Battery case structure and battery

Abstract

The present invention provides a battery case structure and a battery, the battery case structure comprising a case and a fluid injection assembly provided in the case, the fluid injection assembly comprising a connecting member, a sealing member and a sealing insulating structure, the connecting member being drilled in the case and the cell poles inside the case, the connecting member being provided with fluid injection holes, the sealing member being provided on the connecting member and the sealing insulating structure sealing the inside of the cell. The sealing performance of sealing the fluid injection holes is improved, and when the sealing member seals the fluid injection holes, the case becomes impossible to weld through.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 202310170007.7, titled "Battery Case Structure and Battery", filed with the China Patent Office on February 27, 2023, and all of its contents are incorporated herein by reference.

[0002] The present invention relates to the field of battery manufacturing, and specifically to a battery case structure and a battery.

Background Art

[0003] Currently, with the popularization of new energy vehicles, lithium batteries applied to new energy vehicles have attracted increasing attention. Among lithium batteries, prismatic lithium batteries include a case and a sealing member, and a liquid injection hole is provided in a sheet-shaped top cover, through which an electrolyte is injected into the cell of the lithium battery from the liquid injection hole. Existing sealing members seal the liquid injection hole by direct welding, that is, by welding the sealing member to the liquid injection hole of the case with a laser beam.

[0004] On the one hand, laser welding requires a high thickness of the case, needs a thick thickness, and if the thickness of the case is thin, the case is likely to be penetrated by welding, resulting in liquid leakage of the battery. On the other hand, the thickness of the case also affects the energy density of the battery. If the thickness of the case is thick, the utilization rate of the internal space of the battery becomes low, and the energy density of the battery decreases.

[0005] Therefore, in existing batteries, a high thickness of the case is required, and it is impossible to balance the sealing process requirements of the sealing member and the energy density of the battery.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The main object of this application is to provide a battery case structure and a battery, aiming to solve the technical problem that when using an existing sealing member to seal a liquid injection hole, the case is likely to be penetrated by welding. [Means for solving the problem]

[0007] The main object of this application is to provide a battery case structure comprising a case and a liquid injection assembly provided in the case, wherein the liquid injection assembly comprises a connecting member, a sealing member and a sealing insulation structure, wherein the connecting member is drilled in the case and the cell electrode pillars inside the case and is used to fix the case and the cell electrode pillars together, the connecting member is provided with a liquid injection hole for supplying electrolyte into the cell, the sealing member is provided on the connecting member and is used to seal the liquid injection hole, and the sealing insulation structure is provided between the connecting member and the case and between the connecting member and the cell electrode pillars and is used to electrically insulate the connecting member from the case and the cell electrode pillars and to seal the inside of the cell.

[0008] Furthermore, the case and the cell pole are provided with corresponding first and second mounting holes, the connecting member includes a connecting column body, the connecting column body is drilled in the first and second mounting holes, and both ends of the connecting column body are provided with a first flange and a second flange that protrude from the outer circumferential wall of the connecting column body, the first flange is located outside the space enclosed by the case, and the second flange is located inside the space enclosed by the case, the case and the cell pole are fixed between the first flange and the second flange, and the liquid injection hole is provided inside the connecting column body.

[0009] Furthermore, the sealing insulation structure includes a first insulating member, a second insulating member, a third insulating member, and a gasket, wherein the first insulating member is provided between the connecting column body and the case, between the connecting column body and the cell pole column, and between the case and the cell pole column, and is used to electrically insulate the three parties: the connecting column body, the case, and the cell pole column; the second insulating member is provided between the case and the first flange, and is used to electrically insulate the two; the third insulating member is provided between the cell pole column and the second flange, and is used to electrically insulate the two; and the gasket is provided between the cell pole column and the second flange, and is used to seal the gap between the two.

[0010] Furthermore, the first insulating member includes a first insulating portion and a second insulating portion, wherein the first insulating portion is annular and surrounds the outer circumferential surface of the connecting column body and the first mounting hole, and the outer circumferential surface of the connecting column body and the hole wall of the second mounting hole, and the second insulating portion is provided between the case and the cell pole column and is used to electrically insulate the two.

