Protective shell, power battery and power device

Abstract

The utility model relates to the technical field of batteries, particularly provides a protective shell, a power battery and a power device, and aims to solve the problem of how to improve the energy density of the power battery. In order to achieve the purpose, the protective shell is used for containing the power battery and comprises a shell body, the shell body comprises a bottom wall and a side wall connected to the bottom wall, a containing space with an opening is defined between the bottom wall and the side wall, and the containing space is used for containing a battery cell pole group of the power battery; the first pole and the second pole are arranged on the side wall and extend into the accommodating space; the first connecting piece and the second connecting piece are both located in the containing space, the first connecting piece is connected with the first pole, and the second connecting piece is connected with the second pole; the cover plate is arranged at the opening and seals the opening; wherein the first connecting piece is used for connecting a first tab of a battery cell pole group, and the second connecting piece is used for connecting a second tab of the battery cell pole group. The energy density of the power battery can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically providing a protective casing, a power battery, and a power device. Background Technology

[0002] Power batteries are storage batteries that provide power for electric vehicles, ships, etc. Currently, with the continuous improvement of the requirements for battery energy density, some related technologies have adopted a square structure for power batteries to reduce the proportion of the internal space occupied by the positive and negative electrode top covers, thereby achieving the purpose of increasing the cell capacity and energy density.

[0003] However, in the assembly and processing of the aforementioned square batteries, the positive and negative electrode tabs of the battery cell and the terminals on the top cover at both ends of the battery are often affected by factors such as operating space. Therefore, the battery cell tabs often need to have sufficient length to meet the welding requirements between them and the terminals. This not only increases the amount of positive and negative electrode foil used, but also increases the space occupied inside the battery cell, thereby reducing the battery energy density.

[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Utility Model Content

[0005] This application aims to solve the aforementioned technical problem, namely, how to improve the energy density of power batteries.

[0006] In a first aspect, this application provides a protective casing for housing a power battery, the protective casing comprising:

[0007] The housing includes a bottom wall and a side wall connected to the bottom wall, and an accommodating space with an opening is formed between the bottom wall and the side wall, the accommodating space being used to accommodate the cell electrode assembly of the power battery.

[0008] The first pole and the second pole are both disposed on the side wall and extend into the receiving space;

[0009] The first connector and the second connector are both located in the receiving space. The first connector is connected to the first pole post, and the second connector is connected to the second pole post.

[0010] A cover plate, disposed at the opening, closes the opening;

[0011] The first connector is used to connect to the first tab of the battery cell electrode group, and the second connector is used to connect to the second tab of the battery cell electrode group.

[0012] In one technical solution of the above-mentioned protective shell, the first connector includes a first connecting piece and a second connecting piece connected to the first connecting piece, the first connecting piece being connected to the first pole post, and the second connecting piece being connected to the first pole tab.

[0013] The second connector includes a third connecting piece and a fourth connecting piece connected to the third connecting piece. The third connecting piece is connected to the second pole post, and the fourth connecting piece is connected to the second pole tab.

[0014] In one technical solution of the above-mentioned protective shell, the sidewall is perpendicular to the bottom wall;

[0015] The first connecting piece is perpendicular to the second connecting piece, and the second connecting piece is parallel to the bottom wall. The third connecting piece is perpendicular to the fourth connecting piece, and the fourth connecting piece is parallel to the bottom wall.

[0016] In one technical solution of the above-mentioned protective shell, the second connecting piece and / or the fourth connecting piece are disposed close to the bottom wall.

[0017] In one technical solution of the above-mentioned protective shell, the bottom wall and the side wall are integrally formed.

[0018] In one technical solution of the above-mentioned protective shell, the cross-section of the first connector and / or the cross-section of the second connector is L-shaped.

