Lithium battery shell and lithium battery cooling structure

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a lithium battery shell and a lithium battery cooling structure, the lithium battery shell comprises a shell body with two opposite open ends and two liquid collecting cover plates connected with the open ends of the shell body, the shell body comprises an inner shell body and an outer shell body which are both of a hollow structure, and the longitudinal section of the inner shell body is in a runway shape; the longitudinal section of the outer shell is rectangular, the arc-shaped section of the runway shape is tangent to the short edge of the rectangle, the linear section of the runway shape is partially overlapped with the long edge of the rectangle, and four independent cavities are formed at the four corners, not occupied by the inner shell, in the outer shell; a cooling liquid collecting assembly is arranged in the liquid collecting cover plate and communicates with the cavity. The lithium battery cooling structure comprises a lithium battery shell and a core rod provided with a plurality of liquid passing channels. The lithium battery shell provided by the utility model has a rapid cooling function, and is combined with the core rod to cool the exterior and the interior of the lithium battery, so that the cooling effect is good, and the temperature uniformity inside and outside the battery core is favorably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a lithium battery shell and a lithium battery cooling structure. Background Art

[0002] Lithium batteries are an indispensable and important part of electric vehicles. As the smallest energy storage unit of lithium batteries, battery cells are the basis of the entire battery system. Multiple battery cells are combined into a battery module through series or parallel connection, and then form a battery pack. The energy density of the battery cell determines how much electrical energy the battery can store. High-energy-density battery cells can enable the battery to have a longer endurance and a smaller volume.

[0003] Square lithium batteries are relatively mainstream batteries in electric vehicles. They are generally rectangular in shape, with two flat elliptical wound cores placed side by side along the height direction of the battery inside. The outer shell is generally a stamped aluminum shell, and the energy density is relatively high. Square lithium batteries can store more electrical energy in the same volume. However, during the manufacturing process of flat elliptical wound cores, not only is the production efficiency low, but also the heat dissipation ability is poor. There is often a temperature difference of 10-20°C between the internal temperature and the external temperature of the battery cell, which not only affects the performance of the battery cell, but also is not conducive to the cycle life of the battery cell, and will also pose a safety hazard to the battery itself and the surrounding environment.

[0004] Furthermore, the prior art has proposed blade batteries. Blade batteries are a special type of square battery. The prismatic stacked cores obtained by stacking are placed vertically in the length direction of the battery, and the pole ears protrude from both ends. Compared with ordinary square lithium batteries, blade batteries have the advantages of high energy density, simplified structure, good heat dissipation performance, high space utilization rate, and strong safety performance. However, there are problems such as poor alignment, slow production speed, and low yield rate during the manufacturing of long stacked cores, and problems such as easy deformation and difficulty in entering the shell during the manufacturing of long stacked cores. Therefore, the manufacturing cost of blade batteries is high and the production efficiency is low.

[0005] Therefore, this application is proposed. Summary of the Utility Model

[0006] In view of the above-mentioned disadvantages of the prior art, the utility model provides a lithium battery shell and a lithium battery cooling structure.

[0007] In order to achieve the above purpose, the main technical solutions adopted by the utility model include:

[0008] On the one hand, the utility model proposes a lithium battery shell, which includes a shell with openings at both opposite ends and two liquid collecting cover plates;

[0009] The housing includes an inner housing and an outer housing. Both the inner housing and the outer housing are hollow structures. The longitudinal section of the inner housing is in the shape of a runway, and the longitudinal section of the outer housing is rectangular. The arc segment of the runway shape is tangent to the short side of the rectangle, and the straight segment of the runway shape partially coincides with the long side of the rectangle. Four independent cavities are formed at the four corners of the outer housing that are not occupied by the inner housing;

[0010] The liquid collection cover plate includes a liquid collection cover plate surface. An internal liquid passage is provided in the liquid collection cover plate surface. A coolant collection assembly is provided on the outer surface of the liquid collection cover plate surface. Four liquid collection cover plate connection blocks that partially extend are formed at the four corners of the inner surface of the liquid collection cover plate surface and are matched with the cavity structures. A housing coolant passage is provided in the liquid collection cover plate connection blocks. The housing coolant passage is communicated with the coolant collection assembly through the internal liquid passage:

[0011] The two open ends of the housing are respectively sealed and connected to two liquid collection cover plates.

