WO2024058247A1 - Lithium ion battery and method for producing lithium ion battery - Google Patents

Lithium ion battery and method for producing lithium ion battery Download PDF

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Publication number
WO2024058247A1
WO2024058247A1 PCT/JP2023/033546 JP2023033546W WO2024058247A1 WO 2024058247 A1 WO2024058247 A1 WO 2024058247A1 JP 2023033546 W JP2023033546 W JP 2023033546W WO 2024058247 A1 WO2024058247 A1 WO 2024058247A1
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Prior art keywords
compound
ion battery
lithium ion
sealing
lid
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PCT/JP2023/033546
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French (fr)
Japanese (ja)
Inventor
美咲 浅田
武寛 高橋
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日本製鉄株式会社
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Priority to JP2023573442A priority Critical patent/JP7469733B1/en
Publication of WO2024058247A1 publication Critical patent/WO2024058247A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/102—Primary casings, jackets or wrappings of a single cell or a single battery characterised by their shape or physical structure
    • H01M50/103—Primary casings, jackets or wrappings of a single cell or a single battery characterised by their shape or physical structure prismatic or rectangular
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/116—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material
    • H01M50/117—Inorganic material
    • H01M50/119—Metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/116—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material
    • H01M50/122—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/116—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material
    • H01M50/124—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material having a layered structure
    • H01M50/126—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material having a layered structure comprising three or more layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/116—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material
    • H01M50/124—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material having a layered structure
    • H01M50/126—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material having a layered structure comprising three or more layers
    • H01M50/128—Primary casings, jackets or wrappings of a single cell or a single battery characterised by the material having a layered structure comprising three or more layers with two or more layers of only inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/15—Lids or covers characterised by their shape for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/147—Lids or covers
    • H01M50/166—Lids or covers characterised by the methods of assembling casings with lids
    • H01M50/167—Lids or covers characterised by the methods of assembling casings with lids by crimping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/147—Lids or covers
    • H01M50/166—Lids or covers characterised by the methods of assembling casings with lids
    • H01M50/169—Lids or covers characterised by the methods of assembling casings with lids by welding, brazing or soldering
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/184—Sealing members characterised by their shape or structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/19—Sealing members characterised by the material
    • H01M50/191—Inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/19—Sealing members characterised by the material
    • H01M50/195—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/19—Sealing members characterised by the material
    • H01M50/197—Sealing members characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/60—Arrangements or processes for filling or topping-up with liquids; Arrangements or processes for draining liquids from casings
    • H01M50/609—Arrangements or processes for filling with liquid, e.g. electrolytes
    • H01M50/627—Filling ports
    • H01M50/636—Closing or sealing filling ports, e.g. using lids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a lithium ion battery and a method for manufacturing a lithium ion battery.
  • lithium-ion batteries have rapidly expanded to power storage devices that are combined with new energy systems such as solar cells and wind power generation, and storage batteries for automobiles. Therefore, even higher safety is required for lithium ion batteries installed in electric power storage devices, automobile storage batteries, and the like. Therefore, various techniques have been proposed in recent years to further improve the safety of lithium ion batteries.
  • Patent Document 1 proposes a technique of covering at least a part of the surface of an exterior member that houses an electrode body with an insulating member.
  • the side of the insulating member in contact with the exterior member is made of a nonflammable gas generating member that generates nonflammable gas at high temperatures, and the outermost sheath is made of an insulating resin layer, thereby improving the insulation function of the battery and the battery. It has both ignition prevention function.
  • the present inventors have proposed that, in the lithium ion battery as described above, a Ni plating layer is applied to a base steel plate as a material for a housing case in which a battery unit having a positive electrode, a negative electrode, and a separator and an electrolyte containing a lithium salt are housed.
  • a Ni-plated steel plate provided with a surface treatment layer, or a laminated steel plate in which a surface treatment layer is provided on a base steel plate.
  • the main body and lid of the storage case after housing the battery unit and electrolyte are Sealed by welding, typically by welding, or by caulking.
  • the lid of the storage case is provided with a liquid injection port for injecting the electrolyte into the inside of the storage case.
  • the liquid injection port provided in the lid closes the liquid injection port. used and sealed by welding or caulking.
  • the electrolytic solution used in a lithium ion battery contains a lithium salt (for example, a fluorine-containing lithium salt such as LiPF 6 ) as a component thereof.
  • a lithium salt for example, a fluorine-containing lithium salt such as LiPF 6
  • HF hydrofluoric acid
  • part of the Ni plating layer on the Ni-plated steel sheet or the surface treatment layer on the laminated steel sheet may disappear, leaving the base steel sheet exposed.
  • the end portion of the base steel plate on which the Ni plating layer or surface treatment layer is not provided may be exposed to the surface.
  • the present inventors have discovered that if hydrofluoric acid (HF) is generated in such exposed areas of the base steel plate, the generated hydrofluoric acid will corrode the base steel plate and cause red rust.
  • HF hydrofluoric acid
  • the above-mentioned problem regarding the external corrosion resistance of the storage case, which was discovered for the first time by the present inventors, is that the problem with the corrosion resistance of the outer surface of the storage case, which was discovered for the first time by the present inventors, is that it is difficult for parts that do not come into contact with the atmosphere, such as the nonflammable gas generating member disclosed in Patent Document 1, for example. No matter how hard you try, you can't solve the problem. Therefore, it is necessary to develop a new technology that can maintain the corrosion resistance of the lithium ion battery's outer surface even when electrolyte is attached to the outer surface of the lithium ion battery.
  • an object of the present invention is to solve the problem of lithium ion batteries even when electrolyte is attached to the outer surface of the lithium ion battery.
  • An object of the present invention is to provide a lithium ion battery and a method for manufacturing a lithium ion battery that can maintain external corrosion resistance.
  • the inventors of the present invention have conducted extensive studies and found that it is difficult to completely prevent the adhesion of electrolyte and that contact between lithium ion batteries and moisture in the atmosphere Considering that this is unavoidable when considering the use of batteries, we found that it is important to deal with the generated hydrofluoric acid. On top of that, if a means to nullify the hydrofluoric acid produced by reaction with moisture in the atmosphere can be provided on the outer surface of the lithium ion battery, the corrosion resistance of the lithium ion battery's outer surface can be maintained. It occurred to me that this is possible.
  • the gist of the present invention which was completed based on the above findings, is as follows.
  • a lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid, the battery unit having a positive electrode, a negative electrode, and a separator;
  • a material a Ni-plated steel plate in which a Ni plating layer is provided on the base steel plate, or a laminated steel plate in which the base steel plate is provided with a surface treatment layer is used, and the housing case includes the main body portion and the A first sealing portion that is a sealing portion with the lid portion, or a liquid injection port for sealing a liquid injection port provided in the lid portion for injecting the electrolyte into the inside of the storage case.
  • a lithium ion battery having a coating portion containing at least one of a Ca compound, an Al compound, or a La compound on the above portion.
  • the total adhesion amount of the Ca compound, the Al compound, and the La compound in the coating portion is calculated in terms of metal Ca in the case of the Ca compound, metal Al in the case of the Al compound, and metal Al conversion in the case of the La compound.
  • the lithium ion battery according to (1) wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in the resin.
  • the Ca compound is at least one of calcium carbonate, calcium oxide, or calcium hydroxide
  • the Al compound is at least one of aluminum carbonate, aluminum oxide, or aluminum hydroxide
  • a method for manufacturing a lithium ion battery wherein a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolytic solution containing a lithium salt are housed inside a housing case having a main body portion and a lid portion, the method comprising:
  • the lithium ion battery includes a first sealing portion that is a sealing portion between the main body portion and the lid portion, or a liquid injection provided in the lid portion for injecting the electrolyte into the inside of the storage case.
  • At least one of a liquid injection port lid for sealing the mouth and a second sealing portion that is a sealing portion with the lid portion is formed, and the housing case is made of a base steel plate.
  • the main body part of the housing case in which the battery unit and the electrolyte are housed is made of a Ni-plated steel plate in which a Ni-plated layer is provided, or a laminated steel plate in which a surface treatment layer is provided on the base steel plate. and the lid portion; a sealing step of sealing the liquid injection port and the lid portion to form the first sealing portion and the second sealing portion; the main body portion and the lid portion; After sealing the liquid injection port and the lid, a Ca compound, an Al compound, Alternatively, a method for manufacturing a lithium ion battery, comprising a coating step of applying a paint containing at least one of the La compounds. (17) The method for manufacturing a lithium ion battery according to (16), wherein the sealing step is performed in an atmosphere with a dew point of ⁇ 75° C. or lower.
  • FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention.
  • FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention.
  • FIG. 2 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the first embodiment of the present invention.
  • FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment.
  • FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment.
  • FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment.
  • FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment.
  • FIG. 7 is an explanatory diagram schematically showing the material of a housing case for a lithium ion battery according to a second embodiment of the present invention.
  • FIG. 7 is an explanatory diagram schematically showing the material of a housing case for a lithium ion battery according to a third embodiment of the present invention.
  • 1 is a flowchart showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention.
  • 1 is a flowchart showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention.
  • FIGS. 1A to 2B are explanatory diagrams schematically showing lithium ion batteries in each embodiment of the present invention.
  • a lithium ion battery 1 As schematically shown in FIG. 1A, a lithium ion battery 1 according to each embodiment of the present invention has a battery unit 3 having a positive electrode, a negative electrode, and a separator, and an electrolytic solution 5 containing a lithium salt in a main body 11. It is housed inside a housing case 10 having a lid part 13 and a lid part 13.
  • the battery unit 3 includes a positive electrode (not shown), a negative electrode (not shown), a separator (not shown), and various active materials (not shown) provided in the positive electrode and the negative electrode. ) is not particularly limited. Regarding each member constituting the battery unit 3, various materials used in lithium ion batteries can be used as appropriate. Further, the specific structure of the battery unit 3 is not particularly limited, and various structures can be adopted.
  • FIG. 1A shows a battery unit 3 having a rectangular shape for convenience, the shape of the battery unit 3 may be a columnar shape or any other shape.
  • the electrolytic solution 5 may be any one containing a lithium salt that can generate lithium ions, and electrolytic solutions containing various lithium salts (especially lithium salts containing fluorine) can be used as appropriate. It is. Examples of such lithium salts include LiPF 6 , LiBF 4 , and LiN(SO 2 CF 3 ) 2 (also referred to as LiFSI).
  • the housing case 10 of the lithium ion battery 1 houses the battery unit 3 and electrolyte 5 as described above therein, and includes a main body 11, It is composed of a lid part 13.
  • the main body 11 of the storage case 10 is a hollow member having an internal space that can accommodate the battery unit 3 and the electrolyte 5.
  • the main body portion 11 includes a bottom portion (not shown) and a side portion.
  • the main body part 11 has a rectangular bottom surface (not shown) and four side surfaces, and an internal space for accommodating the battery unit 3 and the electrolytic solution 5 is realized. After the battery unit 3 and electrolyte 5 are housed in the internal space of the main body 11, the opening of the main body 11 is closed by the lid 13, as shown in FIG. 1A.
  • FIG. 1A shows a case where the main body portion 11 of the storage case 10 has a square shape.
  • the specific shape of the main body portion 11 is not particularly defined.
  • the main body 11 can have any shape as long as it can accommodate the battery unit 3 and the electrolyte 5.
  • a liquid injection port 15 which is an opening for injecting the electrolytic solution into the inside of the storage case, is provided in a part of the lid part 13A, and after injection of the electrolytic solution, It is also conceivable that the port 15 is closed with the liquid injection port 17.
  • a lid 13A as shown in FIG. 1B may be used instead of the lid 13 shown in FIG. 1A.
  • the opening of the main body 11 is closed by the lid 13 and sealed. Processing is performed. Thereby, the main body part 11 and the lid part 13 of the storage case 10 are integrated. As a result, as schematically shown in FIG. 2A, a sealed portion is formed between the main body portion 11 and the lid portion 13 in the sealed housing case 10.
  • the "sealing section between the main body and the lid portion indicated by a bold line in FIG. 2A)" will be referred to as a first sealing section 21.
  • the opening of the main body 11 is closed by the lid 13A, A sealing process is performed. Further, the liquid injection port 15 provided in the lid portion 13A is closed by the liquid injection port lid 17, and a sealing process is performed. Thereby, the main body portion 11 and the lid portion 13A of the storage case 10 are integrated. As a result, a first sealing portion 21 is formed as a sealing portion between the main body portion 11 and the lid portion 13A, and a sealing portion between the lid portion 13A and the liquid injection port lid 17 is formed.
  • the “sealing portion between the liquid injection port and the lid portion portion indicated by the thick line in FIG. 2B)" will be referred to as the second sealing portion 23.
  • the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed by the lid portions 13, 13A, so the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed with the lid portions 13, 13A, so the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed with the lid portions 13, 13A. All you have to do is focus on the joint with the lid.
  • the liquid injection port 15 in the lid portion 13A is a portion sealed by the liquid injection port cover 17, so the second sealing portion 23 is the liquid injection port in the lithium ion battery of interest. All you have to do is focus on the joint with the liquid injection palate. More specifically, after the entire lithium-ion battery of interest is embedded in resin, the position of the point that passes through the center of the short side of the lithium-ion battery, or the point that passes through the center of the injection port if there is an injection port. The entire lithium ion battery may be cut in the longitudinal direction of the cell case, and the above-mentioned portions of the obtained cross section may be observed using a scanning electron microscope (SEM). At this time, the size of the field of view during observation may be 1000 ⁇ m ⁇ 1000 ⁇ m.
  • SEM scanning electron microscope
  • FIG. 3 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
  • a Ni-plated steel plate or a laminated steel plate is used as a material for the storage case 10 according to this embodiment.
  • a Ni-plated steel plate is used as the material for the housing case 10 according to the present embodiment.
  • FIG. 3 schematically shows the layer structure of the Ni-plated steel sheet 100.
  • the Ni-plated steel plate 100 used as a material for the storage case 10 has a base steel plate 101 and a Ni-plated layer 103 provided on the front and back surfaces of the base steel plate 101. .
  • the base steel plate 101 is a steel plate that becomes the base material of the Ni-plated steel plate 100.
  • the components, metal structure, etc. of the base steel plate 101 are not particularly limited.
  • As the base material steel plate 101 various steel plates such as low carbon aluminum killed steel and IF steel (Interstitial Free Steel: ultra-low carbon steel) can be used as appropriate.
  • the thickness of the base steel plate 101 may be appropriately set depending on the mechanical strength required of the housing case 10, and may be set to about 0.15 to 1.20 mm, for example.
  • the Ni plating layer 103 located on the surface of the base steel plate 101 is a plating layer containing at least Ni.
  • the Ni plating layer 103 may be composed of Ni and impurities, or at least a portion of the Ni constituting the Ni plating layer 103 may be alloyed with Fe derived from the base steel plate 101.
  • the average composition of the Ni plating layer 103 is not particularly limited. Various types of Ni plating, Ni alloy plating, etc. can be used as the Ni plating layer 103 as long as it exhibits corrosion resistance to the electrolytic solution 5 held in the housing case 10.
  • Ni plating layer 103 is a composition consisting of Ni: 95 to 50% by mass, Fe: 5 to 50% by mass, and impurities. Further, the Ni plating layer 103 may further contain any alloy element of Co, Sn, Zn, W, Mo, and Cr in place of a part of Ni. Examples of methods for forming the Ni plating layer 103 include various plating methods such as hot-dip plating using a plating bath and electroplating, thermal spraying, and vapor deposition.
  • the amount of Ni plating layer 103 deposited on one side is, for example, 5 to 50 g/m 2 . It is more preferable that the amount of Ni plating layer 103 deposited on one side is 10 g/m 2 or more, since it is possible to further improve the corrosion resistance of Ni-plated steel sheet 100. On the other hand, it is more preferable that the amount of Ni plating layer 103 deposited on one side be 30 g/m 2 or less, because this makes it possible to further reduce the manufacturing cost of Ni-plated steel sheet 100.
  • the Ni-plated steel sheet 100 may be one that is not heat-treated after plating, or may be one that is heat-treated after plating.
  • a diffusion alloy layer is formed at the interface between the base steel plate 101 and the Ni plating layer 103.
  • the amount of Ni plating layer 103 deposited on one side can be measured by, for example, ICP emission spectroscopy.
  • samples each having a size of 30 mm x 30 mm when viewed from above are cut out from five arbitrary locations on the bottom of the housing case of the lithium ion battery of interest, and each of the Ni plating layers 103 present in the sample is Dissolve with acid (more specifically, 19% hydrochloric acid).
  • acid more specifically, 19% hydrochloric acid
  • the amount of Total-Ni contained in each solution is quantitatively analyzed using an ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation). The fact that the Total-Ni amount exceeds 0 means that the Ni plating layer 103 is present in the obtained sample.
  • the amount of Ni attached per unit area can be determined.
  • the average value of the five Ni adhesion amounts obtained is treated as the adhesion amount per one side of the Ni plating layer 103.
  • the average composition of the Ni plating layer 103 can be similarly determined by ICP emission spectrometry.
  • cutting out a sample from the point of interest if the size of any side of the sample is less than 30 mm, cut the sample from the point of interest so that the area of the sample is 90 mm 2 .
  • various chemical conversion coating layers may be further present between the base steel sheet 101 and the Ni-plated layer 103.
  • the presence of such a chemical conversion coating layer makes it possible to further improve the adhesion between the base steel plate 101 and the Ni plating layer 103.
  • the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the Ni-plated steel sheet 100.
  • Such a chemical conversion coating layer is not particularly limited, and may be formed using various chemical conversion treatments.
  • Examples of such chemical conversion treatments include chromate-based chemical conversion treatments and non-chromate-based chemical conversion treatments.
  • Examples of non-chromate-based chemical conversion treatments include chemical conversion treatments using inorganic compounds such as vanadium compounds, titanium compounds, zirconium compounds, and phosphoric acid compounds, and silica-based chemical conversion treatments.
  • FIGS. 4A and 4B are explanatory diagrams schematically showing a lithium ion battery in this embodiment.
  • FIG. 4A schematically shows a part of a cross section of the storage case 10 cut in the case height direction
  • FIG. 4B shows the vicinity of the liquid injection port 17 of the storage case 10 in the case height direction.
  • a part of a cross section cut in the direction is schematically shown.
  • lid parts 13, 13A, and liquid injection port lid 17 of the storage case 10 are manufactured using the materials shown in FIG. In some cases, the end face of the base steel plate 101 that is not present is exposed to the surface. Further, the main body 11 and the lids 13 and 13A of the storage case 10, and the lid 13A and the liquid injection port 17 are sealed by welding or caulking. At this time, there is a possibility that a part of the Ni plating layer 103 disappears due to such sealing treatment, and the base material steel plate 101 is exposed.
  • FIG. 4A schematically shows an example of a cross section near the first sealing part 21. Note that the shape shown in FIG. 4A is merely an example, and the shape of the vicinity of the first sealing portion 21 in the lithium ion battery 1 according to the present embodiment is not limited to this example.
  • the end surface of the base steel plate 101 on which the Ni plating layer 103 is not provided is exposed to the atmosphere, such as the top surface of the side surface of the main body portion 11 and the end portion of the lid portion 13. It is exposed.
  • FIG. 4B schematically shows an example of a cross section near the second sealing part 23. Note that the shape shown in FIG. 4B is merely an example, and the shape of the vicinity of the second sealing portion 23 in the lithium ion battery 1 according to the present embodiment is not limited to this example.
  • the end surface of the base steel plate 101 is exposed to the atmosphere at the side end of the liquid injection port lid 17.
  • the reason why the Fe content is 80% by mass or more in the exposed iron portion is as follows. That is, if a part of the Ni plating layer 103 disappears due to the sealing process, for example, there is a possibility that an element other than Fe originating from the Ni plating layer 103 may exist in the part.
  • FIGS. 5A and 5B are explanatory diagrams schematically showing the lithium ion battery 1 in this embodiment.
  • FIG. 5A schematically shows a part of a cross section of the storage case 10 cut in the case height direction
  • FIG. 5B shows the vicinity of the liquid injection port 17 of the storage case 10 in the case height direction.
  • a part of a cross section cut in the direction is schematically shown.
  • the coating portion 30 covers the covering target region 201 (or the sealing 203 present in the covering target region 201). It is provided on the region to be covered 201 .
  • the film portion 30 contains at least either a Ca compound or an Al compound.
  • Ca compounds, Al compounds, and La compounds can make hydrofluoric acid (HF) harmless by reacting with it to form fluorides (CaF 2 , AlF 3 , LaF 3 ). . Therefore, by providing the coating portion 30 containing at least one of a Ca compound, an Al compound, or a La compound on the covering target part 201 (or on the sealing 203 existing in the covering target part 201), the covering target part Even if the electrolyte is attached to 201, the generated hydrofluoric acid can be made harmless, and the generation of red rust can be prevented. As a result, in the lithium ion battery 1 according to the present embodiment, even if the electrolyte is attached to the outer surface of the lithium ion battery 1, it is possible to maintain the corrosion resistance of the outer surface of the lithium ion battery 1. .
  • the Ca compound, Al compound, and La compound are compounds that can react with hydrofluoric acid to form a fluoride, and the compounds themselves do not promote corrosion of the Ni-plated steel sheet 100. , it is possible to use various compounds. From the viewpoint that the compounds themselves do not promote corrosion of the Ni-plated steel sheet 100, for example, CaCl 2 and AlCl 3 are excluded from such compound candidates.
  • Such Ca compounds, Al compounds, and La compounds include, for example, hydroxides of Ca, Al, or La, or salts of an anion that is not a strong acid anion and Ca ion, Al ion, or La ion (for example, carbonates of Ca, Al or La), or oxides of Ca, Al or La. More preferably, the reaction products of such Ca compounds, Al compounds, and La compounds with hydrofluoric acid do not have corrosivity to Fe and Ni.
  • Ca compounds include calcium carbonate (CaCO 3 ), calcium oxide (CaO), and calcium hydroxide (Ca(OH) 2
  • Al compounds include aluminum carbonate (Al 2 (CO 3 ) ). ) 3 ), aluminum oxide (Al 2 O 3 ), and aluminum hydroxide (Al(OH) 3
  • La compounds include lanthanum carbonate (La 2 (CO 3 ) 3 ), lanthanum oxide ( Examples include La 2 O 3 ) and lanthanum hydroxide (La(OH) 3 ). These compounds may be used alone or in combination.
  • the coating portion 30 it is preferable that 80% by mass or more of the Ca compounds contained in the coating portion 30 is calcium hydroxide in terms of metallic Ca.
  • the proportion of calcium hydroxide in the Ca compound is more preferably 90% by mass or more.
  • the film portion 30 may be composed of at least one of a Ca compound, an Al compound, or a La compound, or may be composed of at least one of a Ca compound, an Al compound, or a La compound dispersed in a resin. You can leave it there.
  • various resins can be used as the resin that functions as a binder. Examples of such resins include polyvinylidene difluoride (PVDF), epoxy resins, melamine resins, silicone resins, acrylic resins, and polyurethane resins.
  • the coating portion 30 according to the present embodiment is prepared by preparing a treatment agent containing at least one of the Ca compound, Al compound, or La compound as described above, and, if necessary, a resin as described above. It can be formed by applying it to the area to be covered 201 (or the area to be covered 201 present in the seal 203) and drying it. Note that it is important to apply the treatment agent as described above after the battery unit 3 and electrolyte 5 are housed in the housing case 10 and the sealing process is performed, as will be explained again below. This does not mean that it is sufficient to apply the above-mentioned processing agent prior to the sealing process.
  • the following may be performed.
  • SEM scanning electron microscope
  • the coating portion 30 identified as described above is a portion of the first sealing portion 21 or the second sealing portion 23 where the content of Fe is 80% by mass or more (that is, the portion to be coated 201 ) is provided, you can do the following. That is, the cross-sectional observation obtained as above with an energy dispersive X-ray spectrometry (EDS) (for example, JSM-7000F manufactured by JEOL Co., Ltd.) mounted on a scanning electron microscope. A mapping analysis regarding the distribution of each element may be performed by observing a cross section of the sample.
  • EDS energy dispersive X-ray spectrometry
  • the coating portion 30 identified as described above is located in the first sealing portion 21 or the second sealing portion 23. , it can be determined whether or not the Fe content is provided in a portion having a Fe content of 80% by mass or more.
