Cylindrical battery with improved external short circuit performance

Abstract

The utility model relates to cylindrical lithium ion battery, specifically relates to a cylindrical battery of improving external short circuit performance, including cylindrical pole group, positive current collecting piece, steel case and cap, and the middle part of the positive pole end of cylindrical pole group is convex and forms the connecting portion, and the positive current collecting piece includes the current collecting disc setting in the positive pole end of cylindrical pole group, and the connecting portion is inserted into the connecting groove of the lower end surface setting of current collecting disc, and the cylindrical pole group and current collecting disc set up in the steel case and are fixed by the rolling groove of steel case, and the insulating spacer is arranged between the rolling groove lower side of steel case and current collecting disc, and the cap sets up in the positive pole end of steel case, and the cap has the explosion -proof structure and the sealing ring of cap extends to the rolling groove department of steel case, the cylindrical battery of the utility model, through optimizing the structure design and assembly mode of each part of electric core, effectively reduce the heat generation of battery external short circuit, increase the heat dissipation area, thereby the performance of battery in external short circuit test is improved significantly, and the security of battery use is improved.

Description

Technical Field

[0001] This utility model relates to cylindrical lithium-ion batteries, specifically to a cylindrical battery with improved external short-circuit performance. Background Technology

[0002] With the widespread application of lithium-ion batteries in consumer electronics, new energy vehicles, and other fields, battery safety has become an increasingly important concern. Cylindrical lithium-ion batteries are widely used due to their compact structure and ease of standardized production; however, external short circuits are a significant factor affecting their safety performance. When an external short circuit occurs in a cylindrical lithium-ion battery, a large current is generated instantaneously, causing a rapid increase in the battery's internal temperature, potentially leading to serious safety accidents such as battery combustion or explosion. Currently, existing cylindrical lithium-ion battery cell structures suffer from insufficient heat dissipation and uneven current distribution when dealing with external short circuits, making it difficult to effectively reduce the hazards caused by external short circuits. Therefore, improvements to the cell structure are urgently needed to enhance the battery's external short-circuit performance. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a cylindrical battery with improved external short-circuit performance. By optimizing the structural design and assembly method of each component of the battery cell, the heat generated during external short circuit is effectively reduced and the heat dissipation area is increased, thereby significantly improving the battery's performance in external short-circuit tests and enhancing the safety of battery use.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: a cylindrical battery with improved external short-circuit performance, including a cylindrical electrode assembly, a positive current collector, a steel shell, and a cap. The cylindrical electrode assembly is a full-tab electrode assembly. The positive end of the cylindrical electrode assembly protrudes outward to form a connecting part. The positive current collector includes a current collector plate and a current collector handle. The current collector plate is disposed at the positive end of the cylindrical electrode assembly. A connecting groove is provided on the lower end face of the current collector plate. The connecting part extends into the connecting groove and is welded to the current collector plate. The cylindrical electrode assembly and the current collector plate are disposed in the steel shell and fixed by the rolling groove of the steel shell. An insulating gasket is provided between the lower edge of the rolling groove and the current collector plate inside the steel shell. The cap is disposed at the positive end of the steel shell. The cap has an explosion-proof structure and the sealing ring of the cap extends to the rolling groove of the steel shell. The current collector handle is welded to the current collector plate and the cap.

[0005] As an optional technical solution, the cap includes a sealing ring, an orifice plate, an explosion-proof disc, and a top cover. The orifice plate is welded to the manifold, the explosion-proof disc is mounted on the orifice plate, and the top cover is mounted on the explosion-proof disc. An insulating ring is provided between the explosion-proof disc and the orifice plate. The sealing ring is wrapped around the outside of the orifice plate, the explosion-proof disc, and the orifice plate, and an extension is provided at the lower edge of the sealing ring. The cap is located at the positive end of the steel shell, and the extension extends into the groove.

[0006] As an optional technical solution, the current collector is an integral structure, including an outer ring body and an inner disc body disposed within the outer ring body. The lower end face of the inner disc body is provided with a connecting groove. The outer ring body is disposed at the positive end of the cylindrical electrode assembly and located below the groove. The insulating gasket is annular and is disposed between the outer ring body and the groove.

[0007] As an optional technical solution, the connecting part is frustum-shaped, and the inner disc is a hollow frustum-shaped part with an open bottom.

