End cover of cylindrical battery, cylindrical battery and battery module

Abstract

The utility model relates to an end cover of a cylindrical battery, the cylindrical battery and a battery module, and belongs to the field of batteries. The end cover comprises positive and negative electrode confluence pieces electrically connected with positive and negative electrode lugs of the cylindrical battery, the positive and negative electrode confluence pieces are arranged on the positive and negative electrode lugs of the cylindrical battery at intervals, the edges of the positive and negative electrode confluence pieces are respectively provided with a positive electrode conductive handle and a negative electrode conductive handle, and the end cover is buckled on the positive and negative electrode confluence pieces by folding the positive and negative electrode conductive handles. The end cover further comprises an insulating partition plate and a cover plate, and the pole penetrates through the insulating partition plate and penetrates out of the cover plate; the positive conductive handle extends to the inner surface of the cover plate and is electrically connected to the cover plate, and the negative conductive handle extends to the inner surface of the insulating partition plate and is electrically connected to the pole. On the horizontal plane, the gap between the positive electrode bus piece and the negative electrode bus piece is larger than the gap between the positive electrode conductive handle and the negative electrode conductive handle. According to the utility model, the positive and negative collector plates are asymmetrically designed, so that the over-current capability of the positive and negative collector plates at the over-current bottleneck part is obviously improved, and the rate capability of the battery cell is effectively enhanced.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, and relates to an end cover of a cylindrical battery, a cylindrical battery and a battery module. Background Art

[0002] In the field of chemical battery technology, cylindrical batteries have received extensive attention due to their standardized dimensions and ease of large-scale production. Traditional cylindrical battery designs typically leave a small uncoated area at the end of the coated electrode sheet for welding a single tab. However, this method results in a relatively high internal resistance of the battery, which has an adverse effect on the power density of the battery. At the same time, the outer shell assembly of small-sized battery cells accounts for a relatively large proportion, which also weakens its energy density.

[0003] In order to improve the performance of cylindrical battery cells, the industry tends to manufacture larger-sized batteries and adopt multi-tab or full-tab designs. Nevertheless, the prior art still faces a series of challenges. On the one hand, current collectors need to be welded at both ends of the positive and negative electrodes, which not only occupies valuable internal space, reduces the energy density of a single battery cell, but also causes electrons to pass through a relatively long path from the positive electrode to the negative electrode, thereby increasing the resistance.

[0004] To address these deficiencies, some technologies have attempted to place the positive and negative electrode tabs at the same end of the battery cell and use an insulating sheet to separate and weld the positive and negative current collectors. Although this method optimizes space utilization and shortens the electron transmission path, it also brings some new problems, such as limited width of the current collector, increased design complexity leading to higher costs, and unstable welding quality. More seriously, the positive and negative current collectors may come into contact with each other due to the vibration or collision of a single battery, resulting in an internal short circuit of the battery and even potentially dangerous situations such as fire or explosion. Summary of the Utility Model

[0005] In view of this, the purpose of the utility model is to provide an end cover of a cylindrical battery, a cylindrical battery and a battery module, which improve the overcurrent capacity of the battery cell by optimizing the structural forms of the positive and negative current collectors and the cover plate, thereby improving the rate performance of a single battery cell.

[0006] To achieve the above purpose, the utility model provides an end cover of a cylindrical battery for sealing one end of the battery cell of the cylindrical battery, including a positive current collector and a negative current collector electrically connected to the positive tab and the negative tab of the cylindrical battery, the positive current collector and the negative current collector are spaced apart from each other, and positive and negative conductive handles connected to the end cover are respectively arranged at the edges of the two, and the end cover is buckled on the positive current collector and the negative current collector by folding the positive and negative conductive handles.

[0007] The end cover includes an insulating partition and a cover plate arranged from the inside to the outside along the axial direction of the housing. The pole column passes through the insulating partition and passes out of the cover plate. The positive conductive handle extends to the inner surface of the cover plate and is electrically connected to the cover plate, and the negative conductive handle extends to the inner surface of the insulating partition and is electrically connected to the pole column.

[0008] Optionally, on the horizontal plane, the gap between the positive current collector and the negative current collector is greater than the gap between the positive conductive handle and the negative conductive handle.

