WO2023218315A1 - 二次電池及びその作製方法、及び車両 - Google Patents

二次電池及びその作製方法、及び車両 Download PDF

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Publication number
WO2023218315A1
WO2023218315A1 PCT/IB2023/054741 IB2023054741W WO2023218315A1 WO 2023218315 A1 WO2023218315 A1 WO 2023218315A1 IB 2023054741 W IB2023054741 W IB 2023054741W WO 2023218315 A1 WO2023218315 A1 WO 2023218315A1
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Prior art keywords
positive electrode
secondary battery
primary particles
particles
calcium
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English (en)
French (fr)
Japanese (ja)
Inventor
吉谷友輔
小國哲平
宮入典子
石谷哲二
平原誉士
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Semiconductor Energy Laboratory Co Ltd
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Semiconductor Energy Laboratory Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a positive electrode active material, a secondary battery, and a method for manufacturing the same. Or, it relates to a mobile information terminal or a vehicle having a secondary battery.
  • One embodiment of the present invention relates to a product or a manufacturing method. Alternatively, the invention relates to a process, machine, manufacture, or composition of matter. One embodiment of the present invention relates to a semiconductor device, a display device, a light emitting device, a power storage device, a lighting device, an electronic device, or a manufacturing method thereof.
  • a semiconductor device refers to any device that can function by utilizing semiconductor characteristics
  • an electro-optical device, a semiconductor circuit, and an electronic device are all semiconductor devices.
  • a power storage device refers to elements and devices in general that have a power storage function. Examples include a lithium ion secondary battery power storage device (also referred to as a secondary battery), a lithium ion capacitor, and an electric double layer capacitor.
  • lithium ion secondary batteries lithium ion capacitors, air batteries, and various power storage devices have been actively developed.
  • lithium ion secondary batteries with high output and high energy density are used in mobile information terminals such as mobile phones, smartphones, and notebook computers, portable music players, digital cameras, medical equipment, and hybrid vehicles (HVs).
  • HVs hybrid vehicles
  • EVs electric vehicles
  • PSVs plug-in hybrid vehicles
  • Patent Document 1 discloses a positive electrode active material for a lithium ion secondary battery containing calcium.
  • An object of one embodiment of the present invention is to provide a positive electrode active material that does not easily deteriorate.
  • the present invention aims to provide a novel positive electrode active material.
  • one of the challenges is to provide a secondary battery with high safety or reliability.
  • one of the challenges is to provide a secondary battery that does not easily deteriorate.
  • one of the challenges is to provide a long-life secondary battery.
  • one of the challenges is to provide a new secondary battery.
  • a material containing the same amount of transition metals, such as Ni:Co:Mn 1:1:1, contains a large amount of cobalt, which is a noble metal, and therefore tends to increase costs. Attempts are being made to increase the capacity of batteries by using less cobalt and more nickel.
  • NCM in which a large amount of nickel is used has a problem in that oxygen is easily desorbed and deterioration is likely to occur.
  • Another problem is that a phenomenon called cation mixing, in which transition metals such as nickel and manganese enter sites where lithium ions are inserted or desorbed during charging and discharging, tends to occur.
  • NCM NCM
  • Charging or discharging causes occlusion or desorption of lithium ions, causing the primary particles to expand or contract. Volume changes occur as the primary particles expand or contract, and secondary particles crack or become finer as the primary particles disaggregate.
  • One of the causes of cracking or refinement is that the a-axis or c-axis of the NCM crystal changes due to repeated charging or discharging, and the voids between primary particles become larger. Note that although the term "voids between primary particles" is used, it is not used in the sense of space; in the case of a secondary battery, an electrolytic solution is present at the position of the voids. However, in the case of an all-solid-state battery, it is a void.
  • a positive electrode in which a positive electrode active material layer formed on a current collector is formed by mixing powdered NCM with a conductive additive and binding the mixture with a binder.
  • the thickness of the thin layer containing calcium is less than 10 nm.
  • the thin layer containing calcium is an amorphous layer.
  • An amorphous layer has a lower density than a crystal and has voids (free volume), so its structure is relaxed.
  • it is preferable that the thin layer containing calcium further contains aluminum.
  • the calcium-containing layer may include silicon.
  • the layer containing calcium may further contain sulfur.
  • a calcium compound may be attached to at least a portion of the outer surface of the secondary particles.
  • the three-dimensional shape of the secondary particles is spherical or approximately spherical, and the calcium compound is attached so as to cover a part of the outermost surface.
  • the size of this calcium compound is 1 ⁇ m or more and 10 ⁇ m or less.
  • the calcium compound may have a crystalline structure or an amorphous structure.
