Cylindrical battery and battery pack

Abstract

The utility model provides a cylindrical battery and a battery pack, and relates to the technical field of lithium batteries. The cylindrical battery comprises a shell as well as a naked battery cell and an insulating disc which are positioned in the shell, wherein the naked battery cell comprises a winding main body, a positive tab and a negative tab, and the positive tab and the negative tab are connected to the same side of the winding main body, so that the resistance difference caused by different positions of the positive tab and the negative tab is reduced, and the charging and discharging efficiency of the cylindrical battery is improved. On the basis, the insulating disc is located in the shell and comprises a first plate part and a first edge folding part which are connected with each other. Wherein the first plate part is positioned between the positive tab and the negative tab so as to separate and insulate the positive tab and the negative tab. And the first folding part is positioned between the winding main body and the shell so as to separate the insulating positive tab from the shell. It can be understood that compared with insulation paste which is prone to wrinkling and warping, the insulation disc effectively separates the positive electrode lug from the negative electrode lug and the shell based on the chemical stability and the mechanical strength of the insulation disc, and the wrinkling and warping problems are avoided.

Description

Technical Field

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

[0002] The tab design of cylindrical batteries significantly impacts their performance and manufacturing process. Typically, cylindrical batteries utilize opposite-side tabs, with the positive and negative tabs located on opposite sides of the cell. Typically, the positive and negative tabs utilize a full-tab structure, which is typically formed by flattening or rubbing the tabs. The negative current collector is then laser-welded to the full tab, which is then connected to the battery's positive and negative electrode components.

[0003] However, the inventors discovered that the long path between the positive and negative tabs increases the battery's internal resistance, affecting the battery's charge and discharge efficiency. Furthermore, after welding the positive tab to the current collector plate of a bare battery cell, a layer of insulating adhesive is typically applied to the surrounding area to provide insulation from the battery casing. However, improper adhesive application can cause the adhesive to wrinkle or warp, increasing the risk of short circuits. Utility Model Content

[0004] The purpose of the present utility model is to provide a cylindrical battery and a battery pack, which can effectively reduce the internal resistance of the battery and improve the battery power characteristics, and can also ensure the safety of use and prevent the occurrence of accidental short circuits.

[0005] The embodiment of the present utility model is achieved as follows:

[0006] In a first aspect, the present invention provides a cylindrical battery comprising a housing, a bare cell and an insulating disk located inside the housing;

[0007] The bare cell includes a winding body, a positive electrode tab, and a negative electrode tab, and the positive electrode tab and the negative electrode tab are connected to the same side of the winding body;

[0008] The insulating disk includes a first plate portion and a first folded edge portion connected to each other. The first plate portion is located between the positive electrode ear and the negative electrode ear to separate the insulated positive electrode ear from the negative electrode ear. The first folded edge portion is located between the winding body and the shell to separate the insulated positive electrode ear from the shell.

[0009] In an optional embodiment, the first plate portion is a disc-shaped structure, is pressed above the negative electrode tab, and is provided with a through hole corresponding to the positive electrode tab.

[0010] In an optional embodiment, the first folded edge portion is close to the through hole and connected to the side wall of the first plate portion.

[0011] In an optional embodiment, the cylindrical battery further includes a top cover connected to the shell, and the positive electrode tab is a long tab structure with a through hole penetrated therethrough and welded to the top cover.

[0012] In an optional embodiment, the top cover includes a cover plate, a positive electrode column, and an insulating member;

[0013] The cover plate is connected to the shell, the positive pole is riveted to the cover plate and connected to the positive pole ear, and the insulating member is located between the positive pole and the cover plate.

[0014] In an optional embodiment, the cylindrical battery further includes a negative electrode current collecting disk, which is located between the negative electrode tab and the insulating disk and is welded to the negative electrode tab and the shell.

[0015] In an optional embodiment, the negative electrode current collecting disc includes a second plate portion and a second folded edge portion;

[0016] The second plate portion is located between the negative electrode tab and the insulating disk and is welded to the negative electrode tab; the second folded edge portion is connected to the second plate portion and is welded to the shell.

[0017] In an optional embodiment, the cylindrical battery further includes a bottom cover connected to the shell, and the bare cell is located on the bottom cover.