[0011] Furthermore, the third insulating member includes an annular third insulating portion and a fourth insulating portion, the third insulating portion being provided between the cell pole and the second flange and surrounding the gasket, and the fourth insulating portion being provided surrounding the outer circumferential surface of the second flange.

[0012] Furthermore, the second insulating member includes annular fifth insulating portion and sixth insulating portion, the fifth insulating portion being provided between the case and the first flange and surrounding the connecting column body, and the sixth insulating portion being provided surrounding the outer circumferential surface of the first flange.

[0013] Furthermore, a sealing recess is provided on the liquid injection end face of the liquid injection hole of the connecting member, the inner diameter of which is larger than the opening diameter of the liquid injection hole, and the sealing member is provided in the sealing recess and sealed to the connecting member, and is used to close the liquid injection hole.

[0014] Furthermore, the sealing member includes a sealing pin or a sealing ball, the outer diameter of which is larger than the opening diameter of the liquid injection hole.

[0015] Furthermore, the sealing pin is a plastic sealing pin.

[0016] As another technical solution, the present invention further provides a battery including the battery case structure according to the above embodiment and a cell provided inside the battery case structure. [Effects of the Invention]

[0017] The present invention provides a battery case structure comprising a case and a liquid injection assembly provided in the case. The liquid injection assembly includes a connecting member, a sealing member, and a sealing insulation structure. The connecting member is drilled in the case and the cell electrode posts inside the case and is used to fix the case and the cell electrode posts together. The connecting member is provided with a liquid injection hole for supplying electrolyte into the cell. The sealing member is provided on the connecting member and is used to seal the liquid injection hole. The sealing insulation structure is provided between the connecting member and the case, and between the connecting member and the cell electrode posts, and is used to electrically insulate the connecting member from the case and the cell electrode posts, and to seal the inside of the cell. For sealing the liquid injection hole, the injection hole is sealed with a sealing member. In this invention, the liquid injection hole is provided in the connecting member rather than the case. Considering the sealing process requirements, there is only a certain requirement for the thickness of the connecting member. The connecting member penetrates the case, the sealing insulation structure, and the internal electrode posts of the cell, thereby satisfying the requirement for a connecting member to have a certain thickness, and reducing the thickness requirement of the case. As a result, the thickness of the battery case structure can be adjusted to meet both the sealing process requirements of the sealing member and the energy density of the battery. Thus, the problem of the case being easily welded through when the sealing member seals the liquid injection hole is solved, and the sealing performance of the liquid injection hole is improved.

[0018] In the battery provided by the present invention, by adopting the battery case structure provided by the present invention, the thickness of the battery case structure can be well compatible with the sealing process requirements of the sealing member and the energy density of the battery. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic diagram showing a battery case structure according to an embodiment of the present invention. [Figure 2] This is a top view showing a battery case structure according to an embodiment of the present invention. [Modes for carrying out the invention]

[0020] To further clarify the purpose, technical solutions, and advantages of this application, the application will be described in more detail below, along with the drawings and examples. To be understood, the specific examples described herein are for illustrative purposes only and are not intended to limit this application.

[0021] As those skilled in the art will understand, the singular forms “one,” “one,” “above,” and “the said” as used herein may also include the plural form unless otherwise specified. Furthermore, as will be understood, the term “including” as used in the specification of this invention means the presence of features, integers, steps, operations, elements, modules, and / or assemblies, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, modules, assemblies, and / or combinations thereof. As will be understood, where an element is said to be “connected” or “joined” to another element, it may be directly connected or joined to the other element, or there may be an intermediate element. Furthermore, “connected” or “joined” as used herein may include wireless connection or wireless coupling. The term “and / or” as used herein includes all or any modules of one or more items listed in relation, and all combinations thereof.

[0022] As will be understood by those skilled in the art, all terms used herein (including technical and scientific terms) have the same meaning as they are generally understood by those skilled in the art unless otherwise defined. Furthermore, as will be understood, terms as defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an ideal or overly formal sense unless otherwise specifically defined as herein.

