WO2023188062A1 - Groupe d'électrodes, batterie secondaire et bloc-batterie - Google Patents

Groupe d'électrodes, batterie secondaire et bloc-batterie Download PDF

Info

Publication number
WO2023188062A1
WO2023188062A1 PCT/JP2022/015801 JP2022015801W WO2023188062A1 WO 2023188062 A1 WO2023188062 A1 WO 2023188062A1 JP 2022015801 W JP2022015801 W JP 2022015801W WO 2023188062 A1 WO2023188062 A1 WO 2023188062A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
electrode
active material
containing layer
electrode structure
Prior art date
Application number
PCT/JP2022/015801
Other languages
English (en)
Japanese (ja)
Inventor
佑磨 菊地
龍之介 宍戸
祐輝 渡邉
智裕 望月
Original Assignee
株式会社 東芝
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社 東芝 filed Critical 株式会社 東芝
Priority to PCT/JP2022/015801 priority Critical patent/WO2023188062A1/fr
Publication of WO2023188062A1 publication Critical patent/WO2023188062A1/fr

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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • 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
    • 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
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • 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
    • H01M50/443—Particulate 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
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • 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
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • 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

  • Embodiments of the present invention relate to an electrode group, a secondary battery, and a battery pack.
  • a porous separator is placed between the positive electrode and the negative electrode to avoid contact between the positive electrode and the negative electrode.
  • a self-supporting membrane separate from the positive and negative electrodes is used as the separator.
  • An example of this is a microporous membrane made of polyolefin resin.
  • Such a separator is produced, for example, by extruding a melt containing a polyolefin resin composition into a sheet, extracting and removing substances other than the polyolefin resin, and then stretching the sheet.
  • Separators made of resin films need to have mechanical strength so as not to break during battery production, so it is difficult to make them thinner than a certain point. Since the positive electrode and the negative electrode are stacked or wound with a separator interposed therebetween, if the separator is thick, the number of layers of the positive electrode and negative electrode that can be stored per unit volume of the battery is limited. As a result, battery capacity decreases. In addition, separators made of resin films have poor durability, and when used in secondary batteries, the separators deteriorate due to repeated charging and discharging, resulting in a decrease in battery cycleability.
  • the present invention was made in view of the above circumstances, and provides an electrode group having excellent insulation, a secondary battery including this electrode group, and a battery pack including this secondary battery.
  • an electrode group includes a first electrode structure and a second electrode structure at least partially facing the first electrode structure.
  • the first electrode structure includes a first current collector, a first active material-containing layer provided on at least one surface of the first current collector, and inorganic particles. and a first film provided in the first film.
  • the second electrode structure includes a second current collector, a second active material-containing layer provided on at least one surface of the second current collector, and an organic material; and a second film provided on.
  • a volume-based frequency distribution chart obtained by laser diffraction scattering has two peaks.
  • a secondary battery that includes the electrode group according to the embodiment and an electrolyte.
  • a battery pack including the secondary battery according to the embodiment is provided.
  • FIG. 1 is a cross-sectional view showing an example of an electrode group according to an embodiment.
  • FIG. 2 is a perspective view showing a first electrode structure included in the electrode group shown in FIG. 1;
  • FIG. 2 is a perspective view showing a second electrode structure included in the electrode group shown in FIG. 1;
  • FIG. 7 is a perspective view showing another example of the first electrode structure.
  • FIG. 3 is a cross-sectional view showing another example of the electrode group according to the embodiment.
  • FIG. 6 is a perspective view showing the first electrode structure of the electrode group shown in FIG. 5;
  • FIG. 7 is a perspective view showing another example of the first electrode structure.
  • FIG. 3 is a cross-sectional view showing another example of the electrode group according to the embodiment.
  • FIG. 1 is a schematic diagram showing one step in a method for manufacturing an electrode group according to an embodiment.
  • FIG. 10 is a perspective view showing the coating apparatus shown in FIG. 9;
  • FIG. 1 is a schematic diagram of one step in a method for manufacturing a laminate according to an embodiment.
  • FIG. 1 is a partially cutaway perspective view showing an example of a secondary battery according to an embodiment.
  • FIG. 6 is an exploded view of another example of the secondary battery according to the embodiment.
  • FIG. 1 is an exploded perspective view schematically showing an example of a battery pack according to an embodiment.
  • 15 is a block diagram showing an example of an electric circuit of the battery pack shown in FIG. 14.
  • FIG. 3 is a particle size distribution chart related to the first film included in the electrode group manufactured in Example 1.
  • an electrode group includes a first electrode structure and a second electrode structure at least partially facing the first electrode structure.
  • the first electrode structure includes a first current collector, a first active material-containing layer provided on at least one surface of the first current collector, and inorganic particles. and a first film provided in the first film.
  • the second electrode structure includes a second current collector, a second active material-containing layer provided on at least one surface of the second current collector, and an organic material; and a second film provided on.
  • a volume-based frequency distribution chart obtained by laser diffraction scattering has two peaks.
  • the present inventors have achieved excellent insulation properties even with a thin inorganic particle layer. I found out that it shows.
  • FIG. 1 is a cross-sectional view schematically showing an example of an electrode group according to an embodiment.
  • FIG. 2 is a perspective view showing the first electrode structure 1 included in the electrode group 10 shown in FIG.
  • FIG. 3 is a perspective view showing the second electrode structure 2 included in the electrode group shown in FIG.
  • the electrode group shown in FIG. 1 includes a first electrode structure 1 and a second electrode structure 2.
  • the first electrode structure 1 includes a first current collector 1a, a first active material-containing layer 1b provided on at least one surface of the first current collector 1a, and inorganic particles. and a first film 4 provided on the substance-containing layer 1b.
  • the first current collector 1a and the first active material-containing layer 1b may constitute a first electrode.
  • the first current collector 1a is a conductive sheet.
  • a part of the first current collector 1a may be a first current collecting tab 1c on which the first active material-containing layer 1b is not supported.
  • the first current collector tab 1c is formed, for example, on one side of the first current collector 1a to have a substantially constant width along a direction parallel to the side.
  • an XYZ orthogonal coordinate system is adopted as shown in the drawings.
  • the Z axis in the drawing is a direction parallel to the lamination direction of the first electrode structure 1 and the second electrode structure 2.
  • the X axis is a direction parallel to the direction in which the first current collecting tab 1c projects from the first electrode structure 1.
  • the Y-axis is a direction perpendicular to the X-axis and the Z-axis.
  • the first active material-containing layer 1b may be formed, for example, on at least a portion of at least one surface of the first current collector 1a.
  • the first active material-containing layer 1b has, for example, a sheet shape having a first surface 40 and a first back surface 41.
  • the first surface 40 and the first back surface 41 may be main surfaces of the first active material-containing layer 1b.
  • the first back surface 41 is in contact with the first current collector 1a.
  • the first surface 40 is in contact with the first membrane 4 .
  • the first film 4 may be formed, for example, on at least a portion of the main surface (first surface 40) of the first active material-containing layer 1b.
  • the first film 4 may be formed over the entire main surface of the first active material-containing layer 1b.
  • the first film 4 may have a sheet shape having a front surface A and a back surface B.
  • the back surface B of the first film 4 covers the first surface 40 of the first active material-containing layer 1b.
  • the second electrode structure 2 includes a second current collector 2a, a second active material-containing layer 2b provided on at least one surface of the second current collector 2a, and an organic material. and a second film 5 provided on the substance-containing layer 2b.
  • the second current collector 2a and the second active material-containing layer 2b may constitute a second electrode.
  • the second current collector 2a is a conductive sheet.
  • a part of the second current collector 2a may be a second current collecting tab 2c on which the second active material-containing layer 2b is not supported.
  • the second current collector tab 2c is formed, for example, on one side of the second current collector 2a with a substantially constant width along a direction parallel to the side.
  • the second active material-containing layer 2b may be formed, for example, on at least a portion of at least one surface of the second current collector 2a.
  • the second active material-containing layer 2b has, for example, a sheet shape having a second surface 42 and a second back surface 43.
  • the second surface 42 and the second back surface 43 may be the main surfaces of the second active material-containing layer 2b.
  • the second back surface 43 is in contact with the second current collector 2a.
  • the second surface 42 is in contact with the second film 5.
  • the second film 5 includes a second surface 42 of the second active material-containing layer 2b, four side surfaces 44 orthogonal to the second surface 42, and one of the four side surfaces of the second current collector 2a. , covering the three end surfaces 45 exposed on the surface of the second electrode structure 2 and the portion 46 including the boundary with the second active material-containing layer 2b on both main surfaces of the second current collecting tab 2c. There is.
  • the second film 5 has a front surface C and a back surface D. The back surface D of the second film 5 is in contact with the second active material containing layer 2b.
  • the second film 5 includes a boundary between the end surface 45 of the second current collector 2a and the second active material-containing layer 2b on the surface of the second current collector tab 2c.
  • the portion 46 is covered, internal short circuits due to contact between the first electrode structure and the second electrode structure 2 are reduced.
  • the first film 4 and the second film 5 can constitute a separator.
  • the surface A of the first film 4 and the surface C of the second film 5 can be in contact with each other.
  • the first active material containing layer 1b and the second active material containing layer 2b are opposed to each other, for example, with the first film 4 and the second film 5 interposed therebetween. At least a portion of the first active material-containing layer 1b and the second active material-containing layer may be opposed to each other with the first film 4 and the second film 5 interposed therebetween, and the entire surface thereof may be opposed to the first film 4. and may be opposed to each other with the second film 5 interposed therebetween.
  • first and second current collector tabs are not limited to one side of the first and second current collectors, respectively, on which no active material-containing layer is supported.
  • a plurality of strips protruding from one side of the first and second current collectors can be used as the first and second current collection tabs.
  • FIG. FIG. 4 shows another example of the first electrode structure 1.
  • a plurality of strips protruding from one side of the first current collector 1a may be used as the first current collector tab 1c.
  • first electrode structure and second electrode structure One of the first electrode structure and the second electrode structure may function as a positive electrode, and the other may function as a negative electrode.
  • the opposite pole of the first electrode structure is the second electrode structure.
  • the first electrode structure is a positive electrode structure
  • the second electrode structure is a negative electrode structure.
  • the first electrode structure may be a negative electrode structure
  • the second electrode structure may be a positive electrode structure.
  • the first electrode structure includes a porous first active material-containing layer having a first surface and a first back surface.
  • the second electrode structure includes a porous second active material-containing layer having a second surface and a second back surface.
  • the first electrode structure and the second electrode structure are stacked such that the first active material containing layer and the second active material containing layer thereof face each other.
  • the first film 4 and the second film 5 may be interposed between the first active material containing layer and the second active material containing layer.
  • the first electrode structure may further include a first current collector and a first current collection tab.
