CN-122029669-A - Cover, method for manufacturing the same, and sealed battery

Abstract

The invention provides a cover body of a sealed battery, which has a relatively simple structure with few components and can reliably prevent liquid leakage of electrolyte and invasion of moisture from outside. The lid body is used for sealing a battery container having an opening, and comprises terminal members (1, 2), a sealing plate (3) having mounting holes (3 b) for mounting the terminal members, and a sealing member (4) for sealing the terminal members by mounting the terminal members to the mounting holes (3 b), wherein the sealing member comprises polyarylene sulfide resin and acrylic acid ester, the terminal members have a hydroxyl-containing coating on the outer peripheral surface, the sealing plate has a hydroxyl-containing coating on the inner wall surface of the mounting holes, and the terminal members are sealed in the mounting holes of the sealing plate through the sealing member.

Inventors

• Todo Masayoshi
• Wu Cunxiangcheng
• PU DONGHAI
• Nishikoori Yusuke

Assignees

• 日本轻金属株式会社

Dates

Publication Date

20260512

Application Date

20241016

Priority Date

20231016

Claims (9)

1. 1. A lid for sealing a battery container having an opening, comprising: A terminal member; A sealing plate having a mounting hole for mounting the terminal member, and A closing member that mounts the terminal member to the mounting hole of the sealing plate to close it, The closure comprises a polyarylene sulfide resin as a thermoplastic resin, and an acrylate, The terminal member has a hydroxyl-containing coating film on an outer peripheral surface, and the sealing plate has a hydroxyl-containing coating film on an inner wall surface of the mounting hole, The terminal member is enclosed in the mounting hole of the sealing plate via the closing piece.
2. 2. The cover of claim 1, wherein the cover comprises a plurality of layers, The closure contains 0.1 mass% or more and 10 mass% or less of an acrylic ester.
3. 3. The cover of claim 2, wherein the cover comprises a plurality of layers, The acrylic ester is one or more selected from the group consisting of methyl acrylate, ethyl acrylate, butyl acrylate, 2-dimethylaminoethyl acrylate and 2-hydroxyethyl acrylate.
4. 4. The cover of claim 1, wherein the cover comprises a plurality of layers, The hydroxyl group-containing coating film has an oxygen content of 0.1 to 50 mass% in a surface layer having a depth of 3 [ mu ] m from the outermost surface, as measured by EPMA.
5. 5. The cover of claim 1, wherein the cover comprises a plurality of layers, The closure comprises one or more polyolefins selected from the group consisting of polyethylene and polypropylene.
6. 6. The cover of claim 5, wherein the cover comprises a plurality of layers, The closure comprises 0.1 mass% or more and 20 mass% or less of a polyolefin.
7. 7. The cover of claim 1, wherein the cover comprises a plurality of layers, The closure comprises polydimethylsiloxane as an additive.
8. 8. A method for manufacturing a cap according to claim 1, characterized in that, The sealing plate and the terminal member are assembled in a mold, and resin forming the sealing member is injected in a state where a gap is provided between the mounting hole of the sealing plate and the terminal member, so that the terminal member is sealed in the mounting hole of the sealing plate with the sealing member interposed therebetween.
9. 9. A sealed battery, comprising: an electrode body having a positive electrode and a negative electrode; a battery container having an opening and accommodating the electrode body, and The cover of claim 1, wherein the cover closes the opening.

Description

Cover, method for manufacturing the same, and sealed battery Technical Field The present invention relates to a lid, a method for manufacturing the same, and a sealed battery, and more particularly, to a lid capable of providing a sealed battery having a simple structure and excellent sealability, a method for manufacturing the same, and a sealed battery using the same. Background Secondary batteries such as lithium ion batteries that can be repeatedly charged and discharged are widely used in various applications such as transportation means such as automobiles, airplanes, and ships, and power sources for facilities such as factories, buildings, schools, and hospitals, in addition to small-sized mobile devices such as cellular phones and notebook computers. These secondary batteries generally have an electrode body having a positive electrode and a negative electrode housed in a battery container having an opening, and sealed with a lid. The cover is provided with mounting holes corresponding to the positive electrode and the negative electrode, and terminal members are inserted into the mounting holes and connected to leads led out from the electrode body, so that the inside and the outside of the battery can be conducted. However, since the electrolyte of the secondary battery is flammable, a highly airtight lid structure capable of preventing leakage of the liquid is demanded as a lid of the battery. For example, patent document 1 discloses a lid body (upper lid assembly) of a sealed battery, in which an electrode terminal is mounted on an electrode lead-out hole of an upper lid plate via a seal ring, and an annular fixing member (metal holder) is welded to the upper lid plate after covering the electrode terminal. Further, patent document 2 discloses a lid structure in which a hole is formed in a metal lid, a sealing gasket made of thermoplastic resin having a cylindrical portion is inserted from the back surface of the lid, and a metal external terminal is inserted into the cylindrical portion of the sealing gasket, an inner surface of a cavity (hole) of the lid is joined to an outer surface of the cylindrical portion of the sealing gasket by laser irradiation, and an inner surface of the cylindrical portion of the sealing gasket is joined to an outer surface of the external terminal by laser irradiation, thereby firmly sealing. Further, patent document 3 discloses a lid for a sealed battery, in which a terminal member is mounted on a sealing plate having a mounting hole (hole) for mounting the terminal member. In the cover of patent document 3, a sealing material is used which contains a polyarylene sulfide resin as a thermoplastic resin and further contains an inorganic filler whose volume expansion rate with respect to an electrolyte is suppressed, and the terminal member is inserted in a state where the sealing material is bonded to the peripheral edge portion of the mounting hole of the sealing plate. At this time, fine irregularities formed by laser processing, sandblasting, or the like are provided on the contact surfaces of the terminal member and the sealing material and the contact surfaces of the sealing plate and the sealing material, respectively, and these contact surfaces are joined by an anchor effect. The sealing material is obtained by melting the polyarylene sulfide resin and the inorganic filler, and forming the above-described cap by injection molding. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2021-526707 Patent document 2 Japanese patent application laid-open No. 2012-33339 Patent document 3 Japanese patent application laid-open No. 2022-103899 Disclosure of Invention Technical problem to be solved by the invention As described above, in sealed batteries such as lithium ion secondary batteries, it is necessary to reliably prevent leakage of the electrolyte, and various cover structures have been studied so far. However, in the case of the cover structures described in patent documents 1 and 2, the number of components is large, and the number of manufacturing steps is also troublesome, resulting in a reduction in production efficiency. On the other hand, although the cover of patent document 3 has a relatively simple structure in which a gasket such as a seal ring or a seal gasket is not used, an air layer (void) may be formed at the contact surface of the terminal member and the seal material or at the contact surface of the sealing plate and the seal material due to the presence of the inorganic filler contained in the seal material. If moisture (such as moisture derived from air) exists in the air layer, hydrogen fluoride may be generated as a poison from an electrolyte (for example, fluorine-containing compound such as LiPF 6) in the electrolyte solution due to the moisture. Accordingly, the present inventors have made intensive studies to solve the above problems, and as a result, have found that when a terminal member