[0019] In one technical solution of the above-mentioned protective shell, the sidewall includes a first sidewall and a second sidewall opposite to each other, as well as a third sidewall and a fourth sidewall opposite to each other. The first pole post and the first connector are disposed on the first sidewall, and the second pole post and the second connector are disposed on the second sidewall.

[0020] In one technical solution of the above-mentioned protective shell, the distance between the first sidewall and the second sidewall, and the distance between the third sidewall and the fourth sidewall, are both greater than the distance between the cover plate and the bottom wall.

[0021] In one technical solution of the above-mentioned protective shell, insulating elements are provided on both the first and second sidewalls, and the battery cell electrode group is located in the space jointly defined by the insulating elements, the third sidewall, and the fourth sidewall.

[0022] In one technical solution of the above-mentioned protective shell, the cover plate is welded and fixed to the side wall.

[0023] In a second aspect, this application provides a power battery comprising:

[0024] The protective shell as described in any one of the first aspects;

[0025] A battery cell electrode assembly is disposed in the receiving space, wherein the first tab of the battery cell electrode assembly is connected to the first connector, and the second tab of the battery cell electrode assembly is connected to the second connector.

[0026] In a third aspect, this application provides a power device that includes the power battery described in the second aspect.

[0027] By adopting the above technical solution, this application divides the protective shell of the power battery into a shell with an opening on one side and a cover plate. On the side wall of the shell, corresponding to both ends of the cell electrode assembly, a first connector connected to the first terminal post and a second connector connected to the second terminal post are respectively provided. During the assembly of the power battery, after the cell electrode assembly is placed into the shell through the opening side of the shell, the first tab can be directly welded to the first connector to achieve electrical connection between the first tab and the first terminal post. The second tab can be directly welded to the second connector to achieve electrical connection between the second tab and the second terminal post. In this way, compared with the outer shell of the traditional power battery, the two steps of welding the tab to the top cover and welding the top cover to the main shell are eliminated due to the change in the structure of the outer shell. This eliminates the need to reserve too much space at both ends of the shell for easy welding and for the tab to bend, thereby improving the energy density of the power battery, reducing the size of the first tab and the second tab, and saving material costs.

[0028] In addition, compared with the traditional power battery casing with "open at both ends" structure, this application eliminates the need to pass the cell electrode assembly through the casing during assembly. This not only reduces assembly difficulty but also reduces wear between the cell electrode assembly and the casing, thereby reducing the probability of the cell electrode assembly being damaged due to friction, improving the assembly yield of the power battery and the safety of the power battery during operation. Attached Figure Description

[0029] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which:

[0030] Figure 1 This is a schematic diagram of a power battery according to an embodiment of this application;

[0031] Figure 2 This is a three-dimensional schematic diagram of the cell electrode assembly according to an embodiment of this application before it is installed into the housing;

[0032] Figure 3 This is a top view of the battery cell electrode assembly after it has been installed in the housing, according to one embodiment of this application.

[0033] Figure 4 It is along Figure 3 Sectional view of line AA in the middle;

[0034] In the figure, the reference numerals refer to the following:

[0035] 1. Housing; 100. Accommodation space; 11. Bottom wall; 12. Side wall; 121. First side wall; 122. Second side wall; 123. Third side wall; 124. Fourth side wall; 13. First pole post; 14. Second pole post; 15. Insulating component; 2. Cover plate; 3. Cell electrode assembly; 31. First tab; 32. Second tab; 41. First connector; 411. First connecting piece; 412. Second connecting piece; 42. Second connector; 421. Third connecting piece; 422. Fourth connecting piece. Detailed Implementation

[0036] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0037] It should be noted that in the description of this application, terms such as "upper," "lower," "left," "right," "inner," and "outer," which indicate direction or positional relationship, are based on the direction or positional relationship shown in the accompanying drawings. These terms are used merely for ease of description and do not indicate or imply that the relevant device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, ordinal numbers such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] After each component of a square battery is individually manufactured, the cell electrode assembly needs to be assembled with the battery casing. Currently, the casing of a square battery typically includes a main casing with openings at both ends and two top covers installed at both ends of the main casing. Specifically, in the assembly process of the cell electrode assembly with the aforementioned casing, firstly, the tab at one end of the cell electrode assembly needs to be welded and fixed to one of the top covers. Then, the cell electrode assembly is passed through the inside of the main casing, and the tab at the other end of the cell electrode assembly is welded and fixed to the other top cover. Finally, the top cover is welded and fixed to the main casing, thereby completing the assembly.

