Battery module and lithium ion battery

Abstract

The utility model provides a battery module and a lithium ion battery. The battery module comprises a cover plate component which comprises a substrate and two pole columns arranged on the substrate; each connecting piece comprises a first connecting section and a second connecting section which are connected with each other and are arranged at an included angle, and the two first connecting sections are respectively connected with the two polar columns; the battery cell assembly comprises a first battery cell and a second battery cell which are arranged in parallel, the first battery cell comprises a first body and two first tabs, and the second battery cell comprises a second body and two second tabs; wherein the two first tabs are respectively connected with the two first connecting sections, and the two second tabs are respectively connected with the two second connecting sections. According to the technical scheme provided by the utility model, the problem that in the parallel assembly process of four roll cores of the lithium ion battery in the prior art, the tab is easy to tear when the cores are closed is solved.

Description

Technical Field

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

[0002] In the traditional lithium battery manufacturing process, in order to increase the capacity of a single lithium battery and improve the energy density of lithium batteries, four-core parallel assembly and large-size core assembly are generally adopted. However, in the prior art, in the process of four-core parallel assembly, the pole ear tearing phenomenon is prone to occur when the core is assembled. The reason is that the four cores are arranged side by side, which makes the overall thickness of the battery module larger, and the tension on the corresponding pole ears of each core during the assembly process is inconsistent; if a large-size core is used for assembly, there will be a risk of difficulty in core molding. For example, large-size wound batteries are prone to large fluctuations in pole tension, and large-size stacked batteries will have problems such as poor stacking accuracy and difficulty in shelling. Utility Model Content

[0003] The main purpose of the utility model is to provide a battery module and a lithium-ion battery to solve the problem of the tab tearing phenomenon that is easy to occur when the cores are assembled in parallel during the four-winding core assembly of the lithium-ion battery in the prior art.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a battery module, including: a cover member, including a substrate and two poles arranged on the substrate; two connecting members, the connecting member including a first connecting section and a second connecting section that are connected and arranged at an angle, the two first connecting sections are respectively connected to the two poles; a battery cell assembly, including a first battery cell and a second battery cell arranged in parallel, the first battery cell including a first body and two first pole tabs, and the second battery cell including a second body and two second pole tabs; wherein the two first pole tabs are respectively connected to the two first connecting sections, and the two second pole tabs are respectively connected to the two second connecting sections.

[0005] Furthermore, there are two first battery cells, which are arranged in sequence along the Z direction; there are two second battery cells, which are arranged in sequence along the Z direction; along the Y direction, the cover plate component, the two first battery cells and the two second battery cells are arranged in sequence.

[0006] Furthermore, along the X direction, the two second connecting sections are respectively located at two opposite sides of the battery cell assembly, and the two second pole tabs of the second battery cell are bent and respectively attached to the two second connecting sections.

[0007] Furthermore, the first connecting section is located between the cover plate component and the first battery cell, and the two first pole ears of the first battery cell are bent and respectively attached to the two first connecting sections.

[0008] Furthermore, the battery module also includes an insulating shell, which is a cylindrical structure with an opening, the battery cell assembly is located in the insulating shell, the substrate cover is arranged at the open end of the insulating shell, and a plurality of through holes are arranged on one side of the insulating shell away from the open end.

[0009] According to another aspect of the present invention, a lithium-ion battery is provided, comprising a housing and the above-mentioned battery module arranged on the housing.

[0010] Furthermore, the outer shell is a cylindrical structure with one end open and the other end closed, there is one battery module, and the substrate cover is arranged at the open end and connected to the outer shell.

[0011] Furthermore, the shell is a cylindrical structure with one end open and the other end closed, there are multiple battery modules, the multiple battery modules are arranged in rows along the X direction and / or in columns along the Z direction, and the substrate cover of the battery module is arranged at the open end.

[0012] Furthermore, the outer shell is a cylindrical structure with two ends open, and the lithium-ion battery includes two groups of battery modules, which are arranged back to back along the Y direction, and the substrates of the two groups of battery modules are respectively covered at the two open ends.

[0013] Further, the number of each group of battery modules is one or more, and the multiple battery modules are arranged in rows along the X direction and / or in columns along the Y direction.

