CN218039711U

CN218039711U - Lithium ion battery and vehicle comprising same

Info

Publication number: CN218039711U
Application number: CN202222252931.3U
Authority: CN
Inventors: 杨勇
Original assignee: Weilai Automobile Technology Anhui Co Ltd
Current assignee: Weilai Automobile Technology Anhui Co Ltd
Priority date: 2022-08-25
Filing date: 2022-08-25
Publication date: 2022-12-13
Anticipated expiration: 2032-08-25

Abstract

The utility model provides a lithium ion battery and vehicle including it, this lithium ion battery includes: the battery comprises a shell with an opening structure at one end, a top cover and a plurality of battery cells; the battery comprises a shell, a plurality of battery cells and a plurality of battery cores, wherein the battery cells are arranged in the shell in sequence and connected in series, and the polarities of lugs of adjacent battery cells at the same end are opposite; the top cover is covered on the opening structure of the shell, and a positive pole column and a negative pole column are arranged on the top cover; the pole lugs of the two outermost battery cells in the plurality of battery cells are respectively and correspondingly connected to the positive pole column and the negative pole column on the top cover. The utility model discloses a place a plurality of electric core series connection in the casing side by side for adjacent lithium ion battery's positive negative pole is located same one side, has solved that the welding seal that the utmost point ear of casing blind end and electric core or the mass flow body welding lead to is small, the welding slag is difficult for clearing up and has the short circuit risk and weld the unable visual inspection scheduling problem of seal.

Description

Lithium ion battery and vehicle comprising same

Technical Field

The utility model belongs to the technical field of the battery, concretely relates to lithium ion battery and vehicle including it.

Background

The existing lithium ion battery has the advantages of high energy density, good power performance, long cycle life and the like, and is more and more widely applied in the field of new energy automobiles in recent years. Among a plurality of battery structure types, cylindrical lithium ion batteries play an important role in the new energy market due to the characteristics of good safety performance and low cost.

At present, a battery shell is generally arranged in a mode of sealing one end, and in the assembling process, a lug or a current collector at one end of a battery cell needs to be welded with the sealed end of the shell so as to realize electric connection, thereby achieving the purpose of leading out current. Specifically, in the assembly process, the welding pin needs to extend into the closed end of the casing from the axial through hole of the battery cell so as to weld the tab at one end of the battery cell or the current collecting plate with the casing, however, the diameter of the axial through hole of the battery cell is usually small, which leads to a small space for the movable operation of the welding pin, and thus, the welding area is too small, the overcurrent capacity at the welding position is insufficient, and the temperature is high in the use process of the battery. And because blind end welding position overcurrent capacity is not enough, and automobile-used power battery generally requires for power performance higher, and the electric current is great when charging and discharging promptly, and the battery is difficult along the axial heat dissipation, consequently, the performance can become very poor after the battery diameter is done greatly, and the free capacity is difficult to do greatly promptly, in addition, electric core shell blind end also splashes the metal fillings or melts the pearl easily and causes the damage to rolling up the core in welding process, arouses the risk of short circuit.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a lithium ion battery and vehicle including it are provided to solve lithium ion battery utmost point ear and utmost point post and casing welding process in the little battery monomer energy that leads to of welding area that exists little, the welding process in have the potential safety hazard that splashes metal fillings or melting bead etc. and bring.

In order to solve or improve above-mentioned technical problem to a certain extent, according to the utility model discloses an aspect provides a lithium ion battery, includes: the battery comprises a shell with an opening structure at one end, a top cover and a plurality of battery cells;

the battery cells are arranged in the shell, the battery cells are sequentially arranged and connected in series, and the polarities of the lugs of the adjacent battery cells at the same end are opposite;

the top cover covers the opening structure of the shell, and a positive pole column and a negative pole column are arranged on the top cover;

the pole lugs of the two outermost electric cores in the plurality of electric cores are respectively and correspondingly connected to the positive pole column and the negative pole column.

In some embodiments, the cross section of the casing is an oblong, the plurality of battery cells are winding cores, and the space inside the casing not occupied by the winding cores is an electrolyte storage space for storing electrolyte.