[0040] However, in the above process, sufficient space needs to be reserved between the top cover and the cell electrode assembly for bending the tabs in order to achieve welding assembly between the top cover and the main housing. As a result, the size of the tabs and the size of the plastic under the top cover will increase. This will not only increase the amount of positive and negative electrode foil used, increasing material costs, but also increase the space occupied by the tabs at both ends of the battery, which is not conducive to improving the energy density of the battery.

[0041] Reference Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a power battery according to an embodiment of this application, which includes a protective shell and a cell electrode assembly 3, the cell electrode assembly 3 being disposed within the protective shell. The protective shell includes a housing 1 and a cover plate 2. The housing 1 includes a bottom wall 11 and side walls 12. In one embodiment of this application, the bottom wall 11 and side walls 12 are integrally formed to simplify the molding process of the housing 1. A receiving space 100 with an opening is formed between the bottom wall 11 and the side walls 12. The cell electrode assembly 3 is disposed within the receiving space 100. The cover plate 2 is used to connect to the opening, thereby closing the opening. Optionally, the housing 1 and the side walls 12 of the cover plate 2 can be fixed by welding. The closed structure formed after the housing 1 and the cover plate 2 are welded together constitutes the protective shell of the entire power battery.

[0042] Reference Figure 1 and Figure 2 In one embodiment of this application, the power battery is a square battery. Accordingly, the sidewall 12 includes a first sidewall 121 and a second sidewall 122 disposed opposite to each other, and a third sidewall 123 and a fourth sidewall 124 disposed opposite to each other. The first sidewall 121, the second sidewall 122, the third sidewall 123 and the fourth sidewall 124 are all perpendicular to the bottom wall 11.

[0043] A first pole post 13 is fixedly disposed on the first sidewall 121, and a second pole post 14 is fixedly disposed on the second sidewall 122. The first pole post 13 can be integrated with the first sidewall 121 into a single structure, and the second pole post 14 can be integrated with the second sidewall 122 into a single structure. Both the first pole post 13 and the second pole post 14 extend into the receiving space 100. A first connector 41 is fixed to the end of the first pole post 13 that extends into the receiving space 100, and a second connector 42 is fixed to the end of the second pole post 14 that extends into the receiving space 100. Both the first connector 41 and the second connector 42 are located within the receiving space 100. The first connector 41 can be fixed to the first pole post 13 by welding or other means, thereby achieving electrical conduction between the first pole post 13 and the first connector 41. Similarly, the second connector 42 can also be fixed to the second pole post 14 by welding or other means, thereby achieving electrical conduction between the second pole post 14 and the second connector 42.

[0044] One end of the cell electrode assembly 3 has a first tab 31, and the other end has a second tab 32. The first tab 31 is connected to the first connector 41, and the second tab 32 is connected to the second connector 42. Thus, the first terminal 13 is electrically connected to the cell electrode assembly 3 through the first connector 41, and the second terminal 14 is electrically connected to the cell electrode assembly 3 through the second connector 42.

[0045] Reference Figure 2 and Figure 3 ,in, Figure 2 This is a schematic diagram of the cell electrode assembly 3 before it is installed into the housing 1. Figure 3 This is a schematic diagram showing the battery cell electrode assembly 3 after being installed in the housing 1. During the assembly of the power battery, the battery cell electrode assembly 3 is inserted into the housing 1 through the opening of the housing 1. Then, the first electrode tab 31 is welded and fixed to the first connector 41, the second electrode tab 32 is welded and fixed to the second connector 42, and finally the cover plate 2 is welded and fixed to the side wall 12 of the housing 1, thus encapsulating the battery cell electrode assembly 3 in the housing 1.

