Cylindrical battery cell composite collector plate and cylindrical battery cell

Abstract

The utility model provides a cylindrical battery cell composite collector plate and a cylindrical battery cell. The cylindrical battery cell composite collector plate comprises a cathode collector plate and an anode collector plate, wherein the cathode collector plate is respectively welded with a steel shell of the battery cell and a cathode collector in the battery cell; the positive collector plate is used for being respectively welded with a positive tab inside the battery cell and a positive terminal outside the battery cell; and the negative collector plate and the positive collector plate are connected into a whole but are insulated from each other by the insulating plastic. And the dependence on shell diversion is reduced, the internal resistance is reduced, the heating is reduced, the charging efficiency and the overall performance of the battery are improved, the production cost is reduced, and the production efficiency is improved.

Description

Technical Field

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

[0002] In the context of the current global energy transition, the new energy electric vehicle market is experiencing unprecedented expansion, with its market penetration rate increasing year by year, marking that the automotive industry is accelerating towards the direction of green and low-carbon. However, with the rapid growth of the electric vehicle ownership, users' expectations for the endurance and charging efficiency of electric vehicles have also increased. The limitations of the driving range and the relatively long charging time have become two key factors restricting the popularization of electric vehicles and the user experience. Especially for long-distance travel and emergency travel scenarios, the "range anxiety" and "charging waiting" problems of electric vehicles are particularly prominent, which directly affects consumers' purchase intention and usage convenience.

[0003] To address this challenge, electric vehicle manufacturers and battery suppliers are actively engaged in technological innovation, aiming to solve the charging problem of electric vehicles from the battery technology level. The breakthrough of fast charging technology is regarded as the core strategy to alleviate users' charging anxiety and enhance the market competitiveness of electric vehicles. Major enterprises have invested resources in researching and developing more efficient battery charging solutions, aiming to shorten the single charging time and achieve a convenient experience similar to refueling a fuel vehicle, so as to accelerate the market acceptance of electric vehicles.

[0004] In this trend of technological innovation, the design and manufacturing process of traditional cylindrical battery cells are facing the need for upgrading. Most of the existing cylindrical battery cell structures rely on a split current collector plate design, which places the current collector plates at both ends of the battery cell respectively. This not only reduces the product integration degree but also increases the assembly complexity and cost. More importantly, such a design often requires the battery cell housing to be used as the current diversion path, which inevitably increases the internal resistance of the battery cell and generates more heat. The high internal resistance and additional heat generation not only reduce the energy conversion efficiency of the battery but also may accelerate battery aging, shorten the service life, and may pose safety hazards.

[0005] Therefore, developing a new type of cylindrical battery cell structure, aiming to optimize the current collector plate design and reduce the dependence on the housing for current diversion, so as to reduce the internal resistance, reduce heat generation, improve the charging efficiency and the overall performance of the battery, has become a key topic that urgently needs to be overcome in the current battery technology field. This innovation can not only effectively alleviate users' range anxiety but also promote the healthy and rapid development of the new energy vehicle industry and meet the growing demand for green travel. Summary of the Utility Model

[0006] Based on the above, the present utility model provides a cylindrical battery cell composite current collector plate and a cylindrical battery cell, aiming to solve the problems in the prior art that the split current collector plate affects the internal resistance of the battery cell and generates heat.

[0007] A cylindrical battery cell composite current collector plate, comprising:

[0008] A negative current collector plate for welding to the steel shell of the battery cell and the negative current collector inside the battery cell respectively;

[0009] A positive current collector plate for welding to the positive electrode tab inside the battery cell and the positive terminal outside the battery cell respectively;

[0010] Insulating plastic, connecting the negative current collector plate and the positive current collector plate into one body but insulating them from each other.

[0011] Further, the negative current collector plate includes:

[0012] A first welding end face for welding to the negative current collector of the battery cell;

[0013] A flanging part located at the edge of the first welding end face, folded into a vertical plane relative to the first welding end face for welding to the steel shell of the battery cell.

[0014] Further, a bending groove is formed at the intersection of the flanging part and the first welding end face.

[0015] Further, the positive current collector plate includes:

[0016] A second welding end face for welding to the positive electrode tab inside the battery cell;

[0017] A boss protruding from the second welding end face for welding to the positive terminal outside the battery cell.

[0018] Further, both the first welding end face and the second welding end face have an inner boundary and an arc-shaped outer boundary;

[0019] The flanging part is located at the outer boundary of the first welding end face;

[0020] The inner boundary of the first welding end face and the inner boundary of the second welding end face are connected together by insulating plastic.