  • the second electrode structure may further include a second current collector and a second current collection tab.
  • the first active material-containing layer and the second active material-containing layer may be formed on both the main surfaces of the first current collector and the second current collector, respectively, but they can also be formed on only one surface. be.
  • a positive electrode active material and a negative electrode active material are used as the active materials contained in the first active material containing layer and the second active material containing layer.
  • the number of types of active materials can be one or more.
  • the active material included in the first active material-containing layer is referred to as a first active material.
  • the active material included in the second active material-containing layer is referred to as a second active material.
  • lithium transition metal composite oxide As the positive electrode active material, for example, a lithium transition metal composite oxide can be used.
  • lithium transition metal composite oxides include LiCoO 2 , LiNi 1-x Co x O 2 (0 ⁇ x ⁇ 0.3), LiMn x Ni y Co z O 2 (0 ⁇ x ⁇ 0.5, 0 ⁇ y ⁇ 0.5,0 ⁇ z ⁇ 0.5), LiMn 2-x M x O 4 (M is at least one element selected from the group consisting of Mg, Co, Al and Ni, 0 ⁇ x ⁇ 0.2), LiMPO 4 (M is at least one element selected from the group consisting of Fe, Co, and Ni), and the like.
  • lithium titanate As the negative electrode active material, carbon materials such as graphite, tin-silicon alloy materials, etc. can be used, but it is preferable to use lithium titanate. Further, titanium oxide or lithium titanate containing other metals such as (niobium)Nb may also be used as negative electrode active materials. Examples of lithium titanate include Li 4+x Ti 5 O 12 (0 ⁇ x ⁇ 3) having a spinel structure and Li 2+y Ti 3 O 7 (0 ⁇ y ⁇ 3) having a ramsteride structure. Can be mentioned.
  • carbon materials such as graphite, tin-silicon alloy materials, etc. can be used, but it is preferable to use titanium-containing oxides.
  • titanium-containing oxide lithium titanium composite oxide, niobium titanium composite oxide, sodium niobium titanium composite oxide, etc. can be used.
  • lithium titanium oxide examples include spinel structure lithium titanium oxide (for example, general formula Li 4+x Ti 5 O 12 (x is -1 ⁇ x ⁇ 3)), ramsdellite structure lithium titanium oxide (for example, Li 2+x Ti 3 O 7 (-1 ⁇ x ⁇ 3)), Li 1+x Ti 2 O 4 (0 ⁇ x ⁇ 1), Li 1.1+x Ti 1.8 O 4 (0 ⁇ x ⁇ 1), Li 1.07+x These include Ti 1.86 O 4 (0 ⁇ x ⁇ 1), Li x TiO 2 (0 ⁇ x ⁇ 1), and the like. Further, the lithium titanium oxide may be a lithium titanium composite oxide into which a different element is introduced.
  • Niobium titanium composite oxide is, for example, Li a TiM b Nb 2 ⁇ O 7 ⁇ (0 ⁇ a ⁇ 5, 0 ⁇ b ⁇ 0.3, 0 ⁇ 0.3, 0 ⁇ 0.3 , M is at least one element selected from the group consisting of Fe, V, Mo, and Ta).
  • the sodium titanium composite oxide has, for example, the general formula Li 2+V Na 2-W M1 X Ti 6-y-z Nb y M2 z O 14+ ⁇ (0 ⁇ v ⁇ 4, 0 ⁇ w ⁇ 2, 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 6, 0 ⁇ z ⁇ 3, -0.5 ⁇ 0.5, M1 includes at least one selected from Cs, K, Sr, Ba, Ca, M2 includes Zr, Sn,
  • the present invention includes an orthorhombic Na-containing niobium titanium composite oxide represented by V, Ta, Mo, W, Fe, Co, Mn, and Al.
  • the active material may be a single primary particle, a secondary particle that is an agglomeration of primary particles, or a mixture of primary particles and secondary particles.
  • the average particle size of the primary particles of the negative electrode active material is preferably within the range of 0.001 or more and 1 ⁇ m or less.
  • the average particle size can be determined, for example, by observing the negative electrode active material with a scanning electron microscope (SEM).
  • SEM scanning electron microscope
  • the particle shape may be either granular or fibrous. When it is fibrous, it is preferable that the fiber diameter is 0.1 ⁇ m or less.
  • the average particle diameter of the primary particles of the negative electrode active material can be measured from an image observed with a SEM. When lithium titanate having an average particle size of 1 ⁇ m or less is used as the negative electrode active material, a negative electrode active material-containing layer with a highly flat surface can be obtained.
  • the negative electrode potential becomes nobler than that of a lithium ion secondary battery using a general carbon negative electrode, so that lithium metal does not precipitate in principle. Since the negative electrode active material containing lithium titanate has small expansion and contraction due to charge/discharge reactions, it is possible to prevent the crystal structure of the active material from collapsing.
  • the first active material containing layer and the second active material containing layer may contain a binder and a conductive agent in addition to the active material.
  • the conductive agent include acetylene black, carbon black, graphite, or mixtures thereof.
  • the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, styrene-butadiene rubber, or mixtures thereof.
  • the binder has a function of binding the active material and the conductive agent.
  • the contents of the active material, conductive agent, and binder are 80% by mass or more and 97% by mass or less, 2% by mass or more and 18% by mass or less, and 1% by mass or more and 17% by mass or less, respectively. It is preferable that there be.
  • the contents of the negative electrode active material-containing layer are 70% by mass or more and 98% by mass or less, 1% by mass or more and 28% by mass or less, and 1% by mass or more and 28% by mass or less, respectively. It is preferable that there be.
  • the thickness of the first active material-containing layer and the second active material-containing layer may be 5 ⁇ m or more and 100 ⁇ m or less, respectively.
  • the first current collector and the second current collector may be conductive sheets.
  • conductive sheets include foils made of conductive materials.
  • conductive materials include aluminum and aluminum alloys.
  • the thickness of the first current collector and the second current collector may be 5 ⁇ m or more and 40 ⁇ m or less, respectively.
  • the first current collector tab and the second current collector tab may be made of the same material as each current collector, but a current collector tab made of a different material from each current collector is prepared, This may be connected to a current collector by welding or the like.
  • the first film contains inorganic particles.
  • the form of the inorganic particles may be, for example, granular or fibrous.
  • the first film may further include a binder.
  • the thickness of the first film is, for example, in the range of 1 ⁇ m to 5 ⁇ m, preferably in the range of 2 ⁇ m to 4 ⁇ m. If the thickness of the first film is too small, the positive and negative electrodes are likely to short-circuit, and the amount of self-discharge may increase, which is not preferable. On the other hand, if the first film is excessively thick, it is not preferable because there is a possibility that the battery capacity will decrease and the resistance will increase.
  • the thickness of the first film can be measured by scanning electron microscopy (SEM) observation, which will be described later.
  • the content of inorganic particles in the first film is preferably in the range of 80% by mass or more and 99.9% by mass or less. Thereby, the insulation properties of the first film can be increased.
  • inorganic materials constituting inorganic particles include oxides (e.g., Li 2 O, BeO, B 2 O 3 , Na 2 O, MgO, Al 2 O 3 , SiO 2 , P 2 O 5 , CaO, Cr).
  • oxides e.g., Li 2 O, BeO, B 2 O 3 , Na 2 O, MgO, Al 2 O 3 , SiO 2 , P 2 O 5 , CaO, Cr).
  • M is a metal atom such as Na, K, Ca, and Ba
  • n is a number corresponding to the charge of the metal cation Mn +
  • x and y is the number of moles of SiO 2 and H 2 O (2 ⁇ x ⁇ 10, 2 ⁇ y)
  • nitrides e.g.
  • BN silicon carbide
  • SiC zircon
  • ZrSiO 4 carbonates
  • carbonates e.g., MgCO 3 and CaCO 3 , etc.
  • sulfates e.g., CaSO 4 and BaSO 4 , etc.
  • complexes thereof e.g., steatite (MgO -SiO 2 ), forsterite (2MgO.SiO 2 ), cordierite (2MgO.2Al 2 O 3 .5SiO 2 )), tungsten oxide, or mixtures thereof.
  • Examples of other inorganic materials include barium titanate, calcium titanate, lead titanate, ⁇ -LiAlO 2 , LiTiO 3 , solid electrolytes or mixtures thereof.
  • solid electrolytes include solid electrolytes with no or low lithium ion conductivity, and solid electrolytes with lithium ion conductivity.
  • oxide particles with no or low lithium ion conductivity include lithium aluminum oxide (for example, LiAlO 2 , Li x Al 2 O 3 where 0 ⁇ x ⁇ 1), lithium silicon oxide, and lithium zirconium oxide. It will be done.
  • Examples of solid electrolytes having lithium ion conductivity include oxide solid electrolytes with a garnet type structure.
  • Oxide solid electrolytes with a garnet-type structure have the advantage of high reduction resistance and a wide electrochemical window.
  • Examples of oxide solid electrolytes with a garnet-type structure include La 5+x A x La 3-x M 2 O 12 (A is at least one element selected from the group consisting of Ca, Sr, and Ba; M is Nb and ( M is Nb and/or Ta, L is Zr , x is 0.
  • Li 7-3x Al x La 3 Zr 3 O 12 (x is preferably a range of 0.5 or less (including 0))
  • Li 6.25 Al 0.25 La 3 Zr 3 O 12 , Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12, Li 6.4 La 3 Zr 1.6 Ta 0.6 O 12 , Li 7 La 3 Zr 2 O 12 has high ionic conductivity and is electrochemically stable, so it has excellent discharge performance and cycle life performance.
  • examples of the solid electrolyte having lithium ion conductivity include a lithium phosphate solid electrolyte having a NASICON type structure.
  • An example of a lithium phosphate solid electrolyte with a NASICON type structure includes LiM1 2 (PO 4 ) 3 , where M1 is one or more elements selected from the group consisting of Ti, Ge, Sr, Zr, Sn, and Al. included.
  • Preferred examples include Li 1+x Al x Ge 2-x (PO 4 ) 3 , Li 1+x Al x Zr 2-x (PO 4 ) 3 , and Li 1+x Al x Ti 2-x (PO 4 ) 3 .
  • x is preferably in the range of 0 or more and 0.5 or less.
  • each of the illustrated solid electrolytes has high ionic conductivity and high electrochemical stability. Both a lithium phosphate solid electrolyte having a NASICON type structure and an oxide solid electrolyte having a garnet type structure may be used as the solid electrolyte having lithium ion conductivity.
  • the inorganic particles may be made of only one type of the above-mentioned inorganic materials, or may be a mixture of two or more types.
  • the first film is, for example, a porous film containing inorganic particles and binder particles. Although there are inorganic materials that have lithium ion conductivity, such as solid electrolytes, many of the inorganic materials have low electronic conductivity or have insulating properties. Therefore, the first film can function as a partition wall for electrically insulating the positive electrode and the negative electrode.
  • the first membrane can hold the electrolyte in its porous portion, it does not inhibit the permeation of Li ions.
  • the first film containing the above-described type of inorganic material has high insulating properties while having Li ion permeability. From the viewpoint of achieving high insulation, it is preferable that the inorganic particles contain a substance having an energy bandgap value of 3.0 eV or more. Examples of substances with an energy bandgap value of 3.0 eV or more include aluminum oxide and barium sulfate.
  • Aluminum oxide and barium sulfate are preferred because they have an energy bandgap value of about 9 eV.
  • the inorganic particles may consist of aluminum oxide or barium sulfate.
  • binder examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, styrene-butadiene rubber, or mixtures thereof.
  • PTFE polytetrafluoroethylene
  • PVdF polyvinylidene fluoride
  • fluorine rubber fluorine rubber
  • styrene-butadiene rubber or mixtures thereof.
  • the content of the binder in the first film is preferably in the range of 0.01% by mass to 20% by mass.
  • the volume-based frequency distribution chart obtained by the laser diffraction scattering method has two peaks.
  • the frequency distribution chart may include three or more peaks, but preferably includes two peaks.
  • the electrode group including the first film exhibits excellent insulation.
  • One reason for this is thought to be that the density within the layer is improved because two types of particle groups having mutually different particle diameters are present within the layer. It is thought that the density within the layer is increased by particles having a relatively small particle size entering the gaps between particles having a relatively large particle size.
  • the particles included in the first film may include inorganic particles and binder particles.
  • the layer does not contain or substantially does not contain coarse particles.
  • the coarse particles refer to, for example, primary particles having a diameter of 40 ⁇ m or more, or secondary particles obtained by agglomerating primary particles. If the first coating film is formed using a slurry containing a large amount of coarse particles, there is a tendency for coating failure to occur due to the coarse particles. Coating failure occurs, for example, when coarse particles are caught in a coating head provided in a coating device.
  • the term "missing coating” refers to the occurrence of uncoated parts in parts of the coating film that should be formed into a uniform film.
  • the frequency distribution chart of the first film included in the electrode group according to the embodiment includes two peaks with different particle sizes. Therefore, the first film is less likely to have holes due to coating failure. The reason for this will be explained in detail below.
  • the slurry used to form the first film also has a similar particle size distribution.
  • a volume-based frequency distribution chart obtained by a laser diffraction scattering method for the slurry for forming the first film may include two peaks having different particle diameters.
