WO2021145345A1 - 非水電解質二次電池、集電体、及びこれらの製造方法 - Google Patents
非水電解質二次電池、集電体、及びこれらの製造方法 Download PDFInfo
- Publication number
- WO2021145345A1 WO2021145345A1 PCT/JP2021/000883 JP2021000883W WO2021145345A1 WO 2021145345 A1 WO2021145345 A1 WO 2021145345A1 JP 2021000883 W JP2021000883 W JP 2021000883W WO 2021145345 A1 WO2021145345 A1 WO 2021145345A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- current collector
- resin film
- electrode current
- negative electrode
- conductive layer
- Prior art date
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/665—Composites
- H01M4/667—Composites in the form of layers, e.g. coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/661—Metal or alloys, e.g. alloy coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/668—Composites of electroconductive material and synthetic resins
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/70—Carriers or collectors characterised by shape or form
-
- 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
- H01M50/121—Organic 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
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/411—Organic material
- H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
-
- 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
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/531—Electrode connections inside a battery casing
- H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
-
- 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 non-aqueous electrolyte secondary battery, a current collector, and a method for producing these.
- Non-aqueous electrolyte secondary batteries represented by lithium ion secondary batteries have high energy density, excellent storage performance, low temperature operability, etc., and are widely used in portable electronic devices such as mobile phones and laptop computers. ..
- the size of batteries has been increased so that they can be used in transportation equipment such as automobiles, and they are also being used as storage devices for nighttime electric power and electric power generated by natural energy power generation.
- Patent Document 1 describes a multi-layered negative electrode current collector in which copper metal plating layers are formed on both sides of a plastic thin film via adhesive reinforcement layers and antioxidant layers are provided on the surfaces of these copper metal plating layers. ing.
- this negative electrode current collector by applying this negative electrode current collector to a non-aqueous electrolyte secondary battery, the energy density can be improved, the copper metal plating layer can be suppressed from falling off, and its oxidation can also be performed. It is said that the cost can be reduced because the copper metal plating layer can be formed into a thin film.
- the non-aqueous electrolyte secondary battery can maintain sufficient battery performance even when stored at high temperature. Characteristics are required. However, when stored at a high temperature, the battery cell expands due to the influence of gas or the like generated from the electrolytic solution or the like, and the battery element is easily damaged or misaligned, resulting in deterioration of battery performance. Further, since the non-aqueous electrolyte secondary battery is used by repeating charging and discharging many times, it is strongly required to extend the life of the battery performance (improve the cycle characteristics).
- a further object of the present invention is to provide each method for producing the non-aqueous electrolyte secondary battery and the current collector.
- the present inventors have focused on the structure of the current collector and attempted to solve the above problems.
- a resin film on which an ultrathin layered conductive layer having a specific thickness is fixed is applied, and then each current collector of positive and negative electrodes is applied.
- the battery performance of the obtained non-aqueous electrolyte secondary battery is less likely to deteriorate even if it is stored for a long period of time at high temperatures, resulting in cycle characteristics. Also found that it could be excellent.
- the present invention has been further studied and completed.
- a positive electrode current collector having a resin film and a conductive layer arranged on one side of the resin film, and a positive electrode having a positive electrode active material layer in contact with the positive electrode current collector
- a negative electrode current collector having a resin film and a conductive layer arranged on one side of the resin film, and a negative electrode having a negative electrode active material layer in contact with the negative electrode current collector
- a non-aqueous electrolyte secondary battery having a separator arranged between the positive electrode and the negative electrode.
- At least one of the positive electrode current collector and the negative electrode current collector has a thickness of 10 to 1000 nm, and the conductive layer is adhered to the resin film.
- the periphery of the resin film of the positive electrode current collector and the periphery of the resin film of the negative electrode current collector are overlapped and welded, and a non-aqueous electrolyte is contained in the inside surrounded by these resin films.
- Water electrolyte secondary battery [2] The non-aqueous electrolyte secondary battery according to [1], wherein the thickness of the resin film to which the conductive layer having a thickness of 10 to 1000 nm is adhered is 20 ⁇ m or less.
- a method for producing a non-aqueous electrolyte secondary battery which comprises arranging the current collector according to any one of [6] to [9] as at least one of the positive electrode current collector and the negative electrode current collector.
- the method for producing a non-aqueous electrolyte secondary battery according to [11] which includes.
- a method for manufacturing a current collector for a secondary battery which comprises forming a conductive layer having a thickness of 10 to 1000 nm on one side of a resin film by vapor deposition or plating on a portion excluding the periphery of the resin film.
- the numerical range represented by using “-” means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.
- the “non-aqueous electrolyte” means an electrolyte that is substantially free of water. That is, the “non-aqueous electrolyte” may contain a small amount of water as long as it does not interfere with the effects of the present invention.
- the “non-aqueous electrolyte” has a water concentration of 200 ppm (mass basis) or less, preferably 100 ppm or less, and more preferably 20 ppm or less.
- non-aqueous electrolyte in the present invention includes a non-aqueous electrolyte solution having ionic conductivity such as lithium ions, a solid electrolyte, and the like.
- non-aqueous electrolyte secondary battery broadly includes a secondary battery using a non-aqueous electrolyte.
- the non-aqueous electrolyte secondary battery of the present invention does not easily deteriorate in battery performance even when stored at a high temperature for a long period of time, and has excellent cycle characteristics.
- the current collector of the present invention is suitable as a current collector of the non-aqueous electrolyte secondary battery of the present invention. According to the method for producing a non-aqueous electrolyte secondary battery of the present invention, it is possible to obtain a non-aqueous electrolyte secondary battery that does not easily deteriorate in battery performance even when stored at a high temperature for a long period of time and has excellent cycle characteristics. According to the method for producing a current collector of the present invention, a current collector suitable for use in the non-aqueous electrolyte secondary battery of the present invention can be obtained.
- FIG. 1 is a vertical cross-sectional view schematically showing a basic laminated structure of a non-aqueous electrolyte secondary battery.
- FIG. 2 is a vertical cross-sectional view schematically showing an embodiment of the non-aqueous electrolyte secondary battery of the present invention.
- the non-aqueous electrolyte secondary battery of the present invention has a configuration including a positive electrode, a negative electrode, and a separator arranged between the positive electrode and the negative electrode.
- the positive electrode has a positive electrode current collector and a positive electrode active material layer in contact with the positive electrode current collector
- the negative electrode has a negative electrode current collector and a negative electrode active material layer in contact with the negative electrode current collector.
- both the positive electrode current collector and the negative electrode current collector have a resin film and a conductive layer arranged on one side thereof
- the positive electrode current collector and the negative electrode current collector have a conductive layer arranged on one side thereof.
- At least one of the conductive layers has a thickness of 10 to 1000 nm, and at least one of the conductive layers is fixed to the surface of the resin film.
- the fact that the conductive layer is "fixed" to the resin film means that the conductive layer is not simply arranged on the resin film but is fixed on the surface of the resin film. That is, it does not mean that a metal foil is arranged on the resin film, but a state in which the conductive layer is bonded to the resin film by vapor deposition, plating, or the like.
- the conductive layer is preferably a thin-film film formed by thin-film deposition.
- the thickness of each layer such as the constituent layer of the non-aqueous electrolyte secondary battery and the constituent layer of the current collector is randomly set at 100 points in the cross-sectional observation (electron microscope observation) of each layer in the stacking direction. Is measured and used as the arithmetic mean of those 100 measurements.