[0012] Preferably, there are at least two internal liquid passages. The two internal liquid passages are arranged opposite to each other along the two long sides of the liquid collection cover plate surface. The two ends of the internal liquid passage are respectively communicated with two housing coolant passages, and the middle part of the internal liquid passage is communicated with the coolant collection assembly.

[0013] Preferably, the coolant collection assembly includes an integrally formed confluence member, a collection member, and a collection nozzle. The confluence member is communicated with the internal liquid passage, and the confluence member, the collection member, and the collection nozzle form a stepped drainage cavity.

[0014] Preferably, the housing and the liquid collection cover plate are both integrally formed structures.

[0015] Preferably, the open end is inserted into the cavity through the liquid collection cover plate connection block and is hermetically connected to the liquid collection cover plate under the action of glue or a sealing ring.

[0016] Preferably, the thickness T2 of the outer housing satisfies: 0.2 mm ≤ T2 ≤ 8 mm, the thickness T1 of the arc segment of the inner housing satisfies: 0.2 mm ≤ T1 ≤ 8 mm, and the arc angle radius R1 of the arc segment of the inner housing satisfies: 0 mm < R1 ≤ 100 mm.

[0017] On the other hand, the present invention proposes a lithium battery cooling structure, including a lithium battery housing and a mandrel provided with a plurality of liquid passages. The liquid passages are communicated with the coolant collection assembly.

[0018] Preferably, a positioning hole is provided at the center of the mandrel, and a plurality of liquid passages are symmetrically arranged on the upper and lower sides of the positioning hole.

[0019] Preferably, the longitudinal section of the liquid passage is a kidney-shaped hole.

[0020] Compared with the prior art, the lithium battery case proposed by the present utility model has a rapid cooling function. It combines with the mandrel to cool the outside and inside of the lithium battery simultaneously, with good cooling effect, which helps to improve the temperature uniformity inside and outside the battery cell, thereby improving the performance of the battery cell and increasing its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is the external view of the lithium battery case;

[0023] Figure 2 is the assembly schematic diagram of the lithium battery;

[0024] Figure 3 is Figure 2 the three-dimensional structure schematic diagram of the liquid collecting cover plate in

[0025] Figure 4 is Figure 3 the bottom view of

[0026] Figure 5 is Figure 3 the cross-sectional view along the middle of the coolant collecting component;

[0027] Figure 6 is Figure 3 the liquid collecting principle schematic diagram of

[0028] Figure 7 is Figure 2 the three-dimensional structure schematic diagram of the case in

[0029] Figure 8 is Figure 7 the front view of

[0030] Figure 9 is Figure 2 the three-dimensional structure schematic diagram of the mandrel in

[0031] Figure 10 is Figure 9 the front view of

[0032] Figure 11 is the cooling principle schematic diagram of the lithium battery.

[0033] In the figure: 1. Coolant manifold assembly; 2. Explosion-proof valve reserved hole; 3. Shell coolant channel; 4. Terminal reserved hole; 5. Internal liquid passage; 6. Manifold cover plate surface; 7. Manifold cover plate connecting block; 8. Shell; 81. Outer shell; 82. Inner shell; 9. Mandrel; 91. Positioning hole; 92. Liquid passage; 10. Electric core; 11. Collection nozzle; 12. Manifold piece; 13. Busbar piece; 14. Positive cover plate; 15. Positive adapter piece; 16. Positive manifold plate; 17. Negative manifold plate; 18. Negative adapter piece; 19. Negative cover plate; A. Electric core accommodation cavity; B. Coolant accommodation cavity; C. Manifold cover plate. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0035] It should be noted that: components or structures not described in detail below all adopt conventional technical means in the art or are common general knowledge in the art.