[0009] Optionally, the width of the positive conductive handle is greater than the width of the negative conductive handle.

[0010] Optionally, insulating gaskets are provided between the positive current collector and the negative current collector and the insulating partition. Insulating strips are provided on the insulating gaskets, and the insulating strips are embedded in the gap between the positive current collector and the negative current collector.

[0011] Optionally, insulating gaskets are provided between the positive current collector and the negative current collector and the insulating partition. Flange grooves are provided on the insulating gaskets, and the flange grooves are embedded in the gap between the positive current collector and the negative current collector, and their flanges are inserted into the connection gaps between the positive current collector and the negative current collector and the positive ear and the negative ear.

[0012] Optionally, an inclined connecting portion is provided between the negative conductive handle and the negative current collector, so that a height difference is formed between the negative conductive handle and the negative current collector.

[0013] Optionally, at least one insulating boss is provided on the surface of the insulating partition facing the positive current collector and the negative current collector.

[0014] Optionally, a first insulating member is provided between the pole column and the insulating partition, and a second insulating member is provided between the pole column and the cover plate.

[0015] Optionally, both the end of the first insulating member and the negative conductive handle are sleeved on the column body of the pole column, and the first insulating member is located between the platform portion of the pole column and the negative conductive handle.

[0016] Optionally, a pole column seal is provided on the part of the pole column passing through the cover plate, and the second insulating member is provided between the pole column seal and the cover plate.

[0017] Optionally, a liquid injection hole is provided on the cover plate.

[0018] The present utility model also provides a cylindrical battery, including a cylindrical battery cell, a housing for accommodating the battery cell, an end cover hermetically provided at one end of the housing, and a bottom cover hermetically provided at the other end of the housing. The end cover is the end cover of the aforementioned cylindrical battery; at one end of the battery cell close to the end cover, a positive ear and a negative ear are led out. The positive current collector is electrically connected to the positive ear and covers the positive ear, and the negative current collector is electrically connected to the negative ear and covers the negative ear.

[0019] The present utility model also provides a battery module, which includes a plurality of the aforementioned cylindrical batteries, and the plurality of cylindrical batteries are connected in series and / or in parallel with each other.

[0020] The beneficial effects of the present utility model are as follows:

[0021] First of all, the positive and negative busbars of the present utility model adopt an asymmetric design. In particular, the width of the positive conductive handle is greater than that of the negative conductive handle, and the gap between the positive busbar and the negative busbar is greater than the gap between the positive conductive handle and the negative conductive handle. On the one hand, the conductivity of the positive and negative busbars is more matched with the positive and negative electrode tabs of the cylindrical battery. On the other hand, the current-carrying capacity of the positive and negative busbars at the overcurrent bottleneck part is significantly improved, thereby effectively enhancing the rate performance of the battery cell and ensuring that the battery cell can still maintain a stable performance output when passing a large current.

[0022] Secondly, the positive and negative busbars are spaced apart and independent of each other before welding, avoiding mutual interference between the positive and negative electrode tabs. This not only improves the reliability of welding but also ensures the safety during the assembly process of the battery cell. The insulating gasket further ensures the insulation effect between the positive and negative busbars after folding, improving the overall safety of the battery cell. On this basis, the present utility model also proposes a cylindrical battery applying the housing part. Due to its high space utilization rate and use safety, the housing part of the present utility model highly matches the structural form of the cylindrical battery with full electrode tabs at the same end, enabling the cylindrical battery to achieve a higher energy density, shortening the electron path, reducing the resistance, and further improving the discharge rate of the cylindrical battery.

[0023] In addition, based on the end cap provided by the present utility model, the manufacturing process of the cylindrical battery can be greatly optimized. When assembling the battery cell, first weld the positive and negative busbars to the positive and negative electrode tabs of the battery cell, then weld the positive and negative conductive handles to the corresponding structures of the end cap, and finally fold the positive and negative conductive handles, flip and buckle the end cap, and weld the end cap to the housing to complete the assembly process. It can be seen that due to the optimization and update of the structural form of the end cap in the present utility model, the assembly process of the end cap and the battery cell only requires 3 welds, significantly improving the manufacturing efficiency and reducing the production cost.