[0014] By applying the technical solution of the utility model, compared with the prior art that adopts four battery cells to be arranged side by side, which leads to the problem of easy ear tearing when the cores are combined, the utility model welds two battery cells (the first battery cell and the second battery cell) on the first connecting section and the second connecting section respectively. In this way, while increasing the capacity of a single battery module and improving the energy density of the battery module, it can not only avoid increasing the size of a single battery cell to avoid the problems of difficulty in core forming, large fluctuations in the tension of the core pole sheets, poor accuracy of core stacking and difficulty in shelling, but also avoid arranging the two types of cores side by side to avoid increasing the overall thickness of the battery module, so that the tension on the ear is more uniform and stable, thereby reducing the risk of ear tearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0016] Figure 1 A schematic structural diagram of an embodiment of a first battery cell of the utility model is shown;

[0017] Figure 2 A schematic structural diagram of an embodiment of a second battery cell of the utility model is shown;

[0018] Figure 3 A schematic structural diagram of an embodiment of a cover plate component of the utility model is shown;

[0019] Figure 4 Shows Figure 3 A bottom view of a cover plate member;

[0020] Figure 5 A structural schematic diagram showing the assembly process of a battery module of an embodiment of the utility model;

[0021] Figure 6 Shows Figure 5 A top view of a battery module;

[0022] Figure 7 Another structural schematic diagram showing the assembly process of the battery module of the present utility model;

[0023] Figure 8 Shows Figure 7 AA sectional view of the battery module;

[0024] Fig. 9 Another structural schematic diagram showing the assembly process of the battery module of the present utility model;

[0025] Fig.10 Shows Fig. 9 BB cross-sectional view of the battery module;

[0026] Fig.11 Another structural schematic diagram of the battery module of the present utility model during the assembly process is shown;

[0027] Fig.12 A schematic structural diagram of an embodiment of an insulating shell of the utility model is shown;

[0028] Fig.13 A schematic structural diagram of a first embodiment of a lithium-ion battery of the present utility model is shown;

[0029] Fig.14 The structure diagram of the second embodiment of the lithium-ion battery of the utility model is shown;

[0030] Fig.15 The structure diagram of the third embodiment of the lithium-ion battery of the present invention is shown;

[0031] Fig.16 The structure diagram of the fourth embodiment of the lithium-ion battery of the utility model is shown;

[0032] Fig.17 A structural schematic diagram of a fifth embodiment of a lithium-ion battery of the utility model is shown;

[0033] Fig.18 Another structural schematic diagram of the fifth embodiment of the lithium-ion battery of the utility model is shown.

[0034] The above drawings include the following reference numerals:

[0035] 10. First battery cell; 11. First body; 12. First pole ear; 20. Second battery cell; 21. Second body; 22. Second pole ear; 31. Base plate; 32. Pole; 34. Filling hole; 35. Explosion-proof valve; 36. Insulating gasket; 39. Weight-reducing hole; 40. Insulating shell; 41. Through hole; 50. Shell; 51. Open end; 60. Battery module; 70. Connector; 71. First connecting section; 72. Second connecting section. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0037] like Figures 1 to 12 As shown, an embodiment of the utility model provides a battery module. The battery module includes a cover member, two connectors 70 and a cell assembly. The cover member includes a substrate 31 and two poles 32 arranged on the substrate 31; the connector 70 includes a first connecting section 71 and a second connecting section 72 that are connected and arranged at an angle, and the two first connecting sections 71 are respectively connected to the two poles 32; the cell assembly includes a first cell 10 and a second cell 20 arranged in parallel, the first cell 10 includes a first body 11 and two first pole tabs 12, and the second cell 20 includes a second body 21 and two second pole tabs 22; the two first pole tabs 12 are respectively connected to the two first connecting sections 71, and the two second pole tabs 22 are respectively connected to the two second connecting sections 72.

