KR-20260067826-A - SECONDARY BATTERY INCLUDING CAP PLATE AND METHOD FOR MANUFACTURING SAME

Abstract

The present disclosure provides a secondary battery comprising a cap plate and a method for manufacturing the secondary battery. The secondary battery according to the present disclosure comprises an electrode assembly formed by winding a first electrode, a separator, and a second electrode, a case for housing the electrode assembly and an electrolyte, and a cap plate for sealing an opening on one side of the case, wherein the cap plate may include an injection port for injecting an electrolyte and a sealing pin for sealing the injection port.

Inventors

• 이동명
• 박두선
• 김지현
• 강선우
• 김덕현
• 장운석

Assignees

• 삼성에스디아이 주식회사

Dates

Publication Date

20260513

Application Date

20241106

Claims (20)

1. An electrode assembly formed by winding a first electrode, a separator, and a second electrode; A case accommodating the electrode assembly and electrolyte; and Cap plate for sealing one side opening of the above case Includes, The above cap plate is An injection port for injecting the above electrolyte; and A bobby pin sealing the above injection port A secondary battery including
2. In paragraph 1, A secondary battery in which the above bobby pin and the above injection port are joined by welding.
3. In paragraph 1, A secondary battery in which the outer diameter of the above-mentioned bobby pin is larger than the inner diameter of the above-mentioned injection port, and the above-mentioned bobby pin is coupled to the above-mentioned injection port by a press fit method.
4. In paragraph 1, The height of the outer surface of the above-mentioned bobby pin is the same as the height of the inner surface of the above-mentioned injection port, and The central portion of the above-mentioned bobby pin includes a bottom surface having a step difference with the upper surface of the above-mentioned bobby pin, and a secondary battery.
5. In paragraph 1, The above-mentioned pin includes a main body portion inserted into the injection port and a flange portion that contacts the periphery of the injection port among the upper surfaces of the cap plate, and The central portion of the above-mentioned bobby pin includes a bottom surface having a step difference with the upper surface of the above-mentioned bobby pin, and a secondary battery.
6. In paragraph 1, The above-mentioned pin includes a main body portion inserted into the injection port and a flange portion that contacts the periphery of the injection port among the upper surfaces of the cap plate, and The central portion of the above bobby pin includes a bottom surface having a step difference with the upper surface of the above bobby pin, and The above injection port has a step difference with the upper surface of the cap plate and includes a seating portion on which the flange portion is seated, in a secondary battery.
7. In paragraph 1, The above-mentioned bobby pin comprises an upper surface with a concave round shape that gradually decreases from the upper surface of the cap plate, and a lower surface with a convex round shape that gradually decreases from the lower end of the outer surface of the bobby pin. The above secondary battery.
8. In paragraph 1, A secondary battery, wherein the above-mentioned pin comprises a flat upper surface having the same height as the upper surface of the cap plate, and a convex round lower surface that gradually decreases from the bottom of the outer surface of the pin.
9. In paragraph 1, The above injection port is formed to penetrate polygonally from the upper surface to the lower surface of the cap plate, and The above-mentioned bobby pin is a secondary battery having an outer surface shape corresponding to the shape of the inner surface of the injection port.
10. In paragraph 1, The above injection port comprises an inner wall into which the above pin is inserted, and a round-shaped connecting portion connected to the upper surface of the cap plate and the inner wall, in a secondary battery.
11. In paragraph 1, A secondary battery having a case diameter of 40 mm to 50 mm.
12. In paragraph 1, The above cap plate is, A secondary battery comprising a welded portion formed by bending the outer periphery of the cap plate in the extension direction of the case and joining with the inner surface of the opening of the case.
13. In Paragraph 12, A secondary battery in which the terminal of the opening of the above case includes a seating portion on which the outer periphery of the cap plate is seated.
14. In paragraph 1, A secondary battery in which the terminal of the opening of the above case includes a round-shaped side facing the outer periphery of the cap plate.
15. In paragraph 1, The terminal of the opening of the above case has a round-shaped side facing the outer periphery of the cap plate; and A secondary battery comprising a seating portion connected to the side of the above-mentioned round shape and on which the outer periphery of the above-mentioned cap plate is seated.
16. A cap plate that seals one side opening of a case accommodating an electrode assembly formed by winding a first electrode, a separator, and a second electrode, and an electrolyte, An injection port for injecting the above electrolyte; and A bobby pin sealing the above injection port A cap plate including
17. In Paragraph 16, The outer diameter of the above-mentioned bobby pin is larger than the inner diameter of the above-mentioned injection port, and The above-mentioned bobby pin is joined to the above-mentioned injection port by a press fit and welding, and the cap plate.
18. In Paragraph 16, The above injection port is formed to penetrate polygonally from the outer surface to the inner surface of the cap plate, and The above-mentioned bobby pin is a cap plate having an outer surface shape corresponding to the shape of the inner surface of the injection port.
19. In Paragraph 18, The above-mentioned pin comprises a main body portion having an outer surface shape corresponding to the shape of the inner surface of the injection port, and a flange portion in contact with the periphery of the injection port among the upper surfaces of the cap plate, a cap plate.
20. A step of forming an electrode assembly by winding a first electrode, a separator, and a second electrode; A step of inserting the above electrode assembly through an opening on one side of the case; A step of sealing the opening of the above case with a cap plate; The step of injecting an electrolyte through the injection port of the cap plate; and Step of sealing the injection port with a bobby pin Includes, The outer diameter of the above-mentioned bobby pin is larger than the inner diameter of the above-mentioned injection port, and A method for manufacturing a secondary battery, wherein the above-mentioned bobby pin is joined to the above-mentioned injection port by press fitting and welding.

Description

Secondary battery including a cap plate and method for manufacturing the same The present disclosure relates to a secondary battery comprising a cap plate and a method for manufacturing the secondary battery. Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly. Although rechargeable batteries are used in various environments due to their excellent electrical characteristics, conventional small batteries have had limitations in terms of designable energy density. Since the amount of electrical energy that can be stored is limited relative to the size and weight of the battery, there is a gradually increasing demand for large batteries with higher energy density in applications such as electric vehicles. To increase energy capacity and density, the size of secondary batteries is gradually increased, and thin casings can be used. However, in this case, during the manufacturing process or while undergoing repeated charging and discharging over a long period, the battery cells, particularly the cap plates, may gradually deform or warp, potentially causing changes in the overall cell specifications. The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure. FIG. 2 is a plan view showing the appearance of a cap plate and a pin before joining according to one embodiment of the present disclosure. FIGS. 3 to 7 are plan views showing a bobby pin according to one embodiment of the present disclosure. FIG. 8 is a perspective view showing a cap plate according to one embodiment of the present disclosure. FIG. 9 is a plan view showing the appearance of the injection port of a cap plate and the seal pin before coupling according to one embodiment of the present disclosure. FIG. 10 is a plan view showing the appearance after the injection port of a cap plate and a bobby pin are combined according to one embodiment of the present disclosure. FIGS. 11 and FIGS. 12 are cross-sectional views showing a cap plate and a case according to one embodiment of the present disclosure. FIG. 13 is a cross-sectional view showing the opening of a cap plate and a case according to one embodiment of the present disclosure. FIG. 14 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure. FIG. 15 is a flowchart illustrating an example of a method for manufacturing a secondary battery according to the present disclosure. Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. Additionally, as used herein, “comprise, include” and/or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and/or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and/or groups. Additionally, to aid in understanding