[0021] Further, the middle part of the inner boundary of the second welding end face extends outward in an arc to form an arc-shaped convex part;

[0022] The middle part of the inner boundary of the first welding end face is recessed inward in an arc to form an arc-shaped notch;

[0023] When the negative current collector plate and the positive current collector plate are connected together by insulating plastic, the arc-shaped convex part and the arc-shaped notch cooperate with each other.

[0024] Furthermore, the first welding end face has at least one first fixing hole, which is arranged in an arc along the arc-shaped notch;

[0025] When the negative current collector plate and the positive current collector plate are connected together by insulating plastic, the insulating plastic covers the first fixing hole.

[0026] Furthermore, the second welding end face has at least one second fixing hole, which is arranged in an arc along the arc-shaped convex part;

[0027] When the negative current collector plate and the positive current collector plate are connected together by insulating plastic, the insulating plastic covers the second fixing hole.

[0028] Furthermore, the boss is cylindrical, and the central axis of the boss coincides with the center of the arc-shaped convex part.

[0029] A cylindrical battery cell includes the aforementioned cylindrical battery cell composite current collector plate;

[0030] The steel shell of the battery cell and the negative current collector inside the battery cell are respectively welded to the negative current collector plate;

[0031] The positive electrode tab inside the battery cell and the positive terminal outside the battery cell are respectively welded to the positive current collector plate.

[0032] The beneficial technical effects of the present utility model are as follows: By optimizing the design of the current collector plate, the positive and negative current collector plates are combined together, making the structural components of the battery cell highly integrated, reducing the dependence on the outer shell for current conduction, eliminating the problem of relatively large internal resistance of the battery cell caused by current conduction through the shell, thereby reducing the internal resistance, reducing heat generation, improving the charging efficiency and the overall performance of the battery. In addition, due to the high integration of the structural components of the battery cell, the structural components are more convenient in the production process and more convenient in the battery cell assembly process, reducing the production cost and improving the production efficiency. Description of the Drawings

[0033] Figure 1 、 Figure 2 and Figure 4 are schematic structural diagrams of a cylindrical battery cell composite current collector plate provided by the present utility model;

[0034] Figure 3 and Figure 5 are schematic diagrams of the electrical connection between a cylindrical battery cell composite current collector plate provided by the present utility model and the rest of the battery cell;

[0035] Among them,

[0036] 1 - negative current collector plate; 101 - flanging part; 102 - bending groove; 103 - first welding end face; 104 - first fixing hole; 2 - insulating plastic; 3 - positive current collector plate; 301 - second welding end face; 302 - boss; 303 - second fixing hole; 4 - steel shell; 5 - positive terminal. Detailed Embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model 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 belong to the scope of protection of the present utility model.

[0038] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments may be combined with each other.

[0039] The present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments, but it is not limited to the present utility model.

[0040] See Figures 1-5 , the present utility model provides a cylindrical battery cell composite current collector plate, including:

[0041] A negative current collector plate (1), which is used to be welded to the steel shell (4) of the battery cell and the negative current collector inside the battery cell respectively;

[0042] A positive current collector plate (3), which is used to be welded to the positive tab inside the battery cell and the positive terminal (5) outside the battery cell respectively;

[0043] An insulating plastic (2), which connects the negative current collector plate (1) and the positive current collector plate (3) into one body but insulates them from each other.

[0044] Furthermore, the welding method of the negative current collector plate (1) to the steel shell (4) of the battery cell and the negative current collector inside the battery cell is laser welding.

[0045] Furthermore, the welding method of the positive current collector plate (3) to the positive tab inside the battery cell and the positive terminal outside the battery cell is laser welding.

[0046] By optimizing the design of the current collector plate, the positive and negative current collector plates are combined together, making the structural components of the battery cell highly integrated, reducing the dependence on the housing for current conduction, eliminating the problem of relatively large internal resistance of the battery cell caused by current conduction through the housing, thereby reducing the internal resistance, reducing heat generation, improving the charging efficiency and the overall performance of the battery. In addition, due to the high integration of the structural components of the battery cell, the structural components are more convenient in the production process and more convenient in the battery cell assembly process, reducing the production cost and improving the production efficiency.