  • Such a slurry includes at least primary particles having a relatively small particle size and primary particles having a relatively large particle size.
  • the former will be referred to as first particles, and the latter will be referred to as second particles.
  • the slurry may include secondary particles that are aggregates of first particles and/or second particles. These secondary particles are called third particles.
  • the third particles may be the above coarse particles. Since the first particles have a small particle diameter, they tend to aggregate with each other. Therefore, most of the particles constituting the third particles are the first particles. For example, 50% or more by weight of the third particles can be the first particles.
  • the third particles which are mainly composed of aggregates of the first particles
  • the second particles having a relatively large particle size collide with the aggregate that is, the coarse particles (third particles), which are the aggregates of the first particles having a relatively small particle size, resulting in an aggregate.
  • the slurry has excellent dispersibility.
  • the probability of the presence of coarse particles is low, so even if the first film is formed using the slurry, coating defects are unlikely to occur. Therefore, by evaluating the number of coarse particles contained in the slurry after the dispersion treatment, it is possible to evaluate the insulation properties of the first film formed using the slurry.
  • Whether or not the slurry for forming the first film contains coarse particles can be determined using a grind gauge according to Japanese Industrial Standard JIS K 5600.
  • the number of coarse particles contained in 5 mL of slurry is, for example, 15 or less, preferably 10 or less, and more preferably 5 or less. The smaller the number of coarse particles, the lower the probability that coating defects will occur. As a result, the amount of self-discharge can be reduced.
  • the frequency distribution chart for the first film forming slurry does not have two peaks, it is sufficient that the frequency distribution chart for the first film has two peaks. Even in this case, the effect of increasing the density as described above can be obtained, so that an electrode group exhibiting excellent insulation properties can be obtained. It is preferable that the volume-based frequency distribution chart obtained by the laser diffraction scattering method for the first film-forming slurry also includes two peaks having different particle diameters.
  • Two peaks having different particle diameters in the frequency distribution chart for the first film are defined as a first peak and a second peak, respectively, in order from the peak with the smallest particle diameter.
  • the first peak having a small particle size may be, for example, a peak caused by the first particles.
  • the second peak having a large particle size may be, for example, a peak caused by the second particles. Since the number of third particles contained in the first film is very small, they are hardly detected or not detected in the frequency distribution chart.
  • the frequency distribution chart is a graph in which the horizontal axis indicates particle diameter [ ⁇ m] and the vertical axis indicates frequency (frequency distribution) [%].
  • the particle diameter D1 corresponding to the peak top of the first peak is smaller than the particle diameter D2 corresponding to the peak top of the second peak.
  • the particle diameter D1 is, for example, within the range of 0.4 ⁇ m or more and 1.0 ⁇ m or less, preferably within the range of 0.5 ⁇ m or more and 0.9 ⁇ m or less. If the particle size D1 of the first peak is excessively small, agglomerates are likely to be formed, which is not preferable because the frequency of coating failure due to agglomerates (coarse particles) may increase.
  • the particle diameter D2 is, for example, in the range of more than 1.0 ⁇ m and less than 2.0 ⁇ m, preferably in the range of 1.1 ⁇ m or more and less than 1.8 ⁇ m. If the particle diameter D2 of the second peak is excessively large, the number of primary particles having large particle diameters is too large, and the probability of contact between these primary particles increases. As a result, the probability of contact between primary particles having a relatively large particle size and aggregates decreases, and dispersibility tends to be poor. When the dispersibility is poor, coarse particles in the slurry are difficult to crush, and coating omissions may easily occur.
  • the particle diameter D1 corresponding to the peak top of the first peak is 0.4 ⁇ m or more and 1.0 ⁇ m or less
  • the particle diameter D2 corresponding to the peak top of the second peak is more than 1.0 ⁇ m and 2.0 ⁇ m or less. It is preferable that there be.
  • the particle diameters D1 and D2 are within these ranges, it can be considered that the primary particles contained in the first film have a small particle diameter as a whole. Therefore, in this case, since the thickness of the first film can be made sufficiently thin, a high battery capacity can be achieved.
  • the ratio D1/D2 of the particle diameter D1 corresponding to the peak top of the first peak to the particle diameter D2 corresponding to the peak top of the second peak is, for example, in the range of 1.0 or more and 5.0 or less, preferably It is in the range of 1.50 or more and 3.0 or less, more preferably 2.0 or more and 2.5 or less. If the ratio D1/D2 is too high, the number of particles having a large primary particle diameter to collide with the aggregates is insufficient, so that the dispersibility tends to deteriorate. If the ratio D1/D2 is too low, the number of particles having a large primary particle diameter will be too large, reducing the collision probability (frequency) during dispersion and deteriorating the dispersibility. As a result, coarse particles tend to exist in the slurry or in the first film, which tends to cause coating failure.
  • the frequency distribution chart for the first film according to the embodiment is obtained by measuring according to the following procedure.
  • the electrode group is taken out from the battery, and the electrode structure (positive electrode or negative electrode) including the first film containing an inorganic material is taken out.
  • the taken-out electrode structure is immersed in ethyl methyl carbonate to remove Li salt, and then dried. After drying, only the first film of the electrode structure is peeled off with a spatula and immersed in NMP (N-methyl-2-pyrrolidone) solvent. Thereafter, while immersed in the NMP solvent, the first film is dispersed in the NMP solvent using ultrasound to obtain a dispersion solution as a sample. Regarding this dispersion solution, the particle size distribution of the constituent particles is measured using a laser diffraction type distribution measuring device.
  • the dispersion solution may further contain not only the inorganic particles contained in the first film but also a binder component such as PVdF that may be contained in the first film. Since the particle size of the binder component is very small compared to the particle size of the inorganic particles, it is not detected.
  • a measuring device for example, Microtrac MT3100II manufactured by Microtrac Bell Co., Ltd. can be used.
  • ultrasonic treatment when obtaining the above-mentioned dispersion solvent is performed using a sample supply system attached to a laser diffraction type distribution measuring device. Ultrasonication is carried out at a power of 40W for 300 seconds.
  • the first peak and the second peak can be determined from the frequency distribution chart obtained by the above measurement. Furthermore, D10, D50, and D90 of the particles constituting the first film can be determined from this frequency distribution chart. D10, D50, and D90 are particle diameters of particles whose integrated value of particle diameter distribution corresponds to 10%, 50%, and 90%, respectively. D50 is also called the median diameter.
  • the average particle diameter D50 of the inorganic particles can be, for example, within the range of 0.60 ⁇ m to 2.0 ⁇ m. It is preferable that D50 is within this range because the thickness of the first film can be reduced.
  • the D50 of the inorganic particles may preferably be within the range of 0.80 ⁇ m to 1.20 ⁇ m.
  • D10 in the frequency distribution chart above is, for example, 0.10 ⁇ m or more.
  • a high value of D10 means less fine powder.
  • D10 may be 0.20 ⁇ m or more, or 0.30 ⁇ m or more. According to one example, D10 may be 0.60 ⁇ m or less.
  • D10 is 0.10 ⁇ m or more, the proportion of primary particles in the first film is low, so that agglomeration of fine powder can be suppressed. In this case, coarse particles are reduced and high insulation properties can be exhibited.
  • D90 in the above frequency distribution chart is, for example, within the range of 1.50 ⁇ m to 3.0 ⁇ m, although it is not particularly limited.
  • the second film contains organic fibers.
  • the second membrane may be a porous membrane in which organic fibers are deposited in the plane direction and the thickness direction.
  • the second film has a front surface and a back surface. One main surface of the second film corresponds to the front surface, and the other main surface corresponds to the back surface.
  • the organic fiber comprises, for example, at least one organic material selected from the group consisting of polyamideimide, polyamide, polyolefin, polyether, polyimide, polyketone, polysulfone, cellulose, polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVdF).
  • polyolefins include polypropylene (PP) and polyethylene (PE).
  • the number of types of organic fibers can be one or more. Preferred is at least one selected from the group consisting of polyimide, polyamide, polyamideimide, cellulose, PVdF, and PVA, and more preferred is at least one selected from the group consisting of polyimide, polyamide, polyamideimide, cellulose, and PVdF. At least one type of
  • polyimide Since polyimide is insoluble, infusible, and does not decompose even at 250 to 400°C, it is possible to obtain a second film with excellent heat resistance.
  • the organic fiber preferably has a length of 1 mm or more and an average diameter of 2 ⁇ m or less, more preferably an average diameter of 1 ⁇ m or less. Since such a second film has sufficient strength, porosity, air permeability, pore size, electrolyte resistance, oxidation-reduction resistance, etc., it functions well as a separator.
  • the average diameter of organic fibers can be measured by observation with a focused ion beam (FIB) device. Further, the length of the organic fiber is obtained based on length measurement during observation with an FIB device.
  • FIB focused ion beam
  • 30% or more of the total volume of the fibers forming the second membrane is preferably organic fibers with an average diameter of 1 ⁇ m or less, and organic fibers with an average diameter of 350 nm or less. It is more preferable that it is an organic fiber, and even more preferable that it is an organic fiber of 50 nm or less.
  • the volume of the organic fibers having an average diameter of 1 ⁇ m or less accounts for 80% or more of the volume of the entire fibers forming the second film.
  • a scanning ion microscope SIM
  • the organic fibers having a thickness of 40 nm or less occupy 40% or more of the total volume of the fibers forming the second film. The smaller the diameter of the organic fiber, the less the effect of interfering with the movement of ions.
  • cation exchange groups exist on at least a portion of the entire surface of the organic fiber, including the front and back surfaces. Cation exchange groups promote the movement of ions, such as lithium ions, through the separator, thereby enhancing battery performance. Specifically, it becomes possible to perform rapid charging and rapid discharging over a long period of time.
  • the cation exchange group is not particularly limited, but includes, for example, a sulfonic acid group and a carboxylic acid group. Fibers having cation exchange groups on their surfaces can be formed, for example, by electrospinning using a sulfonated organic material.
  • the second film preferably has pores, and the average pore diameter of the pores is preferably 5 nm or more and 10 ⁇ m or less. Further, the porosity is preferably 30% or more and 90% or less. If such pores are provided, a separator with excellent ion permeability and good electrolyte impregnation properties can be obtained. More preferably, the porosity is 40% or more.
  • the average pore diameter and porosity of the pores can be confirmed by mercury intrusion method, calculation from volume and density, SEM observation, SIM observation, and gas desorption method. It is desirable that the porosity be calculated from the volume and density of the second film. Further, the average pore diameter is preferably measured by a mercury intrusion method or a gas adsorption method. A large porosity in the second film means that the effect of interfering with the movement of ions is small.
  • the thickness of the second film is preferably in the range of 12 ⁇ m or less.
  • the lower limit of the thickness is not particularly limited, but may be 1 ⁇ m.
  • the porosity can be increased by making the organic fibers contained in a sparse state, so it is not difficult to obtain a layer with a porosity of about 90%, for example. It is extremely difficult to form a layer with such a high porosity using particles.
  • the second film is more advantageous than the inorganic particle deposit in terms of roughness, breakability, electrolyte content, adhesion, bending properties, porosity, and ion permeability.
  • the second film may contain particles of an organic compound.
  • the particles are made of the same material as the organic fibers, for example.
  • the particles may be formed integrally with the organic fiber.
  • the second film may be formed on the second active material-containing layer, or may be formed on the first film. Alternatively, the second film may be formed on both surfaces of the second active material-containing layer and the first film. In either case, one of the front and back surfaces of the second film can be in contact with the front surface of the first film.
  • the thickness of the first film and the second film, and the thickness of the first active material-containing layer and the second active material-containing layer can be measured by performing SEM observation on the cross section of the electrode.
