Positive electrode bus bar and cylindrical battery

Abstract

The utility model discloses an anode confluence piece and a cylindrical battery. The anode confluence piece comprises a confluence piece main body, a liquid flow hole, an adjusting piece, a welding tongue and an adjusting piece accommodating open slot, adjusting sheet accommodating open slots which are distributed in the radial direction are formed in the converging sheet main body; the outer side of the adjusting sheet accommodating open slot is opened; a radially distributed adjusting sheet is arranged in the adjusting sheet accommodating open slot; one radial end of the adjusting sheet is connected with the inner side wall of the adjusting sheet accommodating open slot; the other radial end of the adjusting sheet is connected with one end of the welding tongue; the other end of the welding tongue protrudes out of the peripheral outer side edge of the convergence sheet main body; and the lower side surface of the bus bar main body is used for being welded and fixed with a positive tab at the top of an external cylindrical battery cell. The positive electrode bus bar on the battery is scientific and reasonable in design, the battery cover can be reliably connected with the positive electrode lug on the battery cell without being bent for multiple times, the internal space of the battery shell needing to be occupied is remarkably saved, and the energy density of the battery is improved.

Description

Technical Field

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

[0002] Lithium-ion batteries have the advantages of high specific energy, many cycle usage times, long storage time, etc. They are not only widely used in portable electronic devices (such as mobile phones, digital video cameras, and laptop computers), but also widely used in large and medium-sized electric devices such as electric vehicles, electric bicycles, and electric tools. Therefore, the performance requirements for lithium-ion batteries are getting higher and higher.

[0003] At present, cylindrical lithium-ion batteries have been widely used in recent years due to their advantages such as standardized production processes, high production efficiency, excellent cycle performance, and good consistency. In the production process of cylindrical batteries, grooving is an important process. The main function of grooving is to help the battery core fix its position during the assembly process and ensure the consistency and stability of the battery during the subsequent forming and welding processes. During the grooving process, a certain groove is established on the battery steel shell through a grooving machine to clamp the battery core inside the battery steel shell, preventing the battery core from shifting and deforming during the subsequent processes, thereby improving the assembly accuracy and quality of the battery.

[0004] For cylindrical batteries, considering the electrical connection between the positive battery cover and the battery core tab, a bendable metal adapter is provided between the positive electrode terminal and the positive electrode tab of the cylindrical battery, which is called a positive current collector (also known as a current collecting plate, current collecting sheet, or current collecting disk). Since the battery electrode group (i.e., the battery core) is welded to the current collector as a whole, during the grooving process of the existing grooving machine on the battery shell, the grooving will also clamp the positive current collector connected to the battery electrode group (i.e., the battery core) at the same time.

[0005] The conventional positive current collector of a cylindrical battery adopts a minimalist rectangular strip structure (i.e., the shape is rectangular) to reduce costs. After the rectangular strip-shaped positive current collector is laser welded to the full tab (i.e., the positive electrode tab) on the battery electrode group (i.e., the battery core), since it needs to be exposed out of the top shell opening of the battery steel shell to be welded to the top cover (i.e., the battery cover), at this time, the longer strip-shaped positive current collector needs to be bent multiple times for assembly, thus wasting a large amount of internal space of the battery steel shell and resulting in a decrease in the battery energy density.

[0006] In addition, since the conventional positive current collector uses more metal materials, it is easy to approach the metal fatigue limit after being bent multiple times and is extremely prone to breakage due to vibration during use, resulting in the failure of the secondary battery and affecting the service life of the battery.

[0007] Therefore, there is an urgent need to develop a technology that can solve the above technical problems. Summary of the Utility Model

[0008] The object of the present utility model is to provide a positive current collector and a cylindrical battery in view of the technical defects existing in the prior art.

[0009] To this end, the present utility model provides a positive current collector, which includes a current collector main body, a liquid flow hole, an adjusting piece, a welding tongue and an adjusting piece accommodating opening groove;

[0010] An adjusting piece accommodating opening groove distributed radially is arranged on the current collector main body;

[0011] The outer side of the adjusting piece accommodating opening groove is open;

[0012] A radially distributed adjusting piece is arranged in the adjusting piece accommodating opening groove;

[0013] One radial end of the adjusting piece is connected to the inner side wall of the adjusting piece accommodating opening groove;

[0014] The other radial end of the adjusting piece is connected to one end of the welding tongue;

[0015] The other end of the welding tongue protrudes outward from the circumferential outer edge of the current collector main body;

[0016] The lower side surface of the current collector main body is used for being welded and fixed to the positive electrode tab at the top of the cylindrical battery cell located outside.

