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EP-4742342-A1 - SECONDARY BATTERY

EP4742342A1EP 4742342 A1EP4742342 A1EP 4742342A1EP-4742342-A1

Abstract

A secondary battery (1) includes an electrode assembly (100) including an electrode laminate (140) having a circular shape where a first electrode (110), a separator, and a second electrode (120) are alternately stacked, a first electrode tab (113) connected to the first electrode (110), and a second electrode tab (123) connected to the second electrode (120), an accommodating can (300) with one open side for accommodating the electrode assembly (100), the accommodating can (300) being electrically connected to the first electrode tab (113), a cap assembly (400) configured to seal the one open side of the accommodating can (300), the cap assembly (400) being electrically connected to the second electrode tab (123), a first contact member (210) between one surface of the electrode laminate (140) that faces a bottom surface of the accommodating can (300) and the first electrode tab (113), and a first fixing member (230) surrounding the first electrode tab (113) between an inner side wall of the accommodating can (300) and an outer circumferential surface of the electrode assembly (100).

Inventors

  • JANG, TAEWOONG

Assignees

  • SAMSUNG SDI CO., LTD.

Dates

Publication Date
20260513
Application Date
20250922

Claims (15)

  1. A secondary battery (1), comprising: an electrode assembly (100) including an electrode laminate (140) having a circular shape where a first electrode (110), a separator (130), and a second electrode (120) are alternately stacked, a first electrode tab (113) connected to the first electrode (110), and a second electrode tab (123) connected to the second electrode (120); an accommodating can (300) with one open side for accommodating the electrode assembly (100), the accommodating can (300) being electrically connected to the first electrode tab (113); a cap assembly (400) configured to seal the one open side of the accommodating can (300), the cap assembly (400) being electrically connected to the second electrode tab (123); a first contact member (210) between one surface of the electrode laminate (140) that faces a bottom surface of the accommodating can (300) and the first electrode tab (113); and a first fixing member (230) surrounding the first electrode tab (113) between an inner side wall of the accommodating can (300) and an outer circumferential surface of the electrode assembly (100).
  2. The secondary battery (1) as claimed in claim 1, wherein the first fixing member (230) comprises: a first surface (231) contacting the first electrode tab (113); and a second surface (232) contacting the accommodating can (300), wherein a width of the first surface (231) is greater than a width of the second surface (232) along a circumference of the electrode assembly (100).
  3. The secondary battery (1) as claimed in claim 1 or 2, wherein a cross-section of the first fixing member (230) perpendicular to a stacking direction of the electrode laminate (140) has an arc shape, a trapezoidal shape, or a step shape between the first surface and the second surface.
  4. The secondary battery (1) as claimed in any of the preceding claims, wherein the first fixing member (230) is bonded to the first electrode tab (113) by an adhesive coated on the first surface.
  5. The secondary battery (1) as claimed in any of the preceding claims, further comprising a second fixing member (240) surrounding the second electrode tab (123) between the inner side wall of the accommodating can (300) and the outer circumferential surface of the electrode assembly (100).
  6. The secondary battery (1) as claimed in claim 5, wherein the second fixing member (240) comprises: a first surface (241) contacting the second electrode tab (123); and a second surface (242) contacting the accommodating can (300), wherein a width of the first surface (241) is greater than a width of the second surface (242) along a circumference of the electrode assembly (100).
  7. The secondary battery (1) as claimed in claim 6, wherein a cross-section of the second fixing member (240) perpendicular to a stacking direction of the electrode laminate (140) has an arc shape, a trapezoidal shape, or a step shape between the first surface and the second surface.
  8. The secondary battery (1) as claimed in any of the preceding claims 5 to 7, wherein at least one of the first fixing member (230) and the second fixing member (240) comprises an insulating material including at least one of Polypropylene, Polyimide, and Polyethylene terephthalate.
  9. The secondary battery (1) as claimed in any of the preceding claims, wherein at least one of the first fixing member (230) and the second fixing member (240) includes a porous insulating material.
  10. The secondary battery (1) as claimed in any of the preceding claims, wherein the first electrode (110) comprises a first coating part (111) on an inner side of a predetermined first arc on an outer circumference of a circular substrate, the first coating part (111) being coated with a first active material, and a first non-coated part (112) on an outer side of the predetermined first arc not coated with the first active material, and wherein the second electrode (120) comprises a second coating part (121) on an inner side of a predetermined second arc on an outer circumference of a circular substrate, the second coating part (121) being coated with a second active material, and a second non-coated part (122) on an outer side of the predetermined second arc not coated with the second active material.
  11. The secondary battery (1) as claimed in any of the preceding claims, wherein the first electrode tab (113) is adhered to a bottom surface of the accommodating can (300) by a pressure from the electrode laminate (140) in response to the cap assembly (400) being coupled to the accommodating can (300).
  12. The secondary battery (1) as claimed in any of the preceding claims, further comprising a second contact member (220) between another surface of the electrode laminate (140) facing the second electrode tab (123) and a bottom surface of the cap assembly (400).
  13. The secondary battery (1) as claimed in claim 12, wherein the second electrode tab (123) is adhered to the bottom surface of the cap assembly (400) by a pressure from the electrode laminate (140) in response to the cap assembly (400) being coupled to the accommodating can (300).
  14. The secondary battery (1) as claimed in any of the preceding claims, wherein the cap assembly (400) comprises: a terminal plate (410) connected to the second electrode tab (123); a cap plate (420) including a first opening, the cap plate (420) being coupled to the one open side of the accommodating can (300); and a cap insulating layer (430) including a second opening, the cap insulating layer (430) being between the terminal plate (410) and the cap plate (420) for insulation.
  15. The secondary battery (1) as claimed in claim 14, wherein the terminal plate (410) comprises: a body (411) connected to the second electrode tab (123); and a protrusion (412) protruding upward from a center of the body (411), the protrusion (412) penetrating the first opening and the second opening, wherein a diameter of the body (411) is greater than a diameter of an outer circumferential surface of the electrode laminate (140).