  • the target electrode group is cut using an ion milling device.
  • the electrode group is cut along the thickness direction.
  • the cross section of the electrode group after cutting is pasted on the SEM sample stage.
  • conductive tape or the like is used to prevent the electrode group from peeling off or floating from the sample stage. Observe the electrode group attached to the SEM sample stage using SEM. Note that when introducing the electrode group into the sample chamber, it is preferable to maintain an inert atmosphere.
  • the secondary battery to be analyzed is brought into a discharge state.
  • the secondary battery can be brought into a discharge state by discharging it to the rated final voltage with a 0.1 C current.
  • the discharged secondary battery is disassembled in a glove box filled with argon. Remove the electrode group to be measured from the disassembled battery.
  • This electrode group is washed with a suitable solvent.
  • a suitable solvent for example, ethyl methyl carbonate can be used. Thereafter, SEM observation is performed according to the above-described procedure.
  • the second film is formed, for example, by electrospinning.
  • the first electrode structure or the second electrode structure on which the second film is to be formed is grounded to serve as a ground electrode.
  • the first electrode structure on which the first film is already formed is prepared.
  • the voltage applied to the spinning nozzle charges the liquid raw material (for example, the raw material solution), and the amount of charge per unit volume of the raw material solution increases due to the volatilization of the solvent from the raw material solution. Due to the continuous volatilization of the solvent and the accompanying increase in the amount of charge per unit volume, the raw material solution discharged from the spinning nozzle extends in the longitudinal direction and forms nano-sized organic fibers at the first electrode, which is the ground electrode. or a second electrode structure.
  • Coulomb force is generated between the organic fiber and the earth electrode due to the potential difference between the nozzle and the earth electrode. Therefore, the contact area with the first film can be increased by the nano-sized organic fibers, and the organic fibers can be deposited on the first electrode structure or the second electrode structure by Coulomb force. It becomes possible to increase the peel strength of the two films from the electrode (second active material-containing layer).
  • the peel strength can be controlled, for example, by adjusting the solution concentration, the sample-nozzle distance, and the like.
  • the second film can be easily formed on the electrode surface.
  • the electrospinning method forms one continuous fiber, so it is possible to ensure a thin film with resistance to breakage due to bending and cracking of the film. If the organic fibers constituting the second film are seamless and continuous, the probability of fraying or partial loss of the second film is low, which is advantageous in terms of suppressing self-discharge.
  • the liquid raw material used for electrospinning for example, a raw material solution prepared by dissolving an organic material in a solvent is used.
  • the organic material include the same materials as those mentioned for the organic materials constituting the organic fibers.
  • the organic material is used by being dissolved in a solvent at a concentration of, for example, about 5 to 60% by mass.
  • the solvent for dissolving the organic material is not particularly limited, and any solvent such as dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), N,N'dimethylformamide (DMF), N-methylpyrrolidone (NMP), water, alcohols, etc.
  • a solvent can be used.
  • electrospinning is performed while melting the sheet-like organic material using a laser or the like. In addition, it is also permissible to mix high boiling point organic solvents and low melting point solvents.
  • the second film is formed by discharging the raw material from the spinning nozzle over the surface of a predetermined electrode while applying voltage to the spinning nozzle using a high voltage generator.
  • the applied voltage is appropriately determined depending on the solvent/solute species, boiling point/vapor pressure curve of the solvent, solution concentration, temperature, nozzle shape, sample-nozzle distance, etc. It can be set to 100kV.
  • the feed rate of the raw material is also appropriately determined depending on the solution concentration, solution viscosity, temperature, pressure, applied voltage, nozzle shape, etc. In the case of a syringe type, the flow rate can be, for example, about 0.1 to 500 ⁇ l/min per nozzle. Furthermore, in the case of multiple nozzles or slits, the supply rate may be determined depending on the opening area.
  • the organic fibers are formed directly on the surface of the electrode in a dry state, it is substantially possible to prevent the solvent contained in the raw material from penetrating into the electrode.
  • the amount of solvent remaining inside the electrode is extremely low, below the ppm level.
  • the residual solvent inside the electrode causes an oxidation-reduction reaction, causing battery loss, leading to a decrease in battery performance.
  • the second film containing an organic material the possibility of such inconvenience occurring is reduced as much as possible, so that battery performance can be improved.
  • the first film may be formed only on at least one main surface of the first active material-containing layer, but it is also possible to further cover at least a portion of the surface of the first current collecting tab with the first film. good. An example of this is shown in FIGS. 5 and 6. For each of the two first active material-containing layers 1b, four side surfaces 47 perpendicular to the main surface are covered with the first film 6. The first film 6 also covers the portions adjacent to the first active material-containing layer 1b (including the boundary with the first active material-containing layer 1b) on both main surfaces of the first current collecting tab 1c. . The location where the first film 6 is provided is close to the end surface of the second electrode structure opposite to the side from which the second current collecting tab 2c extends.
  • the first film 6 By providing the first film 6, it is possible to reduce internal short circuits caused by contact between the first current collecting tab 1c of the first electrode structure and the end surface of the second electrode structure. In addition, when using a plurality of strips protruding from one side of the first current collector 1a as the first current collecting tab 1c as shown in FIG. It is desirable that the first film 6 covers a portion 48 adjacent to the current collector 1a and an end surface 49 of the first current collector 1a located between the first current collector tabs 1c. This configuration is effective in reducing internal short circuits.
  • the second film may be formed on the second electrode structure, but instead of being formed on the second electrode structure, it may be formed on the surface of the first electrode structure. An example of this is shown in FIG.
  • the second film 7 covers the surface of the first film 4 and all end faces of the first electrode structure. Further, the second film 7 also covers portions of both main surfaces of the first current collecting tab 1c, including the boundary with the first active material containing layer 1b.
  • the second electrode structure is arranged such that the second active material containing layer 2b faces the first active material containing layer 1b with a separator 3 formed of the first film 4 and the second film 7 interposed therebetween.
  • a portion of the main surface of the first current collecting tab 1c adjacent to the first active material containing layer 1b is covered with the second film 7, and the side opposite to the side of the first electrode structure from which the first current collecting tab 1c protrudes
  • the end face located at is covered with the second film 7.
  • the electrode group according to the embodiment can be manufactured by, for example, the first or second manufacturing method described below.
  • a slurry containing the first active material (hereinafter referred to as slurry I) and a slurry containing inorganic particles (hereinafter referred to as slurry II) are simultaneously applied to at least one main surface of the first current collector.
  • An example of the coating process is shown in FIGS. 9 and 10.
  • the coating device 60 includes a tank 62 containing slurry I and a tank 63 containing slurry II.
  • the coating device 60 is configured to be able to simultaneously coat slurry I and slurry II onto the base material.
  • the elongated first current collector 1a before being cut into a predetermined size is conveyed to the slurry discharge port of the coating device 60 by the conveyance roller 61.
  • the slurry I outlet 62a is located upstream of the current collector than the slurry II outlet 63a. Therefore, slurry I is discharged onto the current collector before slurry II.
  • Slurry I is applied from the coating device 60 onto the first current collector 1a except for both ends in the short side direction.
  • slurry II is overcoated so as to protrude from the area coated with slurry I. Since Slurry II is coated over Slurry I, Slurry II can easily follow the surface shape of Slurry I.
  • the first active material-containing layer can be formed by drying and pressing slurry I.
  • the first film can be formed by drying and pressing slurry II. In this way, a first electrode structure can be obtained.
  • the first electrode structure may be cut to a desired size.
  • the first film-forming slurry II can be obtained, for example, by obtaining a dispersion liquid in which inorganic particles and a binder are suspended in a suitable solvent, and then performing a dispersion treatment using a bead mill or the like.
  • One method for making the frequency distribution chart for the first film have two peaks is, for example, a method of mixing two types of inorganic particles with different D50s.
  • the inorganic particles contained in the slurry for forming the first film for example, two powders having a D50 of 0.4 ⁇ m to 0.7 ⁇ m and a powder having a D50 of 1.4 ⁇ m to 1.8 ⁇ m are used. : Use a mixture at a ratio of 8 to 8:2. These inorganic particles may be of the same type or different types. As described above, the particle size may be adjusted by further performing a dispersion treatment on the dispersion containing the inorganic particles.
  • the diameter of the beads used is, for example, within the range of 1 mm to 2 mm.
  • the filling rate is, for example, within the range of 40% to 70%.
  • the rotation speed is, for example, within the range of 500 rpm to 3000 rpm.
  • the processing time is, for example, 3 to 10 minutes.
  • the first peak position D1 (particle diameter) will become smaller.
  • the ratio D1/D2 tends to become smaller.
  • D10 becomes too small and aggregates are likely to be formed, which is not preferable.
  • the second peak position D2 (particle diameter) becomes larger. Therefore, the ratio D1/D2 tends to increase.
  • the second electrode structure can be manufactured as follows. After applying the slurry containing the second active material onto the second current collector, the slurry is dried, and the dried slurry is roll pressed to obtain a laminate.
  • the obtained laminate may be a second electrode including a second active material-containing layer on at least one main surface of the second current collector. After cutting the laminate as the second electrode into a predetermined size as necessary, a second film is formed on the laminate by electrospinning. Then, pressing may be performed. Examples of the pressing method include roll pressing.
  • FIG. 11 is a perspective view showing an example of the process of forming a second film on the second electrode.
  • the second film 5 is directly formed by depositing the raw material solution discharged from the nozzle N on the second active material-containing layer 2b and the second current collecting tab 2c as organic fibers.
  • One side of the second current collecting tab 2c and its vicinity are covered with a mask M. Therefore, the second film 5 includes organic fibers deposited across the surface of the second active material-containing layer 2b and the portion of the surface of the second current collecting tab 2c adjacent to the second active material-containing layer 2b. It becomes a porous membrane containing
  • the electrode group of the embodiment can be obtained by stacking the first electrode structure and the second electrode structure so that they face each other with the first film and the second film interposed in between.
  • a second film is formed by electrospinning on the first electrode structure produced by the first manufacturing method. Then, pressing may be performed. In this way, a first electrode structure further having a second film on the first film can be obtained.
  • the slurry is dried, and the dried material is roll pressed and cut into a predetermined size. Obtain 2 electrodes.
  • the electrode group of the embodiment can be obtained by stacking a first electrode structure having a second film and a second electrode so that they face each other with the first film and the second film interposed in between.
  • the electrode group obtained by the first or second manufacturing method may be used as a single electrode group, or a plurality of electrode groups may be stacked and used. Furthermore, one or more electrode groups may be spirally wound. Note that the electrode group may be further pressed.
  • an electrode group includes a first electrode structure and a second electrode structure at least partially facing the first electrode structure.
  • the first electrode structure includes a first current collector, a first active material-containing layer provided on at least one surface of the first current collector, and inorganic particles. and a first film provided in the first film.
  • the second electrode structure includes a second current collector, a second active material-containing layer provided on at least one surface of the second current collector, and an organic material; and a second film provided on.
