EP-4738554-A1 - CAP ASSEMBLY AND BATTERY CELL COMPRISING THE SAME

EP4738554A1EP 4738554 A1EP4738554 A1EP 4738554A1EP-4738554-A1

Abstract

The present disclosure relates to a cap assembly coupled to a case that accommodates an electrode assembly to cover one open side of the case, the cap assembly comprising: a cap plate including a first hole; a cylindrical terminal portion including an insertion hole and inserted into the first hole to be connected to the electrode assembly; a sheet-shaped first insulating member disposed to face the cap plate; and a heat insulating member disposed between the first insulating member and the terminal portion.

Inventors

CHEONG, HOEMIN
JU, SEUNG HOON
PARK, Seong Che

Assignees

SK On Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20251104

Claims (15)

A cap assembly adapted to be coupled to a case that accommodates an electrode assembly to cover one open side of the case, the cap assembly comprising: a cap plate including a first hole; a cylindrical terminal portion including an insertion hole and inserted into the first hole to be connected to the electrode assembly; a sheet-shaped first insulating member disposed to face the cap plate; and a heat insulating member disposed between the first insulating member and the terminal portion.
The cap assembly according to claim 1, further comprising a terminal plate disposed on the cap plate.
The cap assembly according to any one of the preceding claims, further comprising a second insulating member disposed between the cap plate and the terminal plate.
The cap assembly according to any one of the preceding claims, further comprising a gasket disposed between the terminal portion and the cap plate.
The cap assembly according to any one of the preceding claims, wherein the heat insulating member has a plate shape including a ring-shaped second hole.
The cap assembly according to any one of the preceding claims, wherein a diameter of the second hole is greater than a diameter of the insertion hole.
The cap assembly according to any one of the preceding claims, wherein the heat insulating member is formed of any one or a combination of PI (polyimide), PP (polypropylene), PPS (polyphenylene sulfide), and C-PET (crystalline polyethylene terephthalate).
The cap assembly according to any one of the preceding claims, further comprising a support plate coupled to an outer circumferential surface of the terminal portion.
A battery cell comprising: an electrode assembly; a case having an accommodation space formed therein to accommodate the electrode assembly; and a cap assembly coupled to the case to cover one open side of the case, wherein the cap assembly comprises: a cap plate including a first hole; a cylindrical terminal portion including an insertion hole and inserted into the first hole to be connected to the electrode assembly; a sheet-shaped first insulating member disposed to face the cap plate; and a heat insulating member disposed between the first insulating member and the terminal portion.
The battery cell according to any one of the preceding claims, further comprising a current collector plate disposed to face the cap plate and electrically connected to the electrode assembly.
The battery cell according to any one of the preceding claims, wherein the current collector plate includes a connection pin, and the insertion hole and the connection pin are welded to each other.
The battery cell according to any one of the preceding claims, wherein the cap assembly further comprises a support plate disposed between the heat insulating member and the current collector plate.
The battery cell according to any one of the preceding claims, wherein the heat insulating member is disposed between the first insulating member and the support plate, and the first insulating member is disposed between the cap plate and the heat insulating member.
The battery cell according to any one of the preceding claims, wherein the cap assembly further comprises a terminal plate disposed on the cap plate.
The battery cell according to any one of the preceding claims, wherein the cap assembly further comprises a second insulating member disposed between the cap plate and the terminal plate.

Description

BACKGROUND OF THE INVENTION 1. Field The present disclosure relates to a cap assembly and a battery cell including the same. 2. Description of the Related Art Unlike a primary battery, a secondary battery has the convenience of being chargeable and dischargeable, and therefore has attracted much attention as a power source for various mobile devices and electric vehicles. Since the secondary battery can be charged and discharged, it can be applied to various fields such as digital cameras, mobile phones, notebook computers, hybrid vehicles, electric vehicles, and energy storage systems (ESS; Energy Storage System). Such a secondary battery may include a battery cell in which an electrode assembly formed by stacking or winding a positive electrode plate, a negative electrode plate, and a separator into a roll form is accommodated in a case. Meanwhile, the battery cell may be manufactured by a welding process or the like. In this case, heat generated during welding may be transferred to components vulnerable to heat, thereby melting such components. In addition, during use of the battery cell or under a thermal runaway condition, heat may be transmitted to the components, causing them to melt. Accordingly, there is a need for research into technologies for preventing the propagation of heat from a heat source to adjacent components. In general, a battery cell has a structure in which an electrode assembly is accommodated in a case, and may include a cap assembly covering the case. The cap assembly may be coupled to the case and electrically connected to the electrode assembly. An electrode terminal electrically connected to an external component may be formed to protrude outward from the cap assembly. Meanwhile, the cap assembly includes an electrical insulating member, which is vulnerable to heat and may be damaged by heat. Accordingly, there is a demand for a measure to protect the insulating member from heat. SUMMARY OF THE INVENTION According to one aspect of the present disclosure, a task to be solved is to improve the stability of an electrode assembly and/or a battery cell. According to another aspect of the present disclosure, a task to be solved is to improve the heat resistance of the electrode assembly and/or the battery cell. According to another aspect of the present disclosure, a task to be solved is to reduce the manufacturing cost of the electrode assembly and/or the battery cell. According to another aspect of the present disclosure, a task to be solved is to minimize or prevent the propagation of heat from a heat source to adjacent components. According to another aspect of the present disclosure, a task to be solved is to minimize or prevent melting of an insulating plate disposed on a rear surface of a cap plate. Meanwhile, the cap assembly and the battery cell including the same according to the present disclosure may be widely applied to green technology fields such as electric vehicles (EV), battery charging stations, energy storage systems (ESS), photovoltaics, and wind power utilizing battery cells. In addition, the electrode assembly and the battery cell including the same according to the present disclosure may be used in eco-friendly mobility, including electric vehicles and hybrid vehicles, for preventing climate change by suppressing air pollution and greenhouse gas emissions. As a technical means to achieve the technical objects, a cap assembly coupled to a case that accommodates an electrode assembly to cover one open side of the case according to the present disclosure may comprise: a cap plate including a first hole; a cylindrical terminal portion including an insertion hole and inserted into the first hole to be connected to the electrode assembly; a sheet-shaped first insulating member disposed to face the cap plate; and a heat insulating member disposed between the first insulating member and the terminal portion. The cap assembly according to the present disclosure may further include a terminal plate disposed on the cap plate. The cap assembly according to the present disclosure may further include a second insulating member disposed between the cap plate and the terminal plate. The cap assembly according to the present disclosure may further include a gasket disposed between the terminal portion and the cap plate. In one embodiment, the heat insulating member may have a plate shape including a ring-shaped second hole. In one embodiment, a diameter of the second hole may be greater than a diameter of the insertion hole. In one embodiment, the heat insulating member may be formed of any one or a combination of PI (polyimide), PP (polypropylene), PPS (polyphenylene sulfide), and C-PET (crystalline polyethylene terephthalate). The cap assembly according to the present disclosure may further include a support plate coupled to an outer circumferential surface of the terminal portion. As a technical means to achieve the technical objects, a battery cell according to the presen