[0018] In an optional embodiment, the bottom cover is provided with a first groove and a second groove which are sleeved together, and a first boss is formed between the first groove and the second groove, and an O-shaped line is provided on the first boss.

[0019] In a second aspect, the present invention provides a battery pack, comprising a box and a plurality of cylindrical batteries according to any one of the aforementioned embodiments, wherein the cylindrical batteries are located inside the box.

[0020] The beneficial effects of the embodiments of the present utility model include:

[0021] The utility model provides a cylindrical battery and a battery pack, wherein the cylindrical battery includes a shell and a bare cell and an insulating disk located inside the shell. The bare cell includes a winding body, a positive ear and a negative ear, and the positive ear and the negative ear are connected to the same side of the winding body, so that the current does not have to bypass the two ends of the winding body, reducing the resistance difference caused by the different positions of the positive ear and the negative ear, and improving the charging and discharging efficiency of the cylindrical battery. On the basis of the above, the insulating disk is located in the shell, including a first plate portion and a first folded edge portion that are interconnected. The first plate portion is located between the positive ear and the negative ear to separate the insulated positive ear from the negative ear, thereby correspondingly improving the safety of the cylindrical battery and preventing internal short circuits in the cylindrical battery. The first folded edge portion is located between the winding body and the shell to separate the insulated positive ear from the shell, thereby reducing the potential of the positive ear to the shell and avoiding the occurrence of shell corrosion. It can be understood that, compared with the insulating glue that is prone to wrinkling and warping, the above-mentioned insulating disk effectively insulates and separates the positive electrode ear from the negative electrode ear and the shell based on its own chemical stability and mechanical strength, thus avoiding the wrinkling and warping problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of an exploded cylindrical battery provided by an embodiment of the present utility model;

[0024] Figure 2 A partial cross-sectional schematic diagram of a cylindrical battery provided by an embodiment of the present utility model;

[0025] Figure 3 The embodiment of the present invention provides Figure 2 A magnified schematic diagram of point A in the middle;

[0026] Figure 4 This is a schematic cross-sectional view of a cylindrical battery according to an embodiment of the present invention;

[0027] Figure 5 The embodiment of the present invention provides Figure 4 A magnified schematic diagram of point B in the middle;

[0028] Figure 6 This is a schematic diagram of the overall cylindrical battery provided by an embodiment of the present utility model;

[0029] Figure 7 Another overall schematic diagram of a cylindrical battery provided by an embodiment of the present utility model;

[0030] Figure 8 A schematic diagram of the installation of a cylindrical battery provided in an embodiment of the present utility model;

[0031] Figure 9 This is another installation diagram of the cylindrical battery provided by the embodiment of the utility model;

[0032] Figure 10 Another installation diagram of a cylindrical battery provided by an embodiment of the present utility model;

[0033] Figure 11 This is another installation diagram of the cylindrical battery provided in an embodiment of the present utility model.

[0034] Icons: 10-cylindrical battery; 100-shell; 300-bare cell; 310-positive electrode ear; 330-negative electrode ear; 350-winding body; 500-insulating disk; 510-first plate; 511-through hole; 530-first folding edge; 600-negative current collector; 610-second plate; 630-second folding edge; 700-top cover; 710-cover plate; 730-positive electrode column; 750-insulating part; 751-upper plastic; 753-lower plastic; 755-sealing ring; 900-bottom cover; 910-first groove; 911-liquid injection hole; 930-second groove; 950-first boss; 951-O-shaped line. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0037] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0038] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is typically placed when in use. These terms are intended solely to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0040] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0041] Example

[0042] The present invention provides a battery pack, particularly a lithium battery pack. The battery pack includes a housing and a plurality of cylindrical batteries 10, wherein the cylindrical batteries 10 are located within the housing. It is understood that the arrangement of the cylindrical batteries 10 can effectively reduce the internal resistance of the battery and improve the battery power characteristics. Furthermore, it can ensure safety in use and prevent accidental short circuits. The specific structures of the various components of the cylindrical battery 10 provided in this embodiment and their corresponding relationships are described below.

