CN211350864U

CN211350864U - Lithium ion battery

Info

Publication number: CN211350864U
Application number: CN201922496400.7U
Authority: CN
Inventors: 艾思伟; 徐悦斌; 何巍; 刘金成
Original assignee: Eve Energy Co Ltd
Current assignee: Eve Energy Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-08-25
Anticipated expiration: 2029-12-31

Abstract

The utility model discloses a lithium ion battery, including casing, core package and block, the casing seals one end open-ended tubular structure for one end, and the core package sets up in the casing, and the open end at the casing is fixed to the block, and the block is flat, and the center of block is provided with utmost point post, still sets up the groove on the block, and the center that the groove encircleed utmost point post sets up on the block, and utmost point post is located the one end in the casing and is connected with positive ear or the negative pole ear of core package. The cap is arranged in a flat plate shape, so that the space between the cap and the shell can be fully utilized, the space utilization rate in the shell is increased, and the energy density of the core cladding is improved; a circle of scribed lines are annularly arranged on the cover cap, and the scribed lines can be used as a battery pressure release valve, so that the use safety of the battery is improved.

Description

Lithium ion battery

Technical Field

The utility model relates to the technical field of batteries, especially, relate to a lithium ion battery.

Background

At present, the NCM811 is usually adopted by a cylindrical lithium ion battery as a main material of a positive electrode, the gram capacity of the cylindrical lithium ion battery can reach about 200mAh/g at most, and a main material of a negative electrode is usually silicon carbon or pre-lithiated silica. The lithium ion battery is limited by the capacity of the main materials of the positive electrode and the negative electrode, and the 18650 ternary cylindrical core package on the market is taken as an example, the highest capacity of the core package can only reach 3.5Ah, and the highest energy density can only reach 260 wh/kg. In addition, the positive tab and the negative tab of the conventional cylindrical lithium ion battery are both in a single-tab structure, so that ACR (alternating current internal resistance) and DCR (direct current internal resistance) of the core cladding are large, and further, temperature rise is obviously increased in the charging and discharging process, high-rate charging and discharging cannot be performed, and higher potential safety hazard exists.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a lithium ion battery can improve lithium ion battery's core package capacity and energy density.

To achieve the purpose, the embodiment of the present invention adopts the following technical solutions:

the utility model provides a lithium ion battery, includes casing, core package and block, the casing seals one end open-ended tubular structure for one end, the core package sets up in the casing, the block is fixed the open end of casing, the block is flat, the center of block is provided with utmost point post, still set up the groove on the block, the groove encircles the center of utmost point post sets up on the block, utmost point post is located one end in the casing with anodal ear or the negative pole ear of core package are connected.

As a preferable scheme of the lithium ion battery, the shell is a metal shell, and a nickel layer is plated on the surface of the metal shell; and/or the presence of a gas in the gas,

the cap is a metal plate, and the surface of the metal plate is plated with the nickel layer.

As a preferred scheme of the lithium ion battery, the pole is connected with the positive pole lug or the negative pole lug through a connecting plate, the connecting plate is fixed at the opening end of the shell and positioned at one side of the cover cap close to the inside of the shell, the connecting plate is respectively isolated from the cover cap and the shell through an insulating pad, and the center of the connecting plate is electrically communicated with the pole through at least one welding point.

As a preferable scheme of the lithium ion battery, the connecting plate is provided with air holes at least at positions corresponding to the scribed lines.

As a preferable scheme of the lithium ion battery, a circle of supporting part is annularly arranged on an inner wall of the shell, the supporting part is adjacent to the opening end, and the connecting plate and the cap are sequentially stacked on the supporting part.

As a preferable mode of the lithium ion battery, the connection plate includes a plate body spaced from and parallel to the cap, a bent portion extends from a peripheral portion of the plate body toward the cap, an abutting portion extends from one end of the bent portion, which is far away from the plate body, toward one side, which is far away from a center of the plate body, the abutting portion is located between the cap and the support portion, and the welding point is located on the plate body.

As a preferable aspect of the lithium ion battery, the insulating spacer includes a first portion provided between the abutting portion and the supporting portion, a second portion provided between the abutting portion and the cap, and a connecting portion connecting the first portion and the second portion, the connecting portion being located between the abutting portion and an inner wall of the case.