- the periphery of the resin film of the positive electrode current collector and the periphery of the resin film of the negative electrode current collector are overlapped and welded, and the inside surrounded by these resin films is not welded.
- the periphery of the resin film of the positive electrode current collector and the periphery of the resin film of the negative electrode current collector can be directly overlapped with each other.
- the "periphery" of the resin film means the outer circumference of the surface of the resin film and its vicinity.
- the width of the "peripheral" portion of the resin film is 1-50 mm.
- the non-aqueous electrolyte secondary battery of the present invention adopts the configuration of a normal non-aqueous electrolyte secondary battery except that the electrolyte is sealed by the configuration of the current collector and the welding of the resin film constituting the current collector. can do.
- FIG. 1 is a cross-sectional view schematically showing a laminated structure of a general non-aqueous electrolyte secondary battery 10 including an operating electrode when operating as a battery.
- the non-aqueous electrolyte secondary battery 10 has a laminated structure having a negative electrode current collector 1, a negative electrode active material layer 2, a separator 3, a positive electrode active material layer 4, and a positive electrode current collector 5 in this order when viewed from the negative electrode side. ing.
- the negative electrode active material layer and the positive electrode active material layer are filled with a non-aqueous electrolyte (not shown) and separated by a separator 3.
- the separator 3 has holes and functions as a positive / negative electrode separation membrane that insulates between the positive and negative electrodes while allowing electrolytes and ions to pass through in a normal battery use state.
- the negative electrode current collector 1 and the negative electrode active material layer 2 are collectively referred to as a negative electrode
- the positive electrode active material layer 4 and the positive electrode current collector 5 are collectively referred to as a positive electrode.
- the non-aqueous electrolyte secondary battery 20 of the present invention has a negative electrode current collector 23 having a resin film 21 and a conductive layer 22 arranged on one side of the resin film 21, and a negative electrode current collector 23.
- the positive electrode 30 composed of the positive electrode active material layer 29 arranged in contact with each other is laminated so as to face each other via the separator 31.
- Tabs (conductive wiring for connecting electrodes to external circuits) 32 and 33 are connected to the conductive layer 22 of the negative electrode current collector 23 and the conductive layer 27 of the positive electrode current collector 28, respectively.
- the conductive layer 22 does not exist around the surface of the resin film 21 on which the conductive layer 22 is arranged. Therefore, before the production of the non-aqueous electrolyte secondary battery, the periphery of the resin film 21 of the negative electrode current collector 23 is a resin film. The surface of 21 is exposed. Further, the conductive layer 27 does not exist around the surface of the resin film 26 on which the conductive layer 27 is arranged. Therefore, before the production of the non-aqueous electrolyte secondary battery, the periphery of the resin film 26 of the positive electrode current collector 28 is The surface of the resin film 26 is exposed. The exposed portion may be provided with an easily peelable mask or the like before welding. Therefore, as shown in FIG.
- the non-aqueous electrolyte secondary battery of the present invention is welded by directly superimposing the periphery of the resin film 21 and the resin film 26 (if necessary, after peeling off the mask or the like). can do.
- an electrolyte (not shown) can be contained in the inside surrounded by these resin films, and a non-aqueous electrolyte secondary battery can be obtained.
- Welding can be performed by, for example, heat, ultrasonic waves, or the like, and heat welding is preferable.
- At least one conductive layer of the positive electrode current collector and the negative electrode current collector has a thickness of 10 to 1000 nm, and the conductive layer is fixed to the resin film.
- a current collector in which a conductive layer having a thickness of 10 to 1000 nm is adhered to a resin film is referred to as a "current collector (Z)" in the present specification.
- both the positive electrode current collector and the negative electrode current collector are current collectors (Z).
- the materials, electrolytes, members, etc. used in the non-aqueous electrolyte secondary battery of the present invention are not particularly limited except for the configuration of the current collector. As these materials, members and the like, those used for ordinary non-aqueous electrolyte secondary batteries can be appropriately applied.
- the method for producing the non-aqueous electrolyte secondary battery of the present invention is also a usual method except that the non-aqueous electrolyte is contained by the configuration of the current collector and the welding of the resin film constituting the current collector. Can be appropriately adopted.
- Japanese Patent Application Laid-Open No. 2016-201308, Japanese Patent Application Laid-Open No. 2005-108835, Japanese Patent Application Laid-Open No. 2012-185938 and the like can be appropriately referred to.
- the current collector (Z) which is a characteristic configuration of the non-aqueous electrolyte secondary battery of the present invention, will be described below.
- the constituent material of the resin film is not particularly limited, and an electronically insulating resin can be preferably used.
- an electronically insulating resin can be preferably used.
- polyester resin, polyolefin resin, polyimide resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin and the like can be mentioned, and it is preferable to use one or more of the polyester resin and the polyolefin resin, and the ease of welding is easy. From the viewpoint of the above, it is more preferable to use a polyolefin resin.
- polystyrene resin examples include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymerized polypropylene, block copolymerized polypropylene, homopolyprolene, polybutene, and polymethylpentene.
- Ethylene-vinyl acetate copolymer, ionomer resin ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, etc.
- polyethylene or polypropylene is preferable, and polyethylene is more preferable.
- the resin film may have a single-layer structure or a multi-layer structure.
- the resin film has a multi-layer structure, for example, it is on the electrode active material layer side (positive electrode active material layer side or negative electrode active material layer side, and is synonymous with the conductive layer side. )
- the resin film can have a laminated structure of polyester resin and polyethylene resin, and at the final stage of battery production, a polyethylene resin layer constituting the resin film of the positive current collector and a resin film of the negative negative current collector are formed.
- the resin film can have a battery sealing function.
- the thickness of the resin film can be appropriately set as long as the effect of the present invention is not impaired. From the viewpoint of improving storage characteristics and cycle characteristics, for example, it can be 50 ⁇ m or less, more preferably 40 ⁇ m or less, further preferably 30 ⁇ m or less, further preferably 25 ⁇ m or less, and 20 ⁇ m or less. Is particularly preferable.
- the thickness of the resin film is usually 1 ⁇ m or more, may be 2 ⁇ m or more, is preferably 5 ⁇ m or more, and is preferably 7 ⁇ m or more.
- the electron conductivity at the interface between the conductive layer is preferably at most 1 ⁇ 10 5 S (Siemens) / m. Further, the entire resin film, it is also preferred electron conductivity is not more than 1 ⁇ 10 5 S / m. This electron conductivity is at a temperature of 25 ° C.
- the conductive layer is a layer exhibiting electronic conductivity, and is usually composed of a metal material.
- the metal material is not particularly limited, and a known metal material applicable to the current collector of the non-aqueous electrolyte secondary battery can be widely applied.
- the conductive layer preferably contains aluminum, and more preferably is composed of aluminum or an aluminum alloy.
- the conductive layer may be configured to include a metal material such as titanium, stainless steel, or nickel, or an alloy thereof.
- the conductive layer preferably contains at least one of copper and nickel, and more preferably composed of copper or a copper alloy, or nickel or a nickel alloy. ..
- the conductive layer is preferably formed into a thin layer having a thickness of 10 to 1000 nm by vapor deposition (preferably physical vapor deposition), sputtering, plating (preferably electroless plating) or the like.
- the thickness of the conductive layer is preferably 100 to 900 nm, more preferably 120 to 800 nm, further preferably 150 to 800 nm, further preferably 200 to 700 ⁇ m, and even more preferably 250 to 650 nm. Is particularly preferred.