[0036] As Figures 1 - 11 Collectively shown: A lithium battery shell includes a shell 8 with openings at both opposite ends and two manifold cover plates C;

[0037] The shell 8 includes an inner shell 82 and an outer shell 81. Both the inner shell 82 and the outer shell 81 are hollow structures. The interior of the inner shell 82 forms an electric core accommodation cavity A. The longitudinal section of the inner shell 82 is a runway shape, and the longitudinal section of the outer shell 81 is a rectangle. The arc section of the runway shape is tangent to the short side of the rectangle, and the straight section of the runway shape partially coincides with the long side of the rectangle. Four independent cavities are formed at the four corners in the outer shell 81 that are not occupied by the inner shell 82, and the cavities form a coolant accommodation cavity B;

[0038] The manifold cover plate C includes a manifold cover plate surface 6. An internal liquid passage 5 is provided inside the manifold cover plate surface 6. A coolant manifold assembly 1 is provided on the outer surface of the manifold cover plate surface 6. Four corners of the inner surface of the manifold cover plate surface 6 partially extend to form four manifold cover plate connecting blocks 7 that match the cavity structure. A shell coolant channel 3 is provided inside the manifold cover plate connecting block 7. The shell coolant channel 3 is communicated with the coolant manifold assembly 1 through the internal liquid passage 5:

[0039] The two open ends of the shell 8 are respectively sealed and connected to the two manifold cover plates C.

[0040] In specific use, the battery cell 10 (preferably a flat battery cell that matches the structure of the inner housing 82) is placed in the battery cell accommodation cavity A. The positive electrode tab and the negative electrode tab are led out from both ends of the battery cell 10. The positive electrode tab is connected to the positive electrode cover plate 14 through the positive current collector plate 16 and the positive adapter piece 15. The connection methods include but are not limited to any one or more existing connection methods such as welding and riveting. The negative electrode tab is connected to the negative electrode cover plate 19 through the negative current collector plate 17 and the negative adapter piece 18. The connection methods include but are not limited to any one or more existing connection methods such as welding and riveting.

[0041] Cooling principle: The coolant (both the composition and the entry method are prior arts) enters from the coolant collection component 1 of the liquid collection cover plate C at one end, and enters the housing coolant channel 3 through the internal liquid passage 5 inside. Then, it is collected through the internal liquid passage 5 at the other end to another coolant collection component 1 and flows out. During this process, the coolant can take away heat, realizing the cooling of the outside of the battery cell 10 and improving the problems of high temperature and large temperature difference between the inside and outside of the high energy density battery cell.

[0042] As a preferred technical solution, in another embodiment of the present utility model, there are two internal liquid passages 5. The two internal liquid passages 5 are arranged oppositely along the two long sides of the plate surface 6 of the liquid collection cover plate. Both ends of the internal liquid passage 5 are communicated with the two housing coolant channels 3 respectively, and the middle part of the internal liquid passage 5 is communicated with the coolant collection component 1.

[0043] Of course, it is also possible to set multiple internal liquid passages 5. However, considering the processing efficiency and processing cost of the internal liquid passage 5, as well as the cooling effect after the coolant flows through and the energy loss of the coolant itself, the present utility model determines that two are the optimal choices.

[0044] As a preferred technical solution, in another embodiment of the present utility model, the coolant collection component 1 includes a converging part 13, a current collection part 12 and a collection nozzle 11 which are integrally formed. The converging part 13 is communicated with the internal liquid passage 5, and the converging part 13, the current collection part 12 and the collection nozzle 11 form a stepped drainage cavity.