[0038] In the above technical scheme, compared with the prior art that adopts four battery cells to be arranged side by side, which leads to the problem of easy ear tearing when the cores are combined, the utility model welds two battery cells (the first battery cell 10 and the second battery cell 20) on the first connecting section 71 and the second connecting section 72 respectively. In this way, while increasing the capacity of a single battery module and improving the energy density of the battery module, it can not only avoid increasing the size of a single battery cell, so as to avoid the problems of difficulty in core forming, large fluctuation in the tension of the core pole sheet, poor accuracy of core stacking and difficulty in shelling, but also avoid arranging the two types of cores side by side, so as to avoid increasing the overall thickness of the battery module, so that the tension on the ear is more uniform and stable, thereby reducing the risk of ear tearing.

[0039] Specifically, in the embodiment of the present invention, the two first pole tabs 12 are located on the same side of the first body 11; the two second pole tabs 22 are respectively located on opposite sides of the second body 21. In this way, the two first pole tabs located on the same side can be connected to the two poles through the two first connecting sections 71, respectively, and the two second pole tabs 22 located on different sides can be connected to the two second connecting sections 72, respectively.

[0040] It should be noted that in the embodiment of the utility model, the two connectors 70 are respectively a positive electrode connector and a negative electrode connector, the two pole posts 32 are respectively a positive electrode connection post and a negative electrode connection post, the two first pole ears 12 are respectively a first positive pole ear and a first negative pole ear, and the two second pole ears 22 are respectively a second positive pole ear and a second negative pole ear, wherein the first positive pole ear is connected to the positive electrode connection post through the positive connector, the first negative pole ear is connected to the negative electrode connection post through the negative connector, the second positive pole ear is connected to the positive electrode connection post through the positive connector, and the second negative pole ear is connected to the negative electrode connection post through the negative connector.

[0041] Specifically, in the embodiment of the present invention, the connecting member 70 is a metal connecting sheet, and the metal connecting sheet is bent to form a first connecting section 71 and a second connecting section 72 .

[0042] It should be noted that in the embodiment of the present invention, the first battery cell 10 is a winding structure, but it can also be a stacked structure, a wound stacked structure, etc. The present invention does not limit the molding method of the first battery cell 10; the second battery cell 20 is a winding structure, but it can also be a stacked structure, a wound stacked structure, etc. The present invention does not limit the molding method of the second battery cell 20.

[0043] Specifically, in the embodiments of the present invention, Figure 3 and Figure 4 As shown, the cover plate component also includes an insulating gasket 36, and the substrate 31 and two connectors 70 are all conductive metal parts. Among them, the substrate 31 is also provided with a liquid injection hole 34 and an explosion-proof valve 35. The positive electrode connector is electrically connected to the positive electrode column, and the positive electrode connector and the positive electrode column are separated from the substrate 31 by the insulating gasket 36. The negative electrode connector is electrically connected to the negative electrode column, and the negative electrode connector and the negative electrode column are separated from the substrate 31 by the insulating gasket 36. A number of weight-reducing holes 39 are also provided on the insulating gasket 36, which are used to reduce the weight of the insulating gasket 36 and improve the energy density of the battery.

[0044] like Figure 7 and Figure 8 As shown, in the embodiment of the utility model, there are two first battery cells 10, and the two first battery cells 10 are arranged in sequence along the Z direction; there are two second battery cells 20, and the two second battery cells 20 are arranged in sequence along the Z direction, and along the Y direction, the cover plate component, the two first battery cells 10 and the two second battery cells 20 are arranged in sequence.

[0045] Through the above arrangement, when four battery cells are arranged in parallel, it is possible to avoid increasing the size of a single battery cell, and also avoid setting four battery cells in parallel to avoid increasing the overall thickness of the battery module, so that the tension on the tab can be more uniform and stable, thereby reducing the risk of tab tearing.

[0046] It should be noted that, in the embodiment of the present invention, the X direction is the length direction of the battery module, the Y direction is the height direction of the battery module, and the Z direction is the thickness direction of the battery module.

[0047] like Fig. 9 As shown, in the embodiment of the present invention, along the X direction, the two second connecting sections 72 are respectively located at two opposite sides of the battery cell assembly, and the two second pole tabs 22 of the second battery cell 20 are bent and respectively attached to the two second connecting sections 72 .