[0017] In addition, the present utility model also provides a cylindrical battery, which includes the positive current collector as described above, a cylindrical battery cell and a battery positive electrode cover;

[0018] The positive electrode tab at the top of the cylindrical battery cell is welded to the lower side surface of the current collector main body in the positive current collector;

[0019] The welding tongue in the positive current collector is welded to the lower side surface of the battery positive electrode cover.

[0020] It can be seen from the technical solutions provided by the present utility model above that, compared with the prior art, the present utility model provides a positive current collector and a cylindrical battery, the structural design of which is scientific. The positive current collector on the battery is designed scientifically and reasonably, and the battery cover can be reliably connected to the positive electrode tab on the battery electrode group (battery cell) without multiple bends, significantly saving the internal space of the battery shell occupied, thereby improving the energy density of the battery, which has great practical significance.

[0021] In addition, the positive current collector designed by the present utility model is adapted to the existing rolling groove process and will not interfere with the rolling groove operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of a positive current collector provided by the present utility model;

[0023] Figure 2 It is a schematic diagram after the positive current collector is welded to the tab on the cylindrical battery cell provided by the present utility model;

[0024] Figure 3 It is a schematic diagram of the state perpendicular to the main body of the current collector after the welding tongue and the adjusting piece on the positive current collector are bent upward for assembling the cylindrical battery provided by the present utility model;

[0025] Figure 4a It is a structural schematic diagram of the battery case after the grooving operation is completed for assembling the cylindrical battery provided by the present utility model Figure 1 ;

[0026] Figure 4b It is a structural schematic diagram of the battery case after the grooving operation is completed for assembling the cylindrical battery provided by the present utility model Figure 1 ;

[0027] Figure 5a It is a structural schematic diagram when the welding tongue of the positive current collector is welded to the battery positive cap for assembling the cylindrical battery provided by the present utility model Figure 1 ;

[0028] Figure 5b It is a structural schematic diagram when the welding tongue of the positive current collector is welded to the battery positive cap for assembling the cylindrical battery provided by the present utility model Figure 1 ;

[0029] Figure 6 It is a schematic diagram of a state of the positive current collector after capping for assembling the cylindrical battery provided by the present utility model, where surface B is used for welding to the battery positive cap;

[0030] Figure 7a It is a schematic diagram of the overall cylindrical battery after capping

[0031] Figure 7b It is a schematic diagram of the overall cross-section of the cylindrical battery after capping;

[0032] Figure 8 It is a schematic diagram of the upper cross-section of the cylindrical battery after capping;

[0033] Figure 9a It is a three-dimensional enlarged structural schematic diagram of a battery positive cap Figure 1 ;

[0034] Figure 9b It is a three-dimensional enlarged structural schematic diagram of a battery positive cap Figure 2 。 Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0036] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It 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, and thus should not be construed as a limitation to the present utility model.

[0037] In the description of this patent, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", "setting" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more unless otherwise clearly and specifically defined.

[0039] See Figures 1 to 3 、 Figures 4a to 4b 、 Figures 5a to 5b 、 Figure 6 、 Figures 7a to 7b 、 Figure 8 and Figures 9a to 9b , the present utility model provides a positive busbar, including: a busbar main body 10, a liquid flow hole 20, an adjusting piece 30, a welding tongue 40, and an adjusting piece receiving opening groove 50;

[0040] The busbar main body 10 is provided with an adjusting piece receiving opening groove distributed radially;

[0041] The outside of the adjusting piece receiving opening groove 50 (i.e., the side far from the center position of the busbar main body 10) is open;

[0042] There is a regulating piece 30 distributed radially within the regulating piece receiving opening groove 50;

[0043] One radial end of the regulating piece 30 is connected to the inner side wall of the regulating piece receiving opening groove 50 (specifically, it can be integrally formed);

[0044] The other radial end of the regulating piece 30 is connected to one end of the welding tongue 40 (specifically, it can be integrally formed);

[0045] The other end of the welding tongue 40 protrudes outward beyond the circumferential outer edge of the bus bar body 10;

[0046] The lower side surface of the bus bar body 10 is used for welding and fixing with the positive electrode tab at the top of a cylindrical battery cell (i.e., the battery electrode group) located outside.

[0047] In the present utility model, specifically in implementation, one radial end of the regulating piece 30 and the inner side wall of the regulating piece receiving opening groove 50 are integrally formed;

[0048] The other radial end of the regulating piece 30 and one end of the welding tongue 40 are integrally formed.

[0049] In the present utility model, specifically in implementation, there is a gap with a preset width (such as a gap with a width of 1 mm) between the remaining two side surfaces of the regulating piece 30 except for the two radial ends and the side wall of the regulating piece receiving opening groove 50.

