Cylindrical lithium ion battery

Abstract

The utility model discloses a cylindrical lithium ion battery which comprises a shell and a roll core arranged in the shell, an upper insulating sheet is arranged above the roll core, an upper sealing gasket is arranged at the top end of the inner wall of the shell, a cover cap used for covering the shell is arranged at the center of the shell, and a soldering lug is arranged at the center of the top end of the cover cap; the upper sealing gasket is arranged above the roll core, the lower sealing gasket is arranged below the roll core, the upper sealing gasket and the lower sealing gasket are both made of metallized ceramic materials, the advanced metallized ceramic material preparation technology is adopted, and uniformity and stability of a metal layer on the ceramic surface are guaranteed; the peripheral edge of the upper sealing gasket and the peripheral edge of the top end of the inner wall of the shell are subjected to laser welding, the peripheral edge of the lower sealing gasket and the peripheral edge of the bottom end of the inner wall of the shell are subjected to laser welding, the advanced welding technology is introduced, and the connection strength and the sealing effect between the upper sealing gasket and the lower sealing gasket of the roll core and the shell are improved.

Description

Technical Field

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

[0002] With the rapid development of new energy vehicles and portable electronic devices, lithium batteries, as their core power source and power supply component, are attracting increasing attention for their performance and safety. Because round lithium-ion batteries were previously primarily used in electronic products, where operating conditions are far less harsh than those in automobiles, this places higher demands on the sealing properties of round lithium-ion batteries. This is primarily due to the impact of high and low temperatures, shock, and vibration. Battery sealing performance is one of the key factors in ensuring safe and reliable operation.

[0003] The packaging of round lithium-ion batteries is not strictly hermetically sealed; rather, it is achieved by compressing the polypropylene in the battery cover with a punch. Therefore, loose packaging, impact from external temperature fluctuations, and deformation of the battery casing can all lead to a loss of sealing, causing electrolyte leakage. This leaked electrolyte not only corrodes the battery pack but can also cause a short circuit, threatening the safety of passengers. Therefore, there is an urgent need to improve the sealing performance of the battery. Utility Model Content

[0004] The purpose of the utility model is to provide a cylindrical lithium ion battery to solve the problem of improving the sealing performance of the battery.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a cylindrical lithium-ion battery comprising an outer shell and a winding core disposed within the outer shell, wherein an upper sealing gasket is disposed at the top end of the inner wall of the outer shell, a lower insulating sheet is disposed at the bottom end of the winding core, and a lower sealing gasket, an explosion-proof valve, and a gasket are disposed below the lower insulating sheet in order from top to bottom, wherein both the upper sealing gasket and the lower sealing gasket are made of a metallized ceramic material;

[0006] The edges around the upper sealing gasket and the edges around the top end of the inner wall of the shell are laser welded, and the edges around the lower sealing gasket and the edges around the bottom end of the inner wall of the shell are laser welded.

[0007] An upper insulating sheet is provided above the winding core, a through hole is formed through the upper insulating sheet, and a positive electrode ear is led out from the upper end of the winding core through the through hole.

[0008] Wherein, a cap for covering the shell is provided at the center of the shell, and a welding piece is provided at the center of the top end of the cap.

[0009] A center pin is provided at the center of the interior of the shell, one end of the winding core contacts the outer side of the center pin, and the other end of the winding core contacts the inner wall of the shell.

[0010] The gap between the winding core and the shell is filled with electrolyte.

[0011] The winding core is composed of four layers stacked from the inside to the outside, namely, a positive electrode sheet, a first separator, a negative electrode sheet and a second separator, and the winding core is wound outward around the center needle.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The utility model arranges an upper sealing gasket above the winding core and a lower sealing gasket below the winding core. Both the upper sealing gasket and the lower sealing gasket are made of metallized ceramic material and adopts advanced metallized ceramic material preparation technology to ensure the uniformity and stability of the metal layer on the ceramic surface; the edges of the upper sealing gasket are laser welded to the edges of the top of the inner wall of the outer shell, and the edges of the lower sealing gasket are laser welded to the edges of the bottom of the inner wall of the outer shell. Advanced welding technology is introduced to improve the connection strength and sealing effect between the upper and lower sealing gaskets of the winding core and the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the front view of a cylindrical lithium-ion battery of the present invention;

[0015] Figure 2 This is a schematic cross-sectional view of a cylindrical lithium-ion battery of the present invention;

[0016] Figure 3 This is a partial top view enlarged structural diagram of a cylindrical lithium-ion battery of the present invention.