  • the measurement conditions for cross-sectional observation and mapping analysis as described above are an acceleration voltage of 15 kV and an irradiation current of 7.47500 nA.
  • a powder sample is collected from the coating portion 30 and the obtained powder sample is analyzed by X-ray diffraction analysis. do it. More specifically, after collecting 5 g of powder sample from any position on the coating portion 30, analysis is performed using a commercially available X-ray diffraction analyzer (for example, RINT-TTR3 manufactured by RIGAKU) to determine whether Ca, Al, and La are present. It is sufficient to check whether the derived peak exists in the measurement results. Similarly, whether resin is contained in the coating portion 30 can be determined by checking whether a peak derived from C (carbon) exists in the measurement results.
  • X-ray diffraction analyzer for example, RINT-TTR3 manufactured by RIGAKU
  • the compound names of the Ca compound, Al compound, and La compound contained in the film portion 30 after the fact may be specified by assigning the peaks present in the measurement.
  • Cu is used as the X-ray source, and the measurement conditions are: It is sufficient to set the angle to 100 degrees, the entrance slit to 1/2 degrees, and the longitudinal restriction slit to 5 mm.
  • the coating portion 30 according to the present embodiment as described above, by reacting a Ca compound, an Al compound, or a La compound with hydrofluoric acid, the hydrofluoric acid is rendered harmless, so that such a reaction is prevented.
  • a fluoride of Ca, Al or La ie, CaF 2 , AlF 3 , LaF 3
  • the film portion 30 of the lithium ion battery 1 according to the present embodiment may contain a fluoride as a Ca compound, an Al compound, or a La compound.
  • the film portion 30 of the lithium ion battery 1 may be composed of a compound other than a fluoride of at least one of Ca, Al, or La, or may be composed of a compound other than a fluoride of at least one of Ca, Al, or La. It may be composed of a compound other than fluoride and at least one fluoride of Ca, Al or La, or it may be composed of at least one fluoride of Ca, Al or La. sell.
  • the presence or absence of fluorides of Ca, Al, or La can be confirmed by taking a powder sample from the coating portion 30 and analyzing the obtained powder sample by X-ray diffraction analysis.
  • X-ray diffraction analyzer for example, RINT-TTR3 manufactured by RIGAKU
  • Cu was used as the X-ray source, and the measurement conditions were: X-ray output was 50 kV and 300 mA, scan speed was 1 deg/min, step width was 0.01 deg, scan axis was 2 Theta/Theta, and scan range was 5 to 100 deg. , the entrance slit may be 1/2°, and the longitudinal restriction slit may be 5 mm.
  • a fluoride of Ca, Al or La is a reaction product of a Ca compound, an Al compound or a La compound and hydrofluoric acid. Therefore, more of the fluoride is present on the surface of the coating portion 30 than on the surface of the coating portion 201 or the interface with the sealing 203. In other words, in the film portion 30 according to the present embodiment, the fluoride of Ca or Al is unevenly distributed so that it is present in a larger amount on the interface side with the base material steel plate constituting the Ni-plated steel plate 100 or the sealing 203. It becomes like this.
  • the total adhesion amount of the Ca compound, Al compound, and La compound is calculated in terms of metal Ca in the case of Ca compounds, metal Al in the case of Al compounds, and metal La in the case of La compounds.
  • the total of each converted value is preferably 0.001 g/m 2 or more.
  • the total amount of the Ca compound, Al compound, and La compound deposited is more preferably 100.000 g/m 2 or more, and still more preferably 300.000 g/m 2 or more.
  • the total amount of deposited Ca compounds, Al compounds, and La compounds is calculated in terms of metal Ca in the case of Ca compounds, metal Al in the case of Al compounds, and metal La in the case of La compounds. It is preferable that the total of each converted value is 1000.000 g/m 2 or less. Since the Ca compound, Al compound, and La compound may be applied in the form of a paste to the coating target area 201 (or the sealing 203 existing in the coating target area 201), the total amount of the Ca compound, Al compound, and La compound applied is 1000.000 g/ It can be about m2 .
  • the total adhesion amount of the Ca compound, Al compound, and La compound is 1000.000 g/m 2 or less, the first sealing part 21 and the second sealing part 23 can be sealed while suppressing an increase in manufacturing cost. External corrosion resistance can be further improved.
  • the total amount of the Ca compound, Al compound, and La compound deposited also differs depending on the configuration and formation method of the film portion 30.
  • the coating portion 30 formed by applying at least one of a Ca compound, an Al compound, or a La compound that is, a paste of a Ca compound, an Al compound, or a La compound
  • the total adhesion amount is more preferably 800.000 g/m 2 or less, still more preferably 500.000 g/m 2 or less.
  • the total amount of the Ca compound, Al compound, and La compound deposited is more preferably 800. It is .000 g/m 2 or less, more preferably 500.000 g/m 2 or less.
  • the total amount of the Ca compound, Al compound, and La compound deposited can be more preferably about 100.000 g/m 2 or less.
  • the amount of fluoride, which is a reaction product, attached may exceed 0 g/m 2 in terms of fluorine.
  • the amount of fluoride that can exist in the coating part 30 is substantially 0 in terms of fluorine. .200g/ m2 or less.
  • the total adhesion amount of Ca compound, Al compound, and La compound in the coating portion 30 can be measured by ICP emission spectrometry.
  • coating portions 30 having a size of 1 mm x 50 mm when viewed from above are taken from five arbitrary locations, and each of the obtained samples is dissolved in sulfuric acid.
  • the amounts of Ca, Al, and La contained in each solution are quantitatively analyzed using a commercially available ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation).
  • the amount of Ca, the amount of Al, and the amount of La obtained by such quantitative analysis correspond to the converted amount when converted to Ca, the converted amount when converted to Al, and the converted amount when converted to La, respectively.
  • the total amount of deposited Ca compound, Al compound, and La compound can be determined.
  • the average value of the total adhesion amounts of the five Ca compounds, Al compounds, and La compounds obtained is treated as the total adhesion amount of the Ca compound, Al compound, and La compound.
  • the amount of fluoride deposited on the film portion 30 can be measured as follows. First, as samples, coating portions 30 having a size of 1 mm x 50 mm when viewed from above are taken from five arbitrary locations, and each of the obtained samples is dissolved in sulfuric acid. The gas generated during such dissolution is analyzed using a commercially available gas chromatograph (for example, Nexis GC-2030 manufactured by Shimadzu Corporation) to measure the amount of F. By dividing the obtained amount of F by the above-mentioned area, the amount of attached fluoride can be determined. The average value of the five fluoride adhesion amounts obtained is treated as the fluoride adhesion amount. This makes it possible to obtain the amount of fluoride deposited in terms of fluorine.
  • a commercially available gas chromatograph for example, Nexis GC-2030 manufactured by Shimadzu Corporation
  • the proportion of calcium hydroxide in the Ca compound contained in the film portion 30 can be determined as follows. That is, it is assumed that in the sample having the film portion 30 containing calcium hydroxide, all F is combined with Ca. Then, the amount of F is measured for the sample collected in the same manner as above. Based on the F amount obtained by such measurement, the Ca amount is converted under the above assumption. The difference between the total amount of Ca compounds attached and the converted amount of Ca is the amount of Ca in calcium hydroxide. The proportion occupied by calcium hydroxide can be calculated by dividing the amount of Ca in the obtained calcium hydroxide by the total amount of Ca compounds attached.
  • the state of uneven distribution of fluoride in the coating portion 30 can be confirmed, for example, as follows.
  • a sample for cross-sectional observation is cut out from the coating portion 30 on the longitudinal portion of the storage case 10.
  • the cutting direction for obtaining the cross section is perpendicular to the longitudinal direction of the storage case 10.
  • After embedding the obtained sample for cross-sectional observation in resin it may be appropriately polished and measured by observing the obtained cross-section with a scanning electron microscope (SEM). At this time, the size of the field of view during observation may be 1000 ⁇ m ⁇ 1000 ⁇ m.
  • an energy dispersive X-ray spectrometer (for example, JSM-7000F manufactured by JEOL Co., Ltd.) installed in a scanning electron microscope is used to analyze the cross section of the sample for cross-sectional observation obtained as described above.
  • EDS energy dispersive X-ray spectrometer
  • the position where the concentration of fluoride peaks is located closer to the base steel plate than the position half the thickness of the coating 30 is classified as "unevenly distributed”.
  • the measurement conditions for mapping analysis are an acceleration voltage of 15 kV and an irradiation current of 7.47500 nA.
  • the thickness of the film portion 30 can be determined by identifying the portion where element F is present from the obtained mapping results, and measuring the length of the identified portion using the length measurement function implemented in the image analysis application. Bye. Such measurements may be carried out at five arbitrary locations on the cross section of interest, and the obtained measured values may be averaged over the number of measurement locations to determine the thickness of the coating portion 30.
  • the lithium ion battery 1 according to the present embodiment has been described in detail above with reference to FIGS. 1A to 5B.
  • FIG. 6 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
  • a Ni-plated steel plate or a laminated steel plate is used as a material for the storage case 10 according to this embodiment.
  • a laminated steel plate is used as the material for the storage case 10 according to the present embodiment.
  • FIG. 6 schematically shows the layer structure of the laminated steel plate 100A.
  • the laminated steel plate 100A used as a material for the housing case 10 includes a base steel plate 101 and a surface treatment layer 105 provided on the surface of the base steel plate 101.
  • the base steel plate 101 can be the same as the base steel plate 101 of the Ni-plated steel plate 100 described previously, so detailed explanation will be omitted below.
  • the surface treatment layer 105 is a layer formed by laminating the surface of the base steel plate 101 with various resins.
  • various kinds of surface treatment layers can be applied as long as they exhibit corrosion resistance to the electrolytic solution 5 held in the storage case 10.
  • the resin constituting the surface treatment layer 105 include polypropylene (PP) resin, polyethylene terephthalate (PET) resin, and polyethylene (PE) resin. These resins may be used alone or in combination.
  • the thickness of the surface treatment layer 105 per side is preferably 10 to 150 ⁇ m, for example. It is more preferable for the thickness of the surface treatment layer 105 to be 50 ⁇ m or more per side, since it is possible to further improve the corrosion resistance of the laminated steel plate 100A. On the other hand, it is more preferable for the thickness of the surface treatment layer 105 to be 100 ⁇ m or less per side, since this makes it possible to further reduce the manufacturing cost of the laminated steel plate 100A.
  • ICP emission spectrometry may be used. First, samples each having a size of 30 mm x 30 mm when viewed from above are cut out from five arbitrary locations on the bottom of the housing case of the lithium ion battery of interest, and each of the surface treatment layers 105 present in the sample is Dissolve with acid (more specifically, 19% hydrochloric acid). Next, focusing on elements that can be contained in the surface treatment layer 105, each sample is quantitatively analyzed using an ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation).
  • ICP emission spectrometer for example, ICPS-8100 manufactured by Shimadzu Corporation.
  • the amount of Total-C contained in the solution is quantitatively analyzed. For example, when the average value of the five Total-C amounts obtained exceeds 0, it can be determined that the surface treatment layer 105 was present in the laminated steel sheet 100A of interest. In addition, when cutting out a sample from the point of interest, if the size of any side of the sample is less than 30 mm, cut the sample from the point of interest so that the area of the sample is 90 mm 2 . Bye.
  • the thickness of the surface treatment layer 105 can be determined by observing the cross section of the laminated steel plate 100A using a scanning electron microscope (SEM). That is, a sample for cross-sectional observation is cut out from an arbitrary part of the laminated steel plate 100A. At this time, the cutting direction for obtaining the cross section is the thickness direction of the laminated steel plate 100A. After polishing the obtained sample for cross-sectional observation, SEM photographs are taken at five arbitrary locations on the cross-section. The thickness of the surface treatment layer 105 measured in each obtained SEM photograph may be averaged by the number of measurement points, and the obtained average value may be taken as the thickness of the surface treatment layer 105.
  • SEM scanning electron microscope
  • various chemical conversion coating layers may be further present between the base steel sheet 101 and the surface treatment layer 105.
  • the presence of such a chemical conversion coating layer makes it possible to further improve the adhesion between the base steel sheet 101 and the surface treatment layer 105.
  • the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the laminated steel sheet 100A.
  • the description ⁇ Ni-plated steel sheet 100'' may be read as ⁇ laminated steel sheet 100A,'' and the description ⁇ Ni plating layer 103'' may be read as ⁇ surface treatment layer 105.'' Therefore, detailed description of the relationship between the sealing process and the area to be covered by the film part and the film part 30 when the laminated steel plate 100A is used as the material of the housing case 10 will be omitted below.
  • FIG. 7 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
  • a material for the housing case 10 it is also possible to use a surface-treated steel plate 100B in which a Ni plating layer 103 and a surface treatment layer 105 are formed on the surface of a base steel plate 101, as shown in FIG.
  • the Ni plating layer 103 in the surface-treated steel sheet 100B has the same configuration as the Ni plating layer 103 in the Ni-plated steel sheet 100 according to the first embodiment, and has the same effect, so the following will be explained. A detailed explanation will be omitted.
  • the surface treatment layer 105 in the surface treated steel sheet 100B has the same configuration as the surface treatment layer 105 in the laminated steel sheet 100A according to the second embodiment, and has the same effects, so the details will be explained below. Further explanation will be omitted.
  • various types of A chemical conversion coating layer may also be present.
  • the presence of such a chemical conversion coating layer further improves the adhesion between the base steel sheet 101 and the Ni plating layer 103 and the adhesion between the Ni plating layer 103 and the surface treatment layer 105. becomes possible.
  • the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the surface-treated steel sheet 100B.
  • FIGS. 8A and 8B are flowcharts showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention.
  • the main body 11 and lid parts 13, 13A of the storage case 10 are manufactured using Ni-plated steel plate 100, laminated steel plate 100A, and surface-treated steel plate 100B so as to have a desired shape. shall be.
  • FIG. 8A shows a first sealing part 21 that is a sealing part between the main body part 11 and the lid part 13, or a liquid filling port lid 17 for sealing the liquid filling port 15 provided in the lid part 13A.
  • This is a method of manufacturing the lithium ion battery 1 in the case where any of the second sealing parts 23, which are the sealing parts with the liquid port 15, are present.
  • the battery unit 3 is first housed in the housing case 10 (step S11), and then the electrolyte 5 is placed inside the housing case 10. is injected (step S13). Thereafter, the main body portion 11 and the lid portion 13 of the storage case 10 or the liquid injection port cover 17 and the liquid injection port 15 are sealed using a sealing method such as welding or caulking (step S15).
  • FIG. 8B shows the first sealing part 21, which is a sealing part between the main body part 11 and the lid part 13A, and the liquid injection port lid 17 for sealing the liquid injection port 15 provided in the lid part 13A.
  • This is a method for manufacturing a lithium ion battery when a second sealing portion 23 that is a sealing portion with the liquid port 15 is present.
  • the battery unit 3 is first housed in the housing case 10 (step S21), and then a sealing method such as welding or caulking is used. Then, a sealing process is performed between the main body portion 11 of the storage case 10 and the lid portion 13A (step S23). Thereafter, the electrolytic solution 5 is injected into the housing case 10 through the inlet 15 (step S25). Subsequently, the liquid injection port 17 and the liquid injection port 15 are sealed using a sealing method such as welding or caulking (step S27).
  • a sealing method such as welding or caulking
  • the main body portion 11 and the lid portions 13, 13A of the storage case 10 are integrated, and the first sealing portion 21 and the second sealing portion 23 as described above are present.
  • the steps up to the sealing process described above should be performed in an atmosphere that contains as little moisture as possible. It is preferable to carry out the test under low temperature (for example, under an atmosphere with a dew point of ⁇ 75° C. or lower). In other words, it is preferable that the housing case 10 is taken out into the atmosphere at least after the sealing process in the atmosphere as described above is completed.
  • a coating process is performed to form the film portion 30 (step S17, step S29).
  • a paint containing at least one of the Ca compound, Al compound, or La compound as described above is prepared, and the coating amount after drying is within the range as described above. Paint is applied.
  • Such a paint may be a paint in which at least one of a Ca compound, an Al compound, or a La compound is dissolved or dispersed in various organic solvents, or a paint in which at least one of a Ca compound, an Al compound, or a La compound is dissolved or dispersed in various organic solvents. It may also be a paint dispersed in a resin.
  • carbonate esters contained in the electrolytic solution such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), and ethylene carbonate (EC) are used. It is preferable to use
  • such coating treatment is preferably carried out in an atmosphere where moisture content is as low as possible (for example, in an atmosphere with a dew point of ⁇ 75° C. or lower). From this point of view, it is even more preferable that the coating treatment as described above is subsequently performed in the atmosphere in which the sealing treatment as described above has been performed. Furthermore, when the coating process is performed in an atmosphere where a certain amount of moisture is present (for example, when the sealed housing case 10 is taken out into the atmosphere after the sealing process as described above is completed), It is preferable to perform the coating treatment as soon as possible after the sealing treatment.
  • a film portion 30 is formed on the area to be covered 201 of the lithium ion battery 1.
  • the electrolyte adheres to the outer surface of the lithium ion battery 1, and even if the lithium ion battery 1 is exposed to the atmosphere, it will not be affected by hydrofluoric acid. It is possible to prevent the occurrence of red rust.
  • the lithium ion battery according to the present invention will be specifically explained while showing examples and comparative examples. Note that the examples shown below are merely examples of the lithium ion battery according to the present invention, and the lithium ion battery according to the present invention is not limited to the following examples.
  • Test example In the test example shown below, the main body and the lid of the storage case were prepared, as well as the battery unit shown below, and these members were assembled to form a lithium ion battery. After injecting electrolyte through an opening provided in the main body of the storage case, the main body was sealed with a lid, and the external corrosion resistance of the completed lithium ion battery was evaluated.
  • Ni-plated steel plate a nickel-plated steel plate (Super Nickel (registered trademark)) manufactured by Nippon Steel Corporation was used. In this nickel-plated steel sheet, the amount of Ni deposited on one side was 2.0 ⁇ m.
  • ⁇ Laminated steel plate ⁇ Base material steel plate: Tin-free steel manufactured by Nippon Steel Corporation (Cansuper (registered trademark)) ⁇ Surface treatment layer: PP (battery inner side (side facing the battery unit)) / PET (battery outer side)
  • a resin film made of the above-mentioned resin was prepared, and the resin film was pressed against tin-free steel heated to 200°C and fused.
  • the thickness of the surface treatment layer after heat fusion was 50 ⁇ m.
  • ⁇ Surface-treated steel sheet In addition, a surface treatment layer similar to that provided on the laminated steel sheet was formed on the front and back surfaces of the nickel-plated steel sheet manufactured by Nippon Steel Corporation in the same manner as the above-mentioned laminated steel sheet to obtain a surface-treated steel sheet.
  • the main body and lid of the storage case were fabricated using the nickel-plated steel plate, laminated steel plate, and surface-treated steel plate as described above. Note that the main body and lid of the storage case had the same shape as the storage case illustrated in FIG. 1A.
  • Lithium cobalt oxide was used as the positive electrode active material.
  • PVDF polyvinylidene fluoride
  • NMP N-methyl-2-pyrrolidone
  • Electrolyte As the electrolyte, a solution (1M-LiPF 6 EC/DEC (1/1)) in which 1 mol/L of lithium hexafluorophosphate was added to a mixture of ethylene carbonate and diethyl carbonate at a volume ratio of 1:1 was used. there was.
  • Lithium ion battery manufacturing procedure A separator was sandwiched between the positive electrode plate and negative electrode plate obtained as described above, and then wound to form an electrode unit. After the battery unit was crushed into a shape that could be inserted into the internal space of the main body of the housing case, the positive electrode plate was welded to the Al lead, and the negative electrode plate was welded to the Ni lead. The Al lead was welded to the positive terminal provided on the lid of the storage case, and the Ni lead was welded to the negative terminal provided on the lid of the storage case.
  • the inside of the battery was dried in an atmosphere with a dew point of -75°C to remove moisture. Thereafter, under the same atmosphere, the above electrolyte solution was injected through the opening provided in the main body of the storage case. Thereafter, the lid was fixed to the main body by welding or tightening. Thereafter, the obtained lithium ion battery was charged at 3.6V under the same atmosphere. Through this treatment, water remaining in the battery was electrolytically removed. Thereafter, in the same atmosphere, the same type of metal as the lid was welded to the liquid injection port as a liquid injection port cover, thereby completing a lithium ion battery.
  • ⁇ Rust prevention treatment Formation of film part In an atmosphere with a dew point of -75°C or as soon as possible after being taken out to the atmosphere, the sealed part (first sealed part) of the above evaluation sample was treated as shown in Table 1 below. ⁇ Mixture of organic solvent and Ca compound, Al compound, La compound'', ⁇ mixture of resin and Ca compound, Al compound, La compound'', or ⁇ resin alone'' is applied with a brush as a rust preventive treatment agent, Dry. As a result, a film portion corresponding to each antirust treatment agent is formed on the first sealing portion.
  • Ca compounds calcium hydroxide, calcium carbonate, calcium hydrogen carbonate, calcium oxide
  • Al compounds aluminum hydroxide, calcium carbonate, aluminum oxide
  • La compounds lanthanum hydroxide, lanthanum carbonate, lanthanum oxide
  • Organic solvent dimethyl carbonate (DMC), ethyl Methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), ethylene carbonate (EC)
  • DMC dimethyl carbonate
  • EMC ethyl Methyl carbonate
  • DEC diethyl carbonate
  • PC propylene carbonate
  • EC ethylene carbonate
  • Resin PVDF, epoxy resin, melamine resin, silicone resin, acrylic resin, polyurethane resin.
  • the total adhesion amount of Ca compounds, Al compounds, and La compounds, the proportion of calcium hydroxide in Ca compounds, the presence or absence of fluoride, and the The amount of chemical substances attached was analyzed.
  • the ICP emission spectrometer used was ICPS-8100 manufactured by Shimadzu Corporation, and the gas chromatograph used was Nexis GC-2030 manufactured by Shimadzu Corporation.
  • sample for cross-sectional observation was obtained by cutting a different part from the part from which the above powder was obtained using a high-speed precision cutting machine.
  • the obtained sample for cross-sectional observation was filled with resin, wet-polished to #1200 emery paper, and further polished to a mirror surface by diamond polishing (DP-suspension, manufactured by Struers), and used for observation.
  • DP-suspension manufactured by Struers
  • the cross section was observed using backscattered electrons with a SEM (JEOL JSM-7000F) according to the method previously described. SEM-EDS analysis was used for elemental analysis of the cross section.
  • a lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid,
  • a Ni-plated steel plate in which a Ni plating layer is provided on a base steel plate, or a laminated steel plate in which a surface treatment layer is provided on a base steel plate, is used
  • the accommodation case includes a first sealing part that is a sealing part between the main body part and the lid part, or an inlet provided in the lid part for injecting the electrolyte into the interior of the accommodation case.
  • At least one of a liquid injection port for sealing the liquid port and a second sealing portion that is a sealing portion with the lid portion is present,
  • a film portion containing at least one of a Ca compound, an Al compound, or a La compound is provided on a portion of the first sealing portion or the second sealing portion in which the content of Fe is 80% by mass or more.
  • lithium-ion battery Li-ion battery.
  • the total adhesion amount of the Ca compound, the Al compound, and the La compound in the film portion is calculated in terms of metal Ca in the case of the Ca compound, metal Al in the case of the Al compound, and metal La in the case of the La compound.
  • the lithium ion battery according to (1) which is 0.001 g/m 2 or more and 1000.000 g/m 2 or less in terms of conversion.
  • the Ca compound is at least one of calcium carbonate, calcium oxide, or calcium hydroxide
  • the Al compound is at least one of aluminum carbonate, aluminum oxide, or aluminum hydroxide
  • the first sealing part and the second sealing part are constructed by welding or caulking ( The lithium ion battery according to any one of 1) to (8).
  • a method for manufacturing a lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid, the method comprising:
  • the lithium ion battery may include a first sealing portion that is a sealing portion between the main body portion and the lid portion, or an injection hole provided in the lid portion for injecting the electrolyte into the inside of the storage case.