  • the region to which the calcium compound is attached fixes the primary particles and protects the region that does not come into contact with the electrolyte when a secondary battery is produced.
  • calcium compounds are formed on the entire surface of the secondary particles, they may inhibit the movement of lithium ions during charging and discharging, so it is important to ensure that there are no calcium compounds covering the entire surface of the secondary particles. preferable.
  • the secondary particles are aggregates of a plurality of primary particles, and there are gaps between the primary particles within the secondary particles.
  • primary particles include polycrystals or single crystals.
  • the bond between the primary particles may be incomplete and the electrolytic solution may penetrate therethrough. In that case, there is a possibility that deterioration may be accelerated due to the electrolyte coming into contact with a portion where the bond between the primary particles is incomplete.
  • the electrolytic solution comes into contact with a portion where the bonds between the primary particles are incomplete, a film may be formed between the primary particles, and the distance between the primary particles may increase.
  • a thin layer containing calcium (amorphous layer) provided between two adjacent primary particles prevents the electrolyte from coming into contact with the incomplete bond between the primary particles, increasing the distance between the primary particles. can be prevented.
  • the thin layer (amorphous layer) containing calcium is not a film formed on the surface of the primary particle when the electrolyte comes into contact with it, but is already formed before the primary particle and the electrolyte come into contact with each other.
  • the configuration disclosed in this specification has a positive electrode, a negative electrode, and an electrolyte, the positive electrode has a positive electrode active material layer containing nickel, cobalt, and manganese, the positive electrode active material layer has secondary particles, and the positive electrode has a positive electrode active material layer containing secondary particles.
  • the primary particles include a plurality of primary particles, and a layer containing calcium exists between two adjacent primary particles among the plurality of primary particles, and the thickness of the layer containing calcium is 1 nm or more and 10 nm or less.
  • the layer containing calcium is amorphous.
  • the amorphous layer can fix the two primary particles like an adhesive, allowing them to function as one large particle that cannot be broken. Furthermore, lithium ions can be diffused through the amorphous layer and efficiently inserted into or desorbed from the particles.
  • the structure of the primary particles can be said to be positive electrode active material particles in which the surface layer part is NCMA and the inside part is NCM.
  • the amorphous layer has a lower density than the density inside the primary particle (polycrystal or single crystal) and is thought to be more resistant to deformation, so it can flexibly respond to physical changes even if expansion and contraction occur due to charging and discharging. be able to.
  • a thin film (an oxide film or a decomposition product of the electrolyte) may be formed.
  • the formation of a thin electrolyte film has advantages and disadvantages for secondary batteries. Specifically, a thin coating has the advantage of preventing cracking or excessive decomposition of the electrolyte, but has the disadvantage that it can be one of the factors for capacity reduction or deterioration.
  • the amorphous layer is a layer that is formed before contacting with an electrolytic solution used when producing a secondary battery, and is formed at the stage of forming a positive electrode active material layer on a positive electrode current collector. Further, this amorphous layer is not a film formed by contacting with an electrolytic solution. The amorphous layer formed before contacting the electrolyte can also prevent the formation of a film derived from the electrolyte.
  • pressing may be performed after mixing a conductive additive or a binder with multiple secondary particles, and pressing may apply external pressure. Even so, two particles connected by a thin layer (amorphous layer) containing calcium are difficult to break. Further, even if pressure is applied from the outside by pressing, a single particle is difficult to break even if a thin layer (amorphous layer) containing calcium is provided at the cracked portion.
  • the secondary particles are aggregates of at least two primary particles, and the number of primary particles forming the secondary particles includes various types such as 2, 3, 4, or more. . Therefore, one secondary particle may be a collection of aggregates of different numbers of primary particles. When the number of primary particles constituting the secondary particles is small, the surface area is relatively small, so the area where reaction with the electrolytic solution occurs is also reduced.
  • an oxide material having a density lower than that of the primary particles preferably 2.0 g/cm 3 or more and less than 3.3 g/cm 3 is provided between two adjacent primary particles. Even in this case, it is possible that the effects of the configuration disclosed in this specification can be obtained. Therefore, the following configurations are also effective without being limited to calcium or aluminum.
  • a positive electrode has a positive electrode active material including nickel, cobalt, and manganese
  • the positive electrode active material has secondary particles
  • the positive electrode has a positive electrode active material including secondary particles.
  • the primary particles include a plurality of primary particles, an amorphous layer exists between two adjacent primary particles among the plurality of primary particles, and the thickness of the amorphous layer is 1 nm or more and 10 nm or less. Secondary battery.