In some embodiments, the positive pole and the negative pole both penetrate through the top cover, a boss is formed on one side of the top cover facing the battery cells, and the tabs of the two outermost battery cells are respectively and correspondingly connected to the bosses of the positive pole and the negative pole.

In some embodiments, the lithium ion battery further comprises a positive current collector and a negative current collector, wherein the tabs of the two outermost electric cores are correspondingly connected to the positive pole and the negative pole through the positive current collector and the negative current collector respectively.

In some embodiments, the peripheries of the positive current collecting piece and the negative current collecting piece are provided with flanging structures, and the bosses of the positive pole column and the negative pole column are sleeved with the positive current collecting piece and the negative current collecting piece through the flanging structures.

In some embodiments, a step structure is arranged on the periphery of the boss, and when the positive current collecting piece and the negative current collecting piece are sleeved on the boss, the flanging structure abuts against the step structure.

In some embodiments, the step structure is connected with the contact surface of the flanging structure in a welding manner, and the welding direction is perpendicular to the contact surface.

In some embodiments, the welding range of the step structure and the flanging structure is greater than or equal to half of the circumference of the boss.

In some embodiments, the positive post and the negative post are both connected in an insulated manner to the top cap.

According to another aspect of the present invention, there is provided a vehicle including the lithium ion battery according to any one of the above embodiments.

Compared with the prior art, the utility model obvious advantage and beneficial effect have. Borrow by above-mentioned technical scheme, the utility model discloses a lithium ion battery and vehicle including it can reach comparable technical advancement and practicality to have the wide use value in industry, it has following advantage at least:

(one) the utility model discloses a place in the casing side by side after connecting a plurality of electric core series for lithium ion battery's energy doubles, and lithium ion battery's thickness does not increase, has guaranteed lithium ion battery's heat dispersion.

(two) the utility model discloses a place a plurality of electric core series connection side by side in the casing for adjacent lithium ion battery's positive negative pole is located same one side, and it is little, the welding slag is difficult for the clearance and has short circuit risk and weld the unable visual inspection scheduling problem of seal that the welding of the utmost point ear or the mass flow body welding of having solved casing blind end and electric core leads to.

(III) the utility model discloses a lithium ion battery's positive negative pole all is located lithium ion battery's top cap, has solved the inconvenient problem of welding when adopting the battery pack that leads to when the casing is as the negative pole.

(IV) the utility model discloses a lithium ion battery's electric core occupies that casing inner space is less for electrolyte is deposited in more spaces, has reduced the number of times that lithium ion battery supplyed electrolyte, has promoted the life-span of battery single use.

(V) the utility model discloses a mass flow body is provided with flange structure, establishes the mass flow body cover on the boss structure of positive and negative utmost point post through this flange structure, has promoted the area of connection of mass flow body and utmost point post, has guaranteed the compactness that mass flow body and utmost point post are connected.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Drawings

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

fig. 2 is a partially enlarged schematic view of the lithium ion battery shown in fig. 1;

FIG. 3 is another enlarged partial schematic view of the lithium-ion battery shown in FIG. 1;

fig. 4 is a schematic perspective view of the lithium ion battery shown in fig. 1;

fig. 5 is a schematic view of an assembly process of a lithium ion battery according to an embodiment of the present invention.

[ notation ] to show

1. Shell body

2. Top cover

3. Battery cell

4. Pole ear

41. Positive tab

42. Negative electrode tab

5. Positive pole

6. Negative pole

7. Metal sheet

8. Electrolyte storage space

9. Boss

10. Positive electrode current collector

11. Negative current collector

12. Flanging structure

13. Step structure

14. Welding range

15. Insulating member

16. Insulating support

Detailed Description

To further illustrate the technical means and effects of the present invention for achieving the intended purpose of the present invention, the following detailed description will be given with reference to the accompanying drawings and preferred embodiments of the present invention for the specific embodiments and effects of the lithium ion battery and the vehicle including the same according to the present invention.

Referring to fig. 1 to 4 in combination, according to an embodiment of the present invention, a lithium ion battery is provided, which includes a casing 1, a top cap 2 and a plurality of battery cells 3.