  • a volume-based frequency distribution chart obtained by laser diffraction scattering has two peaks.
  • the electrode group according to the embodiment Shows excellent insulation properties.
  • the frequency distribution chart regarding the first film forming slurry for forming the first film which shows a frequency distribution chart having two peaks, also has the same chart shape as the frequency distribution chart for the first film. Since such a slurry for forming the first film has excellent dispersibility, the number of coarse particles contained after dispersion treatment using a bead mill or the like is small. As a result, in the coating process using the slurry, coating omission can be suppressed, so that the resulting electrode group including the first film can achieve high insulation.
  • the secondary battery according to the second embodiment includes the electrode group according to the first embodiment and an electrolyte.
  • the secondary battery may further include an exterior member capable of accommodating the electrode group and the electrolyte.
  • One or more electrode groups can be used in a laminated type, or in a spirally or flat spirally wound manner.
  • the plurality of electrode groups are stacked, for example, so that first electrode structures and second electrode structures are alternately arranged.
  • the secondary battery may further include a first electrode terminal electrically connected to the first current collecting tab, and a second electrode terminal electrically connected to the second current collecting tab.
  • a non-aqueous electrolyte for example, a non-aqueous electrolyte is used.
  • the non-aqueous electrolyte include a liquid non-aqueous electrolyte prepared by dissolving an electrolyte in an organic solvent, a gel-like non-aqueous electrolyte made of a composite of a liquid electrolyte and a polymer material, and the like.
  • the liquid non-aqueous electrolyte can be prepared, for example, by dissolving the electrolyte in an organic solvent at a concentration of 0.5 mol/L or more and 2.5 mol/L or less.
  • Examples of the electrolyte include lithium perchlorate (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium arsenic hexafluoride (LiAsF 6 ), and trifluoromethane.
  • Examples include lithium salts such as lithium sulfonate (LiCF 3 SO 3 ), lithium bistrifluoromethylsulfonylimide [LiN(CF 3 SO 2 ) 2 ], or mixtures thereof. It is preferable that it is resistant to oxidation even at high potentials, and LiPF 6 is most preferable.
  • organic solvents examples include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), and vinylene carbonate, and chain carbonates such as diethyl carbonate (DEC), dimethyl carbonate (DMC), and methyl ethyl carbonate (MEC).
  • cyclic ethers such as tetrahydrofuran (THF), 2methyltetrahydrofuran (2MeTHF), dioxolane (DOX), chain ethers such as dimethoxyethane (DME), diethoxyethane (DEE), ⁇ -butyrolactone (GBL)
  • Examples include acetonitrile (AN) and sulfolane (SL). These organic solvents may be used alone or as a mixture of two or more.
  • polymer material examples include polyvinylidene fluoride (PVdF), polyacrylonitrile (P1N), and polyethylene oxide (PEO).
  • PVdF polyvinylidene fluoride
  • P1N polyacrylonitrile
  • PEO polyethylene oxide
  • non-aqueous electrolyte a room temperature molten salt (ionic melt) containing lithium ions, a polymer solid electrolyte, an inorganic solid electrolyte, etc. may be used.
  • the exterior member for example, a metal container or a laminated film container can be used.
  • the shape of the secondary battery is not particularly limited, and can be in various shapes, such as cylindrical, flat, thin, square, coin-shaped, etc.
  • FIG. 12 is a partially cutaway perspective view showing an example of the secondary battery according to the embodiment.
  • FIG. 12 is a diagram showing an example of a secondary battery using a laminate film as an exterior member.
  • the secondary battery 100 shown in FIG. 12 includes an exterior member 110 made of a laminate film, an electrode group 120, a first electrode terminal 130, a second electrode terminal 140, and a nonaqueous electrolyte (not shown).
  • the electrode group 120 includes a plurality of electrode groups according to the embodiment. These electrode groups are stacked such that the first electrode structures and the second electrode structures are alternately arranged.
  • a non-aqueous electrolyte (not shown) is held or impregnated in the electrode group 120.
  • a first current collection tab of the first electrode structure is electrically connected to the first electrode terminal 130 .
  • a second current collection tab of the second electrode structure is electrically connected to the second electrode terminal 140 .
  • the first electrode terminal 130 and the second electrode terminal 140 are spaced apart from each other, and their tips protrude outward from one side of the exterior member 110.
  • FIG. 13 is an exploded perspective view showing another example of the secondary battery according to the embodiment.
  • FIG. 13 is a diagram showing an example of a secondary battery using a square metal container as an exterior member.
  • the secondary battery shown in FIG. 13 includes an exterior member 20, a wound electrode group 51, a lid 52, a first electrode terminal 53, a second electrode terminal 54, and a non-aqueous electrolyte (not shown).
  • the wound electrode group 51 has a structure in which the electrode group according to the embodiment is wound in a flat spiral shape.
  • the first current collecting tab 25 wound in a flat spiral shape is located on one end surface of the winding shaft
  • the first current collecting tab 25 wound in a flat spiral shape is located on one end surface of the winding shaft.
  • Two current collection tabs 26 are located on the other end surface of the winding shaft.
  • a non-aqueous electrolyte (not shown) is held or impregnated in the electrode group 51.
  • the first electrode lead 27 is electrically connected to the first current collecting tab 25 and also to the first electrode terminal 53. Further, the second electrode lead 28 is electrically connected to the second current collecting tab 26 and also to the second electrode terminal 54 .
  • the electrode group 51 is arranged within the exterior member 20 such that the first electrode lead 27 and the second electrode lead 28 face the main surface side of the exterior member 20 .
  • the lid 52 is fixed to the opening 20a of the exterior member 20 by welding or the like.
  • the first electrode terminal 53 and the second electrode terminal 54 are each attached to the lid 52 via an insulating hermetic seal member (not shown).
  • the secondary battery of the second embodiment described above includes the electrode group according to the first embodiment, and thus exhibits excellent insulation properties.
  • a battery pack includes the secondary battery according to the second embodiment or an assembled battery including a plurality of secondary batteries.
  • the battery pack according to the second embodiment can further include a protection circuit.
  • the protection circuit has a function of controlling charging and discharging of the secondary battery.
  • a circuit included in a device for example, an electronic device, an automobile, etc. that uses a battery pack as a power source may be used as a protection circuit for the battery pack.
  • the battery pack according to the third embodiment may further include an external terminal for power supply.
  • the external terminal for energization is for outputting current from the secondary battery to the outside and/or inputting current from the outside to the secondary battery.
  • current is supplied to the outside through the external terminal for energization.
  • charging current (including regenerated energy from the motive power of an automobile, etc.) is supplied to the battery pack through an external terminal for energization.
  • FIG. 14 is an exploded perspective view schematically showing an example of a battery pack according to the third embodiment.
  • FIG. 15 is a block diagram showing an example of the electric circuit of the battery pack shown in FIG. 14.
  • the battery pack 300 shown in FIGS. 14 and 15 includes a storage container 31, a lid 32, a protective sheet 33, an assembled battery 200, a printed wiring board 34, wiring 35, and an insulating plate (not shown). .
  • the storage container 31 shown in FIG. 14 is a bottomed square container with a rectangular bottom surface.
  • the storage container 31 is configured to be able to accommodate the protective sheet 33, the assembled battery 200, the printed wiring board 34, and the wiring 35.
  • the lid 32 has a rectangular shape.
  • the lid 32 accommodates the assembled battery 200 and the like by covering the accommodation container 31.
  • the container 31 and the lid 32 are provided with an opening or a connection terminal for connection to an external device or the like.
  • the assembled battery 200 includes a plurality of single cells 100, a positive lead 22, a negative lead 23, and an adhesive tape 24.
  • At least one of the plurality of single cells 100 is a secondary battery according to the second embodiment.
  • Each of the plurality of unit cells 100 is electrically connected in series as shown in FIG. 15.
  • the plurality of unit cells 100 may be electrically connected in parallel, or may be connected in a combination of series connection and parallel connection. When a plurality of single cells 100 are connected in parallel, the battery capacity increases compared to when they are connected in series.
  • the adhesive tape 24 fastens the plurality of unit cells 100 together.
  • a heat shrink tape may be used to fix the plurality of cells 100.
  • the protective sheets 33 are arranged on both sides of the assembled battery 200, and after a heat-shrinkable tape is made to go around, the heat-shrinkable tape is heat-shrinked to bundle the plurality of unit cells 100.
  • One end of the positive electrode side lead 22 is connected to the assembled battery 200. One end of the positive electrode side lead 22 is electrically connected to the positive electrode of one or more unit cells 100. One end of the negative electrode side lead 23 is connected to the assembled battery 200. One end of the negative electrode side lead 23 is electrically connected to the negative electrode of one or more unit cells 100.
  • the printed wiring board 34 is installed along one of the inner surfaces of the container 31 in the short side direction.
  • the printed wiring board 34 includes a positive connector 342, a negative connector 343, a thermistor 345, a protection circuit 346, wiring 342a and 343a, an external terminal 350 for energization, and a positive wiring (positive wiring) 348a. and a negative side wiring (negative side wiring) 348b.
  • One main surface of the printed wiring board 34 faces one side of the assembled battery 200.
  • An insulating plate (not shown) is interposed between the printed wiring board 34 and the assembled battery 200.
  • the other end 22a of the positive lead 22 is electrically connected to the positive connector 342.
  • the other end 23 a of the negative lead 23 is electrically connected to the negative connector 343 .
  • the thermistor 345 is fixed to one main surface of the printed wiring board 34. Thermistor 345 detects the temperature of each cell 100 and transmits the detection signal to protection circuit 346.
  • the external terminal 350 for power supply is fixed to the other main surface of the printed wiring board 34.
  • the external terminal 350 for energization is electrically connected to a device existing outside the battery pack 300.
  • External terminal 350 for energization includes a positive terminal 352 and a negative terminal 353.
  • the protection circuit 346 is fixed to the other main surface of the printed wiring board 34.
  • the protection circuit 346 is connected to the positive terminal 352 via the positive wiring 348a.
  • the protection circuit 346 is connected to the negative terminal 353 via the negative wiring 348b.
  • the protection circuit 346 is electrically connected to the positive connector 342 via a wiring 342a.
  • the protection circuit 346 is electrically connected to the negative electrode side connector 343 via wiring 343a. Further, the protection circuit 346 is electrically connected to each of the plurality of unit cells 100 via the wiring 35.
  • the protective sheets 33 are disposed on both inner surfaces of the container 31 in the long side direction and on the inner surface of the container 31 in the short side direction facing the printed wiring board 34 with the assembled battery 200 interposed therebetween.
  • the protective sheet 33 is made of resin or rubber, for example.
  • the protection circuit 346 controls charging and discharging of the plurality of single cells 100. Furthermore, the protection circuit 346 connects the protection circuit 346 to an external terminal for energizing the external device based on the detection signal transmitted from the thermistor 345 or the detection signal transmitted from the individual cells 100 or the assembled batteries 200. 350 (positive side terminal 352, negative side terminal 353).
  • the detection signal transmitted from the thermistor 345 can be, for example, a signal that detects that the temperature of the cell 100 is higher than a predetermined temperature.
  • Examples of the detection signal transmitted from each single cell 100 or assembled battery 200 include signals that detect overcharging, overdischarging, and overcurrent of the single cell 100.
  • the battery voltage may be detected, or the positive electrode potential or the negative electrode potential may be detected. In the latter case, a lithium electrode used as a reference electrode is inserted into each cell 100.
  • protection circuit 346 a circuit included in a device (for example, an electronic device, an automobile, etc.) that uses the battery pack 300 as a power source may be used.