  • the density of the amorphous layer is lower than the density of the primary particles (the density of the crystalline portion of the polycrystal), and is preferably 2.0 g/cm 3 or more and less than 3.3 g/cm 3 .
  • the density is measured using, for example, X-ray reflectivity (XRR).
  • the elements contained in the amorphous layer in addition to calcium, strontium, barium, and magnesium, which are the same Group 2 elements as calcium, can be used. Further, in the above structure, as other elements contained in the amorphous layer, aluminum, gallium, and indium, which are the same Group 13 elements as aluminum, can be used. Further, in the above structure, silicon can be used as the other element contained in the amorphous layer. Further, in the above structure, sulfur can be used as the other element contained in the amorphous layer.
  • One embodiment of the present invention can provide a positive electrode active material that does not easily deteriorate.
  • a novel positive electrode active material can be provided.
  • a highly safe or reliable secondary battery can be provided.
  • a long-life secondary battery can be provided.
  • a new secondary battery can be provided.
  • FIG. 1A shows a photograph of a partial cross section of a secondary particle showing one embodiment of the present invention
  • FIG. 1B shows a schematic diagram thereof
  • FIG. 1C is a partially enlarged view of FIG. 1A
  • FIG. 2 is an enlarged cross-sectional view showing one embodiment of the present invention
  • 3A is a microelectron diffraction image at point 1-1 in FIG. 2
  • FIG. 3B is a microelectron diffraction image at point 1-2 in FIG. 2
  • FIG. 3C is a microelectron diffraction image at point 1-2 in FIG. 1-3 is a microelectron diffraction image.
  • FIG. 4A shows a cross-sectional STEM (Scanning Transmission Electron Microscope) photograph corresponding to FIG.
  • FIG. 5 is a schematic cross-sectional view of secondary particles to which deposits are attached.
  • FIG. 6 is a SEM photograph of the surface of secondary particles to which deposits are attached.
  • FIG. 7A is a scattered electron image (ZC) taken of a cross section near the surface of a secondary particle,
  • FIG. 7B is a schematic diagram thereof, and
  • FIG. 7C is a partially enlarged view of FIG. 7A.
  • FIG. 8A is a HAADF (High-angle Annular Dark Field Scanning TEM)-STEM image corresponding to FIG. 7A
  • FIGS. 8B, 8C, 8D, 8E, and 8F are images of each element. This is an EDX mapping image.
  • FIG. 9 is a diagram showing an example of a secondary particle manufacturing process.
  • FIG. 10 is a STEM image near the boundary line of the primary particle in FIG. 7A.
  • FIG. 11A and FIG. 11B are graphs showing density and composition Ca/Al ratio.
  • FIG. 12A is an exploded perspective view of a coin-type secondary battery
  • FIG. 12B is a perspective view of the coin-type secondary battery
  • FIG. 12C is a cross-sectional perspective view thereof.
  • FIG. 13A shows an example of a cylindrical secondary battery.
  • FIG. 13B shows an example of a cylindrical secondary battery.
  • FIG. 13C shows an example of a plurality of cylindrical secondary batteries.
  • FIG. 13D shows an example of a power storage system having a plurality of cylindrical secondary batteries.
  • 14A to 14C are diagrams illustrating examples of secondary batteries.
  • FIG. 15A and FIG. 15B are diagrams showing the appearance of the secondary battery.
  • 16A to 16C are diagrams illustrating a method for manufacturing a secondary battery.
  • FIG. 17A is a perspective view of a battery pack showing one embodiment of the present invention
  • FIG. 17B is a block diagram of the battery pack
  • FIG. 17C is a block diagram of a vehicle having the battery pack.
  • FIGS. 18A to 18D are diagrams illustrating an example of a transportation vehicle.
  • FIG. 18E is a diagram illustrating an example of an artificial satellite.
  • FIG. 19A is a diagram showing an electric bicycle
  • FIG. 19B is a diagram showing a secondary battery of the electric bicycle
  • FIG. 19C is a diagram explaining a scooter.
  • 20A and 20B are external views showing the charging station.
  • 21A and 21B are cross-sectional observation photographs of this example.
  • FIG. 22 is a cross-sectional observation photograph of a comparative example.
  • FIG. 23 is a graph showing the charge/discharge cycle characteristics of a secondary battery at 45° C., with the vertical axis representing the discharge capacity.
  • FIG. 24 is an example of a schematic cross-sectional view of a Taylor reactor.