- the thickness of the conductive layer is preferably 100 to 1000 nm, preferably 200 to 1000 nm, and preferably 300 to 1000 nm.
- the thickness of the conductive layer 22 of the positive electrode current collector is set to 150 to 800 nm (preferably 200 to 700 nm, more preferably 250 to 650 nm). Thereby, the cycle characteristics can be further improved. Similarly, if the thickness of the conductive layer of the positive electrode current collector is constant in each battery, the thickness of the conductive layer 22 of the negative electrode current collector is 150 to 800 nm (preferably 200 to 700 nm, more preferably 250 to 650 nm). ), The cycle characteristics can be further enhanced.
- the above-mentioned current collector (Z) is arranged as at least one of the positive electrode current collector and the negative electrode current collector, and the periphery of the resin film of both current collectors is placed around each other. It can be produced by a conventional method except that it is welded in layers and a non-aqueous electrolyte is sealed inside surrounded by a resin film.
- the positive electrode current collector and the negative electrode current collector when both the positive electrode current collector and the negative electrode current collector are current collectors (Z), the positive electrode current collector and the negative electrode current collector may be the same or different from each other. ..
- the conductive layer of the positive electrode current collector and the conductive layer of the negative electrode current collector are made of different metal materials. Is also preferable.
- the preferable constituent materials of each conductive layer of the positive electrode and the negative electrode are as described above.
- the resin film to which the conductive layer is fixed also functions as a battery sealing film (a film for encapsulating the non-aqueous electrolyte), and the pressure rises when the battery is stored at a high temperature.
- the laminated structure of the battery elements is less likely to shift due to swelling and contraction of the active material due to repeated charging and discharging, and the desired battery performance can be stably and continuously exhibited.
- the positive electrode current collector or the negative electrode current collector when the positive electrode current collector or the negative electrode current collector is not composed of the current collector (Z), the positive electrode current collector or the negative electrode current collector is not the current collector (Z).
- the structure of the body is not particularly limited as long as it has a conductive layer on the surface of the resin film as a support and the resin film can be welded to the resin film of the current collector (Z).
- the preferred form of the resin film of the positive electrode current collector or the negative electrode current collector that is not the current collector (Z) is the same as the preferred form of the resin film described in the current collector (Z).
- the conductive layer of the positive electrode current collector or the negative electrode current collector which is not the current collector (Z) may be a metal foil, a vapor-deposited film having a thickness of more than 1000 nm, or the like.
- the metal foil does not adhere to the resin film, but by using the other current collector as the current collector (Z), the effect of the present invention is compared with the case where both current collectors are metal foils. Can be enjoyed. This also applies when the conductive layer of the positive electrode current collector or the negative electrode current collector is a vapor-deposited film having a thickness of more than 1000 nm.
- the non-aqueous electrolyte secondary battery of the present invention is, for example, a laptop computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a cordless phone slave unit, a pager, a handy terminal, a mobile fax, a mobile copy, a mobile printer, a headphone.
- Can be installed in electronic devices such as stereos, video movies, LCD TVs, handy cleaners, portable CDs, mini discs, electric shavers, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, memory cards, etc. can.
- ⁇ Preparation of slurry for forming positive electrode active material layer Prepare a slurry containing 85 parts by mass of lithium iron phosphate (LiFePO 4 , also referred to as LFP) as a positive electrode active material, 10 parts by mass of acetylene black as a conductive auxiliary agent, and 5 parts by mass of PVDF (polyvinylidene fluoride) as a binder. Then, it was prepared as a slurry for forming a positive electrode active material layer.
- LiFePO 4 lithium iron phosphate
- acetylene black as a conductive auxiliary agent
- PVDF polyvinylidene fluoride
- PVDF was dissolved in N-methylpyrrolidone (NMP) at a concentration of 8% by mass
- NMP N-methylpyrrolidone
- acetylene black was added to 22.5 g of the obtained solution
- a rotation / revolution mixer (trade name: foaming kneading) was added.
- Mixing was performed at 2000 rpm for 3 minutes using Taro ARE-310 (manufactured by Shinky).
- 16 g of NMP and 30 g of lithium iron phosphate were added and mixed at 2000 rpm for 3 minutes, and further 18 g of NMP was added and mixed at 2000 rpm for 3 minutes to obtain a slurry for forming a positive electrode active material layer.
- ⁇ Preparation of slurry for forming negative electrode active material layer Prepare a slurry containing 95 parts by mass of graphite (artificial graphite) as a negative electrode active material, 3 parts by mass of SBR (styrene-butadiene rubber) as a binder, and 2 parts by mass of CMC (carboxymethyl cellulose) for forming a negative electrode active material layer. It was made into a slurry. Specifically, 40 g of graphite was added to 40 g of a 1.5 mass% CMC aqueous solution, and the mixture was mixed at 2000 rpm for 3 minutes using a rotation / revolution mixer (trade name: Awatori Rentaro ARE-310, manufactured by Shinky Co., Ltd.).
- ⁇ Separator> A polypropylene separator (thickness 20 ⁇ m, porosity 48%, porosity 30 nm) was used.
- the non-aqueous electrolyte secondary battery shown in FIG. 2 was produced.
- -Preparation of positive electrode current collector Using a polyethylene resin film (electron conductivity: 1 ⁇ 10 5 S / m or less) having a thickness of 15 ⁇ m, a length of 80 mm, and a width of 80 mm as the resin film, the periphery (width 10 mm) of the conductive layer forming surface of this film is made of polyimide. After masking with a tape, aluminum was fixed on this surface by a physical vapor deposition method so as to have a thickness of 1 ⁇ m to form a conductive layer. In this way, a positive electrode current collector was obtained.
- the slurry for forming the positive electrode active material layer was applied onto the aluminum conductive layer of the positive electrode current collector obtained above and dried to form a positive electrode active material layer having a thickness of 100 ⁇ m. Then, the polyimide tape was peeled off to obtain a positive electrode.
- non-aqueous electrolyte secondary batteries The obtained positive electrode and negative electrode were laminated via the separator so that the active material layers faced each other, and wiring (tab) was connected to the conductive layer of each current collector to draw out the wiring.
- the electrolytic solution was impregnated between the positive electrode and the negative electrode, and the periphery of the polyethylene resin film of the positive electrode current collector and the periphery of the polyethylene resin film of the negative electrode current collector were overlapped and heat-welded. In this way, a non-aqueous electrolyte secondary battery containing an electrolytic solution inside surrounded by welding of two polyethylene resin films was obtained.
- the obtained non-aqueous electrolyte secondary battery is charged at 25 ° C. at a current value of 25 mA and a final voltage of 3.6 V, and then charged and discharged once at a current value of 25 mA and a final voltage of 2.0 V. Used for.
- Example 2 Example 3, Example 4, Example 5
- the non-water used in the following test examples is the same as in Example 1 except that the thickness of the conductive layer formed by physical vapor deposition of aluminum is as shown in the table below. An electrolyte secondary battery was obtained.
- Example 6 In the production of the negative electrode current collector of Example 1, the non-water used in the following test examples is the same as in Example 1 except that the thickness of the conductive layer formed by physical vapor deposition of copper is as shown in the table below. An electrolyte secondary battery was obtained.
- Example 8 In the production of the negative electrode current collector of Example 1, a non-aqueous electrolyte secondary battery used in the following test examples was obtained in the same manner as in Example 1 except that the conductive layer was formed by physical vapor deposition of nickel.