  • At least one of a liquid injection port for sealing the liquid port and a second sealing part that is a sealing part with the lid part is formed,
  • a Ni-plated steel plate in which a Ni-plated layer is provided on the base steel plate, or a laminated steel plate in which the base steel plate is provided with a surface treatment layer Regarding the storage case in which the battery unit and the electrolyte are stored, the main body and the lid, and the liquid injection port and the lid are sealed, and the first sealing part and the lid are sealed.
  • a method for manufacturing a lithium ion battery including: (11) The method for manufacturing a lithium ion battery according to (10), wherein the sealing step is performed in an atmosphere with a dew point of ⁇ 75° C. or lower.

Abstract

[Problem] To maintain the corrosion resistance of the outer surface of a lithium ion battery even if an electrolyte solution has adhered to the outer surface of the lithium ion battery. [Solution] The present invention relates to a lithium ion battery in which a battery unit that comprises a positive electrode, a negative electrode and a separator and an electrolyte solution that contains a lithium salt are housed in a housing case that has a main body part and a cover part, wherein: an Ni-plated steel sheet or a laminated steel sheet is used as the material of the housing case; at least either a first sealing part which seals the main body part and the cover part or a second sealing part which seals the cover part and a liquid injection port cover for sealing a liquid injection port that is provided in the cover part and is for injecting the electrolyte solution into the housing case; and the first sealing part or the second sealing part has a film part which contains at least one of a Ca compound, an Al compound and an La compound on a portion that has an Fe content of 80% by mass or more.

Description

リチウムイオン電池及びリチウムイオン電池の製造方法Lithium ion battery and lithium ion battery manufacturing method
　本発明は、リチウムイオン電池及びリチウムイオン電池の製造方法に関する。 The present invention relates to a lithium ion battery and a method for manufacturing a lithium ion battery.
　近年、リチウムイオン電池をはじめとする二次電池の用途が、太陽電池や風力発電などの新エネルギーシステムと組み合わせた電力貯蔵用蓄電装置や、自動車用蓄電池等に急速に拡大している。そのため、電力貯蔵用蓄電装置や、自動車用蓄電池等に搭載されるリチウムイオン電池についても、より高い安全性が求められるようになってきている。そこで、リチウムイオン電池の安全性をより向上させるために、近年、様々な技術が提案されている。 In recent years, the use of secondary batteries such as lithium-ion batteries has rapidly expanded to power storage devices that are combined with new energy systems such as solar cells and wind power generation, and storage batteries for automobiles. Therefore, even higher safety is required for lithium ion batteries installed in electric power storage devices, automobile storage batteries, and the like. Therefore, various techniques have been proposed in recent years to further improve the safety of lithium ion batteries.
　例えば、以下の特許文献１では、電極体を収容する外装部材の少なくとも一部の表面を、絶縁部材で被覆する技術が提案されている。かかる技術では、上記絶縁部材において、外装部材と接する側を、高温時に不燃性ガスを発生する不燃性ガス発生部材とし、最外装を絶縁樹脂層とすることで、電池の絶縁機能と、電池の発火防止機能と、を両立させている。 For example, Patent Document 1 below proposes a technique of covering at least a part of the surface of an exterior member that houses an electrode body with an insulating member. In this technology, the side of the insulating member in contact with the exterior member is made of a nonflammable gas generating member that generates nonflammable gas at high temperatures, and the outermost sheath is made of an insulating resin layer, thereby improving the insulation function of the battery and the battery. It has both ignition prevention function.
国際公開第２０２１／０１４９９６号International Publication No. 2021/014996
　本発明者らは、上記のようなリチウムイオン電池において、正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが収容される収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板を用いることに着想した。 The present inventors have proposed that, in the lithium ion battery as described above, a Ni plating layer is applied to a base steel plate as a material for a housing case in which a battery unit having a positive electrode, a negative electrode, and a separator and an electrolyte containing a lithium salt are housed. We came up with the idea of using a Ni-plated steel plate provided with a surface treatment layer, or a laminated steel plate in which a surface treatment layer is provided on a base steel plate.
　上記のようなＮｉめっき鋼板やラミネート鋼板を、収容ケースの本体部及び蓋部の素材として使用した際、電池ユニット及び電解液を収容した後の収容ケースの本体部と、蓋部とは、レーザ溶接等に代表される溶接処理、又は、かしめにより封止される。また、場合によっては、収容ケースの蓋部に、電解液を収容ケースの内部に注入するための注液口を設けておくことも想定される。かかる場合、電池ユニットが収容された本体部の内部に対し、蓋部に設けられた注液口を介して電解液を注入した後、蓋部に設けられた注液口は、注液口蓋を用いて、溶接処理又はかしめにより封止される。 When a Ni-plated steel plate or a laminated steel plate as described above is used as the material for the main body and lid of the storage case, the main body and lid of the storage case after housing the battery unit and electrolyte are Sealed by welding, typically by welding, or by caulking. Further, depending on the case, it is also assumed that the lid of the storage case is provided with a liquid injection port for injecting the electrolyte into the inside of the storage case. In such a case, after the electrolyte is injected into the interior of the main body in which the battery unit is housed through the liquid injection port provided in the lid, the liquid injection port provided in the lid closes the liquid injection port. used and sealed by welding or caulking.
　ここで、上記のような電解液を注入する際に、電解液の一部が、収容ケースの本体部や蓋部の外表面に付着してしまうことが考えられる。リチウムイオン電池に用いられる電解液は、その成分として、リチウム塩（例えば、ＬｉＰＦ６等のふっ素を含有するリチウム塩）を含有している。かかるリチウム塩と大気中の水分とが反応すると、ふっ化水素酸（ＨＦ）が発生する。一方で、封止に用いられる溶接処理やかしめによって、Ｎｉめっき鋼板のＮｉめっき層や、ラミネート鋼板の表面処理層の一部が消失してしまい、母材鋼板が露出している可能性がある。また、収容ケースの構造によっては、Ｎｉめっき層や表面処理層が設けられていない母材鋼板の端部が、表面に露出していることも考えられる。 Here, when injecting the electrolyte as described above, it is conceivable that a part of the electrolyte may adhere to the outer surface of the main body or lid of the storage case. The electrolytic solution used in a lithium ion battery contains a lithium salt (for example, a fluorine-containing lithium salt such as LiPF 6 ) as a component thereof. When such a lithium salt reacts with moisture in the atmosphere, hydrofluoric acid (HF) is generated. On the other hand, due to the welding process and caulking used for sealing, part of the Ni plating layer on the Ni-plated steel sheet or the surface treatment layer on the laminated steel sheet may disappear, leaving the base steel sheet exposed. . Furthermore, depending on the structure of the storage case, the end portion of the base steel plate on which the Ni plating layer or surface treatment layer is not provided may be exposed to the surface.
　本発明者らは、このような母材鋼板の露出部においてふっ化水素酸（ＨＦ）が発生してしまうと、発生したふっ化水素酸が母材鋼板を腐食させて赤錆が発生し、収容ケースの外面耐食性が低下してしまうという課題を、新たに知見するに至った。かかる課題は、Ｎｉめっき鋼板やラミネート鋼板を収容ケースの本体部及び蓋部の素材として使用した場合に初めて生じる課題である。 The present inventors have discovered that if hydrofluoric acid (HF) is generated in such exposed areas of the base steel plate, the generated hydrofluoric acid will corrode the base steel plate and cause red rust. We have discovered a new problem in which the corrosion resistance of the case's exterior surface deteriorates. This problem occurs for the first time when a Ni-plated steel plate or a laminated steel plate is used as the material for the main body and lid of the storage case.
　上記のような、本発明者らが初めて知見した収容ケースの外面耐食性に関する課題は、例えば上記特許文献１に開示されている不燃性ガス発生部材のように、大気と接することのない部分に対していくら工夫を凝らしたとしても、解決することはできない。そのため、リチウムイオン電池の外表面に電解液が付着していた場合であっても、リチウムイオン電池の外面耐食性を保持可能な技術を、新たに実現することが必要となる。 The above-mentioned problem regarding the external corrosion resistance of the storage case, which was discovered for the first time by the present inventors, is that the problem with the corrosion resistance of the outer surface of the storage case, which was discovered for the first time by the present inventors, is that it is difficult for parts that do not come into contact with the atmosphere, such as the nonflammable gas generating member disclosed in Patent Document 1, for example. No matter how hard you try, you can't solve the problem. Therefore, it is necessary to develop a new technology that can maintain the corrosion resistance of the lithium ion battery's outer surface even when electrolyte is attached to the outer surface of the lithium ion battery.
　そこで、本発明は、上記問題に鑑みてなされたものであり、本発明の目的とするところは、リチウムイオン電池の外表面に電解液が付着していた場合であっても、リチウムイオン電池の外面耐食性を保持することが可能な、リチウムイオン電池及びリチウムイオン電池の製造方法を提供することにある。 Therefore, the present invention was made in view of the above problem, and an object of the present invention is to solve the problem of lithium ion batteries even when electrolyte is attached to the outer surface of the lithium ion battery. An object of the present invention is to provide a lithium ion battery and a method for manufacturing a lithium ion battery that can maintain external corrosion resistance.
　上記課題を解決するために、本発明者らが鋭意検討した結果、電解液の付着を完全に防止することは困難であると考えられること、及び、リチウムイオン電池と大気中の水分との接触も電池使用時を考慮すると不可避であることを踏まえ、生成するふっ化水素酸への対応が重要であることを知見した。その上で、大気中の水分との反応で生成されるふっ化水素酸を無効化する手段を、リチウムイオン電池の外表面に設けておくことができれば、リチウムイオン電池の外面耐食性を保持することが可能である旨に想到した。
　上記のような知見に基づき完成された本発明の要旨は、以下の通りである。 In order to solve the above problems, the inventors of the present invention have conducted extensive studies and found that it is difficult to completely prevent the adhesion of electrolyte and that contact between lithium ion batteries and moisture in the atmosphere Considering that this is unavoidable when considering the use of batteries, we found that it is important to deal with the generated hydrofluoric acid. On top of that, if a means to nullify the hydrofluoric acid produced by reaction with moisture in the atmosphere can be provided on the outer surface of the lithium ion battery, the corrosion resistance of the lithium ion battery's outer surface can be maintained. It occurred to me that this is possible.
The gist of the present invention, which was completed based on the above findings, is as follows.
（１）正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池であって、前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板が用いられており、前記収容ケースには、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが存在しており、前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する皮膜部を有する、リチウムイオン電池。
（２）前記皮膜部における、前記Ｃａ化合物、前記Ａｌ化合物及び前記Ｌａ化合物の合計付着量は、前記Ｃａ化合物の場合は金属Ｃａ換算、前記Ａｌ化合物の場合は金属Ａｌ換算、前記Ｌａ化合物の場合は金属Ｌａ換算で、０．００１ｇ／ｍ２以上１０００．０００ｇ／ｍ２以下である、（１）に記載のリチウムイオン電池。
（３）前記皮膜部において、前記Ｃａ化合物、前記Ａｌ化合物及びＬａ化合物は、樹脂中に分散している、（１）に記載のリチウムイオン電池。
（４）前記皮膜部において、前記Ｃａ化合物、前記Ａｌ化合物及びＬａ化合物は、樹脂中に分散している、（２）に記載のリチウムイオン電池。
（５）前記Ｃａ化合物は、炭酸カルシウム、酸化カルシウム、又は、水酸化カルシウムの少なくとも何れかであり、前記Ａｌ化合物は、炭酸アルミニウム、酸化アルミニウム、又は、水酸化アルミニウムの少なくとも何れかであり、前記Ｌａ化合物は、炭酸ランタン、酸化ランタン、又は、水酸化ランタンである、（１）～（４）の何れか１つに記載のリチウムイオン電池。
（６）前記Ｃａ化合物のうち金属Ｃａ換算で８０質量％以上は、水酸化カルシウムである、（５）に記載のリチウムイオン電池。
（７）前記皮膜部は、前記Ｃａ化合物、前記Ａｌ化合物又は前記Ｌａ化合物として、ふっ化物を更に含有する、（５）に記載のリチウムイオン電池。
（８）前記皮膜部は、前記Ｃａ化合物、前記Ａｌ化合物又は前記Ｌａ化合物として、ふっ化物を更に含有する、（６）に記載のリチウムイオン電池。
（９）前記ふっ化物は、前記皮膜部の表面側よりも、前記Ｎｉめっき鋼板又は前記ラミネート鋼板を構成する前記母材鋼板との界面側により多く存在する、（７）に記載のリチウムイオン電池。
（１０）前記ふっ化物は、前記皮膜部の表面側よりも、前記Ｎｉめっき鋼板又は前記ラミネート鋼板を構成する前記母材鋼板との界面側により多く存在する、（８）に記載のリチウムイオン電池。
（１１）前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、（７）に記載のリチウムイオン電池。
（１２）前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、（８）に記載のリチウムイオン電池。
（１３）前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、（９）に記載のリチウムイオン電池。
（１４）前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、（１０）に記載のリチウムイオン電池。
（１５）前記第１封止部、及び、前記第２封止部は、溶接、又は、かしめで構成されている、（１）に記載のリチウムイオン電池。
（１６）正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池の製造方法であって、前記リチウムイオン電池は、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが形成されるものであり、前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板を用い、前記電池ユニットと前記電解液とが収容された前記収容ケースについて、前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部、を封止して、前記第１封止部及び前記第２封止部とする封止工程と、前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部の封止後に、前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する塗料を塗布する塗布工程と、を含む、リチウムイオン電池の製造方法。
（１７）前記封止工程は、露点－７５℃以下の雰囲気下で実施される、（１６）に記載のリチウムイオン電池の製造方法。 (1) A lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid, the battery unit having a positive electrode, a negative electrode, and a separator; As a material, a Ni-plated steel plate in which a Ni plating layer is provided on the base steel plate, or a laminated steel plate in which the base steel plate is provided with a surface treatment layer is used, and the housing case includes the main body portion and the A first sealing portion that is a sealing portion with the lid portion, or a liquid injection port for sealing a liquid injection port provided in the lid portion for injecting the electrolyte into the inside of the storage case. and a second sealing part that is a sealing part with the lid part, and the content of Fe in the first sealing part or the second sealing part is 80% by mass. A lithium ion battery having a coating portion containing at least one of a Ca compound, an Al compound, or a La compound on the above portion.
(2) The total adhesion amount of the Ca compound, the Al compound, and the La compound in the coating portion is calculated in terms of metal Ca in the case of the Ca compound, metal Al in the case of the Al compound, and metal Al conversion in the case of the La compound. The lithium ion battery according to (1), wherein is 0.001 g/m 2 or more and 1000.000 g/m 2 or less in terms of metal La.
(3) The lithium ion battery according to (1), wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in the resin.
(4) The lithium ion battery according to (2), wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in the resin.
(5) The Ca compound is at least one of calcium carbonate, calcium oxide, or calcium hydroxide; the Al compound is at least one of aluminum carbonate, aluminum oxide, or aluminum hydroxide; The lithium ion battery according to any one of (1) to (4), wherein the La compound is lanthanum carbonate, lanthanum oxide, or lanthanum hydroxide.
(6) The lithium ion battery according to (5), wherein 80% by mass or more of the Ca compound in terms of metallic Ca is calcium hydroxide.
(7) The lithium ion battery according to (5), wherein the film portion further contains a fluoride as the Ca compound, the Al compound, or the La compound.
(8) The lithium ion battery according to (6), wherein the film further contains a fluoride as the Ca compound, the Al compound, or the La compound.
(9) The lithium ion battery according to (7), wherein the fluoride is present more on the interface side with the base steel sheet constituting the Ni-plated steel sheet or the laminated steel sheet than on the surface side of the coating portion. .
(10) The lithium ion battery according to (8), wherein the fluoride is present in a larger amount on the interface side with the base steel sheet constituting the Ni-plated steel sheet or the laminated steel sheet than on the surface side of the coating portion. .
(11) The lithium ion battery according to (7), wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
(12) The lithium ion battery according to (8), wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
(13) The lithium ion battery according to (9), wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
(14) The lithium ion battery according to (10), wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
(15) The lithium ion battery according to (1), wherein the first sealing part and the second sealing part are formed by welding or caulking.
(16) A method for manufacturing a lithium ion battery, wherein a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolytic solution containing a lithium salt are housed inside a housing case having a main body portion and a lid portion, the method comprising: The lithium ion battery includes a first sealing portion that is a sealing portion between the main body portion and the lid portion, or a liquid injection provided in the lid portion for injecting the electrolyte into the inside of the storage case. At least one of a liquid injection port lid for sealing the mouth and a second sealing portion that is a sealing portion with the lid portion is formed, and the housing case is made of a base steel plate. The main body part of the housing case in which the battery unit and the electrolyte are housed is made of a Ni-plated steel plate in which a Ni-plated layer is provided, or a laminated steel plate in which a surface treatment layer is provided on the base steel plate. and the lid portion; a sealing step of sealing the liquid injection port and the lid portion to form the first sealing portion and the second sealing portion; the main body portion and the lid portion; After sealing the liquid injection port and the lid, a Ca compound, an Al compound, Alternatively, a method for manufacturing a lithium ion battery, comprising a coating step of applying a paint containing at least one of the La compounds.
(17) The method for manufacturing a lithium ion battery according to (16), wherein the sealing step is performed in an atmosphere with a dew point of −75° C. or lower.
　以上説明したように本発明によれば、リチウムイオン電池の外表面に電解液が付着していた場合であっても、リチウムイオン電池の外面耐食性を保持することが可能となる。 As explained above, according to the present invention, even if the electrolyte is attached to the outer surface of the lithium ion battery, it is possible to maintain the corrosion resistance of the outer surface of the lithium ion battery.
本発明の各実施形態にリチウムイオン電池について模式的に示した説明図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention. 本発明の各実施形態にリチウムイオン電池について模式的に示した説明図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention. 本発明の各実施形態にリチウムイオン電池について模式的に示した説明図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention. 本発明の各実施形態にリチウムイオン電池について模式的に示した説明図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a lithium ion battery in each embodiment of the present invention. 本発明の第１の実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。FIG. 2 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the first embodiment of the present invention. 同実施形態にリチウムイオン電池について模式的に示した説明図である。FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment. 同実施形態にリチウムイオン電池について模式的に示した説明図である。FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment. 同実施形態にリチウムイオン電池について模式的に示した説明図である。FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment. 同実施形態にリチウムイオン電池について模式的に示した説明図である。FIG. 2 is an explanatory diagram schematically showing a lithium ion battery in the same embodiment. 本発明の第２の実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。FIG. 7 is an explanatory diagram schematically showing the material of a housing case for a lithium ion battery according to a second embodiment of the present invention. 本発明の第３の実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。FIG. 7 is an explanatory diagram schematically showing the material of a housing case for a lithium ion battery according to a third embodiment of the present invention. 本発明の各実施形態に係るリチウムイオン電池の製造方法の流れの一例を示した流れ図である。1 is a flowchart showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention. 本発明の各実施形態に係るリチウムイオン電池の製造方法の流れの一例を示した流れ図である。1 is a flowchart showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention.
　以下に添付図面を参照しながら、本発明の好適な実施の形態について詳細に説明する。なお、本明細書及び図面において、実質的に同一の機能構成を有する構成要素については、同一の符号を付することにより重複説明を省略する。 Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals and redundant explanation will be omitted.
（リチウムイオン電池について）
＜リチウムイオン電池の全体的な構成について＞
　まず、図１Ａ～図２Ｂを参照しながら、本発明の各実施形態に係るリチウムイオン電池の全体的な構成について説明する。図１Ａ～図２Ｂは、本発明の各実施形態にリチウムイオン電池について模式的に示した説明図である。 (About lithium ion batteries)
<About the overall structure of lithium-ion batteries>
First, the overall structure of a lithium ion battery according to each embodiment of the present invention will be described with reference to FIGS. 1A to 2B. FIGS. 1A to 2B are explanatory diagrams schematically showing lithium ion batteries in each embodiment of the present invention.
　図１Ａに模式的に示したように、本発明の各実施形態に係るリチウムイオン電池１は、正極、負極及びセパレータを有する電池ユニット３と、リチウム塩を含む電解液５とが、本体部１１と蓋部１３とを有する収容ケース１０の内部に収容されたものである。 As schematically shown in FIG. 1A, a lithium ion battery 1 according to each embodiment of the present invention has a battery unit 3 having a positive electrode, a negative electrode, and a separator, and an electrolytic solution 5 containing a lithium salt in a main body 11. It is housed inside a housing case 10 having a lid part 13 and a lid part 13.
［電池ユニット３及び電解液５について］
　ここで、電池ユニット３を構成する正極（図示せず。）、負極（図示せず。）、セパレータ（図示せず。）、及び、正極や負極に設けられる各種の活物質（図示せず。）については、特に限定されるものではない。これら電池ユニット３を構成する各部材については、リチウムイオン電池に用いられる各種のものを、適宜使用することが可能である。また、電池ユニット３の具体的な構造についても、特に限定されるものではなく、各種の構造を採用することが可能である。 [About the battery unit 3 and electrolyte 5]
Here, the battery unit 3 includes a positive electrode (not shown), a negative electrode (not shown), a separator (not shown), and various active materials (not shown) provided in the positive electrode and the negative electrode. ) is not particularly limited. Regarding each member constituting the battery unit 3, various materials used in lithium ion batteries can be used as appropriate. Further, the specific structure of the battery unit 3 is not particularly limited, and various structures can be adopted.
　また、電池ユニット３の具体的な形状や大きさについても、特に限定されるものではない。図１Ａでは、便宜的に、角型形状を有する電池ユニット３について図示しているが、電池ユニット３の形状は、円柱形状であってもよいし、その他の形状であってもよい。 Furthermore, the specific shape and size of the battery unit 3 are not particularly limited. Although FIG. 1A shows a battery unit 3 having a rectangular shape for convenience, the shape of the battery unit 3 may be a columnar shape or any other shape.
　また、電解液５についても、リチウムイオンを生じうるリチウム塩を含有するものであればよく、各種のリチウム塩（特に、ふっ素を含有するリチウム塩）を含む電解液を、適宜使用することが可能である。そのようなリチウム塩として、例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＮ（ＳＯ２ＣＦ３）２（ＬｉＦＳＩとも呼ばれる。）を挙げることができる。 Further, the electrolytic solution 5 may be any one containing a lithium salt that can generate lithium ions, and electrolytic solutions containing various lithium salts (especially lithium salts containing fluorine) can be used as appropriate. It is. Examples of such lithium salts include LiPF 6 , LiBF 4 , and LiN(SO 2 CF 3 ) 2 (also referred to as LiFSI).
［収容ケース１０について］
　図１Ａに示したように、本実施形態に係るリチウムイオン電池１における収容ケース１０は、上記のような電池ユニット３及び電解液５を、その内部に収容するものであり、本体部１１と、蓋部１３と、で構成されている。 [About storage case 10]
As shown in FIG. 1A, the housing case 10 of the lithium ion battery 1 according to the present embodiment houses the battery unit 3 and electrolyte 5 as described above therein, and includes a main body 11, It is composed of a lid part 13.
　収容ケース１０の本体部１１は、電池ユニット３及び電解液５を収容可能な内部空間を有する中空の部材である。本体部１１は、底面となる部分（図示せず。）及び側面となる部分から構成されている。図１Ａでは、本体部１１は、矩形状の底面（図示せず。）と、４つの側面とで、電池ユニット３及び電解液５を収容する内部空間が実現されている。本体部１１の内部空間に、電池ユニット３及び電解液５が収容された後、本体部１１の開口部分は、図１Ａに示したように、蓋部１３によって閉塞される。 The main body 11 of the storage case 10 is a hollow member having an internal space that can accommodate the battery unit 3 and the electrolyte 5. The main body portion 11 includes a bottom portion (not shown) and a side portion. In FIG. 1A, the main body part 11 has a rectangular bottom surface (not shown) and four side surfaces, and an internal space for accommodating the battery unit 3 and the electrolytic solution 5 is realized. After the battery unit 3 and electrolyte 5 are housed in the internal space of the main body 11, the opening of the main body 11 is closed by the lid 13, as shown in FIG. 1A.
　ここで、図１Ａでは、収容ケース１０の本体部１１は、角型形状を有している場合を図示している。ただし、本体部１１の具体的な形状については、特に規定されるものではない。本体部１１は、電池ユニット３及び電解液５を収容可能な形状であれば、任意の形状を有することができる。 Here, FIG. 1A shows a case where the main body portion 11 of the storage case 10 has a square shape. However, the specific shape of the main body portion 11 is not particularly defined. The main body 11 can have any shape as long as it can accommodate the battery unit 3 and the electrolyte 5.