  • this battery pack 300 includes the external terminal 350 for power supply, as described above. Therefore, this battery pack 300 can output current from the assembled battery 200 to an external device and input current from the external device to the assembled battery 200 via the external terminal 350 for energization. In other words, when the battery pack 300 is used as a power source, the current from the assembled battery 200 is supplied to the external device through the external terminal 350 for energization. Further, when charging the battery pack 300, a charging current from an external device is supplied to the battery pack 300 through the external terminal 350 for energization. When this battery pack 300 is used as an on-vehicle battery, regenerated energy from the motive power of the vehicle can be used as the charging current from an external device.
  • the battery pack 300 may include a plurality of assembled batteries 200.
  • the plurality of assembled batteries 200 may be connected in series, in parallel, or by a combination of series connection and parallel connection.
  • the printed wiring board 34 and the wiring 35 may be omitted.
  • the positive lead 22 and the negative lead 23 may be used as a positive terminal and a negative terminal of an external terminal for energization, respectively.
  • Such a battery pack is used, for example, in applications that require excellent cycle performance when drawing a large current.
  • this battery pack is used, for example, as a power source for electronic equipment, a stationary battery, and an in-vehicle battery for various vehicles.
  • An example of the electronic device is a digital camera.
  • This battery pack is particularly suitable for use as a vehicle battery.
  • the battery pack according to the third embodiment includes the secondary battery according to the second embodiment. Therefore, this battery pack can achieve excellent insulation.
  • Example 1 An electrode group including a first electrode structure as a positive electrode and a second electrode structure as a negative electrode, and a secondary battery including this electrode group were manufactured by the method described below.
  • LiNi 0.33 Co 0.33 Mn 0.33 O 2 particles were prepared as a positive electrode active material, carbon black was prepared as a conductive agent, and polyvinylidene fluoride was prepared as a binder. These were mixed at a mass ratio of 90:5:5 to obtain a mixture. Next, the obtained mixture was dispersed in n-methylpyrrolidone (NMP) solvent to prepare slurry I.
  • Slurry I is a slurry for forming a layer containing a positive electrode active material.
  • slurry II was prepared as the slurry for forming the first film as follows.
  • inorganic particles alumina particles (material 1) with an average particle diameter D50 of 0.6 ⁇ m and alumina particles (material 2) with an average particle diameter D50 of 1.7 ⁇ m are prepared, and these are mixed in a 1:1 mass ratio. The mixture was mixed at the same ratio and subjected to a mixing process using a Henschel mixer.
  • the material with a relatively small D50 is called "Material 1”
  • the material with a relatively large D50 is called "Material 2".
  • Slurry II is a slurry for forming the first layer.
  • slurry I and slurry II were overcoated in this order on both sides of a 20 ⁇ m thick aluminum foil.
  • slurry II was applied onto slurry I before slurry I dried. Thereafter, after drying Slurry I and Slurry II, the dried slurry was subjected to a roll press at a linear pressure of 1 kN/cm and cut into a predetermined size to obtain a positive electrode as a first electrode structure.
  • the thickness of each positive electrode active material containing layer was 20 ⁇ m.
  • both surfaces (principal surfaces) of the positive electrode active material-containing layer were covered with the first film, as shown in FIGS. 1 and 2.
  • the content of the inorganic material in the first film was 98% by mass.
  • a negative electrode as a second electrode was produced by the following method. Lithium titanate particles having an average primary particle diameter of 0.5 ⁇ m, carbon black as a conductive agent, and polyvinylidene fluoride as a binder were prepared. These were mixed at a mass ratio of 90:5:5 to obtain a mixture. The resulting mixture was dispersed in n-methylpyrrolidone (NMP) solvent to prepare a slurry. The obtained slurry was applied to a 20 ⁇ m thick aluminum foil and dried. Next, the dried coating film was pressed to obtain a negative electrode. The thickness of each negative electrode active material containing layer was 50 ⁇ m. Note that a portion not supported by the negative electrode active material-containing layer was provided on one long side of the current collector, and this portion was used as a negative electrode current collection tab.
  • NMP n-methylpyrrolidone
  • organic fibers were deposited on this negative electrode by electrospinning to form a second film.
  • Polyimide was used as the organic material.
  • This polyimide was dissolved in DMAc as a solvent at a concentration of 20% by mass to prepare a raw material solution as a liquid raw material.
  • the obtained raw material solution was supplied to the surface of the positive electrode from a spinning nozzle at a supply rate of 5 ⁇ l/min using a metering pump.
  • a voltage of 20 kV was applied to the spinning nozzle using a high voltage generator, and a layer of organic fibers was formed on the surface of the positive electrode while moving the spinning nozzle over an area of 100 x 200 mm.
  • the electrospinning method was performed with the surface of the negative electrode current collecting tab masked except for a 10 mm portion from the boundary with the positive electrode active material-containing layer on both surfaces (principal surfaces) of the negative electrode current collecting tab.
  • a negative electrode (second electrode structure) having the structure shown in was obtained. That is, the second film includes the surface of the negative electrode active material-containing layer, four side surfaces perpendicular to the respective surfaces (principal surfaces) of the negative electrode active material-containing layer, and three end surfaces exposed on the negative electrode surface of the negative electrode current collector. , and the portion including the boundary with the negative electrode active material-containing layer on the surface of the negative electrode current collector tab.
  • this negative electrode was pressed using a roll press.
  • the average diameter of the organic fibers was 700 nm, and 50% or more of the total volume of the fibers forming the second film was occupied by organic fibers with an average diameter of 1 ⁇ m or less.
  • the average pore diameter of the second membrane was 10 ⁇ m, and the porosity was 45%.
  • the positive electrode and the negative electrode are arranged so that the positive electrode active material-containing layer and the negative electrode active material-containing layer face each other with the first film and the second film interposed therebetween, and are wound into a flat spiral shape.
  • An electrode group with a shape was obtained. After vacuum drying at room temperature overnight, it was left in a glove box with a dew point of -80°C or lower for one day. This was placed in a metal container together with an electrolyte to obtain a non-aqueous electrolyte battery of Example 1.
  • the electrolytic solution was one in which 1 mol/L of LiPF 6 was dissolved as an electrolyte in a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 1:1).
  • Example 1 When producing the first electrode structure, secondary electrode structure was prepared in the same manner as in Example 1, except that titania particles having only one peak in the particle size distribution chart were used as inorganic particles to be mixed in slurry II. A battery was created. The average particle diameter D50 of the titania particles was 0.40 ⁇ m.
  • Example 1 ⁇ Self-discharge performance evaluation>
  • the secondary batteries produced in Example 1 and Comparative Example 1 were each charged until the SOC reached 70%, and then left in a 25° C. environment. Then, the voltage drop rate ⁇ V [mV/d] from the 15th day to the 18th day of standing was measured for each example. As a result, the ⁇ V of the secondary battery according to Example 1 was 0.5 mV/d, and the ⁇ V of the secondary battery according to Comparative Example 1 was 1.0 mV/d. From this result, it can be seen that the voltage drop rate in Example 1 was significantly slower.
  • the voltage drop rate is an index for evaluating self-discharge characteristics.
  • FIG. 16 is a particle size distribution chart obtained by a laser diffraction scattering method for the first film according to Example 1.
  • the horizontal axis shows particle diameter [ ⁇ m]
  • the left vertical axis shows frequency [%]
  • the right vertical axis shows cumulative [%].
  • D10 and D50 were calculated based on the chart shown in FIG. 16, they were 0.50 ⁇ m and 1.1 ⁇ m, respectively.
  • the position (particle diameter) of the first peak P1 was 0.6 ⁇ m, and its frequency was 4%.
  • the position (particle diameter) of the second peak P2 was 1.3 ⁇ m, and its frequency was 5%.
  • the ratio D1/D2 of the first peak position D2 to the second peak position D1 was 2.2.
  • slurry II which was used when producing the first film included in the electrode group according to Example 1 and Comparative Example 1, was tested using a grind gauge according to the method described in the first embodiment.
  • primary particles or secondary particles with a diameter of 40 ⁇ m to 60 ⁇ m, primary particles or secondary particles with a diameter of 60 ⁇ m to 80 ⁇ m, and primary particles or The number of each type of secondary particle present was investigated.
  • Example 2 a secondary battery was produced in the same manner as in Example 1, except that alumina particles with a D50 of 1.5 ⁇ m were used as material 2 when producing the first film-forming slurry. .
  • Example 3 a secondary battery was produced in the same manner as in Example 1, except that alumina particles with a D50 of 2.0 ⁇ m were used as material 2 when producing the first film-forming slurry. .
  • Example 4 when producing the first film forming slurry, alumina particles with a D50 of 0.5 ⁇ m were used as material 1, and alumina particles with a D50 of 1.5 ⁇ m were used as material 2.
  • a secondary battery was produced in the same manner as in Example 1 except for the following.
  • Example 5 when producing the first film forming slurry, alumina particles with a D50 of 0.4 ⁇ m were used as material 1, and alumina particles with a D50 of 1.2 ⁇ m were used as material 2.
  • a secondary battery was produced in the same manner as in Example 1 except for the following.
  • Example 6 when producing the first film forming slurry, alumina particles with a D50 of 0.4 ⁇ m were used as material 1, and alumina particles with a D50 of 0.6 ⁇ m were used as material 2.
  • a secondary battery was produced in the same manner as in Example 1 except for the following.
  • Example 7 when producing the slurry for forming the first film, alumina particles with D50 of 0.4 ⁇ m were used as material 1, alumina particles with D50 of 1.2 ⁇ m were used as material 2, and a bead mill was used.
  • a secondary battery was produced in the same manner as in Example 1, except that the conditions were changed as shown in Table 3.
  • Example 1 As shown in Tables 1 and 2, from the comparison between Example 1 and Comparative Example 1, when the volume-based frequency distribution chart obtained by the laser diffraction scattering method for the first film has two peaks, the voltage It can be seen that the descending speed ⁇ V was able to be significantly lowered. Further, the number of coarse particles contained in the first film forming slurry produced in Example 1 was 0 in any diameter range. In contrast, the first film forming slurry prepared in Comparative Example 1 contained 30 particles with a diameter of 40 ⁇ m to 60 ⁇ m, and 10 particles with a diameter of 60 ⁇ m to 80 ⁇ m. It was.
  • the first film-forming slurry according to Comparative Example 1 had poor dispersibility because the particle size distribution chart of the inorganic particles contained therein had only one peak. Therefore, it is considered that the number of coarse particles contained in the first film-forming slurry was large, and the frequency of coating omissions increased, resulting in poor self-discharge performance.
  • Example 2 From the comparison between Example 2 and Example 3, it can be seen that when the peak position ratio D1/D2 is 3.0 or less, the number of coarse particles in the slurry tends to be small.
  • Example 6 when the particle diameter D1 of the first peak P1 is 1.0 ⁇ m or less and the particle diameter D2 of the second peak P2 is 1.0 ⁇ m or more, The number of coarse particles was 0.
  • Example 6 when the particle diameter D1 of the first peak P1 is 1.0 ⁇ m or less and the particle diameter D2 of the second peak P2 is also 1.0 ⁇ m or less, the number of coarse particles increases. increased slightly. This shows that the slurries according to Examples 4 and 5 had better dispersibility than the slurry according to Example 6.
  • Example 4 From a comparison between Example 4 and Example 7, in Example 4 where D10 was 0.20 ⁇ m or more, the number of coarse particles in the slurry was smaller than in Example 7 where D10 was 0.10 ⁇ m. This is considered to be because in Example 4, the amount of fine powder itself was small, so the number of coarse particles as aggregates was reduced.
  • an electrode group includes a first electrode structure and a second electrode structure at least partially facing the first electrode structure.
  • the first electrode structure includes a first current collector, a first active material-containing layer provided on at least one surface of the first current collector, and inorganic particles. and a first film provided in the first film.
  • the second electrode structure includes a second current collector, a second active material-containing layer provided on at least one surface of the second current collector, and an organic material; and a second film provided on.
  • a volume-based frequency distribution chart obtained by laser diffraction scattering has two peaks. Such an electrode group has excellent insulation properties.
  • Protection circuit 348a ...Plus side wiring (positive side wiring), 348a...Plus side wiring, 348b...Minus side wiring (negative side wiring), 348b...Minus side wiring, 350...External terminal, 352...Positive side terminal, 353...Negative side terminal, A...Front side, B...Back side, C...Front side, D...Back side.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