- Example 9 Example 10, Example 11, Example 12
- the non-water used in the following test examples is the same as in Example 8 except that the thickness of the conductive layer formed by physical vapor deposition of aluminum is as shown in the table below. An electrolyte secondary battery was obtained.
- Example 13 In the preparation of the slurry for forming the positive electrode active material layer of Example 1, LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) was used as the positive electrode active material in the same manner as in Example 1. , A non-aqueous electrolyte secondary battery used in the following test examples was obtained.
- Example 14 In the preparation of the positive electrode current collector of Example 1, a polyethylene resin film having a thickness of 50 ⁇ m as a resin film (electron conductivity: 1 ⁇ 10 5 S / m or less) except for the use of, in the same manner as in Example 1 , A non-aqueous electrolyte secondary battery used in the following test examples was obtained.
- Example 15 In the production of the negative electrode current collector of Example 1, a non-aqueous electrolyte secondary battery used in the following test examples was obtained in the same manner as in Example 1 except that the conductive layer was formed by electroless plating of nickel. ..
- Example 16 In the production of the negative electrode current collector of Example 1, the non-water used in the following test examples is the same as in Example 1 except that the thickness of the conductive layer formed by physical vapor deposition of copper is as shown in the table below. An electrolyte secondary battery was obtained.
- the obtained positive electrode and negative electrode were laminated via the separator so that the active material layers faced each other, and wiring (tab) was connected to the conductive layer of each current collector to draw out the wiring. And impregnated with the electrolyte solution between the positive electrode and the negative electrode, a polyethylene resin film having a thickness of 15 [mu] m (Electronic conductivity: 1 ⁇ 10 5 S / m or less) by using the cathode current collector and the anode current collector The entire laminate was sealed from the outside of the above-mentioned electrolyte solution to obtain a non-aqueous electrolyte secondary battery. Next, charging and discharging were carried out in the same manner as in Example 1 to obtain a non-aqueous electrolyte secondary battery used in the following test examples.
- Comparative Example 2 In Comparative Example 1, aluminum was fixed to a polyethylene resin film (electron conductivity: 1 ⁇ 10 5 S / m or less) having a thickness of 15 ⁇ m as a positive electrode current collector by physical vapor deposition so as to have a thickness of 5 ⁇ m.
- a non-aqueous electrolyte secondary battery used in the following test examples was obtained in the same manner as in Comparative Example 1 except that the one having the conductive layer formed was used.
- the battery was discharged to a final voltage of 2.0 V at a current value of 25 mA.
- the battery was charged at a current value of 50 mA and a final voltage of 3.6 V, and discharged at a current value of 50 mA and a final voltage of 2.0 V.
- OCV Preservation characterization criteria
- Discharge capacity retention rate is 95% or more
- E Discharge capacity retention rate is less than 50%
- the battery was charged with a current value of 50 mA and a final voltage of 3.6 V, and then discharged with a current value of 50 mA and a final voltage of 2.0 V.
- discharge capacity retention rate (%) was calculated by the following formula, and the cycle characteristics were evaluated by applying the following evaluation criteria.
- Discharge capacity retention rate (%) 100 x [Discharge capacity after 500 cycles] / [Reference discharge capacity] -Evaluation criteria for cycle characteristics- A: Discharge capacity retention rate is 90% or more B: Discharge capacity retention rate is 80% or more and less than 90% C: Discharge capacity retention rate is 60% or more and less than 80% D: Discharge capacity retention rate is 50% or more and less than 60% E : Discharge capacity retention rate is less than 50% The results are shown in the table below.