　また、例えば図１Ｂに示したように、蓋部１３Ａの一部に、電解液を収容ケースの内部に注入するための開口部である注液口１５を設け、電解液の注入後に、注液口１５を注液口蓋１７で閉塞するという場合も考えられる。本実施形態に係る収容ケース１０では、図１Ａに示した蓋部１３に換えて、図１Ｂに示したような蓋部１３Ａを用いることも可能である。 Further, as shown in FIG. 1B, for example, a liquid injection port 15, which is an opening for injecting the electrolytic solution into the inside of the storage case, is provided in a part of the lid part 13A, and after injection of the electrolytic solution, It is also conceivable that the port 15 is closed with the liquid injection port 17. In the storage case 10 according to the present embodiment, a lid 13A as shown in FIG. 1B may be used instead of the lid 13 shown in FIG. 1A.
　図１Ａに示したような収容ケース１０においては、電池ユニット３及び電解液５が本体部１１の内部空間に収容された後、本体部１１の開口部は、蓋部１３により閉塞され、封止処理が施される。これにより、収容ケース１０の本体部１１と蓋部１３とは、一体化される。その結果、図２Ａに模式的に示したように、封止後の収容ケース１０においては、本体部１１と蓋部１３との封止部が生じる。以下、かかる「本体部と蓋部との封止部（図２Ａにおいて太線で示した部分）」を、第１封止部２１と称する。 In the storage case 10 as shown in FIG. 1A, after the battery unit 3 and electrolyte 5 are stored in the internal space of the main body 11, the opening of the main body 11 is closed by the lid 13 and sealed. Processing is performed. Thereby, the main body part 11 and the lid part 13 of the storage case 10 are integrated. As a result, as schematically shown in FIG. 2A, a sealed portion is formed between the main body portion 11 and the lid portion 13 in the sealed housing case 10. Hereinafter, the "sealing section between the main body and the lid (portion indicated by a bold line in FIG. 2A)" will be referred to as a first sealing section 21.
　また、図１Ｂに示したような収容ケース１０においては、電池ユニット３及び電解液５が本体部１１の内部空間に収容された後に、本体部１１の開口部は、蓋部１３Ａにより閉塞され、封止処理が施される。また、蓋部１３Ａに設けられた注液口１５は、注液口蓋１７により閉塞され、封止処理が施される。これにより、収容ケース１０の本体部１１と蓋部１３Ａとは、一体化される。その結果、本体部１１と蓋部１３Ａとの封止部として、第１封止部２１が生じるとともに、蓋部１３Ａと注液口蓋１７との封止部が生じる。以下、かかる「注液口蓋と蓋部との封止部（図２Ｂにおいて太線で示した部分）」を、第２封止部２３と称する。 In addition, in the housing case 10 as shown in FIG. 1B, after the battery unit 3 and the electrolyte 5 are housed in the internal space of the main body 11, the opening of the main body 11 is closed by the lid 13A, A sealing process is performed. Further, the liquid injection port 15 provided in the lid portion 13A is closed by the liquid injection port lid 17, and a sealing process is performed. Thereby, the main body portion 11 and the lid portion 13A of the storage case 10 are integrated. As a result, a first sealing portion 21 is formed as a sealing portion between the main body portion 11 and the lid portion 13A, and a sealing portion between the lid portion 13A and the liquid injection port lid 17 is formed. Hereinafter, the "sealing portion between the liquid injection port and the lid portion (portion indicated by the thick line in FIG. 2B)" will be referred to as the second sealing portion 23.
　ここで、図１Ａに示したような収容ケース１０にしろ、図１Ｂに示したような収容ケース１０にしろ、本体部１１の内部に電解液５を注ぐ際には、電解液５の一部が、本体部１１や蓋部１３、１３Ａの外表面（大気に曝される部分）に付着してしまう可能性がある。 Here, when pouring the electrolyte 5 into the main body 11, whether it is the housing case 10 as shown in FIG. 1A or the housing case 10 as shown in FIG. However, there is a possibility that the particles may adhere to the outer surfaces (portions exposed to the atmosphere) of the main body 11 and the lids 13 and 13A.
　なお、既に製造されているリチウムイオン電池について、収容ケース１０における第１封止部２１及び第２封止部２３の位置を事後的に特定するためには、以下のようにすればよい。第１封止部２１は、上記のように、収容ケース１０の本体部１１が、蓋部１３、１３Ａにより封止された部位であるため、着目するリチウムイオン電池における、セルケースの胴体部と蓋部との接合箇所に着目すればよい。また、第２封止部２３は、上記のように、蓋部１３Ａにおける注液口１５が、注液口蓋１７により封止された部位であるため、着目するリチウムイオン電池における、注液口と注液口蓋との接合箇所に着目すればよい。より詳細には、着目するリチウムイオン電池の全体を樹脂に埋め込んだ後に、リチウムイオン電池の短手側中央を通る箇所の位置で、注液口が存在する場合は注液口中央を通る箇所の位置で、リチウムイオン電池の全体をセルケースの長手方向に切断し、得られた断面において上記のような部位を、走査型電子顕微鏡（Ｓｃａｎｎｉｎｇ　Ｅｌｅｃｔｒｏｎ　Ｍｉｃｒｏｓｃｏｐｅ：ＳＥＭ）により観察すればよい。このとき、観察時の視野の大きさは、１０００μｍ×１０００μｍとすればよい。 In addition, in order to specify the positions of the first sealing part 21 and the second sealing part 23 in the housing case 10 after the fact with respect to a lithium ion battery that has already been manufactured, the following may be performed. As described above, the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed by the lid portions 13, 13A, so the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed with the lid portions 13, 13A, so the first sealing portion 21 is a portion where the main body portion 11 of the storage case 10 is sealed with the lid portions 13, 13A. All you have to do is focus on the joint with the lid. In addition, as described above, the liquid injection port 15 in the lid portion 13A is a portion sealed by the liquid injection port cover 17, so the second sealing portion 23 is the liquid injection port in the lithium ion battery of interest. All you have to do is focus on the joint with the liquid injection palate. More specifically, after the entire lithium-ion battery of interest is embedded in resin, the position of the point that passes through the center of the short side of the lithium-ion battery, or the point that passes through the center of the injection port if there is an injection port. The entire lithium ion battery may be cut in the longitudinal direction of the cell case, and the above-mentioned portions of the obtained cross section may be observed using a scanning electron microscope (SEM). At this time, the size of the field of view during observation may be 1000 μm×1000 μm.
≪第１の実施形態≫
＜収容ケース１０の素材について＞
　続いて、図３を参照しながら、本発明の第１の実施形態に係る収容ケース１０の素材について、詳細に説明する。図３は、本実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。 <<First embodiment>>
<About the material of the storage case 10>
Next, with reference to FIG. 3, the material of the storage case 10 according to the first embodiment of the present invention will be described in detail. FIG. 3 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
　本実施形態に係る収容ケース１０の素材としては、Ｎｉめっき鋼板、又は、ラミネート鋼板が用いられる。以下では、本実施形態に係る収容ケース１０の素材として、Ｎｉめっき鋼板が用いられる場合について説明する。 As a material for the storage case 10 according to this embodiment, a Ni-plated steel plate or a laminated steel plate is used. In the following, a case will be described in which a Ni-plated steel plate is used as the material for the housing case 10 according to the present embodiment.
　図３は、Ｎｉめっき鋼板１００の層構造を模式的に示したものである。
　収容ケース１０の素材として用いられるＮｉめっき鋼板１００は、図３に示したように、母材鋼板１０１と、母材鋼板１０１の表裏面に設けられたＮｉめっき層１０３と、を有している。 FIG. 3 schematically shows the layer structure of the Ni-plated steel sheet 100.
As shown in FIG. 3, the Ni-plated steel plate 100 used as a material for the storage case 10 has a base steel plate 101 and a Ni-plated layer 103 provided on the front and back surfaces of the base steel plate 101. .
　母材鋼板１０１は、Ｎｉめっき鋼板１００の基材となる鋼板である。かかる母材鋼板１０１の成分や金属組織等については、特に限定されるものではない。母材鋼板１０１として、例えば、低炭アルミキルド鋼やＩＦ鋼（Ｉｎｔｅｒｓｔｉｔｉａｌ　Ｆｒｅｅ　Ｓｔｅｅｌ：極低炭素鋼）等といった、各種の鋼板を適宜用いることが可能である。 The base steel plate 101 is a steel plate that becomes the base material of the Ni-plated steel plate 100. The components, metal structure, etc. of the base steel plate 101 are not particularly limited. As the base material steel plate 101, various steel plates such as low carbon aluminum killed steel and IF steel (Interstitial Free Steel: ultra-low carbon steel) can be used as appropriate.
　なお、母材鋼板１０１の種類を事後的に特定するためには、ＩＣＰ（Ｉｎｄｕｃｔｉｖｅｌｙ　Ｃｏｕｐｌｅｄ　Ｐｌａｓｍａ：誘導結合プラズマ）発光分光分析法を用いて、ＪＩＳ　Ｇ　１２５８－１：２０１４に従って測定を実施すればよい。 In addition, in order to identify the type of the base material steel plate 101 after the fact, it is sufficient to carry out measurement according to JIS G 1258-1:2014 using ICP (Inductively Coupled Plasma) emission spectrometry. .
　また、母材鋼板１０１の厚みについても、収容ケース１０に求められる機械的強度に応じて適宜設定すればよく、例えば、０．１５～１．２０ｍｍ程度とすればよい。 Further, the thickness of the base steel plate 101 may be appropriately set depending on the mechanical strength required of the housing case 10, and may be set to about 0.15 to 1.20 mm, for example.
　母材鋼板１０１の表面に位置するＮｉめっき層１０３は、Ｎｉを少なくとも含有するめっき層である。Ｎｉめっき層１０３は、Ｎｉ及び不純物で構成されていてもよいし、Ｎｉめっき層１０３を構成するＮｉの少なくとも一部は、母材鋼板１０１に由来するＦｅと合金化していてもよい。かかるＮｉめっき層１０３の平均組成等については、特に限定されるものではない。収容ケース１０内に保持される電解液５に対して耐食性を示すものであれば、Ｎｉめっき層１０３として、各種のＮｉめっきやＮｉ合金めっき等を採用することが可能である。 The Ni plating layer 103 located on the surface of the base steel plate 101 is a plating layer containing at least Ni. The Ni plating layer 103 may be composed of Ni and impurities, or at least a portion of the Ni constituting the Ni plating layer 103 may be alloyed with Fe derived from the base steel plate 101. The average composition of the Ni plating layer 103 is not particularly limited. Various types of Ni plating, Ni alloy plating, etc. can be used as the Ni plating layer 103 as long as it exhibits corrosion resistance to the electrolytic solution 5 held in the housing case 10.
　このようなＮｉめっき層１０３の平均組成として、例えば、Ｎｉ：９５～５０質量％、Ｆｅ：５～５０質量％、及び、不純物からなる組成を挙げることができる。また、Ｎｉめっき層１０３は、Ｎｉの一部に換えて、Ｃｏ、Ｓｎ、Ｚｎ、Ｗ、Ｍｏ、Ｃｒの何れかの合金元素を更に含有していてもよい。かかるＮｉめっき層１０３の形成方法としては、例えば、めっき浴を用いた溶融めっき、電気めっき等といった各種のめっき方法や、溶射、蒸着を挙げることができる。 An example of the average composition of such Ni plating layer 103 is a composition consisting of Ni: 95 to 50% by mass, Fe: 5 to 50% by mass, and impurities. Further, the Ni plating layer 103 may further contain any alloy element of Co, Sn, Zn, W, Mo, and Cr in place of a part of Ni. Examples of methods for forming the Ni plating layer 103 include various plating methods such as hot-dip plating using a plating bath and electroplating, thermal spraying, and vapor deposition.
　また、Ｎｉめっき層１０３の片面当たりの付着量は、例えば５～５０ｇ／ｍ２であることが好ましい。Ｎｉめっき層１０３の片面当たりの付着量が１０ｇ／ｍ２以上となることで、Ｎｉめっき鋼板１００の耐食性を更に向上させることが可能となるため、より好ましい。一方、Ｎｉめっき層１０３の片面当たりの付着量が、３０ｇ／ｍ２以下となることで、Ｎｉめっき鋼板１００の製造コストをより低減することが可能となるため、より好ましい。 Further, it is preferable that the amount of Ni plating layer 103 deposited on one side is, for example, 5 to 50 g/m 2 . It is more preferable that the amount of Ni plating layer 103 deposited on one side is 10 g/m 2 or more, since it is possible to further improve the corrosion resistance of Ni-plated steel sheet 100. On the other hand, it is more preferable that the amount of Ni plating layer 103 deposited on one side be 30 g/m 2 or less, because this makes it possible to further reduce the manufacturing cost of Ni-plated steel sheet 100.
　なお、Ｎｉめっき鋼板１００は、めっき後に熱処理を施さないものであってもよく、めっき後に熱処理を施したものであってもよい。めっき後に熱処理を施した場合には、母材鋼板１０１とＮｉめっき層１０３との界面に、拡散合金層が形成される。 Note that the Ni-plated steel sheet 100 may be one that is not heat-treated after plating, or may be one that is heat-treated after plating. When heat treatment is performed after plating, a diffusion alloy layer is formed at the interface between the base steel plate 101 and the Ni plating layer 103.
　なお、Ｎｉめっき層１０３の片面当たりの付着量は、例えばＩＣＰ発光分光分析法によって測定可能である。まず、着目するリチウムイオン電池における収容ケースの底面の任意の５箇所から、平面視したときの大きさが３０ｍｍ×３０ｍｍであるサンプルをそれぞれ切り出し、かかるサンプルに存在するＮｉめっき層１０３のそれぞれを、酸（より詳細には、１９％塩酸）で溶解する。次に、各溶解液に含まれるＴｏｔａｌ－Ｎｉ量を、ＩＣＰ発光分光分析装置（例えば、島津製作所株式会社製：ＩＣＰＳ－８１００）を用いて定量分析する。Ｔｏｔａｌ－Ｎｉ量が０超の値を示すということは、得られたサンプルにＮｉめっき層１０３が存在していることを意味している。得られたＴｏｔａｌ－Ｎｉ量を、上述のサンプル面積で割ることにより、単位面積当たりのＮｉ付着量を求めることができる。得られた５つのＮｉ付着量の平均値を、Ｎｉめっき層１０３の片面当たりの付着量として取り扱う。また、Ｎｉめっき層１０３の平均組成についても、同様に、ＩＣＰ発光分光分析法によって求めることが可能である。なお、着目した箇所からサンプルを切り出す際に、サンプルの何れかの辺の大きさが３０ｍｍ未満となってしまう場合には、サンプルの面積が９０ｍｍ２となるように、着目した箇所からサンプルを切り出せばよい。 Note that the amount of Ni plating layer 103 deposited on one side can be measured by, for example, ICP emission spectroscopy. First, samples each having a size of 30 mm x 30 mm when viewed from above are cut out from five arbitrary locations on the bottom of the housing case of the lithium ion battery of interest, and each of the Ni plating layers 103 present in the sample is Dissolve with acid (more specifically, 19% hydrochloric acid). Next, the amount of Total-Ni contained in each solution is quantitatively analyzed using an ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation). The fact that the Total-Ni amount exceeds 0 means that the Ni plating layer 103 is present in the obtained sample. By dividing the obtained Total-Ni amount by the above-mentioned sample area, the amount of Ni attached per unit area can be determined. The average value of the five Ni adhesion amounts obtained is treated as the adhesion amount per one side of the Ni plating layer 103. Furthermore, the average composition of the Ni plating layer 103 can be similarly determined by ICP emission spectrometry. In addition, when cutting out a sample from the point of interest, if the size of any side of the sample is less than 30 mm, cut the sample from the point of interest so that the area of the sample is 90 mm 2 . Bye.
　また、上記のようなＮｉめっき鋼板１００において、母材鋼板１０１と、Ｎｉめっき層１０３との間に、更に、各種の化成処理皮膜層（図示せず。）が存在していてもよい。かかる化成処理皮膜層が存在することで、母材鋼板１０１と、Ｎｉめっき層１０３との間の密着性を、より向上させることが可能となる。また、かかる化成処理皮膜層が存在することで、Ｎｉめっき鋼板１００の耐食性を、更に向上させることが可能となる。 Furthermore, in the Ni-plated steel sheet 100 as described above, various chemical conversion coating layers (not shown) may be further present between the base steel sheet 101 and the Ni-plated layer 103. The presence of such a chemical conversion coating layer makes it possible to further improve the adhesion between the base steel plate 101 and the Ni plating layer 103. Furthermore, the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the Ni-plated steel sheet 100.
　かかる化成処理皮膜層については、特に限定されるものではなく、各種の化成処理を利用して形成すればよい。このような化成処理として、例えば、クロメート系化成処理やノンクロメート系化成処理を挙げることができる。ノンクロメート系化成処理としては、例えば、バナジウム化合物、チタン化合物、ジルコニウム化合物、リン酸化合物のような無機化合物を用いた化成処理や、シリカ系化成処理を挙げることができる。 Such a chemical conversion coating layer is not particularly limited, and may be formed using various chemical conversion treatments. Examples of such chemical conversion treatments include chromate-based chemical conversion treatments and non-chromate-based chemical conversion treatments. Examples of non-chromate-based chemical conversion treatments include chemical conversion treatments using inorganic compounds such as vanadium compounds, titanium compounds, zirconium compounds, and phosphoric acid compounds, and silica-based chemical conversion treatments.
＜封止処理と皮膜部による被覆対象部位について＞
　以下では、図４Ａ及び図４Ｂを参照しながら、本実施形態に係るリチウムイオン電池１における封止処理と皮膜部による被覆対象部位について説明する。図４Ａ及び図４Ｂは、本実施形態にリチウムイオン電池について模式的に示した説明図である。図４Ａは、収容ケース１０を、ケース高さ方向に切断した断面の一部を、模式的に示したものであり、図４Ｂは、収容ケース１０の注液口蓋１７の近傍を、ケース高さ方向に切断した断面の一部を、模式的に示したものである。 <About the sealing treatment and the areas covered by the film>
Hereinafter, the sealing process and the portion to be covered by the film portion in the lithium ion battery 1 according to the present embodiment will be described with reference to FIGS. 4A and 4B. FIGS. 4A and 4B are explanatory diagrams schematically showing a lithium ion battery in this embodiment. FIG. 4A schematically shows a part of a cross section of the storage case 10 cut in the case height direction, and FIG. 4B shows the vicinity of the liquid injection port 17 of the storage case 10 in the case height direction. A part of a cross section cut in the direction is schematically shown.
　図３に示したような素材を用いて、収容ケース１０の本体部１１、蓋部１３、１３Ａ、注液口蓋１７を製造した場合、素材とした各種鋼板において、Ｎｉめっき層１０３が設けられていない母材鋼板１０１の端面が、表面に露出する場合がある。また、収容ケース１０の本体部１１と蓋部１３、１３Ａ、及び、蓋部１３Ａと注液口蓋１７は、溶接処理又はかしめによって封止される。この際、かかる封止処理によって、Ｎｉめっき層１０３の一部が消失してしまい、母材鋼板１０１が露出する可能性もある。 When the main body part 11, lid parts 13, 13A, and liquid injection port lid 17 of the storage case 10 are manufactured using the materials shown in FIG. In some cases, the end face of the base steel plate 101 that is not present is exposed to the surface. Further, the main body 11 and the lids 13 and 13A of the storage case 10, and the lid 13A and the liquid injection port 17 are sealed by welding or caulking. At this time, there is a possibility that a part of the Ni plating layer 103 disappears due to such sealing treatment, and the base material steel plate 101 is exposed.
　図４Ａは、第１封止部２１の近傍の断面の一例を、模式的に示したものである。なお、図４Ａに示した形状は、あくまでも一例に過ぎず、本実施形態に係るリチウムイオン電池１における第１封止部２１近傍の形状が、かかる例に限定されるものではない。 FIG. 4A schematically shows an example of a cross section near the first sealing part 21. Note that the shape shown in FIG. 4A is merely an example, and the shape of the vicinity of the first sealing portion 21 in the lithium ion battery 1 according to the present embodiment is not limited to this example.
　図４Ａに示した例では、本体部１１の側面となっている部分の天面や、蓋部１３の端部は、Ｎｉめっき層１０３が設けられていない母材鋼板１０１の端面が、大気に露出した状態となっている。 In the example shown in FIG. 4A, the end surface of the base steel plate 101 on which the Ni plating layer 103 is not provided is exposed to the atmosphere, such as the top surface of the side surface of the main body portion 11 and the end portion of the lid portion 13. It is exposed.
　図４Ｂは、第２封止部２３の近傍の断面の一例を、模式的に示したものである。なお、図４Ｂに示した形状は、あくまでも一例に過ぎず、本実施形態に係るリチウムイオン電池１における第２封止部２３近傍の形状が、かかる例に限定されるものではない。 FIG. 4B schematically shows an example of a cross section near the second sealing part 23. Note that the shape shown in FIG. 4B is merely an example, and the shape of the vicinity of the second sealing portion 23 in the lithium ion battery 1 according to the present embodiment is not limited to this example.
　図４Ｂに示した例では、注液口蓋１７の側端において、母材鋼板１０１の端面が大気に露出した状態となっている。 In the example shown in FIG. 4B, the end surface of the base steel plate 101 is exposed to the atmosphere at the side end of the liquid injection port lid 17.
　図４Ａ及び図４Ｂに例示したような、母材鋼板１０１の端面が露出したような部位や、封止処理によってＮｉめっき層１０３の一部が消失してしまった部位は、母材鋼板１０１の一部が露出して、Ｆｅの含有量が８０質量％以上となっている部位である。このような、リチウムイオン電池を製造するに際して、母材鋼板１０１の端面が露出したような部位や、封止処理によってＮｉめっき層１０３の一部が消失してしまった部位を、以下では、鉄露出部と称することとする。本実施形態では、このような母材鋼板１０１の一部が露出してＦｅの含有量が８０質量％以上となった部位を、以下で詳述するような皮膜部３０による被覆対象部位とする。 As illustrated in FIGS. 4A and 4B, areas where the end face of the base steel plate 101 is exposed or where part of the Ni plating layer 103 has disappeared due to the sealing process are This is a part that is partially exposed and has an Fe content of 80% by mass or more. When manufacturing such a lithium ion battery, parts where the end face of the base material steel plate 101 is exposed or parts where part of the Ni plating layer 103 has disappeared due to the sealing process are hereinafter referred to as iron. This will be referred to as the exposed part. In the present embodiment, such a part where a part of the base steel plate 101 is exposed and the Fe content is 80% by mass or more is the part to be covered with the coating part 30 as described in detail below. .
　なお、鉄露出部において、Ｆｅの含有量が８０質量％以上の部位としている理由は、以下の通りである。すなわち、例えば封止処理によってＮｉめっき層１０３の一部が消失した場合には、かかる部位にＮｉめっき層１０３に由来する、Ｆｅ以外の元素が存在している可能性があるからである。 The reason why the Fe content is 80% by mass or more in the exposed iron portion is as follows. That is, if a part of the Ni plating layer 103 disappears due to the sealing process, for example, there is a possibility that an element other than Fe originating from the Ni plating layer 103 may exist in the part.
　リチウムイオン電池１を製造する際には、収容ケース１０を構成する部材に対して溶接処理又はかしめという封止２０３が施される結果、大気と接触する可能性のある収容ケース１０の表面において、鉄露出部が生じる。また、かかる封止処理により、収容ケース１０の本体部１１と蓋部１３、１３Ａが一体化されるとともに、蓋部１３Ａと注液口蓋１７が一体化される。 When manufacturing the lithium ion battery 1, as a result of applying sealing 203 such as welding or caulking to the members constituting the housing case 10, on the surface of the housing case 10 that may come into contact with the atmosphere, Exposed iron parts are created. Moreover, by this sealing process, the main body part 11 and the lid parts 13, 13A of the storage case 10 are integrated, and the lid part 13A and the liquid injection port lid 17 are integrated.