[0024] Other advantages, objectives, and features of the present utility model will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained through the following specification. Description of the Drawings

[0025] To make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be described in detail and preferably below with reference to the accompanying drawings, where:

[0026] Figure 1 Top view of the end cap of the cylindrical battery provided by the present utility model;

[0027] Figure 2 Three-dimensional schematic diagram of the end cap of the cylindrical battery provided by the present utility model;

[0028] Figure 3 Exploded view of the end cap of the cylindrical battery provided by the present utility model in one direction;

[0029] Figure 4 Exploded view of the end cap of the cylindrical battery provided by the present utility model in another direction;

[0030] Figure 5 Schematic structural diagram of the insulating gasket in one embodiment of the end cap of the cylindrical battery provided by the present utility model;

[0031] Figure 6 Cross-sectional view of the cylindrical battery provided by the present utility model.

[0032] Wherein, Figure 1 (a) is a schematic structural diagram of the end cap without the insulating gasket installed, Figure 1 (b) is a schematic structural diagram of the end cap with the insulating gasket installed;

[0033] Figure 5 (a) is the top view of the insulating gasket in one embodiment of the end cap provided by the present utility model, Figure 5 (b) is the front view of the insulating gasket in one embodiment of the end cap provided by the present utility model.

[0034] Reference numerals:

[0035] 100 - housing; 200 - end cap; 210 - insulating partition; 211 - insulating boss; 220 - cover plate; 221 - liquid injection hole; 230 - insulating gasket; 231 - insulating strip; 232 - flange slot; 300 - positive bus bar; 310 - positive conductive stem; 400 - negative bus bar; 410 - negative conductive stem; 420 - connecting part; 500 - bottom cover; 600 - battery cell; 700 - positive tab; 800 - negative tab; 900 - terminal; 910 - first insulating member; 920 - second insulating member; 930 - platform part; 940 - column body; 950 - terminal seal. Detailed implementation manners

[0036] The following describes the implementation modes of the present utility model through specific examples. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present utility model in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0037] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams rather than physical diagrams, and should not be construed as limitations on the present utility model; in order to better illustrate the embodiments of the present utility model, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0038] In the drawings of the embodiments of the present utility model, the same or similar reference numerals correspond to the same or similar components; in the description of the present utility model, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as limitations on the present utility model. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] The present utility model provides an end cap for a cylindrical battery, a cylindrical battery, and a battery module. By optimizing the structures of the positive and negative current collectors and the cover plate, the utilization rate of the internal space of the housing is improved, the battery energy density is increased, and the overcurrent capacity of the battery cell is significantly enhanced, thereby enhancing the rate performance of the single battery cell.

[0040] As Figures 1 to 4 shown, the end cap 200 of the cylindrical battery provided by the present utility model includes a positive current collector 300 and a negative current collector 400. The positive current collector 300 and the negative current collector 400 are electrically connected to the positive electrode tab 700 and the negative electrode tab 800 of the cylindrical battery at intervals. Positive conductive handles 310 and negative conductive handles 410 are respectively arranged at the edges of the positive current collector 300 and the negative current collector 400. The positive conductive handle 310 and the negative conductive handle 410 are both connected to the end cap 200. By folding the positive conductive handle 310 and the negative conductive handle 410, the end cap 200 is flipped and buckled on the positive current collector 300 and the negative current collector 400.

[0041] Specifically, the end cover 200 includes an insulating partition 210 and a cover plate 220 arranged axially inside to outside of the housing 100 in sequence. The pole column 900 passes through the insulating partition 210 and penetrates out from the cover plate 220. The positive conductive handle 310 extends to the inner surface of the cover plate 220 and is electrically connected thereto, while the negative conductive handle 410 extends to the inner surface of the insulating partition 210 and is electrically connected to the pole column 900. On the horizontal plane, the gap between the positive and negative busbars is greater than the gap between the positive and negative conductive handles. The width of the positive conductive handle 310 can be designed to be greater than that of the negative conductive handle 410 to better adapt to the distribution requirements of the positive and negative currents and improve the overcurrent capacity of the positive and negative currents at the overcurrent bottleneck. This means that when a large current passes through, the battery cell 600 can maintain a more stable performance output, providing strong support for various high-power applications.