- the non-aqueous electrolyte secondary battery in which the current collector (Z) is not used for both the positive and negative electrodes, the battery expands and electrolyzes when the charged battery is stored at a high temperature for a long period of time. A liquid leak occurred.
- the non-aqueous electrolyte secondary batteries of the present invention using the current collector (Z) as the current collector do not easily deteriorate the battery performance even when stored at high temperature for a long period of time, and have excellent cycle characteristics. (Examples 1 to 16).
- Non-aqueous electrolyte secondary battery 1 Negative electrode current collector 2 Negative electrode active material layer 3 Separator 4 Positive electrode active material layer 5 Positive electrode current collector 6 Operating part (light bulb) 20 Non-aqueous electrolyte secondary battery 21, 26 Resin film 22, 27 Conductive layer 23 Negative electrode current collector 24 Negative electrode active material layer 25 Negative electrode 28 Positive electrode current collector 29 Positive electrode active material layer 30 Positive electrode 31 Separator 32, 33 tab
Abstract
Description
また、非水電解質二次電池は充放電を何度も繰り返して使用されるものであるから、電池性能の長寿命化(サイクル特性の向上)も強く求められている。しかし、充放電の繰り返し数(サイクル数)が数百回に達する間には、徐々にガスが発生したり、充放電に伴う活物質の膨張と収縮の影響を繰り返し受けたりするために、やはり電池要素が破損したり位置ずれを生じたりして、電池性能を持続的に、十分に高いレベルで維持することは難しい。
本発明はこれらの知見に基づきさらに検討を重ねて完成されるに至ったものである。
〔1〕
樹脂フィルムとこの樹脂フィルムの片面に配された導電層とを有する正極集電体と、この正極集電体に接する正極活物質層とを有する正極と、
樹脂フィルムとこの樹脂フィルムの片面に配された導電層とを有する負極集電体と、この負極集電体に接する負極活物質層とを有する負極と、
上記正極と上記負極との間に配されたセパレータと
を有する非水電解質二次電池であって、
上記正極集電体及び上記負極集電体の少なくとも一方の導電層が厚さ10~1000nmであり、この導電層は上記樹脂フィルムに固着してなり、
上記正極集電体の上記樹脂フィルムの周囲と上記負極集電体の上記樹脂フィルムの周囲とが重なり溶着されて、これらの樹脂フィルムに囲まれた内部に非水電解質を含有してなる、非水電解質二次電池。
〔2〕
上記の厚さ10~1000nmの導電層が固着している樹脂フィルムの厚さが20μm以下である、〔1〕に記載の非水電解質二次電池。
〔3〕
上記の厚さ10~1000nmの導電層が固着している樹脂フィルムの導電層との界面における電子伝導度が1×105S/m以下である、〔1〕又は〔2〕に記載の非水電解質二次電池。
〔4〕
上記正極集電体の導電層がアルミニウムを含み、上記負極集電体の導電層が銅及びニッケルから選ばれる少なくとも1種を含む、〔1〕~〔3〕のいずれかに記載の非水電解質二次電池。
〔5〕
上記の樹脂フィルムに固着している厚さ10~1000nmの導電層が蒸着膜である、〔1〕~〔4〕のいずれかに記載の非水電解質二次電池。
〔6〕
樹脂フィルムとこの樹脂フィルムの片面に固着された導電層とを有し、この導電層の厚さが10~1000nmである、集電体。
〔7〕
上記樹脂フィルムの厚さが20μm以下である、〔6〕に記載の集電体。
〔8〕
上記導電層が蒸着膜である、〔6〕又は〔7〕に記載の集電体。
〔9〕
上記樹脂フィルムの周囲には上記導電層が配されていない、〔6〕~〔8〕のいずれかに記載の集電体。
〔10〕
正極集電体及び負極集電体の少なくとも一方の集電体として、〔6〕~〔9〕のいずれかに記載の集電体を配することを含む、非水電解質二次電池の製造方法。
〔11〕
正極集電体及び負極集電体として、〔6〕~〔9〕のいずれかに記載の集電体を配することを含む、〔10〕に記載の非水電解質二次電池の製造方法。
〔12〕
上記正極集電体の上記樹脂フィルムの周囲と上記負極集電体の上記樹脂フィルムの周囲とを重ねて溶着することにより、これらの樹脂フィルムに囲まれた内部に非水電解質を封入することを含む、〔11〕に記載の非水電解質二次電池の製造方法。
〔13〕
樹脂フィルムの片面上で、この樹脂フィルムの周囲を除いた部分に、蒸着又はメッキにより厚さ10~1000nmの導電層を形成することを含む、二次電池用集電体の製造方法。
本発明において「非水電解質」とは、水を実質的に含まない電解質を意味する。すなわち、「非水電解質」は本発明の効果を妨げない範囲で微量の水を含んでいてもよい。本発明において「非水電解質」は、水の濃度が200ppm(質量基準)以下であり、100ppm以下が好ましく20ppm以下がより好ましい。なお、非水電解質を完全に無水とすることは現実的に困難であり、通常は水が0.1ppm以上含まれる。
本発明における「非水電解質」は、リチウムイオン等のイオン伝導性を有する非水電解液、固体電解質等が含まれる。
本発明において「非水電解質二次電池」には、非水電解質を用いた二次電池が広く包含される。
本発明の集電体は、本発明の非水電解質二次電池の集電体として好適である。
本発明の非水電解質二次電池の製造方法によれば、高温下で長期保管しても電池性能が低下しにくく、サイクル特性にも優れた非水電解質二次電池を得ることができる。
本発明の集電体の製造方法によれば、本発明の非水電解質二次電池に用いるのに好適な集電体を得ることができる。
本発明の非水電解質二次電池は、正極と、負極と、正極と負極との間に配されたセパレータを含む構成を有する。正極は、正極集電体と、この正極集電体に接する正極活物質層とを有し、負極は、負極集電体と、この負極集電体に接する負極活物質層とを有する。
本発明の非水電解質二次電池は、正極集電体及び負極集電体の両方が、樹脂フィルムと、その片面に配された導電層とを有し、正極集電体及び負極集電体の少なくとも一方は導電層の厚さが10~1000nmであり、この少なくとも一方の導電層は樹脂フィルム表面に固着されている。
本発明において導電層が樹脂フィルムに「固着」されているとは、導電層が樹脂フィルム上に単に配されているのではなく、樹脂フィルム表面に固定化されていることを意味する。すなわち、樹脂フィルム上に金属箔を配したような形態ではなく、蒸着、メッキ処理等により導電層が樹脂フィルムに結合している状態を意味する。なかでも導電層は、蒸着により形成された蒸着膜であることが好ましい。
本発明において、非水電解質二次電池の構成層、集電体の構成層等の各層の厚さは、各層の積層方向の断面観察(電子顕微鏡観察)において、無作為に100か所について厚さを測定し、それら100の測定値の算術平均とする。
本発明において樹脂フィルムの「周囲」とは、樹脂フィルム表面の外周とその近傍を意味する。好ましくは、樹脂フィルムの「周囲」部分の幅は1~50mmである。
図1は、一般的な非水電解質二次電池10の積層構造を、電池として作動させる際の作動電極も含めて、模式化して示す断面図である。非水電解質二次電池10は、負極側からみて、負極集電体1、負極活物質層2、セパレータ3、正極活物質層4、正極集電体5を、この順に有する積層構造を有している。負極活物質層と正極活物質層との間は非水電解質(図示せず)で満たされ、かつセパレータ3で分断されている。セパレータ3は空孔を有し、通常の電池の使用状態では電解質及びイオンを透過しながら正負極間を絶縁する正負極分離膜として機能する。このような構造により、例えばリチウムイオン二次電池であれば、充電時には外部回路を通って負極側に電子(e-)が供給され、同時に電解液を介して正極からリチウムイオン(Li+)が移動してきて負極に蓄積される。一方、放電時には、負極に蓄積されたリチウムイオン(Li+)が電解質を介して正極側に戻され、作動部位6には電子が供給される。図示した例では、作動部位6に電球を採用しており、放電によりこれが点灯するようにされている。なお、セパレータ3を固体電解質で形成した形態とすることもできる。
本発明において、負極集電体1と負極活物質層2とを合わせて負極と称し、正極活物質層4と正極集電体5とを合わせて正極と称す。
図2に示すように、本発明の非水電解質二次電池20は、樹脂フィルム21と樹脂フィルム21の片面に配された導電層22とを有する負極集電体23と、負極集電体23に接して配された負極活物質層24とからなる負極25と、樹脂フィルム26と樹脂フィルム26の片面に配された導電層27とを有する正極集電体28と、正極集電体28に接して配された正極活物質層29とからなる正極30とが、セパレータ31を介して互いに対向して積層されている。
負極集電体23の導電層22と正極集電体28の導電層27には、それぞれタブ(電極を外部回路へと接続する導電性配線)32、33が接続される。