[0048] Through the above arrangement, the two second connecting sections 72 are respectively arranged on opposite sides of the battery cell assembly, so that the two second pole tabs 22 located on both sides of the second body 21 are conveniently connected to the two poles 32 through the two second connecting sections 72. Fig.10 As shown, in the embodiment of the present invention, the first connecting section 71 is located between the cover member and the first battery cell 10, and the two first pole tabs 12 of the first battery cell 10 are bent and respectively attached to the two first connecting sections 71. In this way, the two first pole tabs 12 can be connected to the two poles 32 through the two first connecting sections 71, respectively.

[0049] like Fig.12 As shown, in an embodiment of the utility model, the battery module also includes an insulating shell 40, which is a cylindrical structure with an opening, the battery cell assembly is located in the insulating shell 40, the substrate 31 covers the open end 51 of the insulating shell 40, and a plurality of through holes 41 are provided on one side of the insulating shell 40 away from the open end 51.

[0050] In the above technical solution, the first battery cell 10 and the second battery cell 20 that have been assembled are covered by an insulating shell 40, thereby obtaining a battery module with four battery cells assembled in parallel. The function of the covering insulating shell 40 is to prevent the surface of the battery cell from being scratched when the battery module is put into the shell, to prevent dust from entering the battery cell, to avoid the risk of short circuit caused by mutual contact between battery modules, etc. A number of through holes 41 are provided at the bottom of the insulating shell 40, and their function is to facilitate the flow of electrolyte into each battery module.

[0051] Preferably, in an embodiment of the present utility model, the insulating shell is made of an insulating film.

[0052] Figure 5 , Figure 6This is a schematic diagram of the structure of the battery module assembly step 1 of the utility model, where the cover plate member is placed between the two first battery cells 10, the corresponding first positive electrode ear is placed on the positive electrode connector, and the corresponding first negative electrode ear is placed on the negative electrode connector. The first positive electrode ear and the first negative electrode ear are respectively welded to the positive electrode connector and the negative electrode connector by laser.

[0053] Figure 7 , Figure 8 It is a structural schematic diagram of the second step of assembling the battery module of the present invention, in which two first battery cells 10 are folded together, and the entire first body 11 is located in a frame formed by a positive electrode connector and a negative electrode connector.

[0054] Fig. 9 , Fig.10 It is a structural schematic diagram of the third step of assembling the battery module of the utility model, in which the other two second battery cells 20 are placed below the above-mentioned first battery cell 10, and the second positive electrode ear and the positive electrode connector corresponding to the second battery cell 20 are located on one side of the second body, and the second negative electrode ear and the negative electrode connector are located on the other side of the second body.

[0055] Fig.11 It is a structural schematic diagram of the fourth step of assembling the battery module of the present invention. By laser welding, the first positive electrode ear and the second negative electrode ear corresponding to the second battery cell 20 are welded to the positive electrode connector and the negative electrode connector respectively.

[0056] like Figures 13 to 18 As shown, an embodiment of the present invention provides a lithium-ion battery. The lithium-ion battery comprises a housing 50 and the above-mentioned battery module 60 disposed in the housing 50 .

[0057] Embodiment 1

[0058] like Fig.13 As shown, in the first embodiment of the present invention, the housing 50 is a cylindrical structure with one end open and the other end closed, there is one battery module 60 , and the substrate 31 covers the open end 51 and is connected to the housing 50 .

[0059] In the above technical solution, the battery module 60 is placed in the housing 50 with an opening at one end, and finally the substrate 31 is welded to the housing port by laser welding to achieve the insertion of the battery module into the housing.

[0060] Embodiment 2

[0061] like Fig.14 As shown, in the second embodiment of the present invention, the housing 50 is a cylindrical structure with one end open and the other end closed, there are multiple battery modules 60, and the multiple battery modules 60 are arranged in rows along the X direction, and the substrate 31 of the battery module 60 is covered at the open end 51.

[0062] In the above technical solution, multiple battery modules 60 are arranged along the X direction and then placed in a shell 50 with one end open. Finally, multiple corresponding substrates 31 are welded together and multiple substrates 31 are welded to the ports of the shell 50 by laser welding to realize the insertion of multiple battery modules into the shell.