[0042] Further, an insulating gasket 230 is provided between the positive and negative busbars and the insulating partition 210, and an insulating component is provided thereon that is embedded between the positive and negative busbars to isolate their current channels. In some alternative embodiments, as Figure 4 shown, an insulating strip 231 is provided on the insulating gasket 230, and the insulating strip 231 is embedded in the gap between the positive busbar 300 and the negative busbar 400. In some alternative embodiments, as Figure 5 shown, the insulating gasket 230 is provided with flange slots 232, and the flange slots 232 are embedded in the gap between the positive busbar 300 and the negative busbar 400, and their flanges are respectively clamped into the connection gaps between the positive busbar 300 and the negative busbar 400 and the positive tab 700 and the negative tab 800, ensuring the insulation effect while further enhancing the connection stability between the insulating partition 210 and the positive and negative busbars.

[0043] In some alternative embodiments, since the positive conductive handle 310 is connected to the cover plate 220 and the negative conductive handle 410 is connected to the insulating partition 210, and the two are not on the same horizontal plane, an inclined connecting portion 420 is provided between the negative conductive handle 410 and the negative busbar 400, so as to form a height difference between the negative conductive handle 410 and the negative busbar 400, and at the same time also form a height difference between the negative conductive handle 410 and the positive conductive handle 310, thereby ensuring that the positive and negative busbars are at the same horizontal height, which helps to improve the reliability of their welding with the tabs.

[0044] In some alternative embodiments, as Figure 3 、 Figure 4As shown, a first insulating member 910 and a second insulating member 920 are respectively provided between the terminal post 900, the insulating partition plate 210, and the cover plate 220. The first insulating member 910 and the end of the negative electrode conducting handle 410 are sleeved together on the column body 940 of the terminal post 900. The first insulating member 910 is located between the platform portion 930 of the terminal post 900 and the negative electrode conducting handle 410. The part of the terminal post 900 passing through the cover plate 220 is provided with a terminal post seal 950, and the second insulating member 920 is provided between the terminal post seal 950 and the cover plate 220.

[0045] In some alternative embodiments, by controlling the gap between the positive and negative busbars and the positive and negative electrode conducting handles, the widths of the positive and negative busbars and the positive and negative electrode conducting handles are controlled. For example, the gap between the positive and negative busbars is 4 mm, the gap between the positive and negative electrode conducting handles is 1 mm, and the gap between the positive and negative electrode conducting handles is smaller than the gap between the positive and negative busbars, so that the width of the positive electrode conducting handle is increased, and the current-carrying capacity at the connection between the positive and negative electrode conducting handles and the positive and negative busbars is further improved.

[0046] In some alternative embodiments, as Figure 3 , Figure 4 shown, at least one insulating boss 211 is further provided on the inner surface of the insulating partition plate 210. The insulating boss 211 is fan-shaped to prevent short circuit between the positive and negative electrodes after the end cover 200 is buckled. The cover plate 220 is provided with a liquid injection hole 221 as an injection channel for the electrolyte, which is convenient for checking and supplementing the electrolyte. At the same time, when necessary, the gas generated inside the battery can also be discharged through the liquid injection hole 221 to maintain the internal pressure balance of the battery.

[0047] In some alternative embodiments, the liquid injection hole can also be provided on the bottom cover 500.

[0048] The present utility model also provides a cylindrical battery using the above-mentioned end cover 200. As Figure 6 shown, the battery cell 600 of the cylindrical battery is installed in the housing 100. The above-mentioned end cover 200 is hermetically provided at one end of the housing 100, and the other end of the housing 100 is hermetically provided with a bottom cover 500. A positive electrode tab 700 and a negative electrode tab 800 are led out from one end of the battery cell 600 close to the end cover 200. The positive busbar 300 is electrically connected to the positive electrode tab 700 and covers the positive electrode tab 700. The negative busbar 400 is electrically connected to the negative electrode tab 800 and covers the negative electrode tab 800. Since the housing part provided by the present utility model is highly matched with the structural type of the cylindrical battery with all tabbed ears at the same end, not only can the cylindrical battery achieve a higher energy density, but also the charge and discharge rate of the cylindrical battery is further improved by shortening the electron path and reducing the resistance.