[0047] Furthermore, the negative current collector plate (1) includes:

[0048] A first welding end face (103), which is used to be welded to the negative current collector of the battery cell;

[0049] The hemming part (101) is located at the edge of the first welding end face (103) and is folded relative to the first welding end face (103) to form a vertical plane for welding with the steel shell of the battery cell.

[0050] Furthermore, the hemming part (101) and the first welding end face (103) are integrally formed by the bending process of a mold. The main function of the hemming part (101) is for the welding of the negative current collector plate (1) and the steel shell (4), realizing the electrical connection between the negative electrode inside the battery cell and the external negative electrode. The vertical plane formed by folding the hemming part (101) can just be welded to the steel shell on the side wall of the battery cell.

[0051] Furthermore, a bending groove (102) is formed at the intersection of the hemming part (101) and the first welding end face (103).

[0052] The bending groove (102) is formed by the connection of the hole in the hemming part (101) and the hole at the boundary of the first welding end face (103). The bending groove (102) is formed by stamping the negative current collector plate (1), and its main function is to facilitate the forming of the hemming part (101) and form an elastic structure during the welding of the negative current collector plate (1) and the outside, reducing the stress deformation caused by laser welding.

[0053] The first welding end face (103) is a planar structure, mainly used for welding with the negative current collector inside the battery cell to play an electrical connection role.

[0054] Furthermore, the positive current collector plate (3) includes:

[0055] A second welding end face (301) for welding with the positive electrode tab inside the battery cell;

[0056] A boss (302) protruding from the second welding end face (301) for welding with the positive terminal outside the battery cell.

[0057] The second welding end face (301) is used for welding with the positive electrode tab inside the battery cell to realize electrical connection. The boss (302) is used for welding with the positive terminal (5) outside the battery cell to realize the extraction of the positive electrode inside the battery cell.

[0058] The outer shape of the first welding end face (103) is similar to a semi - circle, and the outer shape of the second welding end face (301) is similar to a semi - circle. The two semi - circle - shaped first welding end faces (103) and second welding end faces (301) are connected together, and the overall shape is similar to a disc shape, which just fits the cylindrical battery cell.

[0059] Furthermore, both the first welding end face (103) and the second welding end face (301) have an inner boundary and an arc - shaped outer boundary;

[0060] The hemming part (101) is located at the outer boundary of the first welding end face (103);

[0061] The inner boundary of the first welding end face (103) and the inner boundary of the second welding end face (301) are connected together by an insulating plastic (2).

[0062] Furthermore, the middle part of the inner boundary of the second welding end face (301) extends outward in an arc to form an arc convex part;

[0063] The middle part of the inner boundary of the first welding end face (103) is recessed inward in an arc to form an arc notch;

[0064] When the negative current collector plate (1) and the positive current collector plate (3) are connected together by the insulating plastic (2), the arc convex part and the arc notch cooperate with each other.

[0065] Since the positive current collector plate (3) is provided with a boss (302) for welding to the positive terminal (5) outside the battery cell. For a cylindrical battery cell, the positive terminal (5) is generally arranged at the central position. Therefore, the middle part of the positive current collector plate (3) protrudes to exactly form an arc convex part, and the arc convex part is used to carry part of the boss (302), so that the boss can exactly correspond to the positive terminal (5) for welding. In this way, in order to ensure the integral disc shape of the negative current collector plate (1) and the positive current collector plate (3), the negative current collector plate (1) is recessed to form an arc notch to create a receiving space for the arc convex part during connection. Furthermore, the first welding end face (103) has at least one first fixing hole (104), which is arranged in an arc along the arc notch;

[0066] When the negative current collector plate (1) and the positive current collector plate (3) are connected together by the insulating plastic (2), the insulating plastic (2) covers the first fixing hole (104).

[0067] The first fixing hole (104) is a through-hole structure, which is mainly used for fixing and positioning during the injection molding of the insulating plastic (2). That is to say, when injecting the insulating plastic (2), the insulating plastic (2) will flow into the first fixing hole (104), making the connection between the insulating plastic (2) and the negative current collector plate (1) tighter.

[0068] Furthermore, the second welding end face (301) has at least one second fixing hole (303), which is arranged in an arc along the arc convex part;

[0069] When the negative current collector plate (1) and the positive current collector plate (3) are connected together by the insulating plastic (2), the insulating plastic (2) covers the second fixing hole (303).

[0070] The second fixing hole (303) is a through-hole structure, which mainly plays a role in fixing and positioning during the injection molding of the insulating plastic (2). That is to say, when the insulating plastic (2) is injection-molded, the insulating plastic (2) will flow into the second fixing hole (303), making the connection between the insulating plastic (2) and the positive current collector plate (3) tighter.