[0050] Specifically in implementation, the remaining two side surfaces of the regulating piece 30 except for the two radial ends are arranged parallel to each other.

[0051] In the present utility model, specifically in implementation, a plurality of liquid flow holes 20 (i.e., through holes for the electrolyte to flow through) are vertically and equally spacedly distributed on the bus bar body 10.

[0052] Specifically in implementation, three liquid flow holes 20 are vertically and equally spacedly distributed on the bus bar body 10.

[0053] It should be noted that the liquid flow holes 20 are symmetrically arranged, and are not limited to an odd or even number, as long as the overall welding strength of the bus bar is not affected.

[0054] In the present utility model, specifically in implementation, the overall shape of the bus bar body 10 is circular.

[0055] In the present utility model, specifically in implementation, the overall shape of the welding tongue 40 is oval;

[0056] In the present utility model, specifically in implementation, the shape of the welding tongue 40 is a combined shape of two semi - circles and a rectangle, and the two semi - circles are respectively located on both sides of the rectangle.

[0057] It should be noted that in the present utility model, the bus bar main body 10, as the main part of the bus bar, has its lower side surface (i.e., the B surface) welded to the battery electrode group (i.e., the battery cell).

[0058] The adjusting piece 30 can be bent and then adjusted along the Figure 1 double-arrow X direction shown. The width of the adjusting piece 30 is set according to the process;

[0059] The welding tongue 40, after its lower side surface (B surface) is bent and turned over, is used to be welded to the battery positive cover (i.e., the battery cover), and can be designed into shapes such as an ellipse or a circle to cooperate with the battery cover to increase the welding area; the upper side surface of the welding tongue 40 is the Figure 1 , Figure 2 A surface shown.

[0060] The adjusting piece accommodating opening groove 50 enables the adjusting piece 30 to be bent on the one hand and facilitates the circulation of the electrolyte on the other hand.

[0061] Based on the positive bus bar provided by the above-presented present utility model, the present utility model also provides a cylindrical battery, which includes the positive bus bar 100 as described above, as well as a cylindrical battery cell 60 and a battery positive cover 70;

[0062] The positive electrode tab (such as a full electrode tab) at the top of the cylindrical battery cell 60 is welded to the lower side surface of the bus bar main body 10 in the positive bus bar 100;

[0063] The welding tongue 40 in the positive bus bar 100 is welded to the lower side surface of the battery positive cover 70.

[0064] In the present utility model, in terms of specific implementation, the positive bus bar 100, the cylindrical battery cell 60, and the battery positive cover 70 are located inside the battery housing 80;

[0065] On the outer circumference of the upper part of the battery housing 80, a circle of concave rolling grooves 90 is provided circumferentially;

[0066] The lower side of the rolling groove 90 is in tight contact with the top surface of the cylindrical battery cell 60.

[0067] In the present utility model, in terms of specific implementation, the shape and size of the bus bar main body 10 in the positive bus bar 100 are smaller than the shape and size of the top surface of the cylindrical battery cell 60.

[0068] In the present utility model, specifically in implementation, the diameter of the bus bar body 10 in the positive bus bar 100 is smaller than the diameter of the cylindrical battery cell 60. That is, the circumferential outer edge of the bus bar body 10 in the positive bus bar 100 is located in the inner direction of the circumferential outer edges of the cylindrical battery cell 60. Therefore, the structural design of the positive bus bar of the present utility model is adapted to the existing rolling groove process applied to the battery case and will not interfere with the rolling groove operation.

[0069] In the present utility model, specifically in implementation, the overall material of the positive bus bar 100 is aluminum.

[0070] It should be noted that for the battery provided by the utility model, the positive end of the battery uses the rolling groove process to fix the battery cell. Through the design of the positive bus bar, it is beneficial to improve the yield rate and reduce costs and increase efficiency.

[0071] To more clearly understand the technical solution of the present utility model, the following describes the assembly process of the battery provided by the present utility model.

[0072] The first step is to weld the B side (i.e., the lower side) of the bus bar body 10 to the positive electrode tab at the top of the wound cylindrical battery cell 60, as shown in Figure 2 shown;

[0073] The second step is to bend the welding tongue 40 and the adjusting piece 30 upward together so that the welding tongue 40 and the adjusting piece 30 are perpendicular to the top surface of the bus bar body 10, as shown in Figure 3 shown;

[0074] The third step is to install the cylindrical battery cell 60 and the positive bus bar 100 as a whole into the battery case 80;

[0075] The third step is to perform a rolling groove operation on the battery case 80 so that the obtained rolling groove 90 presses and fixes the whole battery, as shown in Figure 4a 、 Figure 4b shown;

[0076] The fourth step is to inject liquid;

[0077] The fifth step is to weld the B side of the welding tongue 40 of the positive bus bar (i.e., the lower side surface that has in the initial state of the first step and is the side surface opposite to the A side) to the battery positive electrode cover 70, as shown in Figure 5a 、 Figure 5b so and Figure 9a 、 Figure 9b shown.