＜皮膜部３０について＞
　先程から言及しているように、ふっ素を含有するリチウム塩を含む電解液を注入する際に、電解液の一部が、上記のような鉄露出部に付着していた場合を想定する。かかる場合に、ふっ素を含有するリチウム塩と大気中の水分とが反応すると、ふっ化水素酸が発生し、発生したふっ化水素酸が鉄露出部を腐食させて、赤錆が発生してしまう。そこで、本実施形態に係るリチウムイオン電池では、このような封止部における鉄露出部を被覆対象部位２０１として取り扱い、かかる被覆対象部位２０１に対して、皮膜部３０を設ける。従って、製造されたリチウムイオン電池１から見れば、皮膜部３０が存在している部位が、リチウムイオン電池１の製造過程において、被覆対象部位２０１として取り扱われた部位であるといえる。 <About the film part 30>
As mentioned earlier, when injecting an electrolytic solution containing a fluorine-containing lithium salt, it is assumed that some of the electrolytic solution adheres to the exposed iron parts as described above. In such a case, when the fluorine-containing lithium salt reacts with moisture in the atmosphere, hydrofluoric acid is generated, and the generated hydrofluoric acid corrodes the exposed iron parts, resulting in red rust. Therefore, in the lithium ion battery according to the present embodiment, the iron exposed portion in the sealing portion is handled as the covering target region 201, and the coating portion 30 is provided on the covering target region 201. Therefore, from the perspective of the manufactured lithium ion battery 1, it can be said that the region where the coating portion 30 is present is the region treated as the region to be coated 201 in the manufacturing process of the lithium ion battery 1.
　以下、図５Ａ及び図５Ｂを参照しながら、本実施形態に係るリチウムイオン電池１における皮膜部３０について、詳細に説明する。図５Ａ及び図５Ｂは、本実施形態にリチウムイオン電池１について模式的に示した説明図である。図５Ａは、収容ケース１０を、ケース高さ方向に切断した断面の一部を、模式的に示したものであり、図５Ｂは、収容ケース１０の注液口蓋１７の近傍を、ケース高さ方向に切断した断面の一部を、模式的に示したものである。 Hereinafter, the film portion 30 in the lithium ion battery 1 according to the present embodiment will be described in detail with reference to FIGS. 5A and 5B. 5A and 5B are explanatory diagrams schematically showing the lithium ion battery 1 in this embodiment. FIG. 5A schematically shows a part of a cross section of the storage case 10 cut in the case height direction, and FIG. 5B shows the vicinity of the liquid injection port 17 of the storage case 10 in the case height direction. A part of a cross section cut in the direction is schematically shown.
　図５Ａ及び図５Ｂに例示したように、本実施形態に係るリチウムイオン電池１において、皮膜部３０は、被覆対象部位２０１（又は、被覆対象部位２０１に存在する封止２０３）を覆うように、被覆対象部位２０１上に設けられる。かかる皮膜部３０は、Ｃａ化合物、又は、Ａｌ化合物の少なくとも何れかを含有する。 As illustrated in FIGS. 5A and 5B, in the lithium ion battery 1 according to the present embodiment, the coating portion 30 covers the covering target region 201 (or the sealing 203 present in the covering target region 201). It is provided on the region to be covered 201 . The film portion 30 contains at least either a Ca compound or an Al compound.
　Ｃａ化合物、Ａｌ化合物及びＬａ化合物は、ふっ化水素酸（ＨＦ）と反応してふっ化物（ＣａＦ２、ＡｌＦ３、ＬａＦ３）を形成することで、ふっ化水素酸を無害化することができる。そのため、被覆対象部位２０１上（又は、被覆対象部位２０１に存在する封止２０３上）に、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかを含有する皮膜部３０を設けることで、被覆対象部位２０１に電解液が付着していた場合であっても、発生したふっ化水素酸を無害化することが可能となり、赤錆の発生を防止することができる。これにより、本実施形態に係るリチウムイオン電池１では、リチウムイオン電池１の外表面に電解液が付着していた場合であっても、リチウムイオン電池１の外面耐食性を保持することが可能となる。 Ca compounds, Al compounds, and La compounds can make hydrofluoric acid (HF) harmless by reacting with it to form fluorides (CaF 2 , AlF 3 , LaF 3 ). . Therefore, by providing the coating portion 30 containing at least one of a Ca compound, an Al compound, or a La compound on the covering target part 201 (or on the sealing 203 existing in the covering target part 201), the covering target part Even if the electrolyte is attached to 201, the generated hydrofluoric acid can be made harmless, and the generation of red rust can be prevented. As a result, in the lithium ion battery 1 according to the present embodiment, even if the electrolyte is attached to the outer surface of the lithium ion battery 1, it is possible to maintain the corrosion resistance of the outer surface of the lithium ion battery 1. .
　ここで、Ｃａ化合物、Ａｌ化合物及びＬａ化合物は、ふっ化水素酸と反応してふっ化物を形成しうる化合物であり、かつ、その化合物自体がＮｉめっき鋼板１００の腐食を促進しないものであれば、各種の化合物を用いることが可能である。化合物自体がＮｉめっき鋼板１００の腐食を促進しない、という観点から、例えばＣａＣｌ２、ＡｌＣｌ３は、かかる化合物の候補から除外される。 Here, the Ca compound, Al compound, and La compound are compounds that can react with hydrofluoric acid to form a fluoride, and the compounds themselves do not promote corrosion of the Ni-plated steel sheet 100. , it is possible to use various compounds. From the viewpoint that the compounds themselves do not promote corrosion of the Ni-plated steel sheet 100, for example, CaCl 2 and AlCl 3 are excluded from such compound candidates.
　このようなＣａ化合物、Ａｌ化合物及びＬａ化合物として、例えば、Ｃａ、ＡｌもしくはＬａの水酸化物、又は、強酸のアニオンではないアニオンと、Ｃａイオン、ＡｌイオンもしくはＬａイオンと、の塩（例えば、Ｃａ、ＡｌもしくはＬａの炭酸塩）、又は、Ｃａ、ＡｌもしくはＬａの酸化物が挙げられる。このようなＣａ化合物、Ａｌ化合物及びＬａ化合物は、より好ましくは、ふっ化水素酸との反応生成物がＦｅ及びＮｉに対して腐食性を有さないものである。 Such Ca compounds, Al compounds, and La compounds include, for example, hydroxides of Ca, Al, or La, or salts of an anion that is not a strong acid anion and Ca ion, Al ion, or La ion (for example, carbonates of Ca, Al or La), or oxides of Ca, Al or La. More preferably, the reaction products of such Ca compounds, Al compounds, and La compounds with hydrofluoric acid do not have corrosivity to Fe and Ni.
　このようなＣａ化合物として、例えば、炭酸カルシウム（ＣａＣＯ３）、酸化カルシウム（ＣａＯ）、水酸化カルシウム（Ｃａ（ＯＨ）２）を挙げることができ、Ａｌ化合物として、炭酸アルミニウム（Ａｌ２（ＣＯ３）３）、酸化アルミニウム（Ａｌ２Ｏ３）、水酸化アルミニウム（Ａｌ（ＯＨ）３）を挙げることができ、Ｌａ化合物として、例えば、炭酸ランタン（Ｌａ２（ＣＯ３）３）、酸化ランタン（Ｌａ２Ｏ３）、水酸化ランタン（Ｌａ（ＯＨ）３）を挙げることができる。これらの化合物は、単独で用いてもよいし、組み合わせて用いてもよい。 Examples of such Ca compounds include calcium carbonate (CaCO 3 ), calcium oxide (CaO), and calcium hydroxide (Ca(OH) 2 ), and examples of Al compounds include aluminum carbonate (Al 2 (CO 3 ) ). ) 3 ), aluminum oxide (Al 2 O 3 ), and aluminum hydroxide (Al(OH) 3 ), and examples of La compounds include lanthanum carbonate (La 2 (CO 3 ) 3 ), lanthanum oxide ( Examples include La 2 O 3 ) and lanthanum hydroxide (La(OH) 3 ). These compounds may be used alone or in combination.
　また、かかる皮膜部３０において、含有されるＣａ化合物のうち、金属Ｃａ換算で８０質量％以上は、水酸化カルシウムであることが好ましい。Ｃａ化合物における水酸化カルシウムの割合は、より好ましくは９０質量％以上である。このような状態となることで、第１封止部２１や第２封止部２３における外面耐食性を、更に向上させることが可能である。 In addition, in the coating portion 30, it is preferable that 80% by mass or more of the Ca compounds contained in the coating portion 30 is calcium hydroxide in terms of metallic Ca. The proportion of calcium hydroxide in the Ca compound is more preferably 90% by mass or more. By being in such a state, it is possible to further improve the outer surface corrosion resistance of the first sealing part 21 and the second sealing part 23.
　かかる皮膜部３０は、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかで構成されていてもよいし、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかが、樹脂中に分散した状態で構成されていてもよい。Ｃａ化合物やＡｌ化合物やＬａ化合物を樹脂中に分散させる場合に、バインダーとして機能する樹脂としては、各種の樹脂を用いることが可能である。このような樹脂として、例えば、ポリふっ化ビニリデン（ＰｏｌｙＶｉｎｙｌｉｄｅｎｅ　ＤｉＦｌｕｏｒｉｄｅ：ＰＶＤＦ）、エポキシ樹脂、メラミン樹脂、シリコーン樹脂、アクリル樹脂、ポリウレタン樹脂を挙げることができる。 The film portion 30 may be composed of at least one of a Ca compound, an Al compound, or a La compound, or may be composed of at least one of a Ca compound, an Al compound, or a La compound dispersed in a resin. You can leave it there. When dispersing a Ca compound, an Al compound, or a La compound in a resin, various resins can be used as the resin that functions as a binder. Examples of such resins include polyvinylidene difluoride (PVDF), epoxy resins, melamine resins, silicone resins, acrylic resins, and polyurethane resins.
　本実施形態に係る皮膜部３０は、上記のようなＣａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れか、更に必要に応じて、上記のような樹脂を含む処理剤を準備し、かかる処理剤を被覆対象部位２０１（又は、封止２０３に存在する被覆対象部位２０１）に塗布し、乾燥させることで、形成することができる。なお、上記のような処理剤の塗布は、以下で改めて説明するように、収容ケース１０内に電池ユニット３及び電解液５が収容されて、封止処理が施された後に実施することが重要であり、封止処理に先立って上記のような処理剤を塗布しておけばよい、というものではない。 The coating portion 30 according to the present embodiment is prepared by preparing a treatment agent containing at least one of the Ca compound, Al compound, or La compound as described above, and, if necessary, a resin as described above. It can be formed by applying it to the area to be covered 201 (or the area to be covered 201 present in the seal 203) and drying it. Note that it is important to apply the treatment agent as described above after the battery unit 3 and electrolyte 5 are housed in the housing case 10 and the sealing process is performed, as will be explained again below. This does not mean that it is sufficient to apply the above-mentioned processing agent prior to the sealing process.
　なお、既に製造されているリチウムイオン電池１について、皮膜部３０の設けられている部位を事後的に特定するには、以下のようにすればよい。まず、着目するリチウムイオン電池の全体を樹脂に埋め込んだ後に、リチウムイオン電池の短手側中央を通る箇所の位置で、注液口がある場合は注液口中央を通る箇所の位置で、リチウムイオン電池の全体を収容ケース１０の長手方向に切断して、断面観察用サンプルを得る。得られた断面観察用サンプルについて、適切に研磨を行い、得られた断面を走査型電子顕微鏡（ＳＥＭ）により観察する。このとき、観察時の視野の大きさは、１０００μｍ×１０００μｍとすればよい。このとき、視野中における各構造の視認のされ方の違いから、皮膜部３０の有無を特定することができる。 Incidentally, in order to specify the location where the film portion 30 is provided in the lithium ion battery 1 that has already been manufactured, the following may be performed. First, after embedding the entire lithium-ion battery of interest in resin, lithium The entire ion battery is cut in the longitudinal direction of the storage case 10 to obtain a sample for cross-sectional observation. The obtained sample for cross-sectional observation is appropriately polished, and the obtained cross-section is observed using a scanning electron microscope (SEM). At this time, the size of the field of view during observation may be 1000 μm×1000 μm. At this time, the presence or absence of the coating portion 30 can be determined from the difference in how each structure is visually recognized in the field of view.
　また、上記のようにして特定された皮膜部３０が、第１封止部２１又は第２封止部２３における、Ｆｅの含有量が８０質量％以上の部位（すなわち、上記の被覆対象部位２０１）に設けられているかどうかを、事後的に検証するためには、以下のようにすればよい。すなわち、走査型電子顕微鏡に搭載されたエネルギー分散型Ｘ線分析装置（Ｅｎｅｒｇｙ　Ｄｉｓｐｅｒｓｉｖｅ　Ｘ－ｒａｙ　Ｓｐｅｃｔｒｏｍｅｔｒｙ：ＥＤＳ）（例えば、ＪＥＯＬ株式会社製ＪＳＭ－７０００Ｆ）により、上記のようにして得られた断面観察用サンプルの断面を観察して、各元素の分布状況に関するマッピング分析を実施すればよい。上記のような断面観察結果と、例えば元素Ｆｅに関するマッピング分析結果とを照らし合わせることで、上記のようにして特定された皮膜部３０が、第１封止部２１又は第２封止部２３における、Ｆｅの含有量が８０質量％以上の部位に設けられているかどうかを、判断することができる。ここで、上記のような断面観察及びマッピング分析のための測定条件は、加速電圧１５ｋＶ、照射電流７．４７５００ｎＡとする。 Further, the coating portion 30 identified as described above is a portion of the first sealing portion 21 or the second sealing portion 23 where the content of Fe is 80% by mass or more (that is, the portion to be coated 201 ) is provided, you can do the following. That is, the cross-sectional observation obtained as above with an energy dispersive X-ray spectrometry (EDS) (for example, JSM-7000F manufactured by JEOL Co., Ltd.) mounted on a scanning electron microscope. A mapping analysis regarding the distribution of each element may be performed by observing a cross section of the sample. By comparing the cross-sectional observation results as described above with the mapping analysis results regarding element Fe, for example, it is possible to determine that the coating portion 30 identified as described above is located in the first sealing portion 21 or the second sealing portion 23. , it can be determined whether or not the Fe content is provided in a portion having a Fe content of 80% by mass or more. Here, the measurement conditions for cross-sectional observation and mapping analysis as described above are an acceleration voltage of 15 kV and an irradiation current of 7.47500 nA.
　また、皮膜部３０において、Ｃａ化合物やＡｌ化合物やＬａ化合物の有無を事後的に確認するためには、皮膜部３０から粉末サンプルを採取し、得られた粉末サンプルをＸ線回折分析法により分析すればよい。より詳細には、皮膜部３０の任意の位置から粉末サンプル５ｇを採取したのち、市販のＸ線回折分析装置（例えば、ＲＩＧＡＫＵ製　ＲＩＮＴ－ＴＴＲ３）により分析を実施して、Ｃａ、Ａｌ、Ｌａに由来するピークが測定結果に存在するか否かを確認すればよい。同様に、皮膜部３０に樹脂が含まれているかについては、Ｃ（炭素）に由来するピークが測定結果に存在するか否かを確認すればよい。また、皮膜部３０に含まれるＣａ化合物、Ａｌ化合物、Ｌａ化合物の化合物名を事後的に特定するためには、測定に存在するピークを帰属することで、化合物名を特定すればよい。この際、Ｘ線源としては、Ｃｕを使用し、測定条件は、Ｘ線出力は５０ｋＶ、３００ｍＡとし、スキャンスピード１ｄｅｇ／ｍｉｎとし、ステップ幅０．０１ｄｅｇ、スキャン軸２Ｔｈｅｔａ／Ｔｈｅｔａ、スキャン範囲５～１００ｄｅｇ、入射スリット１／２°、長手制限スリット５ｍｍとすればよい。 In addition, in order to confirm the presence or absence of Ca compounds, Al compounds, and La compounds in the coating portion 30 after the fact, a powder sample is collected from the coating portion 30 and the obtained powder sample is analyzed by X-ray diffraction analysis. do it. More specifically, after collecting 5 g of powder sample from any position on the coating portion 30, analysis is performed using a commercially available X-ray diffraction analyzer (for example, RINT-TTR3 manufactured by RIGAKU) to determine whether Ca, Al, and La are present. It is sufficient to check whether the derived peak exists in the measurement results. Similarly, whether resin is contained in the coating portion 30 can be determined by checking whether a peak derived from C (carbon) exists in the measurement results. Further, in order to specify the compound names of the Ca compound, Al compound, and La compound contained in the film portion 30 after the fact, the compound names may be specified by assigning the peaks present in the measurement. At this time, Cu is used as the X-ray source, and the measurement conditions are: It is sufficient to set the angle to 100 degrees, the entrance slit to 1/2 degrees, and the longitudinal restriction slit to 5 mm.
　また、本実施形態に係る皮膜部３０では、上記のように、Ｃａ化合物やＡｌ化合物やＬａ化合物とふっ化水素酸とを反応させることで、ふっ化水素酸を無害化するため、かかる反応の生成物として、Ｃａ、Ａｌ又はＬａのふっ化物（すなわち、ＣａＦ２、ＡｌＦ３、ＬａＦ３）が生成される。そのため、本実施形態に係るリチウムイオン電池１の皮膜部３０は、Ｃａ化合物、Ａｌ化合物又はＬａ化合物として、ふっ化物を含有しうる。 In addition, in the coating portion 30 according to the present embodiment, as described above, by reacting a Ca compound, an Al compound, or a La compound with hydrofluoric acid, the hydrofluoric acid is rendered harmless, so that such a reaction is prevented. As a product, a fluoride of Ca, Al or La (ie, CaF 2 , AlF 3 , LaF 3 ) is produced. Therefore, the film portion 30 of the lithium ion battery 1 according to the present embodiment may contain a fluoride as a Ca compound, an Al compound, or a La compound.
　すなわち、本実施形態に係るリチウムイオン電池１の皮膜部３０は、Ｃａ、Ａｌ又はＬａの少なくとも何れかのふっ化物以外の化合物で構成される場合もありうるし、Ｃａ、Ａｌ又はＬａの少なくとも何れかのふっ化物以外の化合物と、Ｃａ、Ａｌ又はＬａの少なくとも何れかのふっ化物と、で構成される場合もありうるし、Ｃａ、Ａｌ又はＬａの少なくとも何れかのふっ化物で構成される場合もありうる。ここで、Ｃａ、Ａｌ又はＬａのふっ化物の有無については、皮膜部３０から粉末サンプルを採取し、得られた粉末サンプルをＸ線回折分析法により分析することで、確認することができる。より詳細には、皮膜部３０の任意の部位から粉末サンプル５ｇを採取したのち、市販のＸ線回折分析装置（例えば、ＲＩＧＡＫＵ製ＲＩＮＴ－ＴＴＲ３）により分析を実施して、Ｃａ、Ａｌ、Ｌａ、Ｆに由来するピークが測定結果に存在するか否かを確認すればよい。この際、Ｘ線源としては、Ｃｕを使用し、測定条件は、Ｘ線出力は５０ｋＶ、３００ｍＡとし、スキャンスピード１ｄｅｇ／ｍｉｎ、ステップ幅０．０１ｄｅｇ、スキャン軸２Ｔｈｅｔａ／Ｔｈｅｔａ、スキャン範囲５～１００ｄｅｇ、入射スリット１／２°、長手制限スリット５ｍｍとすればよい。 That is, the film portion 30 of the lithium ion battery 1 according to the present embodiment may be composed of a compound other than a fluoride of at least one of Ca, Al, or La, or may be composed of a compound other than a fluoride of at least one of Ca, Al, or La. It may be composed of a compound other than fluoride and at least one fluoride of Ca, Al or La, or it may be composed of at least one fluoride of Ca, Al or La. sell. Here, the presence or absence of fluorides of Ca, Al, or La can be confirmed by taking a powder sample from the coating portion 30 and analyzing the obtained powder sample by X-ray diffraction analysis. More specifically, after collecting 5 g of powder sample from any part of the coating portion 30, analysis is performed using a commercially available X-ray diffraction analyzer (for example, RINT-TTR3 manufactured by RIGAKU) to detect Ca, Al, La, It is sufficient to check whether a peak derived from F exists in the measurement results. At this time, Cu was used as the X-ray source, and the measurement conditions were: X-ray output was 50 kV and 300 mA, scan speed was 1 deg/min, step width was 0.01 deg, scan axis was 2 Theta/Theta, and scan range was 5 to 100 deg. , the entrance slit may be 1/2°, and the longitudinal restriction slit may be 5 mm.
　Ｃａ、Ａｌ又はＬａのふっ化物は、Ｃａ化合物、Ａｌ化合物又はＬａ化合物とふっ化水素酸との反応生成物である。そのため、かかるふっ化物は、皮膜部３０の表面側よりも、被覆対象部位２０１、又は、封止２０３との界面側により多く存在するようになる。換言すれば、本実施形態に係る皮膜部３０において、Ｃａ又はＡｌのふっ化物は、Ｎｉめっき鋼板１００を構成する母材鋼板、又は、封止２０３との界面側により多く存在するように偏在するようになる。 A fluoride of Ca, Al or La is a reaction product of a Ca compound, an Al compound or a La compound and hydrofluoric acid. Therefore, more of the fluoride is present on the surface of the coating portion 30 than on the surface of the coating portion 201 or the interface with the sealing 203. In other words, in the film portion 30 according to the present embodiment, the fluoride of Ca or Al is unevenly distributed so that it is present in a larger amount on the interface side with the base material steel plate constituting the Ni-plated steel plate 100 or the sealing 203. It becomes like this.
　かかる皮膜部３０において、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、Ｃａ化合物の場合は金属Ｃａ換算、Ａｌ化合物の場合は金属Ａｌ換算、Ｌａ化合物の場合は金属Ｌａ換算としたときのそれぞれの換算値の合計で、０．００１ｇ／ｍ２以上であることが好ましい。Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量が０．００１ｇ／ｍ２以上となることで、上記のようなふっ化水素酸の無害化効果を安定して発現させることが可能となり、第１封止部２１及び第２封止部２３の外面耐食性を、より向上させることができる。Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、より好ましくは１００．０００ｇ／ｍ２以上であり、更に好ましくは３００．０００ｇ／ｍ２以上である。 In the film portion 30, the total adhesion amount of the Ca compound, Al compound, and La compound is calculated in terms of metal Ca in the case of Ca compounds, metal Al in the case of Al compounds, and metal La in the case of La compounds. The total of each converted value is preferably 0.001 g/m 2 or more. By having a total adhesion amount of Ca compounds, Al compounds, and La compounds of 0.001 g/ m2 or more, it becomes possible to stably express the detoxification effect of hydrofluoric acid as described above, and the first The outer surface corrosion resistance of the sealing part 21 and the second sealing part 23 can be further improved. The total amount of the Ca compound, Al compound, and La compound deposited is more preferably 100.000 g/m 2 or more, and still more preferably 300.000 g/m 2 or more.
　一方、皮膜部３０において、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、Ｃａ化合物の場合は金属Ｃａ換算、Ａｌ化合物の場合は金属Ａｌ換算、Ｌａ化合物の場合は金属Ｌａ換算としたときのそれぞれの換算値の合計で、１０００．０００ｇ／ｍ２以下であることが好ましい。Ｃａ化合物やＡｌ化合物やＬａ化合物は、ペーストの状態で被覆対象部位２０１（又は、被覆対象部位２０１に存在する封止２０３）に塗布される場合もあるため、合計付着量は、１０００．０００ｇ／ｍ２程度となりうる。また、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量が１０００．０００ｇ／ｍ２以下となることで、製造コストの増加を抑制しながら、第１封止部２１及び第２封止部２３の外面耐食性を、より向上させることができる。Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、皮膜部３０の構成や形成方法によっても異なる。 On the other hand, in the film portion 30, the total amount of deposited Ca compounds, Al compounds, and La compounds is calculated in terms of metal Ca in the case of Ca compounds, metal Al in the case of Al compounds, and metal La in the case of La compounds. It is preferable that the total of each converted value is 1000.000 g/m 2 or less. Since the Ca compound, Al compound, and La compound may be applied in the form of a paste to the coating target area 201 (or the sealing 203 existing in the coating target area 201), the total amount of the Ca compound, Al compound, and La compound applied is 1000.000 g/ It can be about m2 . Furthermore, since the total adhesion amount of the Ca compound, Al compound, and La compound is 1000.000 g/m 2 or less, the first sealing part 21 and the second sealing part 23 can be sealed while suppressing an increase in manufacturing cost. External corrosion resistance can be further improved. The total amount of the Ca compound, Al compound, and La compound deposited also differs depending on the configuration and formation method of the film portion 30.