[0071] Furthermore, the boss (302) is cylindrical, and the central axis of the boss (302) coincides with the center of the arc-shaped convex part.

[0072] The present utility model also provides a cylindrical battery cell, comprising the aforementioned cylindrical battery cell composite current collector plate;

[0073] The steel shell of the battery cell and the negative current collector inside the battery cell are respectively welded to the negative current collector plate (1);

[0074] The positive electrode tab inside the battery cell and the positive terminal outside the battery cell are respectively welded to the positive current collector plate (3).

[0075] The above are only the preferred embodiments of the present utility model, and do not limit the implementation manners and protection scope of the present utility model. For those skilled in the art, it should be able to realize that all the equivalent replacements and obvious changes made by using the description and illustrations of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A composite current collector for a cylindrical battery cell, characterized in that: include: A negative electrode current collector plate (1) is used to be welded to the steel shell of the battery cell and the negative electrode current collector inside the battery cell respectively; A positive electrode current collecting plate (3) is used to be welded to the positive electrode tab inside the battery cell and the positive electrode terminal outside the battery cell respectively; The insulating plastic (2) connects the negative electrode current collecting disc (1) and the positive electrode current collecting disc (3) into one body but insulates them from each other.

2. A cylindrical battery cell composite current collector according to claim 1, characterized in that: The negative electrode current collecting plate (1) comprises: A first welding end surface (103) used for welding to the negative electrode current collector of the battery cell; The folded edge portion (101) is located at the edge of the first welding end surface (103) and is folded into a vertical surface relative to the first welding end surface (103) for welding with the steel shell of the battery cell.

3. A cylindrical battery composite current collector according to claim 2, characterized in that: A bending groove (102) is formed at the intersection of the folded edge portion (101) and the first welding end surface (103).

4. A cylindrical battery composite current collector according to claim 2, characterized in that: The positive electrode current collecting plate (3) comprises: The second welding end surface (301) is used for welding with the positive electrode tab inside the battery cell; The boss (302) protrudes from the second welding end surface (301) and is used for welding to the positive terminal outside the battery cell.

5. A cylindrical battery cell composite current collector according to claim 4, characterized in that: The first welding end surface (103) and the second welding end surface (301) both have an inner boundary and an arc-shaped outer boundary; The folded edge portion (101) is located at the outer boundary of the first welding end surface (103); The inner boundary of the first welding end surface (103) and the inner boundary of the second welding end surface (301) are connected together via the insulating plastic (2).

6. A cylindrical battery cell composite current collector according to claim 4, characterized in that: The middle portion of the inner boundary of the second welding end surface (301) is extended outward in an arc shape to form an arc-shaped convex portion; The middle portion of the inner boundary of the first welding end surface (103) is inwardly concave in an arc shape to form an arc-shaped notch; When the negative electrode current collecting disc (1) and the positive electrode current collecting disc (3) are connected together via the insulating plastic (2), the arc-shaped protrusion and the arc-shaped notch cooperate with each other.

7. A cylindrical battery cell composite current collector according to claim 6, characterized in that: The first welding end surface (103) has at least one first fixing hole (104) arranged in an arc shape along the arc-shaped notch; When the negative electrode current collecting disc (1) and the positive electrode current collecting disc (3) are connected together via the insulating plastic (2), the insulating plastic (2) covers the first fixing hole (104).

8. A composite current collector for a cylindrical battery cell as claimed in claim 6, characterized in that: The second welding end surface (301) has at least one second fixing hole (303) arranged in an arc shape along the arc-shaped convex portion; When the negative electrode current collecting disc (1) and the positive electrode current collecting disc (3) are connected together via the insulating plastic (2), the insulating plastic (2) covers the second fixing hole (303).

9. A cylindrical battery cell composite current collector according to claim 6, characterized in that: The boss (302) is cylindrical, and the central axis of the boss (302) coincides with the center of the arc-shaped convex portion.

10. A cylindrical battery cell, characterized in that: A cylindrical battery cell composite current collector comprising any one of claims 1 to 9; The steel shell of the battery cell and the negative electrode current collector inside the battery cell are respectively welded to the negative electrode current collecting plate (1); The positive electrode tab inside the battery cell and the positive electrode terminal outside the battery cell are respectively welded to the positive electrode current collecting plate (3).

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