Wherein, one end of the casing 1 is an opening structure, so as to place the battery cell 3 inside the casing 1. The top cover 2 is arranged on the opening structure of the shell 1 in a covering mode, and the top cover 2 is provided with a positive pole post 5 and a negative pole post 6. A plurality of electric cores 3 are placed inside the shell 1, and the plurality of electric cores 3 are arranged in sequence and connected in series.

In one embodiment, the positive and

negative posts

5 and 6 are made of aluminum to facilitate welding during subsequent grouping of the lithium ion battery. The shell 1 and the top cover 2 are made of steel, and the thickness of the shell is set to be 0.3-0.6 mm, so that the thermal safety performance of the lithium ion battery is improved.

As shown in fig. 1, to facilitate the series connection of the battery cells 3, the polarities of the tabs 4 of the adjacent battery cells 3 at the same end are opposite. That is, two adjacent battery cells 3 are located in the tabs 4 at the same end, the tab 4 of one battery cell 3 is a positive tab 41, and the tab 4 of the other battery cell 3 is a negative tab 42. And then can carry out series connection with a plurality of electric cores 3 through sheetmetal 7, after realizing the series connection of electric core 3 through sheetmetal 7, set up insulating support 16 between sheetmetal 7 and casing 1 or top cap 2 to make electric core 3 and casing 1 or top cap 2 insulating.

In the plurality of battery cells 3, the two battery cells 3 located at the outermost side have opposite polarities of the tabs 4 at the same end, that is, the two battery cells 3 located at the outermost side have opposite polarities of the tabs 4 at the same end, the tab 4 of one battery cell 3 is a positive tab 41, and the tab 4 of the other battery cell 3 is a negative tab 42. And then the tabs 4 of the two battery cells 3 at the outermost sides are respectively and correspondingly connected to the positive pole post 5 and the negative pole post 6 arranged on the top cover 2.

In this embodiment, by placing a plurality of battery cells 3 inside the casing 1, and placing adjacent battery cells 3 one on the other, the series connection of the battery cells 3 can be realized through the metal sheet 7, and at the same time, the positive tab 41 of one battery cell 3 and the negative tab 42 of the other battery cell 3 in the two outermost battery cells 3 are located on one side of the opening structure of the casing 1, and are connected to the positive post 5 and the negative post 6 provided on the top cover 2. The problem that the traditional lithium ion battery needs to adopt the shell 1 as a negative electrode, and the lug 4 or the current collector and the shell 1 need to be welded at the closed end of the shell 1, so that the welding area is small, the overcurrent capacity of the lithium ion battery is insufficient, and the capacity of the lithium ion battery cannot be improved is solved. Meanwhile, the problem that short circuit risks exist in the lithium ion battery due to metal scraps in the welding process and the inconvenience in fusion casting cleaning is solved.

In order to realize the opposite polarity of the lugs 4 at the same end of the two outermost battery cells 3, the number of the battery cells 3 is even. E.g. two, four or six etc.

In a specific embodiment, as shown in fig. 1, the number of the battery cells 3 is two. Two electric cores 3 are placed inside the shell 1 side by side, and the polarities of the lugs 4 at the same end of the two electric cores 3 are opposite. The positive electrode tab 41 and the negative electrode tab 42 of the two battery cells 3 facing the bottom of the casing 1 are connected through the metal sheet 7, so that the two battery cells 3 are connected in series. The positive electrode tab 41 and the negative electrode tab 42 of the two battery cells 3 which are open towards the casing 1 are respectively connected to the positive electrode post 5 and the negative electrode post 6 of the top cover 2.

In one embodiment, as shown in fig. 4, the cross-section of the housing 1 is oblong, i.e. one set of opposing sides in the cross-section is straight and the other set of opposing sides is circular. The cross section of the shell 1 is set to be in the shape of an oval, a group of opposite surfaces in the shell 1 are planes, the arrangement of lithium ion batteries in a group is facilitated, the adjacent lithium ion batteries are attached more tightly, the heat conduction among the lithium ion batteries is facilitated, and the heat uniformity among the lithium ion batteries is improved.