[0045] As a preferred technical solution, in another embodiment of the present utility model, the inner housing 82 and the outer housing 81 in the housing 8 are integrally formed, and the liquid collection cover plate C is also an integrally formed structure; specifically, both the housing 8 and the liquid collection cover plate C are formed by extrusion molding. The extrusion molding greatly reduces the number of production lines and welding links of parts, simplifies the production process, reduces the processing difficulty, and helps to improve the quality of the housing 8 and the liquid collection cover plate C. The two have good dimensional compatibility and high production efficiency. On the liquid collection cover plate C, explosion-proof valve reserved holes 2 and pole post reserved holes 4 are also provided on both sides of the coolant collection component 1.

[0046] As a preferred technical solution, in another embodiment of the present utility model, the open end is inserted into the cavity through the liquid collecting cover plate connecting block 7 and is sealedly connected with the liquid collecting cover plate C under the action of glue or a sealing ring.

[0047] As a preferred technical solution, in another embodiment of the utility model, the thickness T2 of the outer shell 81 satisfies: 0.2mm≤T2≤8mm, the thickness T1 of the arc segment of the inner shell 82 satisfies: 0.2mm≤T1≤8mm, and the arc angle radius R1 of the arc segment of the inner shell 82 satisfies: 0mm<R1≤100mm.

[0048] The utility model has been verified through several creative tests that, under the above technical parameters, the shell 8 has a good fixing and supporting effect on the battery cell 10 and can fully protect the battery cell 10. More importantly, the inner shell 82 has a good restraining effect on the battery cell 10 and can effectively suppress the expansion of the battery cell 10, thereby improving the energy density of the lithium battery and increasing the cycle life of the lithium battery; the coolant accommodating chamber B around it has a good cooling effect on the outside of the battery cell 10, which can effectively improve the heat dissipation energy of the battery cell 10 and increase the cycle life of the battery cell 10.

[0049] The utility model also provides a lithium battery cooling structure, including a lithium battery housing and a core rod 9 provided with a plurality of liquid passages 92 , wherein the liquid passages 92 are connected to a cooling liquid collecting assembly 1 .

[0050] The shell 8 is provided with a coolant accommodating chamber B, which can cool the outside of the battery cell 10; a liquid passage 92 is additionally provided inside the core rod 9, and when the coolant passes through the passage, the inside of the battery cell 10 can be cooled. The simultaneous and synchronous cooling of the inside and outside of the battery cell 10 can further enhance the cooling effect of the lithium battery, improve the heat dissipation performance of the battery cell 10, and extend the service life of the battery cell 10.

[0051] As a preferred technical solution, in another embodiment of the present utility model, a positioning hole 91 is provided at the center of the core rod 9 , and a plurality of liquid passages 92 are symmetrically arranged at the upper and lower sides of the positioning hole 91 .

[0052] The positioning hole 91 is mainly provided to ensure the stability and safety of the battery cell 10 during the manufacturing process. It can ensure the accurate position of the core rod 9 during the winding process and prevent the core rod 9 from shifting or rotating during the winding process, thereby ensuring that the positive and negative electrode sheets and the diaphragm can be tightly wound together in a predetermined manner, and help control the consistency of the size and shape of the battery cell 10, reduce the performance fluctuations of the battery cell 10 caused by slight differences in the manufacturing process, and facilitate the assembly and inspection of the battery cell 10; the symmetrically arranged coolant can evenly cool the interior of the battery cell 10 through the liquid passage 92, thereby reducing the temperature difference between the inside and outside of the battery, improving the heat dissipation performance of the battery, and avoiding high temperature runaway of the battery.

[0053] As a preferred technical solution, in another embodiment of the present utility model, the longitudinal section of the liquid passing channel 92 is a kidney-shaped hole. The coolant of the long strip-shaped liquid passing channel 92 reaches a larger range, so the cooling effect is better. Moreover, the mandrel 9 provides guidance and support for the coil core. The design of the kidney-shaped hole can better disperse stress and reduce the risk of damage to the mandrel 9 caused by stress concentration.