[0063] Embodiment 3

[0064] like Fig.15 As shown, in the third embodiment of the present invention, the housing 50 is a cylindrical structure with one end open and the other end closed, there are multiple battery modules 60, and the multiple battery modules 60 are arranged in a row along the Z direction, and the substrate 31 of the battery module 60 is covered at the open end 51.

[0065] In the above technical solution, multiple battery modules 60 are arranged along the Z direction and then placed in a shell 50 with an opening at one end. Finally, multiple corresponding substrates 31 are welded together and multiple substrates 31 are welded to the ports of the shell 50 by laser welding to realize the insertion of multiple battery modules into the shell.

[0066] In another embodiment of the utility model, the housing 50 is a cylindrical structure with one end open and the other end closed, and there are multiple battery modules 60, which are arranged in rows along the X direction and in columns along the Z direction, and the substrate 31 of the battery module 60 is covered at the open end 51. In this way, the multiple battery modules 60 can be arranged in rows and columns.

[0067] Embodiment 4

[0068] like Fig.16 As shown, in the fourth embodiment of the utility model, the outer shell 50 is a cylindrical structure with openings at both ends, and the lithium-ion battery includes two groups of battery modules 60, and the two groups of battery modules 60 are arranged back to back along the Y direction. The substrates 31 of the two groups of battery modules 60 are respectively covered at the two open ends 51, and the number of each group of battery modules 60 is one.

[0069] In the above technical solution, two battery modules 60 are arranged along the Y direction with their tails facing each other, and then placed in a shell 50 with openings at both ends. Finally, the corresponding substrates 31 and the corresponding open ends 51 are welded together by laser welding to realize the insertion of the two battery modules 60 into the shell.

[0070] Embodiment 5

[0071] like Fig.17 and Fig.18As shown, in the fifth embodiment of the utility model, the shell 50 is a cylindrical structure with openings at both ends, and the lithium-ion battery includes two groups of battery modules 60, and the two groups of battery modules 60 are arranged back to back along the Y direction. The substrates 31 of the two groups of battery modules 60 are respectively covered at the two open ends 51, and the number of each group of battery modules 60 is multiple, and the multiple battery modules 60 are arranged in rows along the X direction and / or in columns along the Y direction.

[0072] In the above technical solution, multiple battery modules 60 are arranged along the X direction, Y direction, and Z direction at the same time, and then placed in a shell 50 with two ends opened. Finally, the corresponding substrates 31 and the corresponding open ends 51 are welded together by laser welding to realize the insertion of multiple battery modules 60 into the shell, forming a shell 50 as shown in FIG. Fig.18 The lithium-ion battery shown.

[0073] It should be noted that in the embodiment of the present invention, the battery modules 60 can be arranged along the X direction and the Y direction at the same time, or along the X direction and the Z direction at the same time, or along the Y direction and the Z direction at the same time. When the battery modules 60 are arranged along the Y direction, the tails are all facing each other, and the corresponding housings 50 are open at both ends.

[0074] The utility model firstly uses two types of winding cores to obtain a battery module with four winding cores in parallel, and the four pole tabs are respectively welded on the corresponding metal connecting pieces, so that the tension is more uniform and stable, and the risk of the pole tabs tearing can be reduced; and then several battery modules are placed in the same housing, which can reduce the space occupied by the housing, fastening structure, etc., and improve the energy density of the lithium battery. The utility model also provides several embodiments, which can improve the process adaptability of lithium battery manufacturing.

[0075] It should be noted that, compared with the prior art which requires combining several single cells into modules and configuring corresponding fastening structures in the battery box to fix the single cells, the utility model places several battery modules in a shell, thereby reducing the space occupied by the shell between the single cells and also reducing the number of fastening structures of the battery box, thereby significantly improving the energy density of the lithium battery.

[0076] It should be noted that compared with the prior art, in order to increase the capacity of a single lithium battery, the method of increasing the core size is often adopted, which leads to problems such as difficulty in core molding and low shell qualification rate. The utility model first connects relatively small cores in parallel to obtain battery modules, and then places several battery modules in the same shell, which greatly reduces the manufacturing difficulty.