[0023] FIG. 1 is a structural schematic diagram showing a battery case structure according to an embodiment of the present invention. Referring to FIG. 1, the battery case structure includes a case 110 and a liquid injection assembly provided on the case 110. The liquid injection assembly includes a connection member, a sealing member, and a sealing insulation structure. The connection member is drilled through the case 110 and the cell pole post 200 inside the case 110, and is used to integrally fix the case 110 and the cell pole post 200. The connection member is provided with a liquid injection hole 1211 for supplying electrolyte into the cell. The sealing member is provided on the connection member and is used to seal the liquid injection hole 1211.

[0024] The cell pole post 200 inside the case 110 is electrically connected to the cell tab inside the case and is also electrically connected to the cell outer pole post outside the case.

[0025] The sealing insulation structure is provided between the connection member and the case 110, and between the connection member and the cell pole post 200, and is used to electrically insulate the connection member from the case 110 and the cell pole post 200, and to seal the inside of the cell. The sealing insulation structure can play two roles: electrical insulation between the connection member and the case 110 and the cell pole post 200, and internal sealing of the cell.

[0026] The method by which the sealing member seals the electrolyte injection hole 1211 may involve installing the sealing member on a connecting member and irremovably connecting the sealing member to the connecting member by welding (e.g., laser welding) the sealing member to the connecting member, in order to enhance the sealing performance of the sealing member and avoid battery leakage. As understood, the sealing member of this embodiment seals the electrolyte injection hole 1211 after the electrolyte has been supplied to the inside of the cell. When the sealing member is welded to the connecting member, the thickness of the connecting member needs to be somewhat required, considering that the connecting member is processed and the requirements of the welding process. In this invention, since the electrolyte injection hole is provided on the connecting member and not on the case, there is only a certain requirement for the thickness of the connecting member, and the thickness requirement of the case can be reduced. Generally speaking, in related art, the electrolyte injection hole is provided on the top cover, and when the electrolyte injection hole is sealed, the top cover is welded, and considering the welding process, there is a certain requirement for the thickness of the top cover (a thick top cover is required). In some embodiments of this invention, the electrolyte injection assembly may further be provided on the top cover.

[0027] It should be explained that the electrolyte in a lithium battery is a carrier for ion movement within the battery. It is usually composed of lithium salts and organic solvents. The electrolyte plays a role in moving ions between the positive and negative electrodes of the lithium battery, ensuring that lithium-ion batteries can obtain advantages such as high voltage and high specific energy.

[0028] The battery case structure according to this embodiment includes a connecting member and not only changes the welding of the sealing member and the case 110 in related technologies to welding of the sealing member and the connecting member, but also integrally fixes the case 110 and the cell pole 200, thereby securely fixing the cell pole 200 and improving the strength of the case 110.

[0029] The case 110 and the cell pole 200 are provided with corresponding first and second mounting holes. Referring to Figure 1, the connecting member includes a connecting column body 1212, which is drilled into the first and second mounting holes. As can be understood, the connecting column body 1212 is cylindrical, and the first and second mounting holes have the same dimensions and are concentrically located, so the connecting column body 1212 can be drilled into the first and second mounting holes.

[0030] The connecting column body 1212 is provided with a first flange 1213 and a second flange 1214 at both ends, which protrude from the outer periphery wall of the connecting column body 1212. An injection hole 1211 is provided inside the connecting column body 1212.

[0031] The first flange 1213 is located outside the space enclosed by the case 110, and the second flange 1214 is located inside the space enclosed by the case 110. The case 110 and the cell pole 200 are fixed between the first flange 1213 and the second flange 1214, and an electrolyte injection hole 1211 is provided inside the connecting pole body 1212. As can be understood, after the battery case structure according to this embodiment is assembled as a battery, the first flange 1213 is located outside the battery and the second flange 1214 is located inside the battery.

[0032] Optionally, the connecting member may include a rivet structure for crimping the case 110, the cell pole 200, and the sealing insulation structure together. By replacing the welding of the case 110 and the sealing member in related technologies with riveting the connecting member and the case 110, and welding the sealing member and the connecting member, the thickness requirement for the case 110 for welding is reduced, and the energy density of the battery is improved. In some embodiments, in embodiments where the connecting member has a rivet structure, the method for crimping the rivet structure to the case 110 may be as follows: the rivet structure (the rivet structure before assembly includes only the second flange 1214 and the connecting column body 1212) is passed sequentially through the second mounting hole and the first mounting hole from one side of the case 110 (the inside after it has been assembled as a battery), thereby drilling the connecting column body 1212 into the second mounting hole and the first mounting hole, and then the first flange 1213 is formed on the portion of the connecting column body 1212 located on the other side of the case 110 by processing from the other side of the case 110. It should be explained that the method of attaching the connecting member is not specifically limited as long as the connecting member can be crimped to the case 110, and it is sufficient that the case 110 and the cell pole 200 can be fixed together after the connecting member is attached to the case 110. As can be understood, the rivet structure may be drilled from the other side of the case 110 (the outside after it has been assembled as a battery) through the first and second mounting holes.