[0054] In summary, the lithium battery shell proposed by the present utility model has a rapid cooling function. It combines with the mandrel to cool the outside and inside of the lithium battery at the same time, with a good cooling effect, which helps to improve the problems of high temperature and large temperature difference between the inside and outside of the high energy density battery core.

[0055] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and deformations to the above embodiments within the scope of the present utility model. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A lithium battery housing, characterized in that: It comprises a shell (8) with openings at two opposite ends and two liquid collecting cover plates (C); The shell (8) comprises an inner shell (82) and an outer shell (81), both of which are hollow structures, the longitudinal cross-section of the inner shell (82) is in the shape of a racetrack, and the longitudinal cross-section of the outer shell (81) is in the shape of a rectangle, the arc segment of the racetrack is tangent to the short side of the rectangle, the straight segment of the racetrack is partially overlapped with the long side of the rectangle, and four independent cavities are formed at the four corners of the outer shell (81) not occupied by the inner shell (82); The liquid collecting cover plate (C) comprises a liquid collecting cover plate surface (6), an internal liquid passing channel (5) is arranged in the liquid collecting cover plate surface (6), a cooling liquid collecting assembly (1) is arranged on the outer surface of the liquid collecting cover plate surface (6), four corners of the inner surface of the liquid collecting cover plate surface (6) are partially extended to form four liquid collecting cover plate connecting blocks (7) matching the cavity structure, a shell cooling liquid channel (3) is arranged in the liquid collecting cover plate connecting block (7), and the shell cooling liquid channel (3) is connected to the cooling liquid collecting assembly (1) through the internal liquid passing channel (5): The two open ends of the shell (8) are respectively sealed and connected by two liquid collecting cover plates (C).

2. The lithium battery housing according to claim 1, characterized in that: There are at least two internal liquid passages (5), which are arranged opposite to each other along the two long sides of the liquid collecting cover plate surface (6), the two ends of the internal liquid passages (5) are respectively connected to the two shell cooling liquid passages (3), and the middle of the internal liquid passages (5) is connected to the cooling liquid collecting assembly (1).

3. The lithium battery housing according to claim 1, characterized in that: The coolant collecting assembly (1) comprises an integrally formed collecting piece (13), a collecting piece (12) and a collecting nozzle (11); the collecting piece (13) is in communication with an internal liquid passage (5); and the collecting piece (13), the collecting piece (12) and the collecting nozzle (11) form a stepped drainage cavity.

4. The lithium battery housing according to claim 1, characterized in that: The shell (8) and the liquid collecting cover plate (C) are both integrally formed structures.

5. The lithium battery casing according to claim 1, characterized in that: The open end is inserted into the cavity through a liquid collecting cover plate connecting block (7) and is sealedly connected to the liquid collecting cover plate (C) under the action of glue or a sealing ring.

6. The lithium battery casing according to claim 1, characterized in that: The thickness T2 of the outer shell (81) satisfies: 0.2 mm ≤ T2 ≤ 8 mm, the thickness T1 of the arc segment of the inner shell (82) satisfies: 0.2 mm ≤ T1 ≤ 8 mm, and the arc angle radius R1 of the arc segment of the inner shell (82) satisfies: 0 mm < R1 ≤ 100 mm.

7. A lithium battery cooling structure, characterized in that: It comprises a lithium battery casing as claimed in any one of claims 1 to 6 and a core rod (9) provided with a plurality of liquid passages (92), wherein the liquid passages (92) are connected to a coolant collecting assembly (1).

8. The lithium battery cooling structure according to claim 7, characterized in that: A positioning hole (91) is arranged at the center of the core rod (9), and a plurality of liquid passages (92) are symmetrically arranged on the upper and lower sides of the positioning hole (91).

9. The lithium battery cooling structure according to claim 7, characterized in that: The longitudinal section of the liquid passage (92) is a waist-shaped hole.

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