Un mode de réalisation de la présente invention concerne un groupe d'électrodes qui comprend une première structure d'électrode et une seconde structure d'électrode, dont au moins une partie fait face à la première structure d'électrode. La première structure d'électrode est pourvue : d'un premier collecteur ; d'une première couche contenant un matériau actif qui est disposée sur au moins une surface du premier collecteur ; et d'un premier film qui contient des particules inorganiques et est disposé sur la première couche contenant un matériau actif. La seconde structure d'électrode est pourvue : d'un second collecteur ; d'une seconde couche contenant un matériau actif qui est disposée sur au moins une surface du second collecteur ; et d'un second film qui contient un matériau organique et est disposé sur la seconde couche contenant un matériau actif. Par rapport au premier film, le diagramme de distribution de fréquence basé sur le volume tel qu'obtenu par un procédé de diffraction/diffusion laser présente deux pics.
PCT/JP2022/015801 2022-03-30 2022-03-30 Groupe d'électrodes, batterie secondaire et bloc-batterie WO2023188062A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/015801 WO2023188062A1 (fr) 2022-03-30 2022-03-30 Groupe d'électrodes, batterie secondaire et bloc-batterie

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/015801 WO2023188062A1 (fr) 2022-03-30 2022-03-30 Groupe d'électrodes, batterie secondaire et bloc-batterie

