EP-4742430-A1 - SECONDARY BATTERY

EP4742430A1EP 4742430 A1EP4742430 A1EP 4742430A1EP-4742430-A1

Abstract

The present invention relates to a secondary battery in which battery capacity is improved while having relatively few restriction in shape, and an amount of moisture introduced from the outside is reduced. The secondary battery according to the present invention may include an electrode assembly, an exterior film surrounding a portion of the electrode assembly, and a cap surrounding a remaining portion of the electrode assembly, wherein the cap may include an exterior part coupled to the exterior film; and a terminal part exposed to an outside and an inside of the exterior part and electrically connected to the electrode assembly at a portion thereof, which is exposed to the inside of the exterior part, wherein the terminal part may be restricted in movement in a direction away from the electrode assembly.

Inventors

LEE, JI SUN
KIM, SANG HUN
LEE, JAE HO
CHOI, JI EUN

Assignees

LG Energy Solution, Ltd.

Dates

Publication Date: 20260513
Application Date: 20240828

Claims (15)

A secondary battery comprising: an electrode assembly; an exterior film surrounding a portion of the electrode assembly; and a cap surrounding a remaining portion of the electrode assembly, wherein the cap comprises: an exterior part coupled to the exterior film; and a terminal part exposed to an outside and an inside of the exterior part and electrically connected to the electrode assembly at a portion thereof, which is exposed to the inside of the exterior part, wherein the terminal part is restricted in movement in a direction away from the electrode assembly.
The secondary battery of claim 1, wherein the terminal part comprises: an exposed part exposed to the outside of the exterior part; and a support part connected to the exposed part and supported on the exterior part inside the exterior part to prevent the exposed part from being separated from the exterior part.
The secondary battery of claim 2, wherein the exposed part comprises: an outer member provided in an overlapping shape by a through-hole defined in the exterior part so as to connect the exposed part to the support part; and a passing member disposed along an edge of the outer member and extending from the edge of the outer member toward the inside of the exterior part to pass through the through-hole.
The secondary battery of claim 3, wherein the support part comprises a first member extending from the passing member in a direction perpendicular to an extension direction of the passing member and provided to be hooked on an inner surface of the exterior part.
The secondary battery of claim 4, wherein the support part further comprises a second member extending from the first member toward the electrode assembly and having one end electrically connected to the electrode assembly.
The secondary battery of claim 5, wherein the second member comprises a metal material, and the exterior film comprises a resin layer coupled to the second member by heat and a pressure.
The secondary battery of claim 5, wherein the exterior part comprises: a first cover part covering the first member from the outside of the exterior part; and a second cover part disposed between the second member and the exterior film, coupled to the exterior film and extending from the first cover part toward the electrode assembly.
The secondary battery of claim 7, wherein the support part comprises a metal material, the first cover part comprises a resin material having adhesive properties by heat, and the support part and the first cover part are coupled to each other by heat and a pressure.
The secondary battery of claim 1, wherein the terminal part is disposed to protrude in a direction, which is away from the electrode assembly, from one surface of the exterior part.
The secondary battery of claim 1, wherein, in the cap, one surface of the exterior part is disposed on the same surface as one surface of the terminal part.
The secondary battery of claim 1, wherein the exterior part comprises a metal material, and the exterior film comprises a metal layer coupled to the exterior part by welding.
The secondary battery of claim 1, wherein the exterior part comprises a resin material having adhesive properties by heat, and the exterior film comprises a resin layer coupled to the exterior part by heat and a pressure.
The secondary battery of claim 1, wherein the exterior film and the exterior part are coupled to each other by an adhesive applied between the exterior film and the exterior part.
The secondary battery of claim 1, wherein the exterior part and the terminal part are coupled to each other by an adhesive applied between the exterior part and the terminal part.
A secondary battery comprising: an electrode assembly; an exterior film having an internal space in which the electrode assembly is accommodated and an exterior opening configured to allow the internal space to communicate with an outside; and a cap covering the exterior opening of the exterior film, wherein the cap comprises: an exterior part coupled to the exterior film; and a terminal part exposed to an outside and an inside of the exterior part and electrically connected to the electrode assembly at a portion thereof, which is exposed to the inside of the exterior part, wherein the terminal part is disposed to cover at least a portion of the exterior opening and made of a material having lower moisture permeability than that of a material forming the exterior part.

