Search

KR-102961374-B1 - BATTERY CASE CAPABLE OF DETECTING PHYSICAL DAMAGE AND METHOD FOR DETECTING PHYSICAL DAMAGE OF BATTERY CASE

KR102961374B1KR 102961374 B1KR102961374 B1KR 102961374B1KR-102961374-B1

Abstract

A battery case according to the present invention comprises a laminate sheet in which an inner sealing layer, a metal layer, and an outer resin layer are sequentially laminated, and at least one of the outer resin layer and the inner sealing layer comprises a mechanically luminescent material that emits light upon mechanical stimulation or stress.

Inventors

  • 조정근
  • 김기웅

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260511
Application Date
20220704
Priority Date
20210709

Claims (15)

  1. It includes a laminate sheet in which an inner sealing layer, a metal layer, and an outer resin layer are sequentially laminated, and The above-mentioned outer resin layer and inner sealing layer each comprise a mechanical luminescent material that emits light through mechanical stimulation or stress, and A battery case in which each mechanical luminescent material included in the outer resin layer and the inner sealing layer has a different luminescence spectrum.
  2. In paragraph 1, A battery case comprising at least one of an outer resin layer and an inner sealing layer, the film having a mechanical luminescent material dispersed in a resin matrix.
  3. In paragraph 2, A battery case in which the content of the mechanical luminescent material is 1 to 10 weight percent based on the total weight of the film.
  4. In paragraph 2, A battery case having a film comprising a resin matrix containing one or more selected from the group including polyethylene, polypropylene, polycarbonate, polyester, polyvinyl chloride, acrylic polymer, polyacrylonitrile, polyimide, polyamide, cellulose ester, aramid, polyethylene terephthalate, nylon, and Teflon.
  5. In paragraph 1, The above mechanoluminescent material is ZnS:Mn, ZnS:Cu,Mn, ZnS:Cu,Pb, ZnS:Cu, Pb ,Mn, MgF₂ :Mn, La₂O₂S :Eu, Y₂O₂S :Cu, EuD4TEA, ZnS:Cu, Cl , ZnS:Cu,Mn, Cl , SrAl₂O₄ :Eu, SrAl₂O₄ :Ce, SrAl₂O₄ : Ce , Ho , SrMgAl₆O₇ : Eu, SrCaMgSi₂O₇ :Eu, SrBaMgSi₂O₇ : Eu , Sr₂MgSi₂O₇ : Eu , Ca₂MgSi₂O₇ : Eu ,Dy, CaYAl₃O₇ :Eu ( Ba, Ca ), TiO₃ A battery case comprising one or more selected from the group including :Pr3+, ZnGa₂O₄ :Mn, MgGa₂O₄ :Mn, Ca₂Al₂SiO₇ :Ce, ZrO₂ :Ti, ZnS:Mn,Te, and Nasicon structure phosphors.
  6. In paragraph 1, The outer resin layer has a structure in which two or more films are laminated, and The above films are battery cases comprising different resin matrices.
  7. In paragraph 1, A battery case having an outer resin layer comprising a first film comprising polyethylene terephthalate as a resin matrix and a second film comprising nylon as a resin matrix.
  8. In paragraph 1, A battery case having an internal sealing layer comprising a film containing polypropylene (CPP) as a resin matrix.
  9. delete
  10. A battery cell in which an electrode assembly and an electrolyte are housed within a battery case according to claim 1.
  11. Step of manufacturing a battery cell according to claim 10; and A method for detecting physical damage to a battery case, comprising the step of detecting light emission occurring in the battery case of a manufactured battery cell to detect physical damage occurring in the battery case.
  12. In Paragraph 11, A method for detecting physical damage to a battery case, wherein physical damage occurring in the inner sealing layer is detected by placing the battery cell in a dark room and detecting whether light transmission or light leakage occurs in the inner sealing layer through a mechanically luminescent material.
  13. In Paragraph 11, A method for detecting physical damage to a battery case, wherein the detection of physical damage occurring in the outer resin layer is performed by detecting whether light is emitted by a mechanical light-emitting material from the outside of the battery cell.
  14. In Paragraph 11, A method for detecting physical damage to a battery case, further comprising the step of predicting a gas venting point from the luminescence occurring in the battery case.
  15. In Paragraph 11, The step of detecting physical damage occurring in the battery case is, A method for detecting physical damage to a battery case after applying physical impact to a battery cell or after repeatedly charging and discharging the battery cell.

Description

Battery case capable of detecting physical damage and method for detecting physical damage of battery case The present invention relates to a battery case capable of detecting physical damage and a method for detecting physical damage to a battery cell. Recently, rechargeable secondary batteries are being widely used as an energy source for wireless mobile devices. Furthermore, secondary batteries are attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being proposed as solutions to address air pollution caused by conventional gasoline and diesel vehicles that use fossil fuels. Consequently, the types of applications utilizing secondary batteries are becoming highly diversified due to their advantages, and it is expected that secondary batteries will be applied to a wider range of fields and products in the future than they are today. These secondary batteries are classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium-polymer batteries depending on the composition of the electrodes and electrolytes; among these, the use of lithium-ion polymer batteries is increasing due to their low risk of electrolyte leakage and ease of manufacturing. Generally, secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet. The electrode assembly housed in the battery case is a power generation element capable of charging and discharging, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive and negative electrodes. It is further classified into a jelly-roll type, which is wound with a separator interposed between long sheet-type positive and negative electrodes coated with active material, and a stack type, in which multiple positive and negative electrodes of a predetermined size are sequentially stacked with a separator interposed between them. This pouch-type battery cell is formed by housing an electrode assembly in a storage portion formed in a battery case made of the aforementioned aluminum laminate sheet, and by heat-fusing the aluminum laminate sheet. The electrode leads connected to the electrode assembly are structured to be drawn out to the outside of the battery case. The aluminum laminate sheet has a structure in which a polymer resin layer and an aluminum metal layer are laminated, and generally, the innermost and outermost layers may be composed of polymer resin layers to protect the battery case. Such battery cases may suffer physical damage, such as cracks on their inner or outer surfaces, due to collisions with internal components (e.g., electrode assemblies) or external structures, such as other battery cells or modules. In particular, the storage compartment within the battery case is formed in a concave shape to accommodate the electrode assembly; consequently, the corners of this compartment are thin due to the elongation of the materials constituting the case. Consequently, damage, such as cracks, may occur in these corners if they are subjected to stress during the battery cell assembly process—specifically when receiving impacts while housing the electrode assembly, or when subjected to external impacts from the battery cell itself, or due to repeated swelling. If this damage becomes severe, a venting phenomenon may occur, where internal electrolyte or gas is ejected from the damaged area of the battery case, potentially leading to safety issues. Conventionally, physical damage to such battery cases was checked visually. In addition, to check for damage such as cracks, the finished battery cell was immersed in an infiltrating liquid or sprayed from the outside, after which the battery cell was disassembled to retrospectively check for cracks based on the degree of penetration of the infiltrating liquid or spray. However, in this case, the battery cell had to be destroyed, and there was a problem in that it was difficult to detect minute physical damage. FIG. 1 is a partial cross-sectional view of a battery case according to one embodiment of the present invention. FIG. 2 is a partial cross-sectional view of a battery case according to another embodiment of the present invention. FIGS. 3 and FIGS. 4 are cross-sectional views showing the structure of a battery cell according to the present invention. FIG. 5 is a flowchart showing the sequence of a method for detecting physical damage to a battery case according to the present invention. The present invention will be described in detail below. Prior to this, terms or words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor may appr