したがって、本発明の非水電解質二次電池は図2に示すように、樹脂フィルム21と樹脂フィルム26の各周囲を直に重ね合わせて(必要によりマスク等を剥離してから重ね合わせて)溶着することができる。この溶着により、これらの樹脂フィルムに囲まれた内部に電解質(図示せず)を含有させることができ、非水電解質二次電池を得ることができる。溶着は、例えば熱、超音波等により行うことができ、熱溶着が好ましい。
本発明の非水電解質二次電池は、正極集電体と負極集電体の両方が、集電体(Z)であることが好ましい。
本発明の非水電解質二次電池の特徴的な構成である集電体(Z)について以下に説明する。
-樹脂フィルム-
樹脂フィルムの構成材料に特に制限はなく、電子絶縁性樹脂を好適に用いることができる。例えば、ポリエステル樹脂、ポリオレフィン樹脂、ポリイミド樹脂、ポリテトラフルオロエチレン樹脂、ポリフッ化ビニリデン樹脂等を挙げることができ、ポリエステル樹脂及びポリオレフィン樹脂の1種又は2種以上を用いることが好ましく、溶着の簡便性の観点からポリオレフィン樹脂を用いることがより好ましい。
ポリオレフィン樹脂としては、例えば、低密度ポリエチレン、直鎖状低密度ポリエチレン、中密度ポリエチレン、高密度ポリエチレン、超低密度ポリエチレン、ランダム共重合ポリプロピレン、ブロック共重合ポリプロピレン、ホモポリプロレン、ポリブテン、ポリメチルペンテン、エチレン-酢酸ビニル共重合体、アイオノマー樹脂、エチレン-(メタ)アクリル酸共重合体、エチレン-(メタ)アクリル酸エステル共重合体、エチレン-ブテン共重合体、エチレン-ヘキセン共重合体等が挙げられる。なかでもポリエチレン又はポリプロピレンが好ましく、ポリエチレンがより好ましい。
例えば、樹脂フィルムをポリエステル樹脂とポリエチレン樹脂の積層構造とすることができ、電池作製の最終段階で、正極集電体の樹脂フィルムを構成するポリエチレン樹脂層と、負極集電体の樹脂フィルムを構成するポリエチレン樹脂層の周囲を互いに重ね合わせてヒートシール(熱溶着)することにより、内部に電解液が封入された非水電解質二次電池を得ることができる。すなわち、樹脂フィルムに電池の封止機能を持たせることができる。
導電層は、電子伝導性を示す層であり、通常は金属材料により構成される。この金属材料に特に制限はなく、非水電解質二次電池の集電体に適用可能な公知の金属材料を広く適用することができる。
集電体(Z)を負極集電体として用いる場合、導電層は銅及びニッケルの少なくとも1種を含むことが好ましく、銅もしくは銅合金、又はニッケルもしくはニッケル合金から構成されていることがより好ましい。
また、導電層の厚さは100~1000nmとすることも好ましく、200~1000nmとすることも好ましく、300~1000nmとすることも好ましい。
各電池において負極集電体の導電層の厚さが一定であれば、正極集電体の導電層22の厚さを150~800nm(好ましくは200~700nm、さらに好ましくは250~650nm)とすることにより、サイクル特性をより高めることができる。
同様に、各電池において正極集電体の導電層の厚さが一定であれば、負極集電体の導電層22の厚さを150~800nm(好ましくは200~700nm、さらに好ましくは250~650nm)とすることにより、サイクル特性をより高めることができる。
本発明の非水電解質二次電池は、導電層が固着された樹脂フィルムが電池の封止フィルム(非水電解質を封入するためのフィルム)としても機能し、電池の高温保管時の圧力上昇、充放電の繰り返しによる活物質の膨潤と収縮等によっても電池要素の積層構造にずれが生じにくく、所望の電池性能を安定的に、持続的に発現することができる。
金属箔は樹脂フィルムと固着するものではないが、もう一方の集電体を集電体(Z)とすることにより、両集電体をともに金属箔とした場合に比べて、本発明の効果を享受することができる。このことは、正極集電体又は負極集電体の導電層を、厚さ1000nmを越える蒸着膜等とした場合も同様である。
<非水電解質の調製>
エチレンカーボネート/エチルメチルカーボネート=1/2(質量比)の非水溶媒中に、リチウム塩としてLiPF6を1M濃度となるように溶解し、非水電解液を調製した。
正極活物質としてリン酸鉄リチウム(LiFePO4、LFPとも称す。)を85質量部、導電助剤としてアセチレンブラックを10質量部、バインダーとしてPVDF(ポリフッ化ビニリデン)を5質量部含有するスラリーを調製し、正極活物質層形成用スラリーとした。
具体的には、N-メチルピロリドン(NMP)にPVDFを8質量%の濃度で溶解し、得られた溶液22.5gにアセチレンブラックを3.6g加え、自転公転ミキサー(商品名:泡とり練太郎 ARE-310、シンキー社製)を用いて2000rpmで3分間混合した。ここに、NMP16gとリン酸鉄リチウム30gを追添し、2000rpmで3分間混合し、さらにNMP18gを添加して2000rpmで3分間混合することにより、正極活物質層形成用スラリーを得た。
負極活物質としてグラファイト(人造黒鉛)を95質量部、バインダーとしてSBR(スチレン・ブタジエンゴム)を3質量部、CMC(カルボキシメチルセルロース)を2質量部含有するスラリーを調製し、負極活物質層形成用スラリーとした。
具体的には、1.5質量%CMC水溶液40gにグラファイトを40g加え、自転公転ミキサー(商品名:泡とり練太郎 ARE-310、シンキー社製)を用いて2000rpmで3分間混合した。ここに、1.5質量%CMC水溶液18.7gと純水20gを追添し、2000rpmで3分間混合し、さらに40質量%SBR分散液3g(溶媒:水)を添加して2000rpmで3分間混合することにより、負極活物質層形成用スラリーを得た。
ポリプロピレン製セパレータ(膜厚20μm、気孔率48%、気孔径30nm)を用いた。
図2に示す非水電解質二次電池を作製した。
-正極集電体の作製-
樹脂フィルムとして厚さ15μm、縦80mm、横80mmのポリエチレン樹脂フィルム(電子伝導度:1×105S/m以下)を用いて、このフィルムの、導電層形成面の周囲(幅10mm)をポリイミドテープでマスクした後、この面上にアルミニウムを物理蒸着(physical vapor deposition)法により厚さ1μmとなるように固着させ、導電層を形成した。こうして正極集電体を得た。
上記で得られた正極集電体のアルミニウム導電層上に、上記正極活物質層形成用スラリーを塗工し、乾燥して、厚さ100μmの正極活物質層を形成した。次いでポリイミドテープを剥離して、正極を得た。
樹脂フィルムとして厚さ15μm、縦85mm、横85mmのポリエチレン樹脂フィルム(電子伝導度:1×105S/m以下)を用いて、このフィルムの、導電層形成面の周囲(幅10mm)をポリイミドテープでマスクした後、この面上に銅を物理蒸着(physical vapor deposition)法により厚さ1μmとなるように固着させ、導電層を形成した。こうして負極集電体を得た。
上記で得られた負極集電体の銅導電層上に、上記負極活物質層形成用スラリーを塗工し、乾燥して、厚さ100μmの負極活物質層を形成した。次いでポリイミドテープを剥離して、負極を得た。
得られた正極と負極とを、各活物質層同士が向かい合うように上記セパレータを介して積層し、各集電体の導電層に配線(タブ)を接続して配線を引き出した。正極と負極との間に上記電解液を浸み込ませて、正極集電体のポリエチレン樹脂フィルムの周囲と負極集電体のポリエチレン樹脂フィルムの周囲とを重ね合わせて熱溶着した。こうして、2枚のポリエチレン樹脂フィルムの溶着により囲まれた内部に電解液を含有してなる非水電解質二次電池を得た。
得られた非水電解質二次電池を25℃で、電流値25mA、終止電圧3.6Vで充電後、電流値25mA、終止電圧2.0Vで放電する充放電を1回行い、以降の試験例に用いた。
実施例1の正極集電体の作製において、アルミニウムの物理蒸着により形成する導電層の厚さを下表の通りとしてこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の負極集電体の作製において、銅の物理蒸着により形成する導電層の厚さを下表の通りとしてこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の負極集電体の作製において、導電層をニッケルの物理蒸着により形成したこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例8の正極集電体の作製において、アルミニウムの物理蒸着により形成する導電層の厚さを下表の通りとしてこと以外は、実施例8と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の正極活物質層形成用スラリーの調製において、正極活物質としてLiNi0.5Co0.2Mn0.3O2(NCM523)を用いたこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の正極集電体の作製において、樹脂フィルムとして厚さ50μmのポリエチレン樹脂フィルム(電子伝導度:1×105S/m以下)を用いたこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の負極集電体の作製において、導電層をニッケルの無電解メッキにより形成したこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
実施例1の負極集電体の作製において、銅の物理蒸着により形成する導電層の厚さを下表の通りとしてこと以外は、実施例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
厚さ20μmのアルミニウム箔を正極集電体とし、この正極集電体上に、上記正極活物質層形成用スラリーを塗工し、乾燥して、厚さ100μmの正極活物質層を形成し、正極を得た。
また、厚さ18μmの銅箔を負極集電体とし、この負極集電体上に、上記負極活物質層形成用スラリーを塗工し、乾燥して、厚さ100μmの負極活物質層を形成し、負極を得た。