[0008] Compared with the prior art, the advantages of this utility model are as follows: 1. When an external short circuit occurs in the battery, the raised connecting part in the middle of the cylindrical electrode group can participate in the conduction current, increasing the current conduction area, making the current more evenly distributed, reducing the heat generation of the battery, and avoiding local overheating of the battery; 2. The heat generated by the current collector can be transferred to the cylindrical electrode group, and the large surface area of ​​the cylindrical electrode post can achieve rapid heat dissipation, improving the heat dissipation performance of the battery; 3. By setting an insulating gasket between the lower edge of the groove and the positive current collector, and the sealing ring of the cap extending downward to the groove of the steel shell, double insulation is achieved, effectively blocking the conductive path that may lead to an external short circuit in the battery. At the same time, the explosion-proof structure of the cap further ensures the safety of the battery under abnormal conditions, significantly improving the safety and reliability of battery use, and effectively improving the external short circuit test performance of the battery. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a partial structural diagram of the battery;

[0011] In the figure: 1. Cylindrical pole group, 11. Connecting part, 2. Positive current collector, 3. Steel shell, 31. Groove, 4. Cap, 41. Sealing ring, 42. Orifice plate, 43. Explosion-proof plate, 44. Top cover, 45. Insulating ring, 5. Insulating gasket. Detailed Implementation

[0012] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0013] like Figure 1 As shown, a cylindrical battery with improved external short-circuit performance includes a cylindrical electrode assembly 1, a positive current collector 2, a steel shell 3, and a cap 4. The cylindrical electrode assembly 1 is a full-tab electrode assembly. The middle part of the positive end of the cylindrical electrode assembly 1 protrudes axially outward from the cylindrical electrode assembly 1 to form a connecting part 11 for welding with the positive current collector 2. The positive current collector 2 includes a current collector plate and a current collector handle. The current collector handle is welded to the current collector plate, or the current collector handle and the current collector plate are an integral structure. A connecting groove is provided on the lower end face of the current collector plate. The current collector plate is located at the positive end of the cylindrical electrode assembly 1. The connecting part 11 at the positive end of the cylindrical electrode assembly 1 extends into the connecting groove and is welded to the current collector plate.

[0014] The interior of the steel shell 3 has a space to accommodate the cylindrical electrode assembly 1. The cylindrical electrode assembly 1 and the positive current collector 2 are disposed inside the steel shell 3. The lower edge of the groove 31 of the steel shell 3 cooperates with the positive current collector 2, thereby fixing the cylindrical electrode assembly 1 and the positive current collector 2 into the steel shell 3. An insulating gasket 5 is provided between the current collector and the lower edge of the groove 31. The insulating gasket 5 is circular and is used to block the conductive path between the positive terminal of the cylindrical electrode assembly 1 and the steel shell 3 to avoid short circuit of the battery due to accidental contact.

[0015] The cap 4 has an explosion-proof structure. The cap 4 is located at the positive end of the steel shell 3. The current collector is welded to the cap 4. The sealing ring 41 of the cap 4 extends to the groove 31 of the steel shell 3, blocking the risk of contact between the steel shell 3 and the current collector, improving the insulation performance of the cylindrical electrode assembly 1. The cap 4 also has an explosion-proof structure, which can release pressure when the internal pressure of the battery rises abnormally, ensuring battery safety.

[0016] In this embodiment of the cylindrical battery, when an external short circuit occurs, the protruding connecting portion 11 in the middle of the cylindrical electrode assembly 1 can participate in the conduction current, increasing the current conduction area and enabling the current to be distributed more evenly, reducing the heat generation of the battery and preventing local overheating. The heat generated by the current collector can be transferred to the cylindrical electrode assembly 1, and the large surface area of ​​the cylindrical electrode post can achieve rapid heat dissipation, improving the heat dissipation performance of the battery. In this embodiment of the cylindrical battery, by setting an insulating gasket 5 between the lower edge of the groove 31 and the positive current collector 2, and the sealing ring 41 of the cap 4 extending downward to the groove 31 of the steel shell 3, double insulation is achieved, effectively blocking the conductive path that may lead to an external short circuit of the battery. At the same time, the explosion-proof structure of the cap 4 further ensures the safety of the battery under abnormal conditions, significantly improving the safety and reliability of battery use, and effectively improving the external short circuit test performance of the battery.