As a preferred scheme of the lithium ion battery, a through hole is formed in the center of the cap, the pole is inserted into the through hole, an insulating sealing element is arranged between the peripheral wall of the pole and the hole wall of the through hole, a liquid injection hole is further formed in the cap, and the liquid injection hole and the pole are arranged at intervals.

As a preferred scheme of the lithium ion battery, the core package is a winding core package, a plurality of positive tabs are arranged on positive plates of the winding core package, and one negative tab is arranged on a negative plate of the winding core package.

As a preferred scheme of the lithium ion battery, the positive plate is strip-shaped, the positive tab is arranged along the length direction of the positive plate at intervals, the negative tab is strip-shaped, the negative tab is adjacent to one end of the negative tab in the length direction, and the negative tab is positioned at the outermost ring of the winding type core bag.

The utility model discloses beneficial effect does: the cap is arranged in a flat plate shape, so that the space between the cap and the shell can be fully utilized, the space utilization rate in the shell is increased, and the energy density of the core cladding is improved; a circle of scribed lines are annularly arranged on the cover cap, and the scribed lines can be used as a battery pressure release valve, so that the use safety of the battery is improved.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Fig. 1 is a cross-sectional view of a lithium ion battery according to an embodiment of the present invention.

Fig. 2 is a top view of a lithium ion battery according to an embodiment of the present invention.

Fig. 3 is a development state diagram of the positive plate in the embodiment of the present invention.

Fig. 4 is a development state diagram of the negative electrode sheet in the embodiment of the present invention.

In the figure:

1. a housing; 11. an open end; 12. sealing the end; 13. a support portion; 2. a core package; 21. a positive plate; 22. a negative plate; 23. a positive tab; 24. a negative tab; 3. capping; 31. a liquid injection hole; 32. scribing lines; 4. a pole column; 5. a connecting plate; 51. a plate body; 52. a bending part; 53. an abutting portion; 6. and a seal.

Detailed Description

In order to make the technical problems, technical solutions and technical effects achieved by the present invention more clear, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings, and obviously, the described embodiments are only some embodiments, not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

As shown in fig. 1 and 2, the utility model provides a lithium ion battery, including casing 1, core package 2 and block 3, casing 1 seals one end open-ended tube structure for one end, core package 2 sets up in the casing 1, block 3 fixes the open end 11 of casing 1, block 3 is flat, block 3's center is provided with utmost point post 4, still set up on block 3 and annotate liquid hole 31 and groove 32, annotate liquid hole 31 with utmost point post 4 interval sets up, groove 32 is followed the central annular of utmost point post 4 sets up on block 3, utmost point post 4 is located one end in the casing 1 with core package 2's anodal ear 23 or negative pole ear 24 are connected. The cap 3 is arranged to be flat, so that the space between the cap 3 and the shell 1 can be fully utilized, the space utilization rate in the shell 1 is increased, and the energy density of the core package 2 is improved; by annularly arranging a circle of scribed lines 32 on the cap 3, the scribed lines 32 can be used as a battery pressure relief valve, and the use safety of the battery is improved.

In the present embodiment, the scribing line 32 is a V-shaped groove formed on the cap 3, the notch of the V-shaped groove is located on a side of the cap 3 away from the inside of the casing 1, and the bottom of the V-shaped groove and a side of the cap 3 close to the inside of the casing 1 are spaced apart. Specifically, the score line 32 may be subjected to a pressure of 1.2 Mpa.

The shell 1 and the cap 3 can be welded into a whole, a through hole is formed in the center of the cap 3, the pole 4 is inserted into the through hole, and an insulating sealing element 6 is arranged between the peripheral wall of the pole 4 and the hole wall of the through hole. Casing 1 and block 3 welding are as an organic whole, can promote whole lithium ion battery's structural stability and leakproofness, and sealing member 6 sets up and can realize fixing 4 chucking of utmost point post in the through-hole, also implements electric isolation between utmost point post 4 and block 3 simultaneously, prevents that the two electric conductance from switching on.