　例えば、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れか（すなわち、Ｃａ化合物やＡｌ化合物やＬａ化合物のペースト）を塗布することで形成した皮膜部３０の場合、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、より好ましくは８００．０００ｇ／ｍ２以下であり、更に好ましくは５００．０００ｇ／ｍ２以下である。また、樹脂中にＣａ化合物、Ａｌ化合物又はＬａ化合物が分散している塗料を塗布することで形成した皮膜部３０の場合、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、より好ましくは８００．０００ｇ／ｍ２以下であり、更に好ましくは５００．０００ｇ／ｍ２以下である。 For example, in the case of the coating portion 30 formed by applying at least one of a Ca compound, an Al compound, or a La compound (that is, a paste of a Ca compound, an Al compound, or a La compound), The total adhesion amount is more preferably 800.000 g/m 2 or less, still more preferably 500.000 g/m 2 or less. Further, in the case of the film portion 30 formed by applying a paint in which a Ca compound, an Al compound, or a La compound is dispersed in a resin, the total amount of the Ca compound, Al compound, and La compound deposited is more preferably 800. It is .000 g/m 2 or less, more preferably 500.000 g/m 2 or less.
　また、場合によっては、ふっ化水素酸との反応が終了した後の皮膜部３０について、余剰な部分を除去した上で、リチウムイオン電池を出荷するような状況も考えうる。かかる場合においても、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、より好ましくは１００．０００ｇ／ｍ２以下程度となりうる。 Further, depending on the case, a situation may be considered in which a surplus portion of the film portion 30 after the reaction with hydrofluoric acid is completed is removed before the lithium ion battery is shipped. Even in such a case, the total amount of the Ca compound, Al compound, and La compound deposited can be more preferably about 100.000 g/m 2 or less.
　また、皮膜部３０において、反応生成物であるふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超となりうる。一方、第１封止部２１や第２封止部２３に付着しうる電解液の量を考慮すると、皮膜部３０に存在しうるふっ化物の付着量は、実質的に、ふっ素換算で、０．２００ｇ／ｍ２以下となる。 Further, in the coating portion 30, the amount of fluoride, which is a reaction product, attached may exceed 0 g/m 2 in terms of fluorine. On the other hand, considering the amount of electrolyte that can adhere to the first sealing part 21 and the second sealing part 23, the amount of fluoride that can exist in the coating part 30 is substantially 0 in terms of fluorine. .200g/ m2 or less.
　ここで、皮膜部３０におけるＣａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量は、ＩＣＰ発光分光分析法によって測定可能である。まず、サンプルとして、平面視したときの大きさが１ｍｍ×５０ｍｍである皮膜部３０を、任意の５箇所から採取し、得られたサンプルを、それぞれ硫酸で溶解する。次に、各溶解液に含まれるＣａ量、Ａｌ量及びＬａ量を、市販のＩＣＰ発光分光分析装置（例えば、島津製作所株式会社製：ＩＣＰＳ－８１００）を用いて定量分析する。かかる定量分析により得られるＣａ量、Ａｌ量及びＬａ量は、それぞれ、Ｃａ換算したときの換算量、Ａｌ換算したときの換算量、及び、Ｌａ換算したときの換算量に対応する。そのため、得られたＣａ量、Ａｌ量及びＬａ量の合計を、上述の面積で割ることにより、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量を求めることができる。得られた５つのＣａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量の平均値を、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量として取り扱う。 Here, the total adhesion amount of Ca compound, Al compound, and La compound in the coating portion 30 can be measured by ICP emission spectrometry. First, as samples, coating portions 30 having a size of 1 mm x 50 mm when viewed from above are taken from five arbitrary locations, and each of the obtained samples is dissolved in sulfuric acid. Next, the amounts of Ca, Al, and La contained in each solution are quantitatively analyzed using a commercially available ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation). The amount of Ca, the amount of Al, and the amount of La obtained by such quantitative analysis correspond to the converted amount when converted to Ca, the converted amount when converted to Al, and the converted amount when converted to La, respectively. Therefore, by dividing the sum of the obtained amounts of Ca, Al, and La by the above-mentioned area, the total amount of deposited Ca compound, Al compound, and La compound can be determined. The average value of the total adhesion amounts of the five Ca compounds, Al compounds, and La compounds obtained is treated as the total adhesion amount of the Ca compound, Al compound, and La compound.
　皮膜部３０におけるふっ化物の付着量は、以下のようにして測定可能である。
　まず、サンプルとして、平面視したときの大きさが１ｍｍ×５０ｍｍである皮膜部３０を、任意の５箇所から採取し、得られたサンプルのそれぞれを、硫酸で溶解する。かかる溶解の際に発生したガスを、それぞれ市販のガスクロマトグラフ（例えば、島津製作所株式会社製：Ｎｅｘｉｓ　ＧＣ－２０３０）により分析し、Ｆ量を測定する。得られたＦ量を、上述の面積で割ることにより、ふっ化物の付着量を求めることができる。得られた５つのふっ化物の付着量の平均値を、ふっ化物の付着量として取り扱う。これにより、ふっ素換算でのふっ化物の付着量を得ることができる。 The amount of fluoride deposited on the film portion 30 can be measured as follows.
First, as samples, coating portions 30 having a size of 1 mm x 50 mm when viewed from above are taken from five arbitrary locations, and each of the obtained samples is dissolved in sulfuric acid. The gas generated during such dissolution is analyzed using a commercially available gas chromatograph (for example, Nexis GC-2030 manufactured by Shimadzu Corporation) to measure the amount of F. By dividing the obtained amount of F by the above-mentioned area, the amount of attached fluoride can be determined. The average value of the five fluoride adhesion amounts obtained is treated as the fluoride adhesion amount. This makes it possible to obtain the amount of fluoride deposited in terms of fluorine.
　また、皮膜部３０が含有するＣａ化合物のうち、水酸化カルシウムが占める割合は、以下のようにして特定することが可能である。
　すなわち、水酸化カルシウムを含有する皮膜部３０を有するサンプルにおいて、ＦはすべてＣａと結合すると仮定する。その上で、上記と同様にして採取したサンプルについて、Ｆ量の測定を行う。かかる測定により得られたＦ量に基づき、上記仮定のもとでＣａ量を換算する。Ｃａ化合物の合計付着量と、換算したＣａ量との差が、水酸化カルシウムのＣａ量となる。得られた水酸化カルシウムのＣａ量を、Ｃａ化合物の合計付着量で除することで、水酸化カルシウムが占める割合を算出することができる。 Furthermore, the proportion of calcium hydroxide in the Ca compound contained in the film portion 30 can be determined as follows.
That is, it is assumed that in the sample having the film portion 30 containing calcium hydroxide, all F is combined with Ca. Then, the amount of F is measured for the sample collected in the same manner as above. Based on the F amount obtained by such measurement, the Ca amount is converted under the above assumption. The difference between the total amount of Ca compounds attached and the converted amount of Ca is the amount of Ca in calcium hydroxide. The proportion occupied by calcium hydroxide can be calculated by dividing the amount of Ca in the obtained calcium hydroxide by the total amount of Ca compounds attached.
　また、皮膜部３０におけるふっ化物の偏在状態は、例えば以下のようにして確認することができる。まず、収容ケース１０の長手部分の皮膜部３０から、断面観察用サンプルを切り出す。この際、断面を得るための切断方向は、収容ケース１０の長手方向に対して垂直な方向とする。得られた断面観察用サンプルを樹脂に埋め込んだ後、適切に研磨を行い、得られた断面を走査型電子顕微鏡（ＳＥＭ）により観察することで測定すればよい。このとき、観察時の視野の大きさは、１０００μｍ×１０００μｍとすればよい。より詳細には、走査型電子顕微鏡に搭載されたエネルギー分散型Ｘ線分析装置（ＥＤＳ）（例えば、ＪＥＯＬ株式会社製ＪＳＭ－７０００Ｆ）により、上記のようにして得られた断面観察用サンプルの断面を観察して、各元素の分布状況に関するマッピング分析を実施することで、ふっ化物の偏在状態を確認することが可能である。 Furthermore, the state of uneven distribution of fluoride in the coating portion 30 can be confirmed, for example, as follows. First, a sample for cross-sectional observation is cut out from the coating portion 30 on the longitudinal portion of the storage case 10. At this time, the cutting direction for obtaining the cross section is perpendicular to the longitudinal direction of the storage case 10. After embedding the obtained sample for cross-sectional observation in resin, it may be appropriately polished and measured by observing the obtained cross-section with a scanning electron microscope (SEM). At this time, the size of the field of view during observation may be 1000 μm×1000 μm. More specifically, an energy dispersive X-ray spectrometer (EDS) (for example, JSM-7000F manufactured by JEOL Co., Ltd.) installed in a scanning electron microscope is used to analyze the cross section of the sample for cross-sectional observation obtained as described above. By observing and performing mapping analysis on the distribution of each element, it is possible to confirm the uneven distribution of fluoride.
　このとき、得られた元素Ｆに関するマッピング結果において、ふっ化物の濃度がピークとなる位置が、皮膜部３０の厚みの半分の位置よりも母材鋼板側に位置するものを、「偏在状態にある」と判断する。ここで、マッピング分析のための測定条件は、加速電圧１５ｋＶ、照射電流７．４７５００ｎＡとする。また、皮膜部３０の厚みは、得られたマッピング結果から、元素Ｆが存在している部分を特定し、特定した部分の長さを、画像解析アプリケーションに実装された測長機能を用いて測ればよい。このような測定を、着目した断面の任意の５箇所で実施し、得られた測定値を測定箇所数で平均して、皮膜部３０の厚みとすればよい。 At this time, in the mapping result regarding element F obtained, the position where the concentration of fluoride peaks is located closer to the base steel plate than the position half the thickness of the coating 30 is classified as "unevenly distributed". ”. Here, the measurement conditions for mapping analysis are an acceleration voltage of 15 kV and an irradiation current of 7.47500 nA. In addition, the thickness of the film portion 30 can be determined by identifying the portion where element F is present from the obtained mapping results, and measuring the length of the identified portion using the length measurement function implemented in the image analysis application. Bye. Such measurements may be carried out at five arbitrary locations on the cross section of interest, and the obtained measured values may be averaged over the number of measurement locations to determine the thickness of the coating portion 30.
　なお、上記のＳＥＭ－ＥＤＳを用いた分析方法により、皮膜部３０の元素分析を実施することも可能である。 Note that it is also possible to carry out elemental analysis of the coating portion 30 by the above analysis method using SEM-EDS.
　以上、図１Ａ～図５Ｂを参照しながら、本実施形態に係るリチウムイオン電池１について、詳細に説明した。 The lithium ion battery 1 according to the present embodiment has been described in detail above with reference to FIGS. 1A to 5B.
≪第２の実施形態≫
＜収容ケース１０の素材について＞
　続いて、図６を参照しながら、本発明の第２の実施形態に係る収容ケース１０の素材について、詳細に説明する。図６は、本実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。 <<Second embodiment>>
<About the material of the storage case 10>
Next, with reference to FIG. 6, the material of the storage case 10 according to the second embodiment of the present invention will be described in detail. FIG. 6 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
　本実施形態に係る収容ケース１０の素材としては、Ｎｉめっき鋼板、又は、ラミネート鋼板が用いられる。以下では、本実施形態に係る収容ケース１０の素材として、ラミネート鋼板が用いられる場合について説明する。 As a material for the storage case 10 according to this embodiment, a Ni-plated steel plate or a laminated steel plate is used. Below, a case will be described in which a laminated steel plate is used as the material for the storage case 10 according to the present embodiment.
　図６は、ラミネート鋼板１００Ａの層構造を模式的に示したものである。
　収容ケース１０の素材として用いられるラミネート鋼板１００Ａは、図６に示したように、母材鋼板１０１と、母材鋼板１０１の表面に設けられた表面処理層１０５と、を有している。 FIG. 6 schematically shows the layer structure of the laminated steel plate 100A.
As shown in FIG. 6, the laminated steel plate 100A used as a material for the housing case 10 includes a base steel plate 101 and a surface treatment layer 105 provided on the surface of the base steel plate 101.
　ここで、母材鋼板１０１については、先だって説明したＮｉめっき鋼板１００の母材鋼板１０１と同様のものを使用可能であるため、以下では詳細な説明は省略する。 Here, the base steel plate 101 can be the same as the base steel plate 101 of the Ni-plated steel plate 100 described previously, so detailed explanation will be omitted below.
　表面処理層１０５は、母材鋼板１０１の表面を各種の樹脂でラミネートすることで形成された層である。かかる表面処理層１０５としては、収容ケース１０内に保持される電解液５に対して耐食性を示すものであれば、各種の表面処理層を適用することが可能である。かかる表面処理層１０５を構成する樹脂としては、例えば、ポリプロピレン（ＰＰ）樹脂、ポリエチレンテレフタレート（ＰＥＴ）樹脂、ポリエチレン（ＰＥ）樹脂を挙げることができる。これらの樹脂を、単独で用いてもよいし、複数を組み合わせて用いてもよい。 The surface treatment layer 105 is a layer formed by laminating the surface of the base steel plate 101 with various resins. As the surface treatment layer 105, various kinds of surface treatment layers can be applied as long as they exhibit corrosion resistance to the electrolytic solution 5 held in the storage case 10. Examples of the resin constituting the surface treatment layer 105 include polypropylene (PP) resin, polyethylene terephthalate (PET) resin, and polyethylene (PE) resin. These resins may be used alone or in combination.
　表面処理層１０５の片面当たりの厚みは、例えば、１０～１５０μｍであることが好ましい。表面処理層１０５の片面当たりの厚みが、５０μｍ以上となることで、ラミネート鋼板１００Ａの耐食性を更に向上させることが可能となるため、より好ましい。一方、表面処理層１０５の片面当たりの厚みが、１００μｍ以下となることで、ラミネート鋼板１００Ａの製造コストをより低減することが可能となるため、より好ましい。 The thickness of the surface treatment layer 105 per side is preferably 10 to 150 μm, for example. It is more preferable for the thickness of the surface treatment layer 105 to be 50 μm or more per side, since it is possible to further improve the corrosion resistance of the laminated steel plate 100A. On the other hand, it is more preferable for the thickness of the surface treatment layer 105 to be 100 μm or less per side, since this makes it possible to further reduce the manufacturing cost of the laminated steel plate 100A.
　なお、表面処理層１０５の有無を事後的に判断するには、例えばＩＣＰ発光分光分析法を用いればよい。まず、着目するリチウムイオン電池における収容ケースの底面の任意の５箇所から、平面視したときの大きさが３０ｍｍ×３０ｍｍであるサンプルをそれぞれ切り出し、かかるサンプルに存在する表面処理層１０５のそれぞれを、酸（より詳細には、１９％塩酸）で溶解する。次に、表面処理層１０５に含有されうる元素に着目し、ＩＣＰ発光分光分析装置（例えば、島津製作所株式会社製：ＩＣＰＳ－８１００）を用いて、各サンプルを定量分析する。例えば、表面処理層１０５を構成する樹脂が有している炭素（Ｃ）元素に着目し、溶解液に含まれるＴｏｔａｌ－Ｃ量を定量分析する。例えば、得られた５つのＴｏｔａｌ－Ｃ量の平均値が０超の値を示すことで、着目したラミネート鋼板１００Ａに表面処理層１０５が存在していたと判断することができる。なお、着目した箇所からサンプルを切り出す際に、サンプルの何れかの辺の大きさが３０ｍｍ未満となってしまう場合には、サンプルの面積が９０ｍｍ２となるように、着目した箇所からサンプルを切り出せばよい。 Note that to determine the presence or absence of the surface treatment layer 105 after the fact, for example, ICP emission spectrometry may be used. First, samples each having a size of 30 mm x 30 mm when viewed from above are cut out from five arbitrary locations on the bottom of the housing case of the lithium ion battery of interest, and each of the surface treatment layers 105 present in the sample is Dissolve with acid (more specifically, 19% hydrochloric acid). Next, focusing on elements that can be contained in the surface treatment layer 105, each sample is quantitatively analyzed using an ICP emission spectrometer (for example, ICPS-8100 manufactured by Shimadzu Corporation). For example, focusing on the carbon (C) element contained in the resin constituting the surface treatment layer 105, the amount of Total-C contained in the solution is quantitatively analyzed. For example, when the average value of the five Total-C amounts obtained exceeds 0, it can be determined that the surface treatment layer 105 was present in the laminated steel sheet 100A of interest. In addition, when cutting out a sample from the point of interest, if the size of any side of the sample is less than 30 mm, cut the sample from the point of interest so that the area of the sample is 90 mm 2 . Bye.
　また、表面処理層１０５の厚みは、ラミネート鋼板１００Ａの断面を、走査型電子顕微鏡（ＳＥＭ）により観察することで、特定することができる。すなわち、ラミネート鋼板１００Ａの任意の部位から、断面観察用サンプルを切り出す。この際、断面を得るための切断方向は、ラミネート鋼板１００Ａの板厚方向とする。得られた断面観察用サンプルを研磨した上で、かかる断面の任意の５箇所について、ＳＥＭ写真を撮影する。得られた各ＳＥＭ写真において測定される表面処理層１０５の厚みを、測定箇所数で平均し、得られた平均値を、表面処理層１０５の厚みとすればよい。 Furthermore, the thickness of the surface treatment layer 105 can be determined by observing the cross section of the laminated steel plate 100A using a scanning electron microscope (SEM). That is, a sample for cross-sectional observation is cut out from an arbitrary part of the laminated steel plate 100A. At this time, the cutting direction for obtaining the cross section is the thickness direction of the laminated steel plate 100A. After polishing the obtained sample for cross-sectional observation, SEM photographs are taken at five arbitrary locations on the cross-section. The thickness of the surface treatment layer 105 measured in each obtained SEM photograph may be averaged by the number of measurement points, and the obtained average value may be taken as the thickness of the surface treatment layer 105.
　また、上記のようなラミネート鋼板１００Ａにおいて、母材鋼板１０１と、表面処理層１０５との間に、更に、各種の化成処理皮膜層（図示せず。）が存在していてもよい。かかる化成処理皮膜層が存在することで、母材鋼板１０１と、表面処理層１０５との間の密着性を、より向上させることが可能となる。また、かかる化成処理皮膜層が存在することで、ラミネート鋼板１００Ａの耐食性を、更に向上させることが可能となる。 Furthermore, in the laminated steel sheet 100A as described above, various chemical conversion coating layers (not shown) may be further present between the base steel sheet 101 and the surface treatment layer 105. The presence of such a chemical conversion coating layer makes it possible to further improve the adhesion between the base steel sheet 101 and the surface treatment layer 105. Furthermore, the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the laminated steel sheet 100A.
　収容ケース１０の素材としてラミネート鋼板１００Ａを用いた場合における、封止処理と皮膜部による被覆対象部位との関係、及び、皮膜部３０については、第１の実施形態における該当する部分の説明において、「Ｎｉめっき鋼板１００」という記載を「ラミネート鋼板１００Ａ」と読み替え、「Ｎｉめっき層１０３」という記載を「表面処理層１０５」と読み替えればよい。そのため、以下では、収容ケース１０の素材としてラミネート鋼板１００Ａを用いた場合における、封止処理と皮膜部による被覆対象部位との関係、及び、皮膜部３０については、詳細な説明は省略する。 Regarding the relationship between the sealing process and the area to be covered by the film part when the laminated steel plate 100A is used as the material of the storage case 10, and the film part 30, in the description of the corresponding part in the first embodiment, The description ``Ni-plated steel sheet 100'' may be read as ``laminated steel sheet 100A,'' and the description ``Ni plating layer 103'' may be read as ``surface treatment layer 105.'' Therefore, detailed description of the relationship between the sealing process and the area to be covered by the film part and the film part 30 when the laminated steel plate 100A is used as the material of the housing case 10 will be omitted below.
≪第３の実施形態≫
＜収容ケース１０の素材について＞
　続いて、図７を参照しながら、本発明の第３の実施形態に係る収容ケース１０の素材について、詳細に説明する。図７は、本実施形態に係るリチウムイオン電池の収容ケースの素材について模式的に示した説明図である。 <<Third embodiment>>
<About the material of the storage case 10>
Next, with reference to FIG. 7, the material of the storage case 10 according to the third embodiment of the present invention will be described in detail. FIG. 7 is an explanatory diagram schematically showing the material of the housing case for the lithium ion battery according to the present embodiment.
　収容ケース１０の素材として、図７に示したような、母材鋼板１０１の表面に、Ｎｉめっき層１０３及び表面処理層１０５を形成した表面処理鋼板１００Ｂを用いることも可能である。 As a material for the housing case 10, it is also possible to use a surface-treated steel plate 100B in which a Ni plating layer 103 and a surface treatment layer 105 are formed on the surface of a base steel plate 101, as shown in FIG.
　ここで、かかる表面処理鋼板１００ＢにおけるＮｉめっき層１０３は、第１の実施形態に係るＮｉめっき鋼板１００におけるＮｉめっき層１０３と同様の構成を有し、同様の効果を奏するものであるため、以下では詳細な説明は省略する。また、かかる表面処理鋼板１００Ｂにおける表面処理層１０５は、第２の実施形態に係るラミネート鋼板１００Ａにおける表面処理層１０５と同様の構成を有し、同様の効果を奏するものであるため、以下では詳細な説明は省略する。 Here, the Ni plating layer 103 in the surface-treated steel sheet 100B has the same configuration as the Ni plating layer 103 in the Ni-plated steel sheet 100 according to the first embodiment, and has the same effect, so the following will be explained. A detailed explanation will be omitted. Further, the surface treatment layer 105 in the surface treated steel sheet 100B has the same configuration as the surface treatment layer 105 in the laminated steel sheet 100A according to the second embodiment, and has the same effects, so the details will be explained below. Further explanation will be omitted.
　また、上記のような表面処理鋼板１００Ｂにおいて、母材鋼板１０１と、Ｎｉめっき層１０３との間、又は、Ｎｉめっき層１０３と表面処理層１０５との間の少なくとも何れかに、更に、各種の化成処理皮膜層（図示せず。）が存在していてもよい。かかる化成処理皮膜層が存在することで、母材鋼板１０１と、Ｎｉめっき層１０３との間の密着性や、Ｎｉめっき層１０３と表面処理層１０５との間の密着性を、より向上させることが可能となる。また、かかる化成処理皮膜層が存在することで、表面処理鋼板１００Ｂの耐食性を、更に向上させることが可能となる。 Furthermore, in the surface-treated steel sheet 100B as described above, various types of A chemical conversion coating layer (not shown) may also be present. The presence of such a chemical conversion coating layer further improves the adhesion between the base steel sheet 101 and the Ni plating layer 103 and the adhesion between the Ni plating layer 103 and the surface treatment layer 105. becomes possible. Moreover, the presence of such a chemical conversion coating layer makes it possible to further improve the corrosion resistance of the surface-treated steel sheet 100B.
　収容ケース１０の素材として表面処理鋼板１００Ｂを用いた場合における、封止処理と皮膜部による被覆対象部位との関係、及び、皮膜部３０については、第１の実施形態における該当する部分の説明において、「Ｎｉめっき鋼板１００」という記載を「表面処理鋼板１００Ｂ」と読み替え、「Ｎｉめっき層１０３」という記載を「表面処理層１０５、又は、Ｎｉめっき層１０３と表面処理層１０５の双方」と読み替えればよい。そのため、以下では、収容ケース１０の素材として表面処理鋼板１００Ｂを用いた場合における、封止処理と皮膜部による被覆対象部位との関係、及び、皮膜部３０については、詳細な説明は省略する。 The relationship between the sealing treatment and the area to be covered by the film part when the surface-treated steel plate 100B is used as the material of the storage case 10, and the film part 30 will be explained in the description of the corresponding part in the first embodiment. , the description "Ni-plated steel sheet 100" should be read as "surface-treated steel sheet 100B", and the description "Ni-plated layer 103" should be read as "surface-treated layer 105, or both Ni-plated layer 103 and surface-treated layer 105". That's fine. Therefore, in the following, when the surface-treated steel plate 100B is used as the material of the housing case 10, a detailed explanation of the relationship between the sealing process and the area to be covered by the film part and the film part 30 will be omitted.
