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EP-4742425-A1 - SECONDARY BATTERY

EP4742425A1EP 4742425 A1EP4742425 A1EP 4742425A1EP-4742425-A1

Abstract

A secondary battery includes an electrode assembly including first electrode plates including first substrate tabs arranged in a first direction and second electrode plates including second substrate tabs arranged in a second direction that is opposite to the first direction, with the first electrode plates and the second electrode plates being provided in a stack. A case accommodates the electrode assembly, and a cap assembly includes a pair of current collector plates electrically connected to a first substrate tab and a second substrate tab, respectively, with the cap assembly sealing the case. A greater number of the first substrate tabs are provided on the first electrode plates at a center of the stack than on the first electrode plates at outer portions of the stack.

Inventors

  • KO, JAE WOOK

Assignees

  • Samsung SDI Co., Ltd.

Dates

Publication Date
20260513
Application Date
20250812

Claims (15)

  1. A secondary battery (100) comprising: an electrode assembly (110) including first electrode plates (111) including first substrate tabs (111a) arranged in a first direction and second electrode plates (112) including second substrate tabs (112a) arranged in a second direction that is opposite to the first direction, with the first electrode plates (111) and the second electrode plates (112) being provided in a stack; a case (160) accommodating the electrode assembly (110); and a cap assembly including a pair of current collector plates (120, 130) electrically connected to the first substrate tab (111a) and the second substrate tab (112a), respectively, with the cap assembly sealing the case (160), wherein a greater number of the first substrate tabs (111a) are provided on the first electrode plates (111) at a center of the stack than on the first electrode plates (111) at outer portions of the stack.
  2. The secondary battery (100) as claimed in claim 1, wherein the first substrate tabs (111a) are provided in the center of the stack such that the first substrate tabs (111a) are densified in the center of the stack.
  3. The secondary battery (100) as claimed in claim 1 or 2, wherein the electrode plates (111, 112) are stacked so that the first substrate tabs (111a) are arranged in a rhombus shape.
  4. The secondary battery (100) as claimed in any of claims 1 to 3, wherein the first electrode plates (111) in the stack include at least one first layer (1101) on an inner side, at least one second layer (1102) at the center of the stack, and at least one third layer (1103) on an outer side.
  5. The secondary battery (100) as claimed in claim 4, wherein a number of the first substrate tabs (111a) provided in the second layer (1102) is greater than a number of the first substrate tabs (111a) in the first layer (1101), and the number of the first substrate tabs (111a) provided in the second layer (1102) is greater than a number of the first substrate tabs (111a) in the third layer (1103).
  6. The secondary battery (100) as claimed in claim 4 or 5, wherein the number of the first substrate tabs (111a) in the first layer (1101) and the number of the first substrate tabs (111a) in the third layer (1103) are the same.
  7. The secondary battery (100) as claimed in claim 4 or 5, wherein the first substrate tabs (111a) of each of the first layer (1101), the second layer (1102), and the third layer (1103) protrude a same length from the stack.
  8. The secondary battery (100) as claimed in claim 7, wherein one of the current collector plates (120, 130) is welded to the first substrate tabs (111a), and welding regions of the current collector plate (120, 130) are in a rhombus shape.
  9. The secondary battery (100) as claimed in claim 4 or 5, wherein the first substrate tabs (111a) of the first layer (1101) and the third layer (1103) protrude a same length from the stack, and the first substrate tabs (111a) of the first layer (1101) and the third layer (1103) protrude a different length from the stack than the first substrate tabs (111a) of the second layer (1102) protrude from the stack.
  10. The secondary battery (100) as claimed in claim 4, wherein lengths that the first substrate tabs (111a) in the second layer (1102) protrude from the stack are larger than lengths the first substrate tabs (111a) in the first layer (1101) and the third layer (1103) protrude from the stack.
  11. The secondary battery (100) as claimed in claim 9, wherein lengths the first substrate tabs (111a) in the second layer (1102) protrude from the stack are shorter than lengths the first substrate tabs (111a) in the first layer (1101) and the third layer (1103) protrude from the stack.
  12. The secondary battery (100) as claimed in claim 4 or 5, wherein a side surface of the stack from which the first substrate tabs (111a) of the first electrode plates (111) protrude has a central region and edge regions, the first substrate tabs (111a) in the second layer (1102) are provided in the central region and the edge regions, and the first substrate tabs (111a) provided in the central region in the second layer (1102) and the first substrate tabs (111a) provided in the edge regions in the second layer (1102) have the same protruding length or different protruding lengths.
  13. The secondary battery (100) as claimed in claim 4 or 5, wherein each of the first layer (1101) and the third layer (1103) comprises a plurality of electrode plates (111, 112), and more of the first substrate tabs (111a) are disposed as toward the center of the stack.
  14. The secondary battery (100) as claimed in any of claims 1 to 13, wherein the case (160) comprises a bottom surface (161) and long and short side surfaces (163) extending upward from the bottom surface (161), wherein the cap assembly comprises a first terminal plate (143, 153) electrically connected to the first electrode plate (111), and wherein one of the current collector plates (120, 130) includes a first terminal connecting portion (121) connected to the first terminal plate (143, 153) and a first electrode connecting portion (122) extending from the first terminal connecting portion (121), parallel to the short side surface (163), and coupled to the first electrode plate (111).
  15. The secondary battery (100) as claimed in any of claims 1 to 14, wherein each of the second electrode plates (112) includes at least one second substrate tab, and a greater number of the second substrate tabs (112a) are provided on the second electrode plates (112) at the center of the stack than on the second electrode plates (112) at outer portions of the stack.