[0033] Figure 2 is a top view showing a battery case structure according to an embodiment of the present invention. Referring to Figures 1 and 2, the sealing insulation structure includes a first insulating member 1231, a second insulating member 1232, a third insulating member 1233, and a gasket 1234.

[0034] The first insulating member 1231 is provided between the connecting pole body 1212 and the case 110, between the connecting pole body 1212 and the cell pole 200, and between the case 110 and the cell pole 200, and is used to electrically insulate the three components: the connecting pole body 1212, the case 110, and the cell pole 200.

[0035] The second insulating member 1232 is provided between the case 110 and the first flange and is used to electrically insulate the two.

[0036] The third insulating member 1233 is provided between the cell pole 200 and the second flange 1214 and is used to electrically insulate the two.

[0037] The gasket 1234 is provided between the cell pole 200 and the second flange 1214 and is used to seal the gap between them.

[0038] Specifically, the first insulating member 1231, the second insulating member 1232, and the third insulating member 1233 may be made of any material capable of achieving electrical insulation, and the gasket 1234 may be made of any material capable of achieving sealing, and is not specifically limited herein.

[0039] In some embodiments, the first insulating member 1231 includes a first insulating portion and a second insulating portion.

[0040] The first insulating portion is annular in shape and is provided between the outer circumferential surface of the connecting column body 1212 and the first mounting hole, and between the outer circumferential surface of the connecting column body and the hole wall of the second mounting hole. The second insulating portion is provided between the case 110 and the cell pole 200 and is used to electrically insulate the two.

[0041] In some embodiments, the third insulating member 1233 includes an annular third insulating portion and a fourth insulating portion. The third insulating portion is provided between the cell pole 200 and the second flange 1214 and surrounds the gasket 1234. The fourth insulating portion surrounds the outer circumferential surface of the second flange 1214.

[0042] In some embodiments, the second insulating member 1232 includes annular fifth and sixth insulating portions. The fifth insulating portion is provided between the case 110 and the first flange and surrounds the connecting column body 1212. The sixth insulating portion surrounds the outer circumferential surface of the first flange.

[0043] A sealing recess 1215 is further provided on the liquid injection end face of the liquid injection hole 1211 of the connecting member. The inner diameter of the sealing recess 1215 is larger than the opening diameter of the liquid injection hole 1211. The sealing member is provided within the sealing recess 1215 and is sealed to the connecting member, and is used to close the liquid injection hole 1211.

[0044] Referring to Figure 2, the sealing recess 1215 and the injection hole 1211 may be provided as two concentric cylindrical holes. That is, the center line of the sealing recess 1215 coincides with the center line of the injection hole 1211.

[0045] In some embodiments, the inner diameter of the sealing recess 1215 widens away from the liquid injection end face of the injection hole in the direction away from the case 110.

[0046] The sealing member includes a sealing pin or a sealing ball, the outer diameter of which is larger than the opening diameter of the liquid injection hole 1211.

[0047] Since the outer diameter of the sealing pin or sealing ball is larger than the opening diameter of the injection hole 1211, it is possible to prevent the sealing pin or sealing ball from falling into the injection hole 1211.

[0048] Specifically, the material of the sealing ball may be a metal such as steel, and as can be understood, the material of the sealing ball may be any material that can seal the liquid injection hole 1211, and is not limited by the above embodiment.

[0049] Specifically, the sealing pin may be a plastic sealing pin.

[0050] However, other materials may be used, such as metal, rubber, or a combination of metal and rubber. As can be understood, the material of the sealing pin may be any material capable of sealing the injection hole 1211, and is not limited by the above embodiments.