得られた正極と負極とを、各活物質層同士が向かい合うように上記セパレータを介して積層し、各集電体の導電層に配線(タブ)を接続して配線を引き出した。正極と負極との間に上記電解液を浸み込ませて、厚さ15μmのポリエチレン樹脂フィルム(電子伝導度:1×105S/m以下)を用いて正極集電体と負極集電体の外側から積層体全体を封止することにより上記電解液を含有させ、非水電解質二次電池を得た。
次いで実施例1と同様にして充放電を行い、以降の試験例に用いる非水電解質二次電池を得た。
比較例1において、正極集電体として、厚さ15μmのポリエチレン樹脂フィルム(電子伝導度:1×105S/m以下)上に、物理蒸着によりアルミニウムを厚さ5μmとなるように固着させて導電層を形成したものを用いたこと以外は、比較例1と同様にして、以降の試験例に用いる非水電解質二次電池を得た。
上記で作製した各非水電解質二次電池を用いて、25℃で、電流値50mA、終止電圧3.6Vで充電し、その後、電流値50mA、終止電圧2.0Vで放電した。この放電時の放電容量を基準放電容量とした。
25℃で、電流値50mA、終止電圧3.6Vで充電した。この充電後の電池を50℃の恒温槽内で静置し、30日間放置した。その後、電池を25℃の恒温槽内に移し、電池の状態を観察した。
また、25℃の恒温槽内に移した電池に対して開回路電圧測定(OCV)を行った後、電流値25mAで終止電圧2.0Vまで放電した。
次いで、電流値50mA、終止電圧3.6Vで充電し、電流値50mA、終止電圧2.0Vで放電した。この放電時の放電容量(保存後放電容量)から、下記式により放電容量維持率(%)を算出した。
下記評価基準に当てはめ保存特性を評価した。
放電容量維持率(%)=100×[保存後放電容量]/[基準放電容量]
A:電池の状態に変化が認められない。
B:電池の状態に変化がほとんど認められない。
C:電池が明らかに膨張しているが電解液の漏出は認められない。
D:電池が明らかに膨張しており電解液の漏出も認められる。
(電解液の漏出を認めたものは、他の保存特性試験には付していない。)
A:OCVが2V以上
B:OCVが1.5V以上2V未満
C:OCVが1.5V未満
A:放電容量維持率が95%以上
B:放電容量維持率が90%以上95%未満
C:放電容量維持率が75%以上90%未満
D:放電容量維持率が50%以上75%未満
E:放電容量維持率が50%未満
結果を下表に示す。
上記で作製した各非水電解質二次電池を用いて、25℃で、電流値50mA、終止電圧3.6Vで充電し、その後、電流値50mA、終止電圧2.0Vで放電した。この放電時の放電容量を基準放電容量とした。
35℃の恒温槽に電池を移し、電流値50mA、終止電圧3.6Vで充電し、電流値50mA、終止電圧2.0Vで放電する充放電を1サイクルとし、この充放電を500サイクル繰り返した。その後、25℃で、電流値50mA、終止電圧3.6Vで充電し、次いで電流値50mA、終止電圧2.0Vで放電した。この放電時の放電容量(500サイクル後放電容量)から、下記式により放電容量維持率(%)を算出し、下記評価基準に当てはめサイクル特性を評価した。
放電容量維持率(%)=100×[500サイクル後放電容量]/[基準放電容量]
-サイクル特性の評価基準-
A:放電容量維持率が90%以上
B:放電容量維持率が80%以上90%未満
C:放電容量維持率が60%以上80%未満
D:放電容量維持率が50%以上60%未満
E:放電容量維持率が50%未満
結果を下表に示す。
1 負極集電体
2 負極活物質層
3 セパレータ
4 正極活物質層
5 正極集電体
6 作動部位(電球)
20 非水電解質二次電池
21、26 樹脂フィルム
22、27 導電層
23 負極集電体
24 負極活物質層
25 負極
28 正極集電体
29 正極活物質層
30 正極
31 セパレータ
32、33 タブ
Claims (13)
- 樹脂フィルムと該樹脂フィルムの片面に配された導電層とを有する正極集電体と、該正極集電体に接する正極活物質層とを有する正極と、
樹脂フィルムと該樹脂フィルムの片面に配された導電層とを有する負極集電体と、該負極集電体に接する負極活物質層とを有する負極と、
該正極と該負極との間に配されたセパレータと
を有する非水電解質二次電池であって、
前記正極集電体及び前記負極集電体の少なくとも一方の導電層が厚さ10~1000nmであり、該導電層は前記樹脂フィルムに固着してなり、
前記正極集電体の前記樹脂フィルムの周囲と前記負極集電体の前記樹脂フィルムの周囲とが重なり溶着されて、これらの樹脂フィルムに囲まれた内部に非水電解質を含有してなる、非水電解質二次電池。 - 前記の厚さ10~1000nmの導電層が固着している樹脂フィルムの厚さが20μm以下である、請求項1に記載の非水電解質二次電池。
- 前記の厚さ10~1000nmの導電層が固着している樹脂フィルムの該導電層との界面における電子伝導度が1×105S/m以下である、請求項1又は2に記載の非水電解質二次電池。
- 前記正極集電体の導電層がアルミニウムを含み、前記負極集電体の導電層が銅及びニッケルから選ばれる少なくとも1種を含む、請求項1~3のいずれか1項に記載の非水電解質二次電池。
- 前記の樹脂フィルムに固着している厚さ10~1000nmの導電層が蒸着膜である、請求項1~4のいずれか1項に記載の非水電解質二次電池。
- 樹脂フィルムと該樹脂フィルムの片面に固着された導電層とを有し、該導電層の厚さが10~1000nmである、集電体。
- 前記樹脂フィルムの厚さが20μm以下である、請求項6に記載の集電体。
- 前記導電層が蒸着膜である、請求項6又は7に記載の集電体。
- 前記樹脂フィルムの周囲には前記導電層が配されていない、請求項6~8のいずれか1項に記載の集電体。
- 正極集電体及び負極集電体の少なくとも一方の集電体として、請求項6~9のいずれか1項に記載の集電体を配することを含む、非水電解質二次電池の製造方法。
- 正極集電体及び負極集電体として、請求項6~9のいずれか1項に記載の集電体を配することを含む、請求項10に記載の非水電解質二次電池の製造方法。
- 前記正極集電体の前記樹脂フィルムの周囲と前記負極集電体の前記樹脂フィルムの周囲とを重ねて溶着することにより、これらの樹脂フィルムに囲まれた内部に非水電解質を封入することを含む、請求項11に記載の非水電解質二次電池の製造方法。
- 樹脂フィルムの片面上で、該樹脂フィルムの周囲を除いた部分に、蒸着又はメッキにより厚さ10~1000nmの導電層を形成することを含む、集電体の製造方法。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021571210A JP7386265B2 (ja) | 2020-01-17 | 2021-01-13 | 非水電解質二次電池、集電体、及びこれらの製造方法 |
KR1020227021037A KR20220104782A (ko) | 2020-01-17 | 2021-01-13 | 비수 전해질 이차 전지, 집전체, 및 이들의 제조 방법 |
CN202180007201.2A CN114830400A (zh) | 2020-01-17 | 2021-01-13 | 非水电解质二次电池、集电体及它们的制造方法 |
EP21740752.7A EP4092780A1 (en) | 2020-01-17 | 2021-01-13 | Non-aqueous electrolyte secondary battery, current collector and method for producing same |
US17/844,036 US20220328885A1 (en) | 2020-01-17 | 2022-06-19 | Non-aqueous electrolyte secondary battery, collector, method for manufacturing non-aqueous electrolyte secondary battery, and method for manufacturing collector |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2020006022 | 2020-01-17 | ||
JP2020-006022 | 2020-01-17 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US17/844,036 Continuation US20220328885A1 (en) | 2020-01-17 | 2022-06-19 | Non-aqueous electrolyte secondary battery, collector, method for manufacturing non-aqueous electrolyte secondary battery, and method for manufacturing collector |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2021145345A1 true WO2021145345A1 (ja) | 2021-07-22 |
Family
ID=76863803
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2021/000883 WO2021145345A1 (ja) | 2020-01-17 | 2021-01-13 | 非水電解質二次電池、集電体、及びこれらの製造方法 |
Country Status (6)
Country | Link |
---|---|
US (1) | US20220328885A1 (ja) |
EP (1) | EP4092780A1 (ja) |
JP (1) | JP7386265B2 (ja) |