Description

TECHNICAL FIELD CROSS-REFERENCE TO RELATED APPLICATION The present application claims the benefit of the priority of Korean Patent Application Nos. 10-2023-0117884, filed on September 5, 2023, and 10-2024-0066011, filed on May 21, 2024, which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to a secondary battery, and more particularly, to a secondary battery that is chargeable or dischargeable. BACKGROUND ART In recent years, the price of energy sources increases due to the depletion of fossil fuels, the interest in environmental pollution is amplified, and the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. Accordingly, studies on various power generation technologies such as solar power, wind power, and tidal power are continuing, and power storage devices such as batteries for more efficiently using the generated electrical energy are also of great interest. Furthermore, as technology development and demand for electronic mobile devices and electric vehicles using batteries increase, the demands for batteries as energy sources are rapidly increasing. Thus, many studies on batteries which are capable of meeting various demands have been conducted. Batteries storing electrical energy may be generally classified into primary batteries and secondary batteries. Such a primary battery is a disposable consumable battery. On the other hand, such a secondary battery is a chargeable battery that is manufactured by using a material in which oxidation and reduction processes between current and the material are capable of being repeated. That is, when the reduction reaction to the material is performed by the current, power is charged. When the oxidation reaction to the material is performed by the current, power is discharged. Such charging-discharging are repeatedly performed to generate electricity. Secondary batteries may be classified into cylindrical cells, pouch cells, and prismatic cells according to their shape. Among them, such a pouch cell may be manufactured by accommodating an electrode assembly in the form of a stack of a positive electrode, a negative electrode, a separator, etc. inside a pouch and then sealing an outer portion of the pouch. The pouch cell according to the related art may have a limitation of cracks occurring in a pouch film in a process of molding the pouch film, and may pouch films are discarded after a degassing process. In addition, a moldable depth is limited depending on material characteristics of the pouch film, and thus there is a limit to increase in battery capacity. Thus, there is a need for a type of secondary battery that is capable of improving the battery capacity while having relatively few restriction in shape. DISCLOSURE OF THE INVENTION TECHNICAL PROBLEM An object of the present invention is to provide a secondary battery in which battery capacity is improved while having relatively few restriction in shape, and an amount of moisture introduced from the outside is reduced. TECHNICAL SOLUTION A secondary battery according to the present invention may include an electrode assembly, an exterior film surrounding a portion of the electrode assembly, and a cap surrounding a remaining portion of the electrode assembly, wherein the cap may include an exterior part coupled to the exterior film, and a terminal part exposed to an outside and an inside of the exterior part and electrically connected to the electrode assembly at a portion thereof, which is exposed to the inside of the exterior part, wherein the terminal part may be restricted in movement in a direction away from the electrode assembly. The terminal part may include an exposed part exposed to the outside of the exterior part, and a support part connected to the exposed part and supported on the exterior part inside the exterior part to prevent the exposed part from being separated from the exterior part. The exposed part may include: an outer member provided in an overlapping shape by a through-hole defined in the exterior part so as to connect the exposed part to the support part, and a passing member disposed along an edge of the outer member and extending from the edge of the outer member toward the inside of the exterior part to pass through the through-hole. The support part may include a first member extending from the passing member in a direction perpendicular to an extension direction of the passing member and provided to be hooked on an inner surface of the exterior part. The support part may further include a second member extending from the first member toward the electrode assembly and having one end electrically connected to the electrode assembly. The second member may include a metal material, and the exterior film may include a resin layer coupled to the second member by heat and a pressure. The exterior part may include a first cover part covering the first member from the outside of th