US-20260128480-A1 - SECONDARY BATTERY

US20260128480A1US 20260128480 A1US20260128480 A1US 20260128480A1US-20260128480-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 including a pair of current collector plates are 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

Jae Wook Ko

Assignees

SAMSUNG SDI CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20250528
Priority Date: 20241106

Claims (20)

1 . A secondary battery comprising: 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 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.
2 . The secondary battery as claimed in claim 1 , wherein the first substrate tabs are provided in the center of the stack such that the first electrode plates are densified in the center of the stack.
3 . The secondary battery as claimed in claim 1 , wherein the first electrode plates are stacked so that the first substrate tabs are arranged in a rhombus shape.
4 . The secondary battery as claimed in claim 1 , wherein 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.
5 . The secondary battery as claimed in claim 4 , wherein a number of the first substrate tabs provided in the second layer is greater than the number of first substrate tabs in the first layer, and the number of first substrate tabs provided in the second layer is greater than the number of first substrate tabs in the third layer.
6 . The secondary battery as claimed in claim 5 , wherein the number of first substrate tabs in the first layer and the number of first substrate tabs in the third layer are the same.
7 . The secondary battery as claimed in claim 5 , wherein the first substrate tabs of each of the first layer, the second layer, and the third layer protrude a same length from the stack.
8 . The secondary battery as claimed in claim 7 , wherein one of the current collector plates is welded to the first substrate tabs, and welding regions of the current collector plate are in a rhombus shape.
9 . The secondary battery as claimed in claim 4 , wherein the first substrate tabs of the first layer and the third layer protrude a 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 protrude from the stack.
10 . The secondary battery as claimed in claim 4 , wherein lengths that the first substrate tabs in the second layer protrude from the stack are larger than lengths the first substrate tabs in the first layer and the third layer protrude from the stack.
11 . The secondary battery as claimed in claim 10 , the first substrate tabs of the second layer are bent and welded to one of the current collector plates.
12 . The secondary battery as claimed in claim 9 , wherein lengths the first substrate tabs in the second layer protrude from the stack are shorter than lengths the first substrate tabs in the first layer and the third layer protrude from the stack.
13 . The secondary battery as claimed in claim 12 , the first substrate tabs in the first layer and the third layer are bent and welded to one of the current collector plates.
14 . The secondary battery as claimed in claim 4 , wherein a side surface of the stack from which the first substrate tabs of the first electrode plates protrude has a central region and edge regions, the first substrate tabs in the second layer are provided in the central region and the edge regions, and the first substrate tabs provided in the central region of the second layer and the first substrate tabs provided in the edge regions have the same length or different lengths.
15 . The secondary battery as claimed in claim 14 , wherein the first substrate tabs provided in the edge regions in the second layer protrude longer than the first substrate tabs provided in the central region.
16 . The secondary battery as claimed in claim 15 , wherein the first substrate tabs provided in the edge regions in the second layer are bent and welded to one of the current collector plates.
17 . The secondary battery as claimed in claim 4 , wherein each of the first layer and the third layer comprises a plurality of electrode plates, and more of the first substrate tabs are disposed as toward the center of the stack.
18 . The secondary battery as claimed in claim 1 , wherein the case comprises a bottom surface and long and short side surfaces extending upward from the bottom surface, wherein the cap assembly comprises a first terminal plate electrically connected to the first electrode plate, and wherein one of the current collector plates includes a first terminal connecting portion connected to the first terminal plate and a first electrode connecting portion extending from the first terminal connecting portion, parallel to the short side surface, and coupled to the first electrode plate.
19 . The secondary battery as claimed in claim 1 , wherein each of the second electrode plates includes at least one second substrate tab, and more of the second substrate tabs are disposed in the center of the stack.
20 . The secondary battery as claimed in claim 1 , wherein an outermost layer of the first electrode plates has one first electrode tab.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0155984 filed on Nov. 6, 2024, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. 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 disclosure 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 an embodiment of the present disclosure may include: 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 electrode plates 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, the a number of the first substrate tabs provided in the second layer is greater than the number of first substrate tabs in the first layer and the number of first substrate tabs provided in the second layer is greater than the number of first substrate tabs in the third layer. In some examples, the number of first substrate tabs in the first layer and the number of 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 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 lay