Publications (1)

Publication Number Publication Date
WO2023188062A1 true WO2023188062A1 (fr) 2023-10-05

Family

ID=88200280

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/015801 WO2023188062A1 (fr) 2022-03-30 2022-03-30 Groupe d'électrodes, batterie secondaire et bloc-batterie

Country Status (1)

Country Link
WO (1) WO2023188062A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997001870A1 (fr) * 1995-06-28 1997-01-16 Fuji Photo Film Co., Ltd. Batterie bivalente non aqueuse
JP2018160444A (ja) * 2017-03-23 2018-10-11 株式会社東芝 二次電池、電池パック、及び車両
JP2019153434A (ja) * 2018-03-01 2019-09-12 株式会社東芝 積層体及び二次電池

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997001870A1 (fr) * 1995-06-28 1997-01-16 Fuji Photo Film Co., Ltd. Batterie bivalente non aqueuse
JP2018160444A (ja) * 2017-03-23 2018-10-11 株式会社東芝 二次電池、電池パック、及び車両
JP2019153434A (ja) * 2018-03-01 2019-09-12 株式会社東芝 積層体及び二次電池

Similar Documents

Publication Publication Date Title
US10700327B2 (en) Secondary battery
EP3544084B1 (fr) Groupe d'électrode, batterie secondaire, bloc-batterie, véhicule et alimentation électrique stationnaire
KR101985092B1 (ko) 복합 전해질, 이차 전지, 전지 팩 및 차량
US11411284B2 (en) Laminate and secondary battery
JP6808667B2 (ja) 積層体、積層体の製造方法及び二次電池
JP6571284B2 (ja) 電極、非水電解質電池及び電池パック
CN110392953B (zh) 电极结构体及二次电池
WO2021186716A1 (fr) Électrode, corps multicouche et batterie secondaire
JP2019169300A (ja) 電極複合体、電極群、二次電池、電池パック及び車両
JP7254941B2 (ja) 電極、積層体及び二次電池
WO2023188062A1 (fr) Groupe d'électrodes, batterie secondaire et bloc-batterie
JP6702903B2 (ja) 二次電池
JP6924047B2 (ja) 二次電池
JP7242490B2 (ja) 電池用ユニット及び二次電池
US11888121B2 (en) Secondary battery, battery pack, and vehicle
US20230077637A1 (en) Electrode structure, secondary battery, battery pack, and vehicle
JP7286559B2 (ja) 電極群、非水電解質二次電池、電池パック及び車両
EP4333189A1 (fr) Séparateur pour batterie secondaire au lithium et son procédé de fabrication
EP4310935A1 (fr) Électrode positive, groupe d'électrodes, batterie secondaire et bloc-batterie
KR20230105111A (ko) 전기화학소자용 분리막 및 이를 포함하는 전기화학소자
KR20230026208A (ko) 리튬 이차전지용 분리막 및 이를 구비한 리튬 이차전지
KR20220161218A (ko) 전기화학소자용 세퍼레이터 및 이를 구비한 전기화학소자

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: 22935209

Country of ref document: EP

Kind code of ref document: A1