The plurality of battery cores 3 are winding cores formed by stacking or winding positive plates, negative plates and diaphragms. The diaphragm is arranged between every two adjacent positive plates and negative plates, and the positive tab 41 and the negative tab 42 of the winding core are arranged at two opposite ends of the winding core.

In this embodiment, when a plurality of battery cells 3 are sequentially arranged in the casing 1, a part of the space inside the casing 1 still left unoccupied by the battery cells 3 is the electrolyte storage space 8 to store the electrolyte. Compared with the traditional cylindrical battery, the lithium ion battery of the embodiment has a larger electrolyte storage space 8, reduces the liquid injection processing difficulty of the lithium ion battery, reduces the frequency of electrolyte supplement of the lithium ion battery, and prolongs the service life of the battery in a single use.

In an embodiment, as shown in fig. 1 to fig. 3, in order to facilitate connection of the tabs 4 of the battery cells 3 with the positive post 5 and the negative post 6, the positive post 5 and the negative post 6 disposed on the top cover 2 both penetrate through the top cover 2, and a boss 9 is formed on one side of the top cover 2 facing the battery cells 3, and the tabs 4 of the two outermost battery cells 3 in the plurality of battery cells 3 are respectively connected to the bosses 9 of the positive post 5 and the negative post 6.

In an embodiment, the lithium ion battery further includes a positive electrode current collecting piece 10 and a negative electrode current collecting piece 11, and the tabs 4 of the two outermost electric cores 3 are respectively connected to the positive electrode posts 5 and the negative electrode posts 6 through the corresponding positive electrode current collecting piece 10 and the corresponding negative electrode current collecting piece 11.

Further, as shown in fig. 2 and 3, the positive current collecting piece 10 and the negative current collecting piece 11 both have a flanging structure 12, and the positive current collecting piece 10 and the negative current collecting piece 11 are correspondingly sleeved on the bosses 9 of the positive pole 5 and the negative pole 6 through the flanging structure 12.

In the embodiment, the boss 9 and the flanging structure 12 are arranged, so that the connection area of the current collecting piece and the pole column is increased, the overcurrent capacity of the current collecting piece is increased, and the connection tightness of the current collecting piece and the pole column is ensured.

In one embodiment, as shown in fig. 2, in order to further increase the connection area and connection tightness between the current collecting piece and the pole column, a step structure 13 is provided at the periphery of the boss 9, and when the positive current collecting piece 10 and the negative current collecting piece 11 are sleeved on the boss 9, the flanging structure 12 abuts against the step structure 13.

Further, in order to improve the connection strength between the current collecting piece and the boss 9, the current collecting piece and the boss 9 are connected by welding. The welding position is the contact surface of the step structure 13 and the flanging structure 12, and the welding direction is perpendicular to the contact surface of the step structure 13 and the flanging structure 12. As shown in fig. 4, in order to ensure the welding strength and facilitate the welding, the welding range 14 is equal to or greater than half of the circumference of the boss 9, i.e., the welding range 14 is equal to or less than 180 °.

After the welding of this embodiment is accomplished, the outward appearance of seal all can adopt visual inspection to improve the reliability of welding, have apparent effect to improving lithium ion battery's product quality.

In one embodiment, as shown in fig. 2 and 3, the positive and

negative posts

5 and 6 are insulated from the top cap 2 by an insulator 15. Preferably, the insulating member 15 is made of insulating plastic, but the insulating member 15 may be made of other materials, so as to achieve the insulating function.

In addition, insulating paint can be sprayed between the positive pole 5 and the negative pole 6 and the top cover 2, and the insulation between the positive pole 5 and the top cover 2 and the insulation between the negative pole 6 and the top cover 2 can be realized.

According to the utility model discloses an embodiment still provides a lithium ion battery's assembly method, as shown in fig. 5, specifically includes:

step one, processing the pole ear of the winding core formed by winding, wherein the processing mainly comprises kneading and folding modes.

And step two, selecting two winding cores which are subjected to the lug treatment to be placed side by side, wherein the polarities of the lugs at the same end of the two winding cores are opposite. And connecting the positive tab of one of the two winding cores at the bottom with the negative tab of the other winding core through a metal sheet to realize the internal series connection of the two winding cores. The positive tab of one of the two winding cores at the upper part is welded with the positive current collecting plate, and the negative tab of the other winding core is welded with the negative current collecting plate.