[0077] The above-mentioned lithium-ion battery has all the advantages of the above-mentioned battery module 60, which will not be described in detail here.

[0078] From the above description, it can be seen that the above-mentioned embodiments of the utility model achieve the following technical effects: compared with the prior art that adopts four battery cells to be arranged side by side, which leads to the problem of easy ear tearing when the cores are combined, the utility model welds two battery cells (the first battery cell and the second battery cell) on the first connecting section and the second connecting section respectively. In this way, while increasing the capacity of a single battery module and improving the energy density of the battery module, it can not only avoid increasing the size of a single battery cell, so as to avoid the problems of difficulty in core forming, large fluctuations in the tension of the core pole sheets, poor accuracy of core stacking and difficulty in shelling, but also avoid arranging the two types of cores side by side, so as to avoid increasing the overall thickness of the battery module, so that the tension on the ear is more uniform and stable, thereby reducing the risk of ear tearing.

[0079] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A battery module, characterized in that: include: A cover plate component, comprising a base plate (31) and two poles (32) arranged on the base plate (31); Two connecting members (70) comprising a first connecting section (71) and a second connecting section (72) connected to each other and arranged at an angle, wherein the two first connecting sections (71) are respectively connected to the two poles (32); A battery cell assembly, comprising a first battery cell (10) and a second battery cell (20) arranged in parallel, wherein the first battery cell (10) comprises a first body (11) and two first pole tabs (12), and the second battery cell (20) comprises a second body (21) and two second pole tabs (22); The two first pole tabs (12) are respectively connected to the two first connecting sections (71), and the two second pole tabs (22) are respectively connected to the two second connecting sections (72).

2. The battery module according to claim 1, characterized in that: There are two first battery cells (10), and the two first battery cells (10) are arranged in sequence along the Z direction; There are two second battery cells (20), and the two second battery cells (20) are arranged in sequence along the Z direction. Along the Y direction, the cover plate component, the two first battery cells (10) and the two second battery cells (20) are arranged in sequence.

3. The battery module according to claim 2, characterized in that: Along the X direction, the two second connecting sections (72) are respectively located on opposite sides of the battery cell assembly, and the two second pole tabs (22) of the second battery cell (20) are bent and respectively attached to the two second connecting sections (72).

4. The battery module according to claim 2, characterized in that: The first connecting section (71) is located between the cover plate component and the first battery cell (10), and the two first pole tabs (12) of the first battery cell (10) are bent and respectively attached to the two first connecting sections (71).

5. The battery module according to any one of claims 1 to 4, characterized in that: The battery module further comprises an insulating shell (40), the insulating shell (40) being a cylindrical structure with an opening, the battery cell assembly being located in the insulating shell (40), the substrate (31) being arranged to cover the opening end (51) of the insulating shell (40), and a plurality of through holes (41) being arranged on a side of the insulating shell (40) away from the opening end (51).

6. A lithium ion battery, characterized in that: A battery module (60) according to any one of claims 1 to 5 comprising a housing (50) and arranged on the housing (50).

7. The lithium-ion battery according to claim 6, characterized in that: The outer shell (50) is a cylindrical structure with one end open and the other end closed. There is one battery module (60). The substrate (31) is covered at the open end (51) and connected to the outer shell (50).

8. The lithium-ion battery according to claim 6, characterized in that: The housing (50) is a cylindrical structure with one end open and the other end closed. There are a plurality of battery modules (60), which are arranged in rows along the X direction and / or in columns along the Z direction. The base plate (31) of the battery module (60) is covered at the open end (51).

9. The lithium-ion battery according to claim 6, characterized in that: The housing (50) is a cylindrical structure with two ends open. The lithium-ion battery comprises two groups of battery modules (60). The two groups of battery modules (60) are arranged back to back along the Y direction. The base plates (31) of the two groups of battery modules (60) are respectively and correspondingly covered at the two open ends (51).

10. The lithium ion battery according to claim 9, characterized in that: The number of each group of battery modules (60) is one or more, and the plurality of battery modules (60) are arranged in rows along the X direction and / or in columns along the Y direction.

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