[0046] As described above, this application divides the protective shell of the power battery into a shell 1 with an opening on one side and a cover plate 2. On the side wall 12 of the shell 1, corresponding to the two ends of the cell electrode assembly 3, a first connector 41 connected to the first terminal 13 and a second connector 42 connected to the second terminal 14 are respectively provided. During the assembly of the power battery, after the cell electrode assembly 3 is placed into the shell 1 through the opening side of the shell 1, the first tab 31 can be directly welded to the first connector 41 to achieve electrical connection between the first tab 31 and the first terminal 13, and the second tab 32 can be directly welded to the second connector 42 to achieve electrical connection between the second tab 32 and the second terminal 14. In this way, compared with the outer shell of the traditional power battery, the structure of the outer shell is changed, eliminating the two steps of welding the tab to the top cover and welding the top cover to the main shell. As a result, the two ends of the shell 1 do not need to reserve too much space for welding and for bending the tabs, thereby improving the energy density of the power battery, reducing the size of the first tab 31 and the second tab 32, and saving material costs.

[0047] On the other hand, since the housing 1 has an opening on only one side, the cell electrode assembly 3 can be directly placed into the housing 1 through the opening. Compared with the structure of traditional power batteries, it is not necessary to pass the cell electrode assembly 3 through the housing 1. This not only reduces the assembly difficulty, but also reduces the wear between the cell electrode assembly 3 and the housing 1, thereby reducing the probability of the cell electrode assembly 3 being damaged due to friction, improving the assembly yield of the power battery and the safety of the power battery during operation.

[0048] Reference Figure 3 and Figure 4In one embodiment of this application, both the first connector 41 and the second connector 42 have L-shaped cross-sections. The first connector 41 includes a first connecting piece 411 and a second connecting piece 412 that are connected to each other and perpendicular to each other. The first connecting piece 411 is connected to the first pole post 13, and the second connecting piece 412 is connected to the first pole tab 31. The second connector 42 includes a third connecting piece 421 and a fourth connecting piece 422 that are connected to each other and perpendicular to each other. The third connecting piece 421 is connected to the second pole post 14, and the fourth connecting piece 422 is connected to the second pole tab 32.

[0049] Thus, after the first connector 41 is welded and fixed to the housing 1, the first connecting piece 411 is parallel to the first side wall 121, the third connecting piece 421 is parallel to the second side wall 122, and the second connecting piece 412 and the fourth connecting piece 422 are parallel to the bottom wall 11. In this state, the mating surfaces of the first tab 31 and the second connecting piece 412, as well as the mating surfaces of the second tab 32 and the fourth connecting piece 422, all face the opening of the housing 1, making it easier to perform welding operations between the first tab 31 and the second connecting piece 412, and between the second tab 32 and the fourth connecting piece 422.

[0050] In one embodiment of this application, the second connecting piece 412 and / or the fourth connecting piece 422 are disposed close to the bottom wall 11, thereby forming a space for welding operations between the first connecting piece 411 and the second connecting piece 412, and / or, forming a space for welding operations between the third connecting piece 421 and the fourth connecting piece 422. Simultaneously, the placement of the second connecting piece 412 and / or the fourth connecting piece 422 close to the bottom wall 11 also facilitates the insertion of the battery cell electrode assembly 3 into the housing 1, preventing the second connecting piece 412 and / or the fourth connecting piece 422 from interfering with the insertion process of the battery cell electrode assembly 3 into the housing.