In the present embodiment, the positive tab 23 of the core pack 2 is connected to the terminal 4, such that the terminal 4 serves as the positive terminal of the entire lithium ion battery, while the negative tab 24 of the core pack 2 is welded to the inner wall of the sealing end 12 of the casing 1, and the casing 1 and the cap 3 serve as the negative terminal of the battery. Of course, in other embodiments, positive tab 23 may be connected to housing 1 and negative tab 24 may be connected to terminal 4.

In one embodiment, the casing 1 is an aluminum casing, a nickel layer is plated on the outer surface of the aluminum casing, the cap 3 is an aluminum plate, and the nickel layer is plated on the outer surface of the aluminum plate. The shell 1 and the cap 3 are both made of metal aluminum, so that the weight of the whole lithium ion battery can be reduced, and the nickel layer plated on the surface can effectively prevent the metal aluminum from being oxidized.

In other embodiments, any one of the housing 1 and the cap 3 may be made of other metals.

In one embodiment, the post 4 is connected to the positive tab 23 through a connecting plate 5, the connecting plate 5 is fixed at the open end 11 of the housing 1 and located at one side of the cap 3 close to the inside of the housing 1, the connecting plate 5 is separated from the cap 3 and the housing 1 through an insulating pad (not shown in the figure), and the center of the connecting plate 5 is electrically communicated with the post 4 through at least one welding point. Through being connected connecting plate 5 with the mode and the utmost point post 4 of adoption welding point, can make the welding point form power-off protection device, when lithium ion battery's electric current was too big, the welding point can break off and realize power-off protection.

Specifically, two welding points are provided between the connecting plate 5 and the pole 4.

In this embodiment, the connecting plate 5 may be parallel to the cap 3, and the connecting plate 5 is provided with air holes (not shown) at least corresponding to the positions of the score lines 32. The air holes are arranged opposite to the scribed lines 32, so that the pressure relief of the core package 2 can be realized in a matched manner, and the use safety of the lithium ion battery is improved. Of course, the air hole may be provided at other positions of the connecting plate 5, for example, the air hole is provided at a position corresponding to the pole 4 in the middle of the connecting plate 5.

The inner wall of the shell 1 is annularly provided with a circle of supporting parts 13, the supporting parts 13 are adjacent to the opening end 11, and the connecting plate 5 and the cover cap 3 are sequentially stacked on the supporting parts 13. The difficulty of assembling the cap 3 and the connecting plate 5 with the housing 1 can be reduced by providing the annular support portion 13.

The connecting plate 5 includes a plate body 51 spaced from and parallel to the cap 3, a bent portion 52 extends from a peripheral portion of the plate body 51 toward the cap 3, an abutting portion 53 extends from one end of the bent portion 52 away from the plate body 51 toward a side away from a center of the plate body 51, the abutting portion 53 is located between the cap 3 and the supporting portion 13, and the welding point is located on the plate body 51. The connecting plate 5 of this structure is convenient for fix with casing 1, also can make its position (board body 51 promptly) of being connected with utmost point post 4 realize contactless with block 3 simultaneously, avoids still setting up insulating pad at board body 51 part and keeps apart connecting plate 5 and block 3, has reduced the use amount of insulating pad, also need not to set up the hole of dodging that supplies the welding point to pass through on insulating pad simultaneously, has reduced the operation degree of difficulty.

The insulating spacer for isolating the abutting portion 53 of the connecting plate 5 from the cap 3 and the case 1, respectively, includes a first portion provided between the abutting portion 53 and the supporting portion 13, a second portion provided between the abutting portion 53 and the cap 3, and a connecting portion connecting the first portion and the second portion, the connecting portion being located between the abutting portion 53 and the inner wall of the case 1.

At least one air hole (not shown) is formed in each of the plate body 51 and the abutting portion 53, and when a plurality of air holes are formed in each of the plate body 51 and the abutting portion 53, the plurality of air holes may be formed to fill the plate body 51 and the abutting portion 53 or may be uniformly formed in each of the plate body 51 and the abutting portion 53.