[0049] The present utility model provides a battery module, which is composed of a plurality of the above-mentioned cylindrical batteries. The plurality of cylindrical batteries can be connected in series or in parallel with each other to meet the requirements of different application scenarios.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and not to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present utility model can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present utility model.

Claims

1. An end cap for a cylindrical battery, used to seal one end of a battery core (600) of the cylindrical battery, characterized in that: It includes a positive current collector plate (300) and a negative current collector plate (400) that are electrically connected to the positive tab (700) and the negative tab (800) of the cylindrical battery. The positive current collector plate (300) and the negative current collector plate (400) are spaced apart from each other, and positive conductive handles (310) and negative conductive handles (410) connected to the end cap (200) are respectively provided at the edges of the two. The end cap (200) is buckled on the positive current collector plate (300) and the negative current collector plate (400) by folding the positive conductive handle (310) and the negative conductive handle (410); The end cap (200) includes an insulating partition (210) and a cover plate (220) arranged from the inside to the outside along the axis of the housing (100). A pole column (900) passes through the insulating partition (210) and passes out of the cover plate (220); the positive conductive handle (310) extends to the inner surface of the cover plate (220) and is electrically connected to the cover plate (220), and the negative conductive handle (410) extends to the inner surface of the insulating partition (210) and is electrically connected to the pole column (900).

2. The end cap according to claim 1, characterized in that: On the horizontal plane, the gap between the positive current collector plate (300) and the negative current collector plate (400) is greater than the gap between the positive conductive handle (310) and the negative conductive handle (410).

3. The end cap according to claim 1, characterized in that: Insulating gaskets (230) are provided between the positive current collector plate (300) and the negative current collector plate (400) and the insulating partition (210). Insulating strips (231) are provided on the insulating gaskets (230), and the insulating strips (231) are embedded in the gap between the positive current collector plate (300) and the negative current collector plate (400).

4. The end cap according to claim 1, characterized in that: At least one insulating boss (211) is provided on the inner surface of the insulating partition (210).

5. The end cap according to claim 1, wherein: A first insulating member (910) is provided between the pole column (900) and the insulating partition (210), and a second insulating member (920) is provided between the pole column (900) and the cover plate (220).

6. The end cap according to claim 5, characterized in that: The ends of the first insulating member (910) and the negative conductive handle (410) are both sleeved on the column body (940) of the pole column (900). The first insulating member (910) is located between the platform portion (930) of the pole column (900) and the negative conductive handle (410); a pole column seal (950) is provided on the part of the pole column (900) passing out of the cover plate (220), and the second insulating member (920) is provided between the pole column seal (950) and the cover plate (220).

7. The end cap according to claim 1, characterized in that: An inclined connecting portion (420) is provided between the negative conductive handle (410) and the negative current collector plate (400), so that a height difference is formed between the negative conductive handle (410) and the negative current collector plate (400).

8. The end cap according to claim 1, characterized in that: The width of the positive conductive handle (310) is greater than the width of the negative conductive handle (410).

9. A cylindrical battery, comprising a cylindrical battery cell (600), a housing (100) for accommodating the battery cell (600), an end cap (200) hermetically provided at one end of the housing (100), and a bottom cover (500) hermetically provided at the other end of the housing (100), characterized in that: The end cap (200) is the end cap (200) of the cylindrical battery according to any one of claims 1 to 8; at one end of the battery cell (600) close to the end cap (200), a positive electrode tab (700) and a negative electrode tab (800) are led out. The positive current collector plate (300) is electrically connected to the positive electrode tab (700) and covers the positive electrode tab (700), and the negative current collector plate (400) is electrically connected to the negative electrode tab (800) and covers the negative electrode tab (800).

10. A battery module, characterized in that: It includes a plurality of cylindrical batteries as described in claim 9, and the plurality of cylindrical batteries are connected in series and / or in parallel with each other.

Images