[0043] Figure 1 This is an exploded schematic diagram of a cylindrical battery 10 provided in an embodiment of the present invention. Figure 2 For a cross-sectional view of a cylindrical battery 10 provided in an embodiment of the present invention, please refer to Figure 1 and Figure 2 The present invention provides a cylindrical battery 10 , comprising a shell 100 and a bare cell 300 and an insulating disk 500 located inside the shell 100 .

[0044] Among them, the bare battery cell 300 includes a winding body 350, a positive electrode ear 310 and a negative electrode ear 330, and the positive electrode ear 310 and the negative electrode ear 330 are connected to the same side of the winding body 350, so that the current does not have to bypass the two ends of the winding body 350, reducing the resistance difference caused by the different positions of the positive electrode ear 310 and the negative electrode ear 330, reducing the ohmic resistance of the cylindrical battery 10, and improving the charging and discharging efficiency of the cylindrical battery 10.

[0045] It should be noted that the wound body 350 includes a positive electrode sheet, a negative electrode sheet, and a separator. During the preparation process, the positive electrode sheet, the negative electrode sheet, and the separator are stacked and wound around the central axis. During this process, the corresponding positive electrode tab 310 and negative electrode tab 330 extend from the same side of the wound body 350.

[0046] Based on the above, the insulating disk 500 is located within the housing 100 and includes a first plate portion 510 and a first folded edge portion 530, which are interconnected. The first plate portion 510 is located between the positive tab 310 and the negative tab 330, thereby isolating the positive tab 310 from the negative tab 330, thereby improving the safety of the cylindrical battery 10 and preventing internal short circuits in the cylindrical battery 10. The first folded edge portion 530 is located between the wound body 350 and the housing 100, isolating the positive tab 310 from the housing 100, thereby reducing the potential of the positive tab 310 relative to the housing 100 and preventing corrosion of the housing 100.

[0047] It is understood that, unlike insulating adhesives that are prone to wrinkling and warping, the insulating disk 500, due to its inherent chemical stability and mechanical strength, effectively insulates and separates the positive and negative tabs 310 and 330 from the housing 100, thus preventing these issues. Furthermore, it facilitates installation and simultaneously provides structural support, protecting the bare cells 300 within the cylindrical battery 10 from physical damage from impact or vibration. Optionally, the insulating disk 500 can be made of plastic.

[0048] In some embodiments, to facilitate insulation and separation of the positive electrode tab 310 and the negative electrode tab 330 by the first plate portion 510, the first plate portion 510 is a disc-shaped structure that is pressed against the negative electrode tab 330 and has a through-hole 511 corresponding to the positive electrode tab 310. Based on this, the positive electrode tab 310 can extend from the through-hole 511 and be located above the first plate portion 510, while the negative electrode tab 330 is located below the first plate portion 510. The two have significantly different spatial positions, effectively achieving separation and insulation, thereby preventing short circuits.

[0049] On the basis of the above, if Figure 3 As shown, Figure 3 The embodiment of the present invention provides Figure 2 An enlarged schematic diagram of point A in the middle. Since the through-hole 511 is located at the location of the positive electrode tab 310, to ensure effective insulation and isolation of the first folded edge 530 while saving material for the first folded edge 530, the first folded edge 530 is located close to the through-hole 511 and connected to the side wall of the first plate portion 510. Optionally, the through-hole 511 may be square or have other configurations that match the positive electrode tab 310, which will not be described in detail in this application.

[0050] See also Figure 4 and Figure 5,in, Figure 5 The embodiment of the present invention provides Figure 4 An enlarged schematic diagram of point B in the figure. In some embodiments, the cylindrical battery 10 further includes a top cover 700 connected to the housing 100. The positive electrode tab 310 has a long tab structure and is penetrated by a through hole 511 for welding to the top cover 700. It is understood that the long tab structure of the positive electrode tab 310 can provide a larger contact area, reduce the use of positive current collector plates, and ensure better welding results, thereby reducing the weight of the cylindrical battery 10.

[0051] like Figure 5 and Figure 6 As shown, the top cover 700 includes a cover plate 710, a positive electrode post 730, and an insulating member 750. The cover plate 710 is connected to the housing 100, and the positive electrode post 730 is riveted to the cover plate 710 and welded to the positive tab 310 to facilitate the transfer of the current generated inside the cylindrical battery cell to the external circuit. Optionally, the positive tab 310 is formed using ultrasonic welding.