（リチウムイオン電池の製造方法について）
　次に、図８Ａ及び図８Ｂを参照しながら、本発明の各実施形態に係るリチウムイオン電池の製造方法の一例を説明する。図８Ａ及び図８Ｂは、本発明の各実施形態に係るリチウムイオン電池の製造方法の流れの一例を示した流れ図である。 (About the manufacturing method of lithium ion batteries)
Next, an example of a method for manufacturing a lithium ion battery according to each embodiment of the present invention will be described with reference to FIGS. 8A and 8B. FIGS. 8A and 8B are flowcharts showing an example of the flow of a method for manufacturing a lithium ion battery according to each embodiment of the present invention.
　以下の説明に先立ち、Ｎｉめっき鋼板１００やラミネート鋼板１００Ａや表面処理鋼板１００Ｂを用いて、所望の形状となるように、収容ケース１０の本体部１１及び蓋部１３、１３Ａが製造されているものとする。 Prior to the following description, the main body 11 and lid parts 13, 13A of the storage case 10 are manufactured using Ni-plated steel plate 100, laminated steel plate 100A, and surface-treated steel plate 100B so as to have a desired shape. shall be.
　図８Ａは、本体部１１と蓋部１３との封止部である第１封止部２１、又は、蓋部１３Ａに設けられた注液口１５を封止するための注液口蓋１７と注液口１５との封止部である第２封止部２３のいずれかが存在する場合のリチウムイオン電池１の製造方法である。 FIG. 8A shows a first sealing part 21 that is a sealing part between the main body part 11 and the lid part 13, or a liquid filling port lid 17 for sealing the liquid filling port 15 provided in the lid part 13A. This is a method of manufacturing the lithium ion battery 1 in the case where any of the second sealing parts 23, which are the sealing parts with the liquid port 15, are present.
　図８Ａに示したように、上記のようなリチウムイオン電池１の製造方法では、まず、収容ケース１０内に電池ユニット３が収納され（ステップＳ１１）、その後、収容ケース１０内に、電解液５が注入される（ステップＳ１３）。その後、溶接又はかしめといった封止方法を用いて、収容ケース１０の本体部１１と蓋部１３、又は、注液口蓋１７と注液口１５との封止処理が行われる（ステップＳ１５）。 As shown in FIG. 8A, in the method for manufacturing the lithium ion battery 1 as described above, the battery unit 3 is first housed in the housing case 10 (step S11), and then the electrolyte 5 is placed inside the housing case 10. is injected (step S13). Thereafter, the main body portion 11 and the lid portion 13 of the storage case 10 or the liquid injection port cover 17 and the liquid injection port 15 are sealed using a sealing method such as welding or caulking (step S15).
　図８Ｂは、本体部１１と蓋部１３Ａとの封止部である第１封止部２１、及び、蓋部１３Ａに設けられた注液口１５を封止するための注液口蓋１７と注液口１５との封止部である第２封止部２３が存在する場合のリチウムイオン電池の製造方法である。 FIG. 8B shows the first sealing part 21, which is a sealing part between the main body part 11 and the lid part 13A, and the liquid injection port lid 17 for sealing the liquid injection port 15 provided in the lid part 13A. This is a method for manufacturing a lithium ion battery when a second sealing portion 23 that is a sealing portion with the liquid port 15 is present.
　図８Ｂに示したように、上記のようなリチウムイオン電池１の製造方法では、まず、収容ケース１０内に電池ユニット３が収納され（ステップＳ２１）、その後、溶接又はかしめといった封止方法を用いて、収容ケース１０の本体部１１と蓋部１３Ａとの封止処理が行われる（ステップＳ２３）。その後、収容ケース１０内に、注液口１５を介して電解液５が注入される（ステップＳ２５）。続いて、溶接又はかしめといった封止方法を用いて、注液口蓋１７と注液口１５との封止処理が行われる（ステップＳ２７）。 As shown in FIG. 8B, in the method for manufacturing the lithium ion battery 1 as described above, the battery unit 3 is first housed in the housing case 10 (step S21), and then a sealing method such as welding or caulking is used. Then, a sealing process is performed between the main body portion 11 of the storage case 10 and the lid portion 13A (step S23). Thereafter, the electrolytic solution 5 is injected into the housing case 10 through the inlet 15 (step S25). Subsequently, the liquid injection port 17 and the liquid injection port 15 are sealed using a sealing method such as welding or caulking (step S27).
　これにより、収容ケース１０の本体部１１と蓋部１３、１３Ａとが一体化され、先だって説明したような第１封止部２１や第２封止部２３が存在するようになる。 As a result, the main body portion 11 and the lid portions 13, 13A of the storage case 10 are integrated, and the first sealing portion 21 and the second sealing portion 23 as described above are present.
　ここで、収容ケース１０への電池ユニット３の収納方法や、収容ケース１０内への電解液５の注入方法、及び、封止方法については、公知の各種の方法を適宜採用すればよい。 Here, various known methods may be employed as appropriate for the method of storing the battery unit 3 in the housing case 10, the method of injecting the electrolyte 5 into the housing case 10, and the sealing method.
　ただし、収容ケース１０の外表面に付着しうる電解液と、大気中の水分との反応を考慮すると、上記のような封止処理を施す工程までの工程は、水分のなるべく少なくなるような雰囲気下（例えば、露点－７５℃以下の雰囲気下）で実施されることが好ましい。換言すれば、収容ケース１０は、少なくとも、上記のような雰囲気下における封止処理が終了した後に、大気中に取り出されることが好ましい。 However, considering the reaction between the electrolyte that may adhere to the outer surface of the storage case 10 and moisture in the atmosphere, the steps up to the sealing process described above should be performed in an atmosphere that contains as little moisture as possible. It is preferable to carry out the test under low temperature (for example, under an atmosphere with a dew point of −75° C. or lower). In other words, it is preferable that the housing case 10 is taken out into the atmosphere at least after the sealing process in the atmosphere as described above is completed.
　次に、例えば図８Ａや図８Ｂに即して形成された第１封止部２１及び第２封止部２３におけるＦｅ含有率が８０質量％以上である部位（すなわち、被覆対象部位２０１）に対して、皮膜部３０を形成するための塗布処理を実施する（ステップＳ１７、ステップＳ２９）。かかる塗布処理を実施するに際して、先だって説明したようなＣａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかを含有する塗料を準備し、乾燥後の付着量が先だって説明したような範囲となるように、塗料が塗布される。 Next, for example, in the first sealing part 21 and the second sealing part 23 formed in accordance with FIG. 8A and FIG. On the other hand, a coating process is performed to form the film portion 30 (step S17, step S29). When carrying out such a coating process, a paint containing at least one of the Ca compound, Al compound, or La compound as described above is prepared, and the coating amount after drying is within the range as described above. Paint is applied.
　かかる塗料は、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかを各種の有機溶媒に溶解又は分散させた塗料であってもよいし、Ｃａ化合物、Ａｌ化合物又はＬａ化合物の少なくとも何れかを各種の樹脂中に分散させた塗料であってもよい。なお、有機溶媒を用いる場合には、ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）、ジエチルカーボネート（ＤＥＣ）、プロピレンカーボネート（ＰＣ）、エチレンカーボネート（ＥＣ）といった、電解液に含まれる炭酸エステル類を用いることが好ましい。 Such a paint may be a paint in which at least one of a Ca compound, an Al compound, or a La compound is dissolved or dispersed in various organic solvents, or a paint in which at least one of a Ca compound, an Al compound, or a La compound is dissolved or dispersed in various organic solvents. It may also be a paint dispersed in a resin. In addition, when using an organic solvent, carbonate esters contained in the electrolytic solution such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), and ethylene carbonate (EC) are used. It is preferable to use
　また、かかる塗布処理は、水分のなるべく少なくなるような雰囲気下（例えば、露点－７５℃以下の雰囲気下）で実施されることが好ましい。かかる観点から、上記のような封止処理が行われた雰囲気下で、引き続いて、上記のような塗料の塗布処理が行われることがより一層好ましい。また、水分がある程度存在する雰囲気下で塗布処理を実施する場合（例えば、上記のような封止処理が終了した後、封止の完了した収容ケース１０を大気中に取り出した場合）には、封止処理後なるべく早く、塗布処理を行うことが好ましい。 Further, such coating treatment is preferably carried out in an atmosphere where moisture content is as low as possible (for example, in an atmosphere with a dew point of −75° C. or lower). From this point of view, it is even more preferable that the coating treatment as described above is subsequently performed in the atmosphere in which the sealing treatment as described above has been performed. Furthermore, when the coating process is performed in an atmosphere where a certain amount of moisture is present (for example, when the sealed housing case 10 is taken out into the atmosphere after the sealing process as described above is completed), It is preferable to perform the coating treatment as soon as possible after the sealing treatment.
　なお、被覆対象部位２０１への塗料の塗布方法については、公知の各種の塗布方法を適用することが可能である。 Note that various known coating methods can be applied to the coating target site 201.
　上記のような塗料の塗布後、塗布された塗料を乾燥・固化させることで、リチウムイオン電池１の被覆対象部位２０１に対し、皮膜部３０が形成されることとなる。かかる皮膜部３０が形成されることで、リチウムイオン電池１の外表面に電解液が付着しており、大気中にリチウムイオン電池１が曝された場合であっても、ふっ化水素酸に起因する赤錆の発生を防止することができる。 After applying the paint as described above, by drying and solidifying the applied paint, a film portion 30 is formed on the area to be covered 201 of the lithium ion battery 1. By forming such a film portion 30, the electrolyte adheres to the outer surface of the lithium ion battery 1, and even if the lithium ion battery 1 is exposed to the atmosphere, it will not be affected by hydrofluoric acid. It is possible to prevent the occurrence of red rust.
　なお、塗料の乾燥・固化後に、必要に応じて、余剰な皮膜部３０の除去処理等を実施してもよい。 Note that after the paint is dried and solidified, a process such as removing the excess film portion 30 may be performed as necessary.
　以上、図８Ａ及び図８Ｂを参照しながら、本発明の各実施形態に係るリチウムイオン電池１の製造方法について説明した。 The method for manufacturing the lithium ion battery 1 according to each embodiment of the present invention has been described above with reference to FIGS. 8A and 8B.
　以下、実施例及び比較例を示しながら、本発明に係るリチウムイオン電池について、具体的に説明する。なお、以下に示す実施例は、本発明の係るリチウムイオン電池の一例に過ぎず、本発明に係るリチウムイオン電池が下記の例に限定されるものではない。 Hereinafter, the lithium ion battery according to the present invention will be specifically explained while showing examples and comparative examples. Note that the examples shown below are merely examples of the lithium ion battery according to the present invention, and the lithium ion battery according to the present invention is not limited to the following examples.
（試験例）
　以下に示す試験例では、収容ケースの本体部と、蓋部と、を準備するとともに、以下に示す電池ユニットを準備し、これらの部材を組み上げることで、リチウムイオン電池とした。収容ケースの本体部に設けられた開口部から電解液を注液した後、本体部を蓋部で封止し、完成したリチウムイオン電池について、その外面耐食性を評価した。 (Test example)
In the test example shown below, the main body and the lid of the storage case were prepared, as well as the battery unit shown below, and these members were assembled to form a lithium ion battery. After injecting electrolyte through an opening provided in the main body of the storage case, the main body was sealed with a lid, and the external corrosion resistance of the completed lithium ion battery was evaluated.
＜収容ケースの本体部及び蓋部＞
◇Ｎｉめっき鋼板
　Ｎｉめっき鋼板として、日本製鉄株式会社製のニッケルめっき鋼板（スーパーニッケル（登録商標））を用いた。かかるニッケルめっき鋼板において、片面当たりのＮｉ付着量は、２．０μｍであった。 <Main body and lid of storage case>
◇Ni-plated steel plate As the Ni-plated steel plate, a nickel-plated steel plate (Super Nickel (registered trademark)) manufactured by Nippon Steel Corporation was used. In this nickel-plated steel sheet, the amount of Ni deposited on one side was 2.0 μm.
◇ラミネート鋼板
　・母材鋼板：日本製鉄株式会社製のティンフリースチール（キャンスーパー（登録商標））
　・表面処理層：ＰＰ（電池内面側（電池ユニットと対向する側））／ＰＥＴ（電池外面側） ◇Laminated steel plate ・Base material steel plate: Tin-free steel manufactured by Nippon Steel Corporation (Cansuper (registered trademark))
・Surface treatment layer: PP (battery inner side (side facing the battery unit)) / PET (battery outer side)
　上記の樹脂からなる樹脂フィルムをそれぞれ準備し、２００℃に加熱したティンフリースチールに樹脂フィルムを押し当て、融着させることで作製した。なお、熱融着後の表面処理層の厚みは、５０μｍであった。 A resin film made of the above-mentioned resin was prepared, and the resin film was pressed against tin-free steel heated to 200°C and fused. The thickness of the surface treatment layer after heat fusion was 50 μm.
◇表面処理鋼板
　また、上記の日本製鉄株式会社製のニッケルめっき鋼板の表裏面に対し、上記ラミネート鋼板に設けた表面処理層と同様のものを同様にして形成し、表面処理鋼板とした。 ◇Surface-treated steel sheet In addition, a surface treatment layer similar to that provided on the laminated steel sheet was formed on the front and back surfaces of the nickel-plated steel sheet manufactured by Nippon Steel Corporation in the same manner as the above-mentioned laminated steel sheet to obtain a surface-treated steel sheet.
　上記のようなニッケルめっき鋼板、ラミネート鋼板及び表面処理鋼板を用いて、収容ケースの本体部及び蓋部を作製した。なお、収容ケースの本体部及び蓋部は、図１Ａに例示した収容ケースと同様の形状とした。 The main body and lid of the storage case were fabricated using the nickel-plated steel plate, laminated steel plate, and surface-treated steel plate as described above. Note that the main body and lid of the storage case had the same shape as the storage case illustrated in FIG. 1A.
＜電池ユニット＞
◇正極板
　正極活物質として、コバルト酸リチウムを用いた。かかる正極活物質と、アセチレンブラックとポリふっ化ビニリデン（ＰＶＤＦ）とを、質量比でコバルト酸リチウム：アセチレンブラック：ＰＶＤＦ＝１０：１０：１となるように混合した。その後、水生ディスパージョンとしてＡｌ箔に塗布した後、乾燥した。得られたものを、所定の厚みとなるよう圧延し、所定の大きさに切り出したものを、正極板とした。 <Battery unit>
◇Positive electrode plate Lithium cobalt oxide was used as the positive electrode active material. The positive electrode active material, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of lithium cobalt oxide:acetylene black:PVDF=10:10:1. Thereafter, the aqueous dispersion was applied to Al foil and dried. The obtained product was rolled to a predetermined thickness and cut into a predetermined size, which was used as a positive electrode plate.
◇負極板
　負極活物質として、非晶質カーボンを用いた。非晶質カーボンを、導電材であるアセチレンブラックと乾式混合して混合物とした。その後、ポリふっ化ビニリデンを溶解させたＮ－メチル－２－ピロリドン（ＮＭＰ）を、混合物に均一に分散させて、質量比でカーボン：アセチレンブラック：ＰＶＤＦ＝８８：５：７となるペーストを作成した。得られたペーストを、Ｃｕ箔に塗布して乾燥した後、所定厚みとなるよう圧延してから、所定の大きさに切り出したものを負極板とした。 ◇Negative electrode plate Amorphous carbon was used as the negative electrode active material. Amorphous carbon was dry mixed with acetylene black, which is a conductive material, to form a mixture. Then, N-methyl-2-pyrrolidone (NMP) in which polyvinylidene fluoride is dissolved is uniformly dispersed in the mixture to create a paste with a mass ratio of carbon: acetylene black: PVDF = 88:5:7. did. The resulting paste was applied to a Cu foil, dried, rolled to a predetermined thickness, and then cut into a predetermined size to form a negative electrode plate.
◇セパレータ
　セパレータにはポリエチレン微多孔膜を用いた。 ◇Separator A microporous polyethylene membrane was used as the separator.
＜電解液＞
　電解液として、エチレンカーボネート：ジエチルカーボネートを体積比で１：１混合したものに、６ふっ化リン酸リチウムを１ｍｏｌ／Ｌ添加した溶液（１Ｍ－ＬｉＰＦ６　ＥＣ／ＤＥＣ（１／１））を用いた。 <Electrolyte>
As the electrolyte, a solution (1M-LiPF 6 EC/DEC (1/1)) in which 1 mol/L of lithium hexafluorophosphate was added to a mixture of ethylene carbonate and diethyl carbonate at a volume ratio of 1:1 was used. there was.
＜リチウムイオン電池の製造手順＞
　上記のようにして得られた正極板と負極板との間にセパレータを挟み込んだ後、捲回して、電極ユニットとした。かかる電池ユニットを、収容ケースの本体部の内部空間に挿入可能な形状につぶした後、正極板はＡｌリードに、負極板はＮｉリードに溶接した。Ａｌリードを、収容ケースの蓋部に設けられた正極端子に溶接するとともに、Ｎｉリードを、収容ケースの蓋部に設けられた負極端子に溶接した。 <Lithium ion battery manufacturing procedure>
A separator was sandwiched between the positive electrode plate and negative electrode plate obtained as described above, and then wound to form an electrode unit. After the battery unit was crushed into a shape that could be inserted into the internal space of the main body of the housing case, the positive electrode plate was welded to the Al lead, and the negative electrode plate was welded to the Ni lead. The Al lead was welded to the positive terminal provided on the lid of the storage case, and the Ni lead was welded to the negative terminal provided on the lid of the storage case.
　露点－７５℃の雰囲気下で電池内を乾燥させ、水分を除去した。その後、同雰囲気下で、収容ケースの本体部に設けられた開口部より、上記の電解液を注入した。その後、蓋部を、溶接又は巻き締めにより、本体部に固定した。その後、同雰囲気下において、得られたリチウムイオン電池を、３．６Ｖで充電した。かかる処理により、電池内に残存した水分を電解除去した。その後、同雰囲気下において、注液口に対し、注液口蓋として、蓋部と同じ種類の金属を溶接して、リチウムイオン電池の完成体とした。 The inside of the battery was dried in an atmosphere with a dew point of -75°C to remove moisture. Thereafter, under the same atmosphere, the above electrolyte solution was injected through the opening provided in the main body of the storage case. Thereafter, the lid was fixed to the main body by welding or tightening. Thereafter, the obtained lithium ion battery was charged at 3.6V under the same atmosphere. Through this treatment, water remaining in the battery was electrolytically removed. Thereafter, in the same atmosphere, the same type of metal as the lid was welded to the liquid injection port as a liquid injection port cover, thereby completing a lithium ion battery.
＜耐食性評価＞
◇評価用サンプルの準備
　上記のようにして得られるリチウムイオン電池について、電解液が外表面に付着している状況を模擬するために、露点－７５℃の雰囲気下において、本体部と蓋部との封止部分（すなわち、第１封止部）に対して、刷毛で、上記の電解液（ＬｉＰＦ６＋ＥＣ／ＤＥＣ）を塗布した。 <Corrosion resistance evaluation>
◇Preparation of samples for evaluation Regarding the lithium ion battery obtained as described above, in order to simulate the situation where the electrolyte is attached to the outer surface, the main body and lid were assembled in an atmosphere with a dew point of -75°C. The above electrolyte solution (LiPF 6 +EC/DEC) was applied with a brush to the sealed portion (that is, the first sealed portion).
◇防錆処理：皮膜部の形成
　露点－７５℃の雰囲気下、又は、大気取り出し後なるべくはやく、上記の評価用サンプルの封止部分（第１封止部）に対し、以下の表１に示した「有機溶媒とＣａ化合物、Ａｌ化合物、Ｌａ化合物の混合物」、「樹脂とＣａ化合物、Ａｌ化合物、Ｌａ化合物の混合物」、又は、「樹脂のみ」を、防錆処理剤として刷毛で塗布し、乾燥させた。これにより、第１封止部上に、各防錆処理剤に対応した皮膜部が形成されることとなる。 ◇Rust prevention treatment: Formation of film part In an atmosphere with a dew point of -75°C or as soon as possible after being taken out to the atmosphere, the sealed part (first sealed part) of the above evaluation sample was treated as shown in Table 1 below. ``Mixture of organic solvent and Ca compound, Al compound, La compound'', ``mixture of resin and Ca compound, Al compound, La compound'', or ``resin alone'' is applied with a brush as a rust preventive treatment agent, Dry. As a result, a film portion corresponding to each antirust treatment agent is formed on the first sealing portion.
　ここで、用いたＣａ化合物、Ａｌ化合物、Ｌａ化合物、有機溶媒、樹脂は、それぞれ以下の通りであり、いずれも市販の一般試薬と同様のものである。
　Ｃａ化合物：水酸化カルシウム、炭酸カルシウム、炭酸水素カルシウム、酸化カルシウム
　Ａｌ化合物：水酸化アルミニウム、炭酸カルシウム、酸化アルミニウム
　Ｌａ化合物：水酸化ランタン、炭酸ランタン、酸化ランタン
　有機溶媒：ジメチルカーボネート（ＤＭＣ）、エチルメチルカーボネート（ＥＭＣ）、ジエチルカーボネート（ＤＥＣ）、プロピレンカーボネート（ＰＣ）、エチレンカーボネート（ＥＣ）
　樹脂：ＰＶＤＦ、エポキシ樹脂、メラミン樹脂、シリコーン樹脂、アクリル樹脂、ポリウレタン樹脂。 Here, the Ca compound, Al compound, La compound, organic solvent, and resin used are as follows, and all are the same as commercially available general reagents.
Ca compounds: calcium hydroxide, calcium carbonate, calcium hydrogen carbonate, calcium oxide Al compounds: aluminum hydroxide, calcium carbonate, aluminum oxide La compounds: lanthanum hydroxide, lanthanum carbonate, lanthanum oxide Organic solvent: dimethyl carbonate (DMC), ethyl Methyl carbonate (EMC), diethyl carbonate (DEC), propylene carbonate (PC), ethylene carbonate (EC)
Resin: PVDF, epoxy resin, melamine resin, silicone resin, acrylic resin, polyurethane resin.
◇評価方法
　上記のような防錆処理後の評価用サンプルを、大気雰囲気下（すなわち、水分が存在する雰囲気下）で保持した。保持開始から１ヵ月後に外観を観察し、赤錆発生有無を観察した。第１封止部の面積と、観察から得られた赤錆発生状況とから、赤錆発生率を算出し、以下の評価基準に基づき評価を行った。以下の評点「Ａ」～「Ｃ」を合格とした。
　　評点「Ａ」：赤錆発生率０％
　　評点「Ｂ」：赤錆発生率０％超１％以下
　　評点「Ｃ」：赤錆発生率１％超５％以下
　　評点「Ｄ」：赤錆発生率５％超 ◇Evaluation method The evaluation sample after the anti-corrosion treatment as described above was held in an atmospheric atmosphere (that is, in an atmosphere containing moisture). One month after the start of holding, the appearance was observed and the presence or absence of red rust was observed. The red rust occurrence rate was calculated from the area of the first sealed portion and the red rust occurrence status obtained from observation, and evaluation was performed based on the following evaluation criteria. The following grades of "A" to "C" were considered acceptable.
Rating "A": Red rust occurrence rate 0%
Rating "B": Red rust occurrence rate over 0% and 1% or less Rating "C": Red rust occurrence rate over 1% and 5% or less Rating "D": Red rust occurrence rate over 5%
◇皮膜部についての分析
　赤錆発生有無を確認した後の評価用サンプルのそれぞれについて、皮膜部からサンプルを採取した。有機溶媒を用いた防錆処理剤に対応するサンプルについては、第１封止部から粉末を刷毛で回収した。また、樹脂を用いた防錆処理剤に対応するサンプルについては、第１封止部の一部を削り取って回収後、冷凍粉砕して粉末状にした。 ◇Analysis of the coating part After confirming the presence or absence of red rust, a sample was taken from the coating part of each evaluation sample. For samples corresponding to the antirust treatment agent using an organic solvent, powder was collected from the first sealing part with a brush. In addition, as for the sample corresponding to the antirust treatment agent using resin, a part of the first sealing part was scraped off and collected, and then frozen and crushed into powder.