[0017] In the figure: 10, outer shell; 20, winding core; 21, positive electrode sheet; 22, first diaphragm; 23, negative electrode sheet; 24, second diaphragm; 30, center needle; 40, upper insulating sheet; 50, positive electrode ear; 60, cap; 61, welding piece; 62, upper sealing gasket; 70, lower insulating sheet; 80, lower sealing gasket; 81, explosion-proof valve; 82, gasket. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] See also Figure 1-3The utility model provides a technical solution: a cylindrical lithium-ion battery, including an outer shell 10 and a winding core 20 arranged inside the outer shell 10, an upper sealing gasket 62 is provided at the top of the inner wall of the outer shell 10, a lower insulating sheet 70 is provided at the bottom end of the winding core 20, and a lower sealing gasket 80, an explosion-proof valve 81 and a gasket 82 are provided below the lower insulating sheet 70 from top to bottom. The upper sealing gasket 62 and the lower sealing gasket 80 are both made of metallized ceramic material, and advanced metallized ceramic material preparation technology is adopted to ensure the uniformity and stability of the metal layer on the ceramic surface;

[0020] The edges of the upper sealing gasket 62 are laser welded to the edges of the top of the inner wall of the outer shell 10, and the edges of the lower sealing gasket 80 are laser welded to the edges of the bottom of the inner wall of the outer shell 10. Advanced welding technology is introduced to improve the connection strength and sealing effect between the upper and lower sealing gaskets of the winding core and the outer shell 10.

[0021] Among them, an upper insulating sheet 40 is provided above the winding core 20, and a through hole is opened on the upper insulating sheet 40. A positive ear 50 is led out from the upper end of the winding core 20 through the through hole. The positive ear 50 is adhered with a positive ear 50 protective tape. When the battery is injected with electrolyte or when the battery is short-circuited and overheated to generate gas, the electrolyte flows through the through hole, which plays a drainage role.

[0022] A cap 60 for covering the outer shell 10 is provided at the center of the outer shell 10 , and a welding piece 61 is provided at the center of the top of the cap 60 , and the welding piece 61 is used to seal the top opening of the battery.

[0023] A center pin 30 is provided at the center of the shell 10 , one end of the winding core 20 contacts the outer side of the center pin 30 , and the other end of the winding core 20 contacts the inner wall of the shell 10 .

[0024] The gap between the winding core 20 and the outer shell 10 is filled with electrolyte. Before the cylindrical lithium-ion battery is injected with electrolyte, there is a gap between the winding core 20 and the inner wall of the outer shell 10, allowing the electrolyte to infiltrate the electrode group.

[0025] Among them, the core 20 is composed of four layers from the inside to the outside, namely the positive electrode sheet 21, the first separator 22, the negative electrode sheet 23 and the second separator 24. The core 20 is wound outward around the center needle 30. When winding, the negative electrode sheet 23 and the positive electrode sheet 21 are parallel to each other and are located on the outside of the positive electrode sheet 21. The first separator 22 is used to separate the negative electrode sheet 23 and the positive electrode sheet 21 to avoid short circuit. The second separator 24 is located on the outer side of the negative electrode sheet 23, that is, it is located on the outside of the negative electrode sheet at the beginning of winding, and is wound together with the negative electrode sheet 23 to form a spiral winding structure.

[0026] Working principle: When in use, an upper sealing gasket 62 is set above the winding core 20 and a lower sealing gasket 80 is set below the winding core 20. The upper sealing gasket 62 and the lower sealing gasket 80 are both made of metallized ceramic materials. Advanced metallized ceramic material preparation technology is used to ensure the uniformity and stability of the metal layer on the ceramic surface; the edges of the upper sealing gasket 62 are laser welded to the edges of the top of the inner wall of the outer shell 10, and the edges of the lower sealing gasket 80 are laser welded to the edges of the bottom of the inner wall of the outer shell 10. Advanced welding technology is introduced to improve the connection strength and sealing effect between the sealing gasket on the winding core and the outer shell 10.

[0027] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A cylindrical lithium-ion battery comprising a housing (10) and a winding core (20) disposed inside the housing (10), characterized in that: An upper sealing gasket (62) is provided at the top end of the inner wall of the shell (10), a lower insulating sheet (70) is provided at the bottom end of the winding core (20), and a lower sealing gasket (80), an explosion-proof valve (81) and a gasket (82) are provided below the lower insulating sheet (70) in order from top to bottom, wherein the upper sealing gasket (62) and the lower sealing gasket (80) are both made of metallized ceramic material; The edges of the upper sealing gasket (62) and the edges of the top of the inner wall of the outer shell (10) are laser welded, and the edges of the lower sealing gasket (80) and the edges of the bottom of the inner wall of the outer shell (10) are laser welded.

2. A cylindrical lithium-ion battery according to claim 1, characterized in that: An upper insulating sheet (40) is provided above the winding core (20), a through hole is provided through the upper insulating sheet (40), and a positive electrode tab (50) is led out from the upper end of the winding core (20) through the through hole.

3. The cylindrical lithium-ion battery according to claim 1, wherein: A cover cap (60) for covering the housing (10) is provided at the center of the housing (10), and a welding piece (61) is provided at the center of the top end of the cover cap (60).

4. The cylindrical lithium-ion battery according to claim 1, wherein: A center needle (30) is provided at the center of the interior of the shell (10), one end of the winding core (20) contacts the outside of the center needle (30), and the other end of the winding core (20) contacts the inner wall of the shell (10).

5. The cylindrical lithium-ion battery according to claim 1, wherein: The gap between the winding core (20) and the shell (10) is filled with electrolyte.

6. The cylindrical lithium-ion battery according to claim 4, characterized in that: The winding core (20) is composed of four layers stacked from the inside to the outside, namely, a positive electrode sheet (21), a first separator (22), a negative electrode sheet (23) and a second separator (24). The winding core (20) is wound outward around the central needle (30).

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