Description

BACKGROUND 1. Field The present invention relates to a secondary battery. 2. Description of Related Art Recently, the growing demand for wearable devices such as Bluetooth-enabled headphones, earphones, smart watches, and body-worn medical devices has increased the demand for ultra-small secondary batteries having a high energy density and a sufficiently small size. Such secondary batteries are significantly smaller in height than width, depending on the nature of applications, and may be referred to as coin batteries and button batteries. A secondary battery includes an electrode assembly including a positive electrode and a negative electrode, an accommodating can for accommodating the electrode assembly, an electrode terminal connected to the electrode assembly, etc. The electrode assembly has a winding type or a stack type to be accommodated in a can. The above information disclosed in this background section is for enhancement of understanding of the background of the present invention, and therefore, it may contain information that does not constitute related (or prior) art. SUMMARY OF THE INVENTION The invention concerns a secondary battery, including an electrode assembly including an electrode laminate having a circular shape where a first electrode, a separator, and a second electrode are alternately stacked, a first electrode tab connected to the first electrode, and a second electrode tab connected to the second electrode, an accommodating can with one open side for accommodating the electrode assembly, the accommodating can being electrically connected to the first electrode tab, a cap assembly configured to seal the one open side of the accommodating can, the cap assembly being electrically connected to the second electrode tab, a first contact member between one surface of the electrode laminate that faces a bottom surface of the accommodating can and the first electrode tab, and a first fixing member surrounding the first electrode tab between an inner side wall of the accommodating can and an outer circumferential surface of the electrode assembly. The first fixing member may include a first surface contacting the first electrode tab, and a second surface contacting the accommodating can, wherein a width of the first surface may be greater than a width of the second surface along a circumference of the electrode assembly. A cross-section of the first fixing member perpendicular to a stacking direction of the electrode laminate may have an arc shape. A cross-section of the first fixing member perpendicular to a stacking direction of the electrode laminate may have a trapezoidal shape. A cross-section of the first fixing member perpendicular to a stacking direction of the electrode laminate may have a step shape between the first surface and the second surface. The first fixing member may be bonded to the first electrode tab by an adhesive coated on the first surface. The secondary battery may further include a second fixing member surrounding the second electrode tab between an inner side wall of the accommodating can and an outer circumferential surface of the electrode assembly. The second fixing member may include a first surface contacting the second electrode tab, and a second surface contacting the accommodating can, wherein a width of the first surface may be greater than a width of the second surface along a circumference of the electrode assembly. A cross-section of the second fixing member perpendicular to a stacking direction of the electrode laminate may have an arc shape. A cross-section of the second fixing member perpendicular to a stacking direction of the electrode laminate may have a trapezoidal shape. A cross-section of the second fixing member perpendicular to a stacking direction of the electrode laminate may have a step shape between the first surface and the second surface. At least one of the first fixing member and the second fixing member may include an insulating material including at least one of Polypropylene, Polyimide, and Polyethylene terephthalate. At least one of the first fixing member and the second fixing member may include a porous insulating material. The first electrode may include a first coating part on an inner side of a predetermined first arc on an outer circumference of a circular substrate, the first coating part being coated with a first active material, and a first non-coated part on an outer side of the predetermined first arc not coated with the first active material, and wherein the second electrode includes a second coating part on an inner side of a predetermined second arc on an outer circumference of a circular substrate, the second electrode being coated with a second active material, and a second non-coated part on an outer side of the predetermined second arc not coated with the second active material. The first electrode tab may be adhered to a bottom surface of the accommodating can by a pressure from the electrode laminate in resp