And step three, respectively welding the positive current collecting piece and the negative current collecting piece welded on the upper part of the winding core with the bosses of the positive pole and the negative pole arranged on the top cover to realize the electric connection of the pole and the pole ear, and installing an insulating protection bracket at the bottom of the winding core.

And step four, putting the half-sheets of the lithium ion battery finished in the step three into the shell, and finishing the sealing welding of the top cover and the shell.

According to the utility model discloses an embodiment still provides a vehicle, including the lithium ion battery of any one of above-mentioned embodiment.

The utility model discloses a plurality of electric cores are placed in the casing side by side after being connected in series, so that the energy of the lithium ion battery is doubled, and the thickness of the lithium ion battery is not increased, thereby ensuring the heat dispersion performance of the lithium ion battery; the battery cells are connected in series and are placed in the shell side by side, so that the positive and negative electrodes of adjacent lithium ion batteries are positioned on the same side, and the problems that the welding seal overcurrent capacity is small, welding slag is not easy to clean, short circuit risk exists, the welding seal cannot be visually checked and the like caused by welding the closed end of the shell and the lugs or the current collectors of the battery cells are solved; the positive electrode and the negative electrode of the lithium ion battery are both positioned on the top cover of the lithium ion battery, so that the problem of inconvenience in welding when a battery pack is used as a negative electrode by adopting the shell is solved; the battery cell of the lithium ion battery occupies a smaller space in the shell, so that more space is used for storing the electrolyte, the frequency of supplementing the electrolyte by the lithium ion battery is reduced, and the service life of the battery in single use is prolonged; the current collector is provided with a flanging structure, and the current collector is sleeved on the boss structures of the positive and negative poles through the flanging structure, so that the connection area of the current collector and the poles is increased, and the tightness of connection of the current collector and the poles is ensured.

The above description is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments, and although the present invention has been disclosed with the preferred embodiments, it is not limited to the present invention, and any skilled person in the art can make some modifications or equivalent embodiments without departing from the scope of the present invention, but all the technical matters of the present invention are within the scope of the present invention.

Claims

1. A lithium ion battery, comprising: the battery comprises a shell with an opening structure at one end, a top cover and a plurality of battery cells;

the top cover is covered on the opening structure of the shell, and a positive pole column and a negative pole column are arranged on the top cover;

2. The lithium ion battery of claim 1, wherein the cross section of the casing is an oval shape, the plurality of electric cores are winding cores, and a space inside the casing not occupied by the plurality of winding cores is an electrolyte storage space for storing electrolyte.

3. The lithium ion battery of claim 1, wherein the positive post and the negative post both penetrate through the top cap, and form a boss on a side of the top cap facing the battery cells, and tabs of two battery cells at the outermost side are respectively connected to the bosses of the positive post and the negative post.

4. The lithium ion battery of claim 3, further comprising a positive current collector and a negative current collector, wherein the tabs of the two outermost cells are correspondingly connected to the positive pole and the negative pole through the positive current collector and the negative current collector, respectively.

5. The lithium ion battery of claim 4, wherein the peripheries of the positive current collecting piece and the negative current collecting piece are provided with flanging structures, and the positive current collecting piece and the negative current collecting piece are sleeved on the bosses of the positive pole column and the negative pole column through the flanging structures.

6. The lithium ion battery of claim 5, wherein a step structure is arranged on the periphery of the boss, and when the positive current collector and the negative current collector are sleeved on the boss, the flanging structure abuts against the step structure.

7. The lithium ion battery of claim 6, wherein the step structure is welded to the contact surface of the flanging structure, and the welding direction is perpendicular to the contact surface.

8. The lithium ion battery of claim 7, wherein the welding range of the step structure and the flanging structure is greater than or equal to half of the circumference of the boss.

9. The lithium ion battery of any one of claims 1 to 8, wherein the positive post and the negative post are both in insulated connection with the top cap.

10. A vehicle characterized by comprising the lithium ion battery of any one of claims 1 to 9.