　上記のようにして採取した粉末のそれぞれについて、先だって説明した方法に即して、Ｃａ化合物、Ａｌ化合物及びＬａ化合物の合計付着量、Ｃａ化合物に占める水酸化カルシウムの割合、ふっ化物の有無、ふっ化物の付着量をそれぞれ分析した。用いたＩＣＰ発光分光分析装置は、島津製作所株式会社製：ＩＣＰＳ－８１００であり、用いたガスクロマトグラフは、島津製作所株式会社製：Ｎｅｘｉｓ　ＧＣ－２０３０である。 For each of the powders collected as described above, the total adhesion amount of Ca compounds, Al compounds, and La compounds, the proportion of calcium hydroxide in Ca compounds, the presence or absence of fluoride, and the The amount of chemical substances attached was analyzed. The ICP emission spectrometer used was ICPS-8100 manufactured by Shimadzu Corporation, and the gas chromatograph used was Nexis GC-2030 manufactured by Shimadzu Corporation.
　また、上記の粉末を取得した部位とは異なる部位から、断面観察用サンプルを切り出し、先だって説明した方法に即して、ふっ化物の分布状態を確認した。ふっ化物のピークが、皮膜部の厚みの半分の位置よりも鋼板側にあるものを、「偏在している」状態にあると評価した。以下に示す表１においては、「偏在している」状態にあるものを、「ＹＥＳ」と表記している。 In addition, a sample for cross-sectional observation was cut out from a site different from the site from which the above powder was obtained, and the distribution state of fluoride was confirmed in accordance with the method described previously. When the peak of fluoride was located closer to the steel plate than the half-thickness position of the film, it was evaluated as being in a "unevenly distributed" state. In Table 1 shown below, those in the "unevenly distributed" state are written as "YES".
　なお、断面観察用サンプルは、上記の粉末を取得した部位とは異なる部位を、高速精密切断機で切断することで得た。得られた断面観察用サンプルを、樹脂埋め後、エメリー紙＃１２００まで湿式研磨し、更に、ダイアモンド研磨（Ｓｔｒｕｅｒｓ製：ＤＰ－懸濁液）することで鏡面に仕上げ、観察に供した。 Note that the sample for cross-sectional observation was obtained by cutting a different part from the part from which the above powder was obtained using a high-speed precision cutting machine. The obtained sample for cross-sectional observation was filled with resin, wet-polished to #1200 emery paper, and further polished to a mirror surface by diamond polishing (DP-suspension, manufactured by Struers), and used for observation.
　ＳＥＭ（ＪＥＯＬ株式会社製ＪＳＭ－７０００Ｆ）を用い、先だって説明した方法に従って、反射電子を用いて、得られた断面を観察した。断面の元素分析には、ＳＥＭ－ＥＤＳ分析を用いた。 Using a SEM (JSM-7000F manufactured by JEOL Co., Ltd.), the obtained cross section was observed using reflected electrons according to the method described above. SEM-EDS analysis was used for elemental analysis of the cross section.
＜各封止部のＦｅ質量％分析＞
◇分析用サンプルの作製
　収容ケースの本体部、蓋部のそれぞれについて、上記の耐食性評価用のリチウムイオン電池の製造手順と同様に作製した後、上記と同様にして封止した。かかる製造手順により得られるリチウムイオン電池は、耐食性評価用のリチウムイオン電池と同様の第１封止部が形成されることとなる。 <Fe mass % analysis of each sealing part>
◇Preparation of samples for analysis The main body and lid of the storage case were prepared in the same manner as the manufacturing procedure of the lithium ion battery for corrosion resistance evaluation described above, and then sealed in the same manner as above. In a lithium ion battery obtained by such a manufacturing procedure, a first sealing portion similar to that of a lithium ion battery for evaluation of corrosion resistance is formed.
◇分析
　それぞれの封止部を、高速精密切断機で切断し、断面観察用サンプルを切り出した。得られた断面観察用サンプルを、樹脂埋め後、エメリー紙＃１２００まで湿式研磨し、更に、ダイアモンド研磨（Ｓｔｒｕｅｒｓ製：ＤＰ－懸濁液）することで鏡面に仕上げ、観察に供した。 ◇Analysis Each sealed portion was cut using a high-speed precision cutter to cut out samples for cross-sectional observation. The obtained sample for cross-sectional observation was filled with resin, wet-polished to #1200 emery paper, and further polished to a mirror surface by diamond polishing (DP-suspension, manufactured by Struers), and used for observation.
　ＳＥＭ（ＪＥＯＬ株式会社製ＪＳＭ－７０００Ｆ）を用い、先だって説明した方法に従って、反射電子を用いて、得られた断面を観察した。断面の元素分析には、ＳＥＭ－ＥＤＳ分析を用いた。 The cross section was observed using backscattered electrons with a SEM (JEOL JSM-7000F) according to the method previously described. SEM-EDS analysis was used for elemental analysis of the cross section.
　得られた結果を、以下の表１にあわせて示した。 The obtained results are also shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表１から明らかなように、本発明の実施例に該当するサンプルについては、優れた外面耐食性を示す一方で、本発明の比較例に該当するサンプルについては、優れた外面耐食性が得られなかった。 As is clear from Table 1 above, the samples corresponding to the examples of the present invention exhibit excellent external corrosion resistance, while the samples corresponding to the comparative examples of the present invention do not exhibit excellent external corrosion resistance. Ta.
　以上、添付図面を参照しながら本発明の好適な実施形態について詳細に説明したが、本発明はかかる例に限定されない。本発明の属する技術の分野における通常の知識を有する者であれば、特許請求の範囲に記載された技術的思想の範疇内において、各種の変更例又は修正例に想到し得ることは明らかであり、これらについても、当然に本発明の技術的範囲に属するものと了解される。 Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person with ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea stated in the claims. It is understood that these also naturally fall within the technical scope of the present invention.
　今回開示された実施形態は、全ての点で例示であって制限的なものではない。上記の実施形態は、添付の特許請求の範囲、後述するような本発明の技術的範囲に属する構成及びその主旨を逸脱することなく、様々な形態で省略、置換、変更されてもよい。例えば、上記実施形態の構成要件は、その効果を損なわない範囲内で、任意に組み合わせることが可能である。また、当該任意の組み合せからは、組み合わせにかかるそれぞれの構成要件についての作用及び効果が当然に得られるとともに、本明細書の記載から当業者には明らかな他の作用及び他の効果が得られる。 The embodiments disclosed herein are illustrative in all respects and are not restrictive. The above-described embodiments may be omitted, replaced, or modified in various forms without departing from the scope of the appended claims and the configurations and gist of the present invention as described below. For example, the constituent features of the above embodiments can be combined arbitrarily within a range that does not impair the effects. Further, from the arbitrary combination, the functions and effects of the respective constituent elements related to the combination can be obtained as a matter of course, and other functions and other effects that are obvious to a person skilled in the art from the description of this specification can be obtained. .
　また、本明細書に記載された効果は、あくまで説明的又は例示的なものであって、限定的ではない。つまり、本発明に係る技術は、上記の効果とともに、又は、上記の効果に代えて、本明細書の記載から当業者には明らかな他の効果を奏しうる。 Furthermore, the effects described in this specification are merely explanatory or illustrative, and are not limiting. In other words, the technology according to the present invention can produce other effects that are obvious to those skilled in the art from the description of this specification, in addition to or in place of the above effects.
　なお、以下のような構成も、本発明の技術的範囲に属する。
（１）
　正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池であって、
　前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板が用いられており、
　前記収容ケースには、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが存在しており、
　前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する皮膜部を有する、リチウムイオン電池。
（２）
　前記皮膜部における、前記Ｃａ化合物、前記Ａｌ化合物及び前記Ｌａ化合物の合計付着量は、前記Ｃａ化合物の場合は金属Ｃａ換算、前記Ａｌ化合物の場合は金属Ａｌ換算、前記Ｌａ化合物の場合は金属Ｌａ換算で、０．００１ｇ／ｍ２以上１０００．０００ｇ／ｍ２以下である、（１）に記載のリチウムイオン電池。
（３）
　前記皮膜部において、前記Ｃａ化合物、前記Ａｌ化合物及びＬａ化合物は、樹脂中に分散している、（１）又は（２）に記載のリチウムイオン電池。
（４）
　前記Ｃａ化合物は、炭酸カルシウム、酸化カルシウム、又は、水酸化カルシウムの少なくとも何れかであり、
　前記Ａｌ化合物は、炭酸アルミニウム、酸化アルミニウム、又は、水酸化アルミニウムの少なくとも何れかであり、
　前記Ｌａ化合物は、炭酸ランタン、酸化ランタン、又は、水酸化ランタンである、（１）～（３）の何れか１つに記載のリチウムイオン電池。
（５）
　前記Ｃａ化合物のうち金属Ｃａ換算で８０質量％以上は、水酸化カルシウムである、（１）～（４）の何れか１つに記載のリチウムイオン電池。
（６）
　前記皮膜部は、前記Ｃａ化合物、前記Ａｌ化合物又は前記Ｌａ化合物として、ふっ化物を更に含有する、（１）～（５）の何れか１つに記載のリチウムイオン電池。
（７）
　前記ふっ化物は、前記皮膜部の表面側よりも、前記Ｎｉめっき鋼板又は前記ラミネート鋼板を構成する前記母材鋼板との界面側により多く存在する、（６）に記載のリチウムイオン電池。
（８）
　前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、（６）又は（７）に記載のリチウムイオン電池。
（９）
　前記第１封止部、及び、前記第２封止部は、溶接、又は、かしめで構成されている、（
１）～（８）の何れか１つに記載のリチウムイオン電池。
（１０）
　正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池の製造方法であって、
　前記リチウムイオン電池は、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが形成されるものであり、
　前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板を用い、
　前記電池ユニットと前記電解液とが収容された前記収容ケースについて、前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部、を封止して、前記第１封止部及び前記第２封止部とする封止工程と、
　前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部の封止後に、前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する塗料を塗布する塗布工程と、
を含む、リチウムイオン電池の製造方法。
（１１）
　前記封止工程は、露点－７５℃以下の雰囲気下で実施される、（１０）に記載のリチウムイオン電池の製造方法。 Note that the following configurations also belong to the technical scope of the present invention.
(1)
A lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid,
As the material of the storage case, a Ni-plated steel plate in which a Ni plating layer is provided on a base steel plate, or a laminated steel plate in which a surface treatment layer is provided on a base steel plate, is used,
The accommodation case includes a first sealing part that is a sealing part between the main body part and the lid part, or an inlet provided in the lid part for injecting the electrolyte into the interior of the accommodation case. At least one of a liquid injection port for sealing the liquid port and a second sealing portion that is a sealing portion with the lid portion is present,
A film portion containing at least one of a Ca compound, an Al compound, or a La compound is provided on a portion of the first sealing portion or the second sealing portion in which the content of Fe is 80% by mass or more. , lithium-ion battery.
(2)
The total adhesion amount of the Ca compound, the Al compound, and the La compound in the film portion is calculated in terms of metal Ca in the case of the Ca compound, metal Al in the case of the Al compound, and metal La in the case of the La compound. The lithium ion battery according to (1), which is 0.001 g/m 2 or more and 1000.000 g/m 2 or less in terms of conversion.
(3)
The lithium ion battery according to (1) or (2), wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in the resin.
(4)
The Ca compound is at least one of calcium carbonate, calcium oxide, or calcium hydroxide,
The Al compound is at least one of aluminum carbonate, aluminum oxide, or aluminum hydroxide,
The lithium ion battery according to any one of (1) to (3), wherein the La compound is lanthanum carbonate, lanthanum oxide, or lanthanum hydroxide.
(5)
The lithium ion battery according to any one of (1) to (4), wherein 80% by mass or more of the Ca compound in terms of metallic Ca is calcium hydroxide.
(6)
The lithium ion battery according to any one of (1) to (5), wherein the film portion further contains a fluoride as the Ca compound, the Al compound, or the La compound.
(7)
The lithium ion battery according to (6), wherein the fluoride is present in a larger amount on the interface side with the base steel sheet constituting the Ni-plated steel sheet or the laminated steel sheet than on the surface side of the coating portion.
(8)
The lithium ion battery according to (6) or (7), wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
(9)
The first sealing part and the second sealing part are constructed by welding or caulking (
The lithium ion battery according to any one of 1) to (8).
(10)
A method for manufacturing a lithium ion battery, in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid, the method comprising:
The lithium ion battery may include a first sealing portion that is a sealing portion between the main body portion and the lid portion, or an injection hole provided in the lid portion for injecting the electrolyte into the inside of the storage case. At least one of a liquid injection port for sealing the liquid port and a second sealing part that is a sealing part with the lid part is formed,
As the material of the storage case, a Ni-plated steel plate in which a Ni-plated layer is provided on the base steel plate, or a laminated steel plate in which the base steel plate is provided with a surface treatment layer,
Regarding the storage case in which the battery unit and the electrolyte are stored, the main body and the lid, and the liquid injection port and the lid are sealed, and the first sealing part and the lid are sealed. A sealing step as a second sealing part;
After sealing the main body part and the lid part, and the liquid injection port and the lid part, on a part where the content of Fe is 80% by mass or more in the first sealing part or the second sealing part. a coating step of applying a paint containing at least one of a Ca compound, an Al compound, or a La compound;
A method for manufacturing a lithium ion battery, including:
(11)
The method for manufacturing a lithium ion battery according to (10), wherein the sealing step is performed in an atmosphere with a dew point of −75° C. or lower.
　　　１　　リチウムイオン電池
　　　３　　電池ユニット
　　　５　　電解液
　　１０　　収容ケース
　　１１　　本体部
　　１３、１３Ａ　　蓋部
　　１５　　注液口
　　１７　　注液口蓋
　　２１　　第１封止部
　　２３　　第２封止部
　　３０　　皮膜部
　１００　　Ｎｉめっき鋼板
　１００Ａ　　ラミネート鋼板
　１００Ｂ　　表面処理鋼板
　１０１　　母材鋼板
　１０３　　Ｎｉめっき層
　１０５　　表面処理層
　２０１　　被覆対象部位
　２０３　　封止
  1 Lithium ion battery 3 Battery unit 5 Electrolyte 10 Storage case 11 Main body 13, 13A Lid 15 Liquid inlet 17 Liquid inlet cover 21 First sealing part 23 Second sealing part 30 Film part 100 Ni-plated steel plate 100A Laminate Steel plate 100B Surface treated steel plate 101 Base steel plate 103 Ni plating layer 105 Surface treatment layer 201 Part to be covered 203 Sealing

Claims (17)

  1. 　正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池であって、
    　前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板が用いられており、
    　前記収容ケースには、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが存在しており、
    　前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する皮膜部を有する、リチウムイオン電池。     A lithium ion battery in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid,
    As the material of the storage case, a Ni-plated steel plate in which a Ni plating layer is provided on a base steel plate, or a laminated steel plate in which a surface treatment layer is provided on a base steel plate, is used,
    The accommodation case includes a first sealing part that is a sealing part between the main body part and the lid part, or an inlet provided in the lid part for injecting the electrolyte into the interior of the accommodation case. At least one of a liquid injection port for sealing the liquid port and a second sealing portion that is a sealing portion with the lid portion is present,
    A film portion containing at least one of a Ca compound, an Al compound, or a La compound is provided on a portion of the first sealing portion or the second sealing portion in which the content of Fe is 80% by mass or more. , lithium-ion battery.
  2. 　前記皮膜部における、前記Ｃａ化合物、前記Ａｌ化合物及び前記Ｌａ化合物の合計付着量は、前記Ｃａ化合物の場合は金属Ｃａ換算、前記Ａｌ化合物の場合は金属Ａｌ換算、前記Ｌａ化合物の場合は金属Ｌａ換算で、０．００１ｇ／ｍ２以上１０００．０００ｇ／ｍ２以下である、請求項１に記載のリチウムイオン電池。 The total adhesion amount of the Ca compound, the Al compound, and the La compound in the film portion is calculated in terms of metal Ca in the case of the Ca compound, metal Al in the case of the Al compound, and metal La in the case of the La compound. The lithium ion battery according to claim 1, which is 0.001 g/m 2 or more and 1000.000 g/m 2 or less in terms of conversion.
  3. 　前記皮膜部において、前記Ｃａ化合物、前記Ａｌ化合物及びＬａ化合物は、樹脂中に分散している、請求項１に記載のリチウムイオン電池。 The lithium ion battery according to claim 1, wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in a resin.
  4. 　前記皮膜部において、前記Ｃａ化合物、前記Ａｌ化合物及びＬａ化合物は、樹脂中に分散している、請求項２に記載のリチウムイオン電池。 The lithium ion battery according to claim 2, wherein in the film portion, the Ca compound, the Al compound, and the La compound are dispersed in a resin.
  5. 　前記Ｃａ化合物は、炭酸カルシウム、酸化カルシウム、又は、水酸化カルシウムの少なくとも何れかであり、
    　前記Ａｌ化合物は、炭酸アルミニウム、酸化アルミニウム、又は、水酸化アルミニウムの少なくとも何れかであり、
    　前記Ｌａ化合物は、炭酸ランタン、酸化ランタン、又は、水酸化ランタンである、請求項１～４の何れか１項に記載のリチウムイオン電池。     The Ca compound is at least one of calcium carbonate, calcium oxide, or calcium hydroxide,
    The Al compound is at least one of aluminum carbonate, aluminum oxide, or aluminum hydroxide,
    The lithium ion battery according to claim 1, wherein the La compound is lanthanum carbonate, lanthanum oxide, or lanthanum hydroxide.
  6. 　前記Ｃａ化合物のうち金属Ｃａ換算で８０質量％以上は、水酸化カルシウムである、請求項５に記載のリチウムイオン電池。 The lithium ion battery according to claim 5, wherein 80% by mass or more of the Ca compound in terms of metallic Ca is calcium hydroxide.
  7. 　前記皮膜部は、前記Ｃａ化合物、前記Ａｌ化合物又は前記Ｌａ化合物として、ふっ化物を更に含有する、請求項５に記載のリチウムイオン電池。 The lithium ion battery according to claim 5, wherein the film portion further contains a fluoride as the Ca compound, the Al compound, or the La compound.
  8. 　前記皮膜部は、前記Ｃａ化合物、前記Ａｌ化合物又は前記Ｌａ化合物として、ふっ化物を更に含有する、請求項６に記載のリチウムイオン電池。 The lithium ion battery according to claim 6, wherein the film further contains a fluoride as the Ca compound, the Al compound, or the La compound.
  9. 　前記ふっ化物は、前記皮膜部の表面側よりも、前記Ｎｉめっき鋼板又は前記ラミネート鋼板を構成する前記母材鋼板との界面側により多く存在する、請求項７に記載のリチウムイオン電池。 The lithium ion battery according to claim 7, wherein the fluoride is present in a larger amount on the interface side with the base steel sheet forming the Ni-plated steel sheet or the laminated steel sheet than on the surface side of the coating portion.
  10. 　前記ふっ化物は、前記皮膜部の表面側よりも、前記Ｎｉめっき鋼板又は前記ラミネート鋼板を構成する前記母材鋼板との界面側により多く存在する、請求項８に記載のリチウムイオン電池。 The lithium ion battery according to claim 8, wherein the fluoride is present in a larger amount on the interface side with the base steel sheet forming the Ni-plated steel sheet or the laminated steel sheet than on the surface side of the coating portion.
  11. 　前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、請求項７に記載のリチウムイオン電池。 The lithium ion battery according to claim 7, wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
  12. 　前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、請求項８に記載のリチウムイオン電池。 The lithium ion battery according to claim 8, wherein the amount of the fluoride attached is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
  13. 　前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、請求項９に記載のリチウムイオン電池。 The lithium ion battery according to claim 9, wherein the amount of the fluoride adhered is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
  14. 　前記ふっ化物の付着量は、ふっ素換算で、０ｇ／ｍ２超０．２００ｇ／ｍ２以下である、請求項１０に記載のリチウムイオン電池。 The lithium ion battery according to claim 10, wherein the amount of the fluoride adhered is more than 0 g/m 2 and less than 0.200 g/m 2 in terms of fluorine.
  15. 　前記第１封止部、及び、前記第２封止部は、溶接、又は、かしめで構成されている、請求項１に記載のリチウムイオン電池。 The lithium ion battery according to claim 1, wherein the first sealing part and the second sealing part are constructed by welding or caulking.
  16. 　正極、負極及びセパレータを有する電池ユニットと、リチウム塩を含む電解液とが、本体部と蓋部とを有する収容ケースの内部に収容されたリチウムイオン電池の製造方法であって、
    　前記リチウムイオン電池は、前記本体部と前記蓋部との封止部である第１封止部、又は、前記蓋部に設けられた前記電解液を前記収容ケースの内部に注入するための注液口を封止するための注液口蓋と、前記蓋部との封止部である第２封止部、の少なくとも何れかが形成されるものであり、
    　前記収容ケースの素材として、母材鋼板にＮｉめっき層が設けられたＮｉめっき鋼板、又は、母材鋼板に表面処理層が設けられたラミネート鋼板を用い、
    　前記電池ユニットと前記電解液とが収容された前記収容ケースについて、前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部、を封止して、前記第１封止部及び前記第２封止部とする封止工程と、
    　前記本体部と前記蓋部、及び、前記注液口蓋と前記蓋部の封止後に、前記第１封止部又は前記第２封止部においてＦｅの含有量が８０質量％以上である部分上に、Ｃａ化合物、Ａｌ化合物、又は、Ｌａ化合物の少なくとも何れかを含有する塗料を塗布する塗布工程と、
    を含む、リチウムイオン電池の製造方法。     A method for manufacturing a lithium ion battery, in which a battery unit having a positive electrode, a negative electrode, and a separator, and an electrolyte containing a lithium salt are housed inside a housing case having a main body and a lid, the method comprising:
    The lithium ion battery may include a first sealing portion that is a sealing portion between the main body portion and the lid portion, or an injection hole provided in the lid portion for injecting the electrolyte into the inside of the storage case. At least one of a liquid injection port for sealing the liquid port and a second sealing part that is a sealing part with the lid part is formed,
    As the material of the storage case, a Ni-plated steel plate in which a Ni-plated layer is provided on the base steel plate, or a laminated steel plate in which the base steel plate is provided with a surface treatment layer,
    Regarding the storage case in which the battery unit and the electrolyte are stored, the main body and the lid, and the liquid injection port and the lid are sealed, and the first sealing part and the lid are sealed. A sealing step as a second sealing part;
    After sealing the main body part and the lid part, and the liquid injection port and the lid part, on a part where the content of Fe is 80% by mass or more in the first sealing part or the second sealing part. a coating step of applying a paint containing at least one of a Ca compound, an Al compound, or a La compound;
    A method for manufacturing a lithium ion battery, including:
  17. 　前記封止工程は、露点－７５℃以下の雰囲気下で実施される、請求項１６に記載のリチウムイオン電池の製造方法。
          The method for manufacturing a lithium ion battery according to claim 16, wherein the sealing step is performed in an atmosphere with a dew point of −75° C. or lower.
PCT/JP2023/033546 2022-09-15 2023-09-14 Lithium ion battery and method for producing lithium ion battery WO2024058247A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004220863A (en) * 2003-01-10 2004-08-05 Sony Corp Battery and its manufacturing method
JP2012186007A (en) * 2011-03-04 2012-09-27 Sumitomo Electric Ind Ltd Electrical part, nonaqueous electrolyte battery, and lead wire and sealing container therefor
JP2013008691A (en) * 2009-03-02 2013-01-10 Lg Chem Ltd Pouch and secondary battery comprising the same
WO2014054406A1 (en) * 2012-10-02 2014-04-10 スリーボンドファインケミカル株式会社 Sealant composition for nonaqueous electrolyte cell

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004220863A (en) * 2003-01-10 2004-08-05 Sony Corp Battery and its manufacturing method
JP2013008691A (en) * 2009-03-02 2013-01-10 Lg Chem Ltd Pouch and secondary battery comprising the same
JP2012186007A (en) * 2011-03-04 2012-09-27 Sumitomo Electric Ind Ltd Electrical part, nonaqueous electrolyte battery, and lead wire and sealing container therefor
WO2014054406A1 (en) * 2012-10-02 2014-04-10 スリーボンドファインケミカル株式会社 Sealant composition for nonaqueous electrolyte cell

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