In one embodiment, as shown in fig. 1, 3 and 4, the core package 2 is a winding core package, the positive tab 21 of the winding core package is provided with a plurality of positive tabs 23, and the negative tab 22 of the winding core package is provided with one negative tab 24. The anode adopts a multi-lug structure, so that the internal resistance of the core bag 2 can be effectively reduced, the temperature rise of the core bag 2 in the using process is further reduced, and the potential safety hazard in the charging and discharging process is reduced.

Furthermore, the positive electrode tabs 23 of the core pack 2 are ultrasonically welded to the aluminum strip, the aluminum strip is ultrasonically welded to the connecting plate 5, and the negative electrode tabs 24 are directly welded to the sealing end 12 of the case 1.

In this embodiment, the positive plate 21 is a long strip, the positive tab 23 is disposed along the length direction of the positive plate 21 at intervals, the negative plate 22 is a long strip, the negative tab 24 is adjacent to one end of the negative plate 22 in the length direction, and the negative tab 24 is located at the outermost ring of the winding core package.

Gummed paper is pasted on the upper end face and the lower end face of the core package 2 and used for isolating the core package 2 from the shell 1 or the connecting plate 5.

In the description herein, it is to be understood that the terms "upper" and the like are used in a descriptive sense and based on the orientation or positional relationship shown in the drawings for convenience in description and simplicity of operation, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, configuration and operation in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description herein, references to the description of "an embodiment" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be appropriately combined to form other embodiments as will be appreciated by those skilled in the art.

The technical principle of the present invention is described above with reference to specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without any inventive effort, which would fall within the scope of the present invention.

Claims

1. The utility model provides a lithium ion battery, includes casing, core package and block, the casing seals one end open-ended tubular structure for one end, the core package sets up in the casing, the block is fixed the open end of casing, its characterized in that, the block is flat, the center of block is provided with utmost point post, still set up the groove on the block, the groove encircles the center of utmost point post sets up on the block, utmost point post is located one end in the casing with the anodal ear or the negative pole ear of core package are connected.

2. The lithium ion battery of claim 1, wherein the casing is a metal casing, and a nickel layer is plated on the surface of the metal casing; and/or the presence of a gas in the gas,

3. The lithium ion battery of claim 1, wherein the terminal post is connected to the positive electrode tab or the negative electrode tab through a connection plate, the connection plate is fixed to the open end of the casing and located at one side of the cap close to the inside of the casing, the connection plate is respectively isolated from the cap and the casing through an insulation pad, and the center of the connection plate is in electrical communication with the terminal post through at least one welding point.

4. The lithium ion battery of claim 3, wherein the connecting plate is provided with air holes at least at positions corresponding to the scribe lines.

5. The lithium ion battery of claim 3, wherein a ring of support portion is annularly disposed on an inner wall of the housing, the support portion is adjacent to the open end, and the connection plate and the cap are sequentially stacked on the support portion.

6. The lithium ion battery of claim 5, wherein the connecting plate comprises a plate body spaced from and parallel to the cap, a periphery of the plate body extends toward the cap with a bent portion, an end of the bent portion away from the plate body extends toward a side away from a center of the plate body with an abutting portion, the abutting portion is located between the cap and the supporting portion, and the welding point is located on the plate body.

7. The lithium ion battery of claim 6, wherein the insulating gasket comprises a first portion disposed between the abutment portion and the support portion, a second portion disposed between the abutment portion and the cap, and a connecting portion connecting the first portion and the second portion, the connecting portion being located between the abutment portion and an inner wall of the case.

8. The lithium ion battery according to any one of claims 1 to 7, wherein a through hole is formed in the center of the cap, the post is inserted into the through hole, an insulating sealing member is arranged between the outer peripheral wall of the post and the wall of the through hole, and a liquid injection hole is further formed in the cap and spaced from the post.

9. The lithium ion battery according to any one of claims 1 to 7, wherein the core package is a winding core package, a plurality of positive tabs are disposed on positive tabs of the winding core package, and one negative tab is disposed on a negative tab of the winding core package.

10. The lithium ion battery of claim 9, wherein the positive plate is elongated, the positive tabs are spaced apart along a length direction of the positive plate, the negative plate is elongated, the negative tab is adjacent to one end of the negative plate in the length direction, and the negative tab is located at an outermost ring of the winding core package.