[0052] The insulating member 750 is located between the positive electrode post 730 and the cover plate 710 to provide insulation and prevent short circuits or corrosion. It should also be noted that the insulating member 750 includes an upper plastic member 751, a lower plastic member 753, and a sealing ring 755 located between the upper and lower plastic members 751 and 753. During the riveting process between the positive electrode post 730 and the cover plate 710, the insulating member 750 is subjected to the riveting pressure and secured together, effectively insulating and isolating the positive electrode post 730 and the cover plate 710.

[0053] Please refer again Figure 1 In some embodiments, the cylindrical battery 10 further includes a negative electrode current collector plate 600, which is located between the negative electrode tab 330 and the insulating disk 500 and is welded to the negative electrode tab 330 and the housing 100. It should be noted that the primary function of the negative electrode current collector plate 600 is to collect current. It can provide a large current collection surface, reducing the occurrence of cold or poor welding. Optionally, the negative electrode tab 330 in this application is a full-tab pole.

[0054] Based on the above, to facilitate simultaneous welding of the negative electrode current collecting disc 600 to the negative electrode tab 330 and the housing 100, the negative electrode current collecting disc 600 includes a second plate portion 610 and a second folded edge portion 630. The second plate portion 610 is located between the negative electrode tab 330 and the insulating disc 500 and is welded to the negative electrode tab 330. The second folded edge portion 630 is connected to the second plate portion 610 and is welded to the housing 100. Optionally, the negative electrode current collecting disc 600 has a fan-shaped structure, which further reduces the weight of the cylindrical battery cell based on the above-mentioned reduction in the use of positive electrode current collecting discs.

[0055] In order to facilitate direct observation of the welding of various components and effectively improve the welding quality of cylindrical battery cells, the shell 100 in this application adopts a double-pass structure. Figure 7 As shown, the cylindrical battery 10 further includes a bottom cover 900 connected to the housing 100, and the bare cell 300 is located on the bottom cover 900. It is understood that the two ends of the two-way housing 100 are welded to the top cover 700 and the bottom cover 900 respectively.

[0056] Furthermore, the bottom cover 900 is formed with a first groove 910 and a second groove 930 that are nested together. A first boss 950 is sandwiched between the first groove 910 and the second groove 930, and an O-shaped scoreline 951 is provided on the first boss 950. This arrangement, on the one hand, helps reduce stress concentration in the bottom cover 900 and improves its tensile strength and fatigue resistance. On the other hand, it creates a space between the bare battery cell 300 and the O-shaped scoreline 951, allowing the gas contained therein to form a controlled deformation when the internal pressure of the battery reaches a certain value, thereby stably exploding.

[0057] In addition, it should be noted that the wall of the first groove 910 is provided with an injection hole 911 for injecting electrolyte. Accordingly, the cylindrical battery 10 also includes a sealing member provided at the injection hole 911, which is sealed to the injection hole 911 by laser welding, thereby protecting the interior of the cylindrical battery 10 from corrosion and influence of the external environment.

[0058] The utility model provides a cylindrical battery 10, such as Figures 8 to 11 As shown, its working principle and workflow are as follows:

[0059] First, the bottom cover 900 and the shell 100 are laser welded. Afterwards, the bare cell 300 is placed in the shell 100, the negative current collector 600 is placed on the upper end surface of the negative tab 330, and the second plate portion 610 and the negative tab 330 are laser welded, and the second folded edge portion 630 and the inner wall of the shell 100 are laser welded. After that, the long tab structure is ultrasonically welded together to form the positive tab 310, so that the positive tab 310 passes through the through hole 511 of the first plate portion 510 and is laser welded to the positive column 730. Finally, after the positive tab 310 is bent, it is buckled on the first plate portion 510, and the cover plate 710 and the shell 100 are laser welded and sealed.