KR (1) | KR20220104782A (ja) |
CN (1) | CN114830400A (ja) |
WO (1) | WO2021145345A1 (ja) |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63121244A (ja) * | 1986-11-11 | 1988-05-25 | Dainippon Printing Co Ltd | フレキシブル薄型電池 |
JPS63168964A (ja) * | 1986-12-29 | 1988-07-12 | Ricoh Co Ltd | 薄型電池および該電池を用いたカセツト電池 |
JP2734656B2 (ja) * | 1989-07-06 | 1998-04-02 | 株式会社ユアサコーポレーション | 電 池 |
JP2005108835A (ja) | 2003-09-26 | 2005-04-21 | Samsung Sdi Co Ltd | リチウムイオン二次電池 |
JP2012185938A (ja) | 2011-03-03 | 2012-09-27 | Sharp Corp | 非水系二次電池 |
WO2013027306A1 (ja) * | 2011-08-22 | 2013-02-28 | パナソニック株式会社 | 薄型二次電池 |
JP2016201308A (ja) | 2015-04-13 | 2016-12-01 | 富士フイルム株式会社 | 非水電解液および非水二次電池 |
JP2018524759A (ja) | 2015-06-18 | 2018-08-30 | 24エム・テクノロジーズ・インコーポレイテッド24M Technologies, Inc. | シングルパウチバッテリセル及びその製造方法 |
JP2020006022A (ja) | 2018-07-11 | 2020-01-16 | 株式会社カプコン | ゲームシステム |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2000306611A (ja) | 1999-04-21 | 2000-11-02 | Mitsubishi Materials Corp | シート状電池 |
JP5148902B2 (ja) | 2007-03-16 | 2013-02-20 | 日本電信電話株式会社 | 全固体型リチウム二次電池製造方法および全固体型リチウム二次電池 |
CN102971816B (zh) | 2010-06-28 | 2015-10-07 | 株式会社村田制作所 | 蓄电设备及其制造方法 |
WO2018056307A1 (ja) | 2016-09-20 | 2018-03-29 | マクセルホールディングス株式会社 | 空気電池およびパッチ |
JP2019057473A (ja) | 2017-09-22 | 2019-04-11 | セイコーインスツル株式会社 | 電気化学セル |
-
2021
- 2021-01-13 WO PCT/JP2021/000883 patent/WO2021145345A1/ja unknown
- 2021-01-13 JP JP2021571210A patent/JP7386265B2/ja active Active
- 2021-01-13 EP EP21740752.7A patent/EP4092780A1/en active Pending
- 2021-01-13 CN CN202180007201.2A patent/CN114830400A/zh active Pending
- 2021-01-13 KR KR1020227021037A patent/KR20220104782A/ko unknown
-
2022
- 2022-06-19 US US17/844,036 patent/US20220328885A1/en active Pending
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63121244A (ja) * | 1986-11-11 | 1988-05-25 | Dainippon Printing Co Ltd | フレキシブル薄型電池 |
JPS63168964A (ja) * | 1986-12-29 | 1988-07-12 | Ricoh Co Ltd | 薄型電池および該電池を用いたカセツト電池 |
JP2734656B2 (ja) * | 1989-07-06 | 1998-04-02 | 株式会社ユアサコーポレーション | 電 池 |
JP2005108835A (ja) | 2003-09-26 | 2005-04-21 | Samsung Sdi Co Ltd | リチウムイオン二次電池 |
JP2012185938A (ja) | 2011-03-03 | 2012-09-27 | Sharp Corp | 非水系二次電池 |
WO2013027306A1 (ja) * | 2011-08-22 | 2013-02-28 | パナソニック株式会社 | 薄型二次電池 |
JP2016201308A (ja) | 2015-04-13 | 2016-12-01 | 富士フイルム株式会社 | 非水電解液および非水二次電池 |
JP2018524759A (ja) | 2015-06-18 | 2018-08-30 | 24エム・テクノロジーズ・インコーポレイテッド24M Technologies, Inc. | シングルパウチバッテリセル及びその製造方法 |
JP2020006022A (ja) | 2018-07-11 | 2020-01-16 | 株式会社カプコン | ゲームシステム |
Also Published As
Publication number | Publication date |
---|---|
KR20220104782A (ko) | 2022-07-26 |
JP7386265B2 (ja) | 2023-11-24 |
US20220328885A1 (en) | 2022-10-13 |
CN114830400A (zh) | 2022-07-29 |
EP4092780A1 (en) | 2022-11-23 |
JPWO2021145345A1 (ja) | 2021-07-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5541957B2 (ja) | 積層型二次電池 | |
JP2011065984A (ja) | 非水系電解液二次電池用セパレータ及び非水系電解液二次電池 | |
KR20060111839A (ko) | 초고용량 캐패시터을 구비하는 전극 조립체 및 이를포함하는 리튬 이차 전지 | |
KR102103378B1 (ko) | 가스 흡착제가 포함되어 있는 전극 리드를 구비한 전지셀 | |
US20220336820A1 (en) | Non-aqueous electrolyte secondary battery, collector, and method for manufacturing non-aqueous electrolyte secondary battery | |
US9099252B2 (en) | Apparatus and associated methods | |
JP6062668B2 (ja) | 二次電池及び二次電池モジュール | |
US20140370379A1 (en) | Secondary battery and manufacturing method thereof | |
JPH1173943A (ja) | 非水系電解液二次電池 | |
JP7246196B2 (ja) | 全固体リチウム二次電池 | |
JP2011222128A (ja) | 二次電池 | |
JP2011198600A (ja) | 電池用電極板およびそれを用いた電池 | |
WO2021145345A1 (ja) | 非水電解質二次電池、集電体、及びこれらの製造方法 | |
JP2014165054A (ja) | 非水電解質二次電池 | |
JP6178183B2 (ja) | 非水電解質電池、組電池及び蓄電池装置 | |
WO2021235154A1 (ja) | 二次電池 | |
JP2013118058A (ja) | 蓄電デバイス | |
WO2022000329A1 (zh) | 一种电化学装置及电子装置 | |
JP6953982B2 (ja) | 電気化学デバイス及び電気化学デバイスパック | |
JP2016207447A (ja) | 非水電解液二次電池 | |
JPH11121040A (ja) | リチウム二次電池 | |
JP2000323173A (ja) | 非水電解液二次電池 | |
JP4040264B2 (ja) | 電極体の評価方法 | |
WO2022196616A1 (ja) | 電極およびその製造方法、ならびに電池 | |
WO2023243554A1 (ja) | 二次電池用電極および二次電池 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21740752 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2021571210 Country of ref document: JP Kind code of ref document: A |
|
ENP | Entry into the national phase |
Ref document number: 20227021037 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2021740752 Country of ref document: EP Effective date: 20220817 |