US-20260128430-A1 - SECONDARY BATTERY

US20260128430A1US 20260128430 A1US20260128430 A1US 20260128430A1US-20260128430-A1

Abstract

Provided is a secondary battery that can improve structural efficiency. The secondary battery includes: a power generating element; and an exterior part housing the power generating element thereinside, wherein the exterior part has: a cylindrical part having openings in respective two facing faces thereof; inner lids placed in the openings, respectively; and first resin placed so as to cover each of the openings, and each face of the inner lids on opening sides, the first resin is placed so as to fill each space between the cylindrical part and the inner lids, and the cylindrical part and the inner lids are united into one body with the first resin.

Inventors

Sadao Fujisaki

Assignees

TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date: 20260507
Application Date: 20251203
Priority Date: 20211206

Claims (10)

1 . A secondary battery comprising: a power generating element; and an exterior part housing the power generating element there inside, wherein the exterior part has: a cylindrical part having openings in respective two facing faces thereof; inner lids placed in the openings, respectively; and a first resin placed so as to cover each of the openings, and each face of the inner lids on opening sides, the first resin is disposed adjacent to the cylindrical part and the inner lids, and the cylindrical part and the inner lids are united into one body with the first resin.
2 . The secondary battery according to claim 1 , a thickness of each inner lid may be thinner than the thickness of the power generating element.
3 . The secondary battery according to claim 1 , a thickness of each inner lid may be thinner than the thickness of the cylindrical part. The secondary battery according to claim 1 , further comprising: an electrode terminal connected to the power generating element, wherein the inner lids each have the face placed on the opening side of the cylindrical part, a protruding part protruding towards an inside of the cylindrical part from an entire circumference of the face, and a space surrounded by the protruding part, at least one of the inner lids has a through hole in the face thereof, the electrode terminal is arranged so as to be thorough the through hole, the first resin placed on a side of said at least one of the inner lids, said at least one of the inner lids being penetrated by the electrode terminal, is placed so as to further cover at least part of a periphery of the electrode terminal, and so as to fill a space between the through hole and the electrode terminal, and the cylindrical part, the inner lids, and the electrode terminal are united into one body with the first resin.
5 . The secondary battery according to claim 1 , wherein the exterior part has a second resin filling an inside thereof, and the cylindrical part, the inner lids, an electrode terminal, and the power generating element are united into one body with the second resin.
6 . The secondary battery according to claim 1 , wherein the power generating element is wrapped in an insulating resin film having water vapor barrier properties.
7 . The secondary battery according to claim 1 , wherein the cylindrical part is a cylindrical metal body, or a cylindrically shaped metal laminate film.
8 . The secondary battery according to claim 1 , wherein the cylindrical part is formed of two metal plates and a third resin, the metal plates each have a bottom face, and protruding parts protruding in the same direction from facing end portions of the bottom face, the metal plates are superposed on each other as facing in the opposite directions, the protruding parts overlap with each other in respective opposite side faces of the cylindrical part, the third resin is placed so as to cover each of the side faces of the cylindrical part, and the end portions of the metal plates overlap such that in each of the side faces are united into one body with the third resin.
9 . The secondary battery according to claim 1 , wherein the cylindrical part is formed of one metal plate and a third resin, the metal plate is shaped into a cylinder, end portions of the metal plate overlap with each other in one side face of the cylindrical part, the third resin is placed so as to cover the side face, where one or more end portions overlap with each other, and the overlapping end portions of the metal plate are united into one body with the third resin.
10 . The secondary battery according to claim 1 , wherein the cylindrical part has a rectangular cross-sectional shape in a width direction.
11 . The secondary battery according to claim 1 , wherein the cylindrical part has a thickness of 0.05 mm to 0.2 mm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. application Ser. No. 17/961,837, filed Oct. 7, 2022, which in turn claims priority to Japanese Patent Application No. 2021-198102. The disclosures of the prior applications are incorporated herein by reference in the entirety. FIELD The present application relates to a secondary battery. BACKGROUND Batteries including lithium ion secondary batteries are widely used as portable power sources for personal computers and mobile terminals, and power supplies for driving vehicles. A laminated type is known as an example of a type of battery. The structure of a laminated type battery is that a power generating element is sealed inside an exterior laminate formed by laminating film laminate sheets. The laminated type battery has a sealing area that is formed by welding edge portions of the exterior laminate which are arranged as facing each other in a state where terminals electrically joined to the power generating element protrude outward from the inside of the exterior laminate. This causes the power generating element to be sealed inside the exterior laminate. The laminated type battery is also provided with sealing areas outside the power generating element which are formed by laminating and welding the laminate sheets. Conventionally, to downsize batteries in structure has been pursued. For example, Patent Literature 1 discloses the technique of downsizing a laminated type battery by bending sealing areas along ends of the battery. CITATION LIST Patent Literature Patent Literature 1: JP 2020-173900 A SUMMARY Technical Problem A laminated type battery can be downsized according to the technique of Patent Literature 1. However, further improvement in structural efficiency of secondary batteries has been desired. For example, a laminated type battery can be downsized by narrowing the width of a sealing area where electrode terminals are held (sealing width). Generally, the sealing width is necessary to be set in more than 3 mm for the following reasons: (1) a narrower sealing width prevents appropriate heat welding, which may cause a seal failure; (2) because an exterior laminate is not so rigid, an external impact may cause the adhesion at a sealing area with a narrower sealing width to be lost, so that the adhesive face cannot be kept; (3) when terminals are not parallel to the adhesive face of an exterior laminate in heat welding, a narrower sealing width weakens correction force by which the inclination is restored, which prevents appropriately heat welding, and thus, causes the probability of a seal failure to be much higher; and (4) in heat welding, a narrower sealing width causes the pressure applied to a sealing area with a heat welding head to be higher per area, so that a metal layer inside an exterior laminate bites into terminals across an insulating layer. Such metal layer's biting into terminals causes a short circuit, which is undesirable. For the above reasons, it has been difficult to narrow the sealing width to downsize a laminated type battery. An object of the present disclosure is to provide a secondary battery that can improve structural efficiency. Solution to Problem As one aspect to solve the above problem, the present disclosure is provided with a secondary battery comprising: a power generating element; and an exterior part housing the power generating element thereinside, wherein the exterior part has: a cylindrical part having openings in respective two facing faces thereof; inner lids placed in the openings, respectively; and a first resin placed so as to cover each of the openings, and each face of the inner lids on opening sides, the first resin is placed so as to fill each space between the cylindrical part and the inner lids, and the cylindrical part and the inner lids are united into one body with the first resin. The secondary battery may be in the following mode. That is, the secondary battery may further comprise: an electrode terminal connected to the power generating element, wherein the inner lids may each have the face placed on the opening side of the cylindrical part, a protruding part protruding towards an inside of the cylindrical part from an entire circumference of the face, and a space surrounded by the protruding part, at least one of the inner lids may have a through hole in the face thereof, the electrode terminal may be arranged so as to be thorough the through hole, the first resin arranged on a side of said at least one of the inner lids, said at least one of the inner lids being penetrated by the electrode terminal, may be arranged so as to further cover at least part of a periphery of the electrode terminal, and so as to fill a space between the through hole and the electrode terminal, and the cylindrical part, the inner lids, and the electrode terminal may be united into one body with the first resin. The secondary battery may be in the following modes. That is, the exterior