[0078] The sixth step is to fasten the battery positive electrode cover 70 (i.e., seal the cover). At this time, the adjusting piece 30 will be bent adaptively to obtain the battery after sealing, as shown in Figure 6 、 Figure 7a 、 Figure 7bas shown

[0079] Compared with the prior art, the novel battery provided by the present utility model has the following beneficial effects:

[0080] 1. The positive bus bar of the present utility model uses less material;

[0081] 2. After being assembled, the positive bus bar of the present utility model is beneficial to saving the internal space of the battery and increasing the energy density of the battery;

[0082] 3. The number of bending times of the positive bus bar of the present utility model is reduced, the risk of fracture is reduced, and thus the risk of battery failure is reduced.

[0083] 4. The structural design of the positive bus bar of the present utility model is adapted to the rolling groove process and will not interfere with the rolling groove operation;

[0084] 5. The positive bus bar of the present utility model is provided with an adjustable part (i.e., the adjusting piece), and only one bending is required after assembly, saving space and preventing fracture.

[0085] 6. The adjustable part (i.e., the adjusting piece) is arranged inside the bus bar body, so that the material used for the bus bar disk is saved.

[0086] The above are only the preferred embodiments of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model.

Claims

1. A positive busbar, characterized in that: It comprises a busbar body (10), a liquid flow hole (20), an adjustment plate (30), a welding tongue (40) and an adjustment plate accommodating opening groove (50); The busbar body (10) is provided with radially distributed adjustment plate accommodating opening grooves; The adjusting piece accommodates the outer opening of the opening slot (50); The adjusting piece accommodating opening groove (50) has a radially distributed adjusting piece (30); One radial end of the adjustment piece (30) is connected to the inner side wall of the adjustment piece accommodating opening groove (50); The other radial end of the adjusting plate (30) is connected to one end of the welding tongue (40); The other end of the welding tongue (40) protrudes outward from the circumferential outer edge of the busbar body (10); The lower side surface of the busbar body (10) is used to be welded and fixed to the positive electrode ear at the top of the cylindrical battery core (60) located outside.

2. The positive electrode bus bar according to claim 1, characterized in that: One radial end of the adjusting piece (30) is integrally formed with the inner side wall of the adjusting piece accommodating opening groove (50); The other radial end of the regulating sheet (30) and one end of the welding tongue (40) are integrally formed.

3. The positive electrode bus bar according to claim 1, characterized in that: There is a gap of a preset width between the remaining two side surfaces of the adjustment piece (30) except the two radial ends and the side wall of the adjustment piece accommodating opening groove (50).

4. The positive electrode bus bar according to claim 3, characterized in that: The side surfaces of the regulating piece (30) other than the two radial ends are arranged parallel to each other.

5. The positive electrode bus bar according to claim 1, wherein: A plurality of liquid flow holes (20) distributed at equal intervals are vertically penetrated through the busbar body (10).

6. The positive electrode bus bar according to any one of claims 1 to 5, characterized in that: The overall shape of the busbar body (10) is circular; The shape of the welding tongue (40) is a combination of two semicircles and a rectangle, and the two semicircles are respectively located on both sides of the rectangle.

7. A cylindrical battery, characterized in that: Comprising a positive electrode busbar as claimed in any one of claims 1 to 6, as well as a cylindrical battery cell (60) and a battery positive electrode cover (70); The positive electrode ear on the top of the cylindrical battery cell (60) is welded to the lower side of the busbar body (10) in the positive busbar; The welding tongue (40) in the positive electrode busbar is welded to the lower side surface of the positive electrode cover (70) of the battery.

8. The cylindrical battery according to claim 7, characterized in that: The positive electrode busbar, the cylindrical battery cell (60) and the battery positive electrode cover (70) are located inside the battery housing (80); A circle of inwardly concave rolling grooves (90) is arranged around the outer circumference of the upper part of the battery housing (80); The lower side of the rolling groove (90) is in tight contact with the top surface of the cylindrical battery core (60).

9. The cylindrical battery according to claim 7, characterized in that: The shape and size of the busbar body (10) in the positive busbar are smaller than the shape and size of the top surface of the cylindrical battery core (60).

10. The cylindrical battery according to claim 7, characterized in that: The diameter of the busbar body (10) in the positive busbar is smaller than the diameter of the cylindrical battery core (60).

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