 can be limited, so that the sealing effect is prevented from being influenced due to dislocation of the elastic sealing element 4.

The elastic sealing member 4 may be made of a material that can be elastically compressed such as a sealant, a fluororubber, PFA, PBT, PP, or the like.

In this embodiment, a gap 5 is provided between the ends of the first bead 33 and the second bead 21 and the cover body 31, so as to prevent the ends of the first bead 33 and the second bead 21 from scratching the cover body 31 during the folding process. The end of the first bead 33 is the end remote from the cover body 31 before being unsevered, and the end of the second bead 21 is the end corresponding to the end of the first bead 33.

In this embodiment, the first curled edge 33 and the second curled edge 21 are obliquely pressed inward, and an inverted frustum-shaped structure 11 is formed on a side of the cover body 31 facing away from the negative electrode tab. The heights of the first and

second beads

33 and 21 can be reduced, the overall height of the lithium battery can be reduced, and the aesthetic appearance thereof can be enhanced. In particular, after the first and

second beads

33 and 21 are folded and formed, the first and

second beads

33 and 21 may be pressed toward the inner circumference by a mechanical device such that the first and

second beads

33 and 21 are obliquely disposed.

In this embodiment, the positive end of the housing 2 is provided with a through hole 22; the lithium battery further comprises a positive terminal 6, a positive tab and an insulating assembly 7, wherein the positive tab is connected to the other end of the winding core 1, one end of the positive terminal 6 is connected with the positive tab, and the other end of the positive terminal extends to the outside of the shell 2 through the through hole 22; the positive terminal 6 is connected with the housing 2 in an insulating manner by the insulating member 7.

The novel structure type positive electrode is arranged, the existing positive electrode cover plate and positive electrode connecting sheets are canceled, the external conductive function of the positive electrode cover plate is replaced by the positive electrode terminal 6 of which one end extends to the outside of the through hole 22 of the shell 2, the connection function of the positive electrode connecting sheets and the positive electrode lugs is replaced by the positive electrode terminal 6, the sealing function of the positive electrode cover plate is replaced by the insulating assembly 7, and the structure type of the positive electrode of the lithium battery is simplified. The lithium battery overcomes the defects of various redundancies of the internal structure of the battery and low assembly production efficiency of the finished battery in the prior art, thereby providing the lithium battery with simplified internal structure and high safety performance.

In this embodiment, an annular limiting groove 61 is formed on the outer periphery of the positive electrode terminal 6, the through hole 22 is sleeved on the outer periphery of the groove bottom of the annular limiting groove 61, the groove wall located inside the housing 2 is a first groove wall, and the groove wall located outside the housing 2 is a second groove wall; the positive electrode terminal 6 is formed into an "i" shape by an annular limiting groove 61. The insulation assembly 7 includes a first insulation portion 71, a second insulation portion 72, and a seal ring 73. A first insulating portion 71 is provided between the first groove wall and the housing 2; the second insulating part 72 is sleeved on the second groove wall and is positioned between the second groove wall and the shell 2; the seal ring 73 is disposed in the annular limiting groove 61 and is sandwiched between the bottom of the annular limiting groove 61 and the through hole 22.

The positive terminal 6 may be connected to the housing 2 by injection molding, and the seal ring 73 may be installed by extrusion, or injection molding. The first insulating portion 71 may be made of a polymer plastic material such as PP, PPS, PFA, PBT, and the second insulating portion 72 may be made of a polymer plastic material such as PPS, PP, PFA, PBT, and the positive electrode terminal 6 is made of a metal material, preferably aluminum.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims

1. A lithium battery, comprising:

a winding core (1);

the negative electrode lug is connected to one end of the winding core (1);

the shell (2) is sleeved outside the winding core (1); one end of the shell (2) along the axis direction is a negative electrode end, and the other end is a positive electrode end;

and the negative electrode cover plate (3) is in penetration welding with the negative electrode lug, and the periphery of the negative electrode cover plate (3) is in sealing arrangement with the negative electrode end of the shell (2).

2. The lithium battery according to claim 1, wherein the negative electrode cover plate (3) comprises a cover plate body (31), a pressure relief area (311) and a welding area (312) wound on the periphery of the pressure relief area (311) are arranged on the cover plate body (31), the pressure relief area (311) is provided with an explosion-proof valve, and the welding area (312) and the negative electrode tab are welded in a penetrating manner.

3. The lithium battery according to claim 2, wherein the explosion-proof valve has a groove-like structure formed by punching and grooving in a direction away from the negative electrode tab.

4. A lithium battery according to claim 2 or 3, characterized in that the negative electrode cover plate (3) further comprises a connecting edge (32), and the connecting edge (32) is protruded around the periphery of the cover plate body (31) towards the direction facing away from the negative electrode tab and is in sealing connection with the negative electrode end of the shell (2).

5. The lithium battery according to claim 4, characterized in that the connecting edge (32) forms a first bead (33) inwardly Zhou Fanshe, the negative end of the housing (2) forms a second bead (21) inwardly Zhou Fanshe, and the second bead (21) is wrapped around the outside of the first bead (33).

6. The lithium battery according to claim 5, further comprising an elastic seal (4) interposed between the first bead (33) and the second bead (21).

7. Lithium battery according to claim 5 or 6, characterized in that a gap (5) is provided between the ends of the first and second bead (33, 21) and the cover body (31).

8. The lithium battery according to claim 7, characterized in that the first bead (33) and the second bead (21) are inclined inwards, and an inverted frustum-shaped structure (11) is formed on the side of the cover plate body (31) facing away from the negative electrode tab.

9. The lithium battery according to any one of claims 1-3, 5-6, 8, characterized in that the positive end of the casing (2) is provided with a through hole (22); the lithium battery further comprises a positive terminal (6), a positive lug and an insulating component (7), wherein the positive lug is connected to the other end of the winding core (1), one end of the positive terminal (6) is connected with the positive lug, and the other end of the positive terminal extends to the outside of the shell (2) through the through hole (22); the positive terminal (6) is connected with the shell (2) in an insulating way through the insulating component (7).

10. The lithium battery according to claim 9, wherein an annular limiting groove (61) is formed in the periphery of the positive electrode terminal (6), the through hole (22) is sleeved on the periphery of the groove bottom of the annular limiting groove (61), the groove wall positioned in the shell (2) is a first groove wall, and the groove wall positioned outside the shell (2) is a second groove wall; the insulation assembly (7) comprises:

a first insulating portion (71) provided between the first groove wall and the housing (2);

a second insulating part (72) sleeved on the second groove wall and positioned between the second groove wall and the shell (2);

the sealing ring (73) is arranged in the annular limiting groove (61) and is clamped between the groove bottom of the annular limiting groove (61) and the through hole (22).