Description

BACKGROUND 1. Field Embodiments of the present disclosure relate to a secondary battery. 2. Description of the Related Art Unlike a primary battery, a secondary battery may be charged and discharged. Low-capacity secondary batteries having a single battery cell packaged in the form of a pack are widely employed in small, portable electronic devices, such as smart phones, feature phones, laptop computers, digital cameras, camcorders, and the like, while large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles, electric vehicles, and the like, as well as batteries for power storage. The secondary battery includes an electrode assembly consisting of a positive electrode and a negative electrode, a case that accommodates the electrode assembly, and electrode terminals connected to the electrode assembly. The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art. SUMMARY The present invention is set out in the appended set of claims, wherein the drawings and respective description relate to advantageous embodiments thereof. The present invention provides a secondary battery having improved reactivity in a centrally located electrode plate by varying the number of tabs of different electrode plates, thereby allowing all the electrode plates within an electrode assembly to react uniformly. However, the technical problems to be achieved in the embodiment of the disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned herein will be clearly understood from the following description by those skilled in the art to which the disclosure belongs. An exemplary secondary battery according to the present invention for solving the above technical problem, includes: an electrode assembly first electrode plates including first substrate tabs arranged in a first direction and second electrode plates including second substrate tabs arranged in a second direction that is opposite to the first direction, with the first electrode plates and the second electrode plates being provided in a stack; a case accommodating the electrode assembly; and a cap assembly including a pair of current collector plates electrically connected to a first substrate tab and a second substrate tab, respectively, with the cap assembly sealing the case, wherein a greater number of the first substrate tabs are provided on the first electrode plates at a center of the stack than on the first electrode plates at outer portions of the stack. In some examples, the first substrate tabs may be provided in the center of the stack such that the first substrate tabs are densified on the center of the stack. In some examples, the first electrode plates may be stacked so that the first substrate tabs are arranged in a rhombus shape. In some examples, the first electrode plates in the stack include at least one first layer on an inner side, at least one second layer at the center of the stack, and at least one third layer on an outer side. In some examples, a number of the first substrate tabs provided in the second layer is greater than a number of the first substrate tabs in the first layer and the number of the first substrate tabs provided in the second layer is greater than a number of the first substrate tabs in the third layer. In some examples, the number of the first substrate tabs in the first layer and the number of the first substrate tabs in the third layer may be the same. In some examples, the first substrate tabs in each of the first layer, the second layer, and the third layer may protrude to the same length from the stack. In some examples, a current collector plate may be welded to the first substrate tabs, and the welding regions of the current collector plate may be in a rhombus shape. In some examples, the first substrate tabs of the first layer and the third layer may protrude to the same length from the stack, and the first substrate tabs of the first layer and the third layer protrude a different length from the stack than the first substrate tabs of the second layer may protrude from the stack. In some examples, the lengths that the first substrate tabs in the second layer protrude from the stack may be larger than the lengths the first substrate tabs in the first layer and the third layer protrude from the stack. In some examples, the first substrate tabs may be pressed on the basis of the second layer, and the pressed first substrate tabs of the second layer may be bent and welded to a current collector plate. In some examples, the lengths the first substrate tabs in the second layer protrude from the stack may be shorter than the lengths the first substrate tabs in the first layer and the third layer protrude from the stack. In some examples, the first substrate tabs in the first layer,