[0051] Reference Figure 1 and Figure 2 In one embodiment of this application, the distance between the first sidewall 121 and the second sidewall 122 and the distance between the third sidewall 123 and the fourth sidewall 124 are both greater than the distance between the cover plate 2 and the bottom wall 11, making the power battery as a whole "flat", that is, "blade battery", thus further improving the energy density of the power battery.

[0052] Insulators 15 are provided on both the first sidewall 121 and the second sidewall 122. The insulators 15 can be made of materials such as plastic. Specifically, the cell electrode assembly 3 is located within the space defined by the insulators 15, the third sidewall 123, and the fourth sidewall 124. The insulators 15 not only prevent the cell electrode assembly 3 from directly contacting the external conductive parts of the casing 1, reducing the risk of short circuits and electric shocks, but also seal and prevent leakage for the entire power battery.

[0053] This application also discloses a power device, which includes the power battery in any of the above embodiments. It should be noted that the power device described in this application includes, but is not limited to, devices requiring power, such as electric vehicles, electric ships, electric trains, and even electric aircraft.

[0054] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A protective casing for housing a power battery, characterized in that, The protective shell includes: The housing includes a bottom wall and a side wall connected to the bottom wall, and an accommodating space with an opening is formed between the bottom wall and the side wall, the accommodating space being used to accommodate the cell electrode assembly of the power battery. The first pole and the second pole are both disposed on the side wall and extend into the receiving space; The first connector and the second connector are both located in the receiving space. The first connector is connected to the first pole post, and the second connector is connected to the second pole post. A cover plate, disposed at the opening, closes the opening; The first connector is used to connect to the first tab of the battery cell electrode group, and the second connector is used to connect to the second tab of the battery cell electrode group.

2. The protective shell according to claim 1, characterized in that, The first connector includes a first connecting piece and a second connecting piece connected to the first connecting piece. The first connecting piece is connected to the first pole post, and the second connecting piece is connected to the first pole tab. The second connector includes a third connecting piece and a fourth connecting piece connected to the third connecting piece. The third connecting piece is connected to the second pole post, and the fourth connecting piece is connected to the second pole tab.

3. The protective shell according to claim 2, characterized in that, The sidewall is perpendicular to the bottom wall; The first connecting piece is perpendicular to the second connecting piece, and the second connecting piece is parallel to the bottom wall. The third connecting piece is perpendicular to the fourth connecting piece, and the fourth connecting piece is parallel to the bottom wall.

4. The protective shell according to claim 3, characterized in that, The second connecting piece and / or the fourth connecting piece are disposed close to the bottom wall.

5. The protective shell according to claim 3, characterized in that, The cross-section of the first connector and / or the cross-section of the second connector are L-shaped.

6. The protective shell according to claim 1, characterized in that, The bottom wall and the side wall are integrally formed.

7. The protective shell according to any one of claims 1 to 6, characterized in that, The sidewall includes a first sidewall and a second sidewall opposite to each other, as well as a third sidewall and a fourth sidewall opposite to each other. The first pole post and the first connector are disposed on the first sidewall, and the second pole post and the second connector are disposed on the second sidewall.

8. The protective shell according to claim 7, characterized in that, The distance between the first sidewall and the second sidewall, and the distance between the third sidewall and the fourth sidewall, are both greater than the distance between the cover plate and the bottom wall.

9. The protective shell according to claim 7, characterized in that, Insulating elements are provided on both the first and second sidewalls, and the battery cell electrode group is located within the space defined by the insulating elements, the third sidewall, and the fourth sidewall.

10. The protective shell according to claim 1, characterized in that, The cover plate is welded and fixed to the side wall.

11. A power battery, characterized in that, include: Protective casing as described in any one of claims 1 to 10; A battery cell electrode assembly is disposed in the receiving space, wherein the first tab of the battery cell electrode assembly is connected to the first connector, and the second tab of the battery cell electrode assembly is connected to the second connector.

12. A power unit, characterized in that, Includes the power battery as described in claim 11.

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