[0051] Optionally, the battery may include a battery case structure and cells. The battery case structure may include a case 110 and a fluid injection assembly. The fluid injection assembly may include connecting members, sealing members and a sealing insulation structure. The connecting members may include a connecting column body 1212, a first flange and a second flange 1214. The sealing insulation structure may include a first insulating member 1231, a second insulating member 1232, a third insulating member 1233 and a gasket 1234. The first insulating member 1231 may include a first insulating portion and a second insulating portion. The second insulating member 1232 may include a fifth insulating portion and a sixth insulating portion. The third insulating member 1233 may include a third insulating portion and a fourth insulating portion.

[0052] A battery may include a battery case structure according to the above embodiment and cells provided inside the battery case structure.

[0053] It should be noted that, in this specification, the terms “including,” “equipped with,” or any other variations thereof are intended to cover non-exclusive inclusion, thereby including not only those elements but also other elements not expressly enumerated, or elements specific to such process, apparatus, article, or method. Unless further limited, an element limited by the expression “including one…” does not preclude the existence of other identical elements in a process, apparatus, article, or method that includes that element.

[0054] The foregoing describes only preferred embodiments of this application and does not limit the scope of the patent. Equivalent configurations or equivalent flow transformations, or direct or indirect applications to other related technical fields, made using the contents of the specification and accompanying drawings of this application are also included within the scope of the patent protection of this application. [Explanation of symbols]

[0055] 110 cases 200 Cell Pole Column 1211 Injection hole 1212 Connecting column body 1213 First Flange 1214 Second flange 1215 Sealing recess 1231 First insulating member 1232 Second insulating member 1233 Third insulating member 1234 Gasket

Claims

1. The apparatus includes a case and a liquid injection assembly provided in the case, wherein the liquid injection assembly includes a connecting member, a sealing member and a sealing insulating structure, wherein the connecting member is drilled in the case and the cell electrode column inside the case and is used to fix the case and the cell electrode column together, and the connecting member is provided with a liquid injection hole for supplying electrolyte into the cell, The sealing member is provided on the connecting member and is used to seal the liquid injection hole. The sealing and insulating structure is provided between the connecting member and the case, and between the connecting member and the cell pole, and is used to electrically insulate the connecting member from the case and the cell pole, and to seal the inside of the cell. The case and the cell pole are provided with corresponding first and second mounting holes. The connecting member includes a connecting column body, the connecting column body is drilled in the first mounting hole and the second mounting hole, and both ends of the connecting column body are provided with a first flange and a second flange that protrude from the outer circumferential wall of the connecting column body, the first flange is located outside the space enclosed by the case, and the second flange is located inside the space enclosed by the case, and the case and the cell pole column are fixed between the first flange and the second flange. The battery case structure includes the liquid injection hole provided inside the main body of the connecting column.

2. The sealing insulation structure includes a first insulating member, a second insulating member, a third insulating member, and a gasket, wherein the first insulating member is provided between the connecting column body and the case, between the connecting column body and the cell pole column, and between the case and the cell pole column, and is used to electrically insulate the connecting column body, the case, and the cell pole column. The battery case structure according to claim 1, wherein the second insulating member is provided between the case and the first flange and is used to electrically insulate the case and the first flange, the third insulating member is provided between the cell electrode column and the second flange and is used to electrically insulate the cell electrode column and the second flange, and the gasket is provided between the cell electrode column and the second flange and is used to seal the gap between the cell electrode column and the second flange.

3. The first insulating member includes a first insulating portion and a second insulating portion, wherein the first insulating portion is annular and is provided so as to surround the outer circumferential surface of the connecting column body and the first mounting hole, and between the outer circumferential surface of the connecting column body and the hole wall of the second mounting hole. The battery case structure according to claim 2, wherein the second insulating portion is provided between the case and the cell pole and is used to electrically insulate the case and the cell pole.

4. The third insulating member includes an annular third insulating portion and a fourth insulating portion, the third insulating portion being provided between the cell pole and the second flange and surrounding the gasket, The battery case structure according to claim 2, wherein the fourth insulating portion is provided surrounding the outer circumferential surface of the second flange.