[0017] Please see Figure 1The cap 4 includes a sealing ring 41, a perforated plate 42, an explosion-proof disc 43, and a top cover 44. The perforated plate 42 is welded to the manifold. The explosion-proof disc 43 is disposed on the perforated plate 42, and the top cover 44 is disposed on the explosion-proof disc 43. The explosion-proof disc 43 is the explosion-proof structure of the cap 4. An insulating ring 45 is disposed between the explosion-proof disc 43 and the perforated plate 42. The insulating ring 45 is a circular gasket structure, located between the outer ring area of ​​the explosion-proof disc 43 and the outer ring area of ​​the perforated plate 42. The insulating ring 45 raises the explosion-proof disc 43 to provide sufficient space above the perforated plate 42 for the installation of the explosion-proof disc 43 and for deformation during pressure relief. The top cover 44 protrudes upward in the middle to provide sufficient space between the perforated plate 42 and the top cover 44 for the deformation of the explosion-proof disc 43 during pressure relief. The sealing ring 41 is fastened around the outside of the orifice plate 42, the explosion-proof sheet 43 and the orifice plate 42. The sealing ring 41 fixes the relative positions of the orifice plate 42, the explosion-proof sheet 43 and the orifice plate 42. An extension is provided at the lower edge of the sealing ring 41. The extension is a downwardly extending bowl-shaped structure.

[0018] When the cap 4 is installed on the positive end of the steel shell 3, the sealing ring 41 covers the orifice plate 42, the explosion-proof plate 43 and the orifice plate 42 and isolates the three from the steel shell 3. The extension of the sealing ring 41 extends into the inner edge of the groove 31 of the steel shell 3, blocking the risk of contact between the steel shell 3 and the current collector and improving the insulation performance of the cylindrical pole group 1.

[0019] The current collector includes an outer ring and an inner disc. The outer ring is circular, and the inner disc is inside the outer ring with its outer edge connected to the inner edge of the outer ring. The inner disc and outer ring are an integral structure. A connecting groove is provided on the lower end face of the inner disc. The outer ring is located at the positive end of the cylindrical electrode assembly 1 and below the groove 31. The insulating gasket 5 is circular and is located between the outer ring and the groove 31. Furthermore, the connecting part 11 is a truncated cone-shaped protrusion, and the inner disc is a hollow truncated cone with an open bottom. The inner cavity of the inner disc is adapted to the connecting part 11. When the outer ring is placed on the cylindrical electrode assembly 1, the top of the connecting part 11 can just contact the top surface of the inner cavity of the inner disc.

[0020] In this specification, the terms "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cylindrical battery with improved external short-circuit performance, characterized in that: The assembly includes a cylindrical electrode assembly (1), a positive current collector (2), a steel shell (3), and a cap (4). The cylindrical electrode assembly (1) is a full-ear electrode assembly. The positive end of the cylindrical electrode assembly (1) protrudes outward to form a connecting part (11). The positive current collector (2) includes a current collector plate and a current collector handle. The current collector plate is located at the positive end of the cylindrical electrode assembly (1). A connecting groove is provided on the lower end face of the current collector plate. The connecting part (11) extends into the connecting groove and is welded to the current collector plate. The pole group (1) and the collector plate are set inside the steel shell (3) and fixed by the groove (31) of the steel shell (3). An insulating gasket (5) is provided between the lower edge of the groove (31) and the collector plate inside the steel shell (3). The cap (4) is set at the positive end of the steel shell (3). The cap (4) has an explosion-proof structure and the sealing ring (41) of the cap (4) extends to the groove (31) of the steel shell (3). The collector handle is welded to the collector plate and the cap (4).

2. A cylindrical battery with improved external short-circuit performance according to claim 1, characterized in that: The cap (4) includes a sealing ring (41), an orifice plate (42), an explosion-proof plate (43), and a top cover (44). The orifice plate (42) is welded to the manifold. The explosion-proof plate (43) is placed on the orifice plate (42), and the top cover (44) is placed on the explosion-proof plate (43). An insulating ring (45) is provided between the explosion-proof plate (43) and the orifice plate (42). The sealing ring (41) is wrapped around the outside of the orifice plate (42), the explosion-proof plate (43), and the orifice plate (42). An extension is provided at the lower edge of the sealing ring (41). The cap (4) is placed at the positive end of the steel shell (3), and the extension extends into the groove (31).

3. A cylindrical battery with improved external short-circuit performance according to claim 2, characterized in that: The current collector is an integral structure, including an outer ring body and an inner plate body disposed within the outer ring body. A connecting groove is provided on the lower end face of the inner plate body. The outer ring body is disposed at the positive end of the cylindrical pole group (1) and located below the rolling groove (31). The insulating pad (5) is annular and disposed between the outer ring body and the rolling groove (31).

4. A cylindrical battery with improved external short-circuit performance according to claim 3, characterized in that: The connecting part (11) is a frustum shape, and the inner plate is a hollow frustum shape with an open bottom.

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