[0060] In summary, the present invention provides a cylindrical battery 10 and a battery pack, wherein the cylindrical battery 10 includes a housing 100 and a bare cell 300 and an insulating disk 500 located inside the housing 100. The bare cell 300 includes a winding body 350, a positive tab 310, and a negative tab 330, and the positive tab 310 and the negative tab 330 are connected to the same side of the winding body 350, so that the current does not need to bypass both ends of the winding body 350, reducing the resistance difference caused by the different positions of the positive tab 310 and the negative tab 330, and improving the charge and discharge efficiency of the cylindrical battery 10. Based on the above, the insulating disk 500 is located inside the housing 100 and includes a first plate portion 510 and a first folded edge portion 530 that are connected to each other. The first plate portion 510 is located between the positive tab 310 and the negative tab 330 to separate and insulate the positive tab 310 from the negative tab 330, thereby correspondingly improving the safety of the cylindrical battery 10 and preventing internal short circuits in the cylindrical battery 10. The first folded edge portion 530 is located between the winding body 350 and the shell 100 to separate and insulate the positive tab 310 from the shell 100, thereby reducing the potential of the positive tab 310 to the shell 100 and preventing corrosion of the shell 100. It can be understood that compared to insulating glue that is prone to wrinkling and warping, the above-mentioned insulating disk 500, based on its own chemical stability and mechanical strength, effectively insulates and separates the positive tab 310 from the negative tab 330 and the shell 100, avoiding wrinkling and warping problems.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A cylindrical battery, characterized in that: It comprises a housing (100), and a bare battery core (300) and an insulating disk (500) located inside the housing (100); The bare battery cell (300) comprises a winding body (350), a positive electrode tab (310), and a negative electrode tab (330), and the positive electrode tab (310) and the negative electrode tab (330) are connected to the same side of the winding body (350); The insulating disk (500) includes a first plate portion (510) and a first folded edge portion (530) connected to each other, wherein the first plate portion (510) is located between the positive electrode tab (310) and the negative electrode tab (330) to separate and insulate the positive electrode tab (310) from the negative electrode tab (330), and the first folded edge portion (530) is located between the winding body (350) and the shell (100) to separate and insulate the positive electrode tab (310) from the shell (100).

2. The cylindrical battery according to claim 1, characterized in that: The first plate portion (510) is in a disc-type structure, is pressed onto the negative electrode tab (330), and is provided with a through hole (511) corresponding to the positive electrode tab (310).

3. The cylindrical battery according to claim 2, characterized in that: The first folded edge portion (530) is close to the through hole (511) and is connected to the side wall of the first plate portion (510).

4. The cylindrical battery according to claim 2, characterized in that: The cylindrical battery (10) further includes a top cover (700) connected to the housing (100); the positive electrode tab (310) is a long tab structure and is penetrated by the through hole (511) and welded to the top cover (700).

5. The cylindrical battery according to claim 4, characterized in that: The top cover (700) includes a cover plate (710), a positive pole (730), and an insulating member (750); The cover plate (710) is connected to the housing (100), the positive pole (730) is riveted to the cover plate (710) and connected to the positive pole ear (310), and the insulating member (750) is located between the positive pole (730) and the cover plate (710).

6. The cylindrical battery according to claim 1, characterized in that The cylindrical battery (10) further includes a negative electrode current collecting disk (600), the negative electrode current collecting disk (600) being located between the negative electrode tab (330) and the insulating disk (500), and being welded to the negative electrode tab (330) and the housing (100).

7. The cylindrical battery according to claim 6, characterized in that: The negative electrode current collecting disc (600) comprises a second plate portion (610) and a second folded edge portion (630); The second plate portion (610) is located between the negative electrode tab (330) and the insulating disk (500), and is welded to the negative electrode tab (330); the second folded edge portion (630) is connected to the second plate portion (610), and is welded to the housing (100).

8. The cylindrical battery according to claim 1, characterized in that: The cylindrical battery (10) further includes a bottom cover (900) connected to the housing (100), and the bare battery cell (300) is located on the bottom cover (900).

9. The cylindrical battery according to claim 8, characterized in that: The bottom cover (900) is provided with a sleeved first groove (910) and a second groove (930), and a first boss (950) is formed between the first groove (910) and the second groove (930), and an O-shaped engraved line (951) is provided on the first boss (950).

10. A battery pack, characterized in that: The invention comprises a box body and a plurality of cylindrical batteries (10) according to any one of claims 1 to 9, wherein the cylindrical batteries (10) are located inside the box body.

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