5. The second insulating member includes an annular fifth insulating portion and a sixth insulating portion, the fifth insulating portion being provided between the case and the first flange and surrounding the connecting column body, The battery case structure according to claim 2, wherein the sixth insulating portion is provided surrounding the outer circumferential surface of the first flange.

6. The battery case structure according to claim 1, wherein a sealing recess is further provided on the liquid injection end face of the liquid injection hole of the connecting member, the inner diameter of the sealing recess is larger than the opening diameter of the liquid injection hole, and the sealing member is provided in the sealing recess and is sealed to the connecting member, and is used to close the liquid injection hole.

7. The battery case structure according to claim 1, wherein the sealing member includes a sealing pin or a sealing ball, and the outer diameter of the sealing pin or sealing ball is larger than the opening diameter of the liquid injection hole.

8. The battery case structure according to claim 7, wherein the sealing pin is a plastic sealing pin.

9. A battery comprising a battery case structure and a cell provided inside the battery case structure, The battery case structure includes a case and a liquid injection assembly provided in the case, the liquid injection assembly includes a connecting member, a sealing member and a sealing insulating structure, wherein the connecting member is drilled in the case and the cell electrode pillars inside the case and is used to fix the case and the cell electrode pillars together, the connecting member is provided with a liquid injection hole for supplying electrolyte into the cell, The sealing member is provided on the connecting member and is used to seal the liquid injection hole. The sealing and insulating structure is provided between the connecting member and the case, and between the connecting member and the cell pole, and is used to electrically insulate the connecting member from the case and the cell pole, and to seal the inside of the cell. The case and the cell pole are provided with corresponding first and second mounting holes. The connecting member includes a connecting column body, the connecting column body is drilled in the first mounting hole and the second mounting hole, and both ends of the connecting column body are provided with a first flange and a second flange that protrude from the outer circumferential wall of the connecting column body, the first flange is located outside the space enclosed by the case, and the second flange is located inside the space enclosed by the case, and the case and the cell pole column are fixed between the first flange and the second flange. A battery is provided in the main body of the connecting column, with the liquid injection hole provided inside.

10. The sealing insulation structure includes a first insulating member, a second insulating member, a third insulating member, and a gasket, wherein the first insulating member is provided between the connecting column body and the case, between the connecting column body and the cell pole column, and between the case and the cell pole column, and is used to electrically insulate the connecting column body, the case, and the cell pole column. The battery according to claim 9, wherein the second insulating member is provided between the case and the first flange and is used to electrically insulate the case and the first flange, the third insulating member is provided between the cell electrode column and the second flange and is used to electrically insulate the cell electrode column and the second flange, and the gasket is provided between the cell electrode column and the second flange and is used to seal the gap between the cell electrode column and the second flange.

11. The first insulating member includes a first insulating portion and a second insulating portion, wherein the first insulating portion is annular and is provided so as to surround the outer circumferential surface of the connecting column body and the first mounting hole, and between the outer circumferential surface of the connecting column body and the hole wall of the second mounting hole. The battery according to claim 10, wherein the second insulating portion is provided between the case and the cell pole and is used to electrically insulate the case and the cell pole.

12. The third insulating member includes an annular third insulating portion and a fourth insulating portion, the third insulating portion being provided between the cell pole and the second flange and surrounding the gasket, The battery according to claim 11, wherein the fourth insulating portion is provided surrounding the outer circumferential surface of the second flange.

13. The second insulating member includes an annular fifth insulating portion and a sixth insulating portion, the fifth insulating portion being provided between the case and the first flange and surrounding the connecting column body, The battery according to claim 12, wherein the sixth insulating portion is provided surrounding the outer circumferential surface of the first flange.

14. The battery according to claim 13, wherein a sealing recess is further provided on the liquid injection end face of the liquid injection hole of the connecting member, the inner diameter of the sealing recess is larger than the opening diameter of the liquid injection hole, and the sealing member is provided in the sealing recess and is sealed to the connecting member, and is used to close the liquid injection hole.

15. The battery according to claim 14, wherein the sealing member includes a sealing pin or a sealing ball, and the outer diameter of the sealing pin or sealing ball is larger than the opening diameter of the liquid injection hole.

16. The battery according to claim 15, wherein the sealing pin is a plastic sealing pin.

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