  • FIG. 5 is a schematic cross-sectional view conceptually showing an example of the structure of one secondary particle constituting the positive electrode active material. Further, FIG. 5 is a schematic diagram showing one particle of powder in a state before contact with an electrolyte as a secondary battery, that is, before forming a positive electrode active material layer. In reality, as shown in the SEM photograph of the secondary particles in FIG. 6, a number of primary particles that are difficult to count constitute one spherical secondary particle. Note that in this specification, the term spherical does not refer to a true spherical shape, but has a broad meaning including an elliptical sphere or a distorted spherical shape.
  • FIG. 5 shows four main characteristics.
  • the first is the presence of the amorphous layer 11, the second is the presence of the amorphous layer 12, the third is the presence of the protective layer CA, and the fourth is the presence of the protective layer AL.
  • FIG. 6 shows in which one secondary particle has up to three characteristics, but there is no particular limitation, and a certain secondary particle can have one characteristic. However, it is also possible to consider a modification in which other secondary particles have other characteristics, and it is preferable to have one or more characteristics among a large number of secondary particles. When at least one of the many secondary particles has at least the first or second characteristic, the adhesion between the primary particles is improved.
  • the present inventors discovered that, as shown in FIG. It has been found that by providing a thin layer containing calcium (amorphous layer 11) between the surface and the second surface, cracking of secondary particles can be reduced. By providing an amorphous layer between the primary particles, it is possible to realize a positive electrode active material layer with fewer cracks in the secondary particles as a whole.
  • FIG. 1A is a SEM photograph of a part of the inside of a secondary particle according to one of the present embodiments
  • FIG. 1B is a schematic diagram thereof.
  • a total of two primary particles, a primary particle 10a and a primary particle 10b can be confirmed. It can be seen that there is almost no gap between the primary particles 10a and 10b. Further, although there is almost no gap between the primary particles 10a and 10b, a thin amorphous layer 11 is present.
  • FIG. 1C is an enlarged view of the boundary between the primary particles 10a and 10b.
  • the boundary between the primary particles 10a and 10b is partially straight and can be clearly seen.
  • FIG. 2 is an enlarged view of the same location as FIG. 1C
  • FIG. 3 shows the results of analysis using microelectron diffraction at three points.
  • points 1-1 and 1-3 clear spots (diffraction patterns consistent with a layered rock salt type) can be seen, indicating high crystallinity.
  • points 1-1 and 1-3 have a layered rock salt type crystal structure.
  • point 1-2 which is near the boundary between the two primary particles, the diffraction pattern is unclear, and it can be seen from the microelectron diffraction image in FIG. 3B that this is a region with low crystallinity. This region with low crystallinity is also called an amorphous region.
  • FIG. 4A shows EDX-ray extraction in the vicinity of the boundary, that is, a straight line section from point P1 to point P2 of the amorphous layer, and the results are shown in a table.
  • EDX-ray extraction results shown in FIG. 4A aluminum, calcium, sulfur, silicon, and calcium are detected.
  • FIG. 4B shows EDX-ray extraction for a straight line portion from point P3 to point P4, with the position shifted parallel to the straight line from P1 to P2.
  • the thin amorphous layer is capable of diffusing lithium, and hardly inhibits the movement of lithium ions during charging and discharging. Further, when an amorphous layer exists between two primary particles located on the surface of the secondary particles, the side surface of the amorphous layer comes into contact with the electrolyte. Lithium thus moves from the electrolyte region into the amorphous layer and from the amorphous layer into the primary particles. Therefore, electrically, the amorphous layer functions as one of the paths for lithium.
  • the amorphous layer fixes two primary particles like an adhesive and functions as a particle group of one large particle that cannot be broken.
  • the present inventors have found that cracking of the secondary particles can also be reduced by providing a protective layer CA on the outside of the secondary particles as shown in FIG.
  • a protective layer CA By providing the protective layer CA, a part of the surface of the secondary particles can be fixed and protected. Further, in FIG. 6, it can be seen that the protective layer CA is provided on the outside of the secondary particles.
  • the protective layer CA is a composite oxide containing lithium carbonate, calcium, or a mixture thereof.
  • a protective layer CA which looks like a deposit, can be seen on the secondary particles, and when the surface of this part is analyzed by SEM-EDX, calcium is detected, so it is assumed that they are lumps of calcium oxide.
  • a protective layer AL that looks like a deposit can be seen in other parts, and when that part is analyzed by EDX, aluminum is detected, so it is assumed that it is a lump of aluminum oxide.
  • FIG. 7A a cross-sectional STEM image of a portion of the surface of the secondary particles is shown in FIG. 7A, and adjacent primary particles 10c and 10d and their boundary regions can be confirmed.
  • FIG. 7B the schematic diagram of FIG. 7A is FIG. 7B.
  • EDX a thin amorphous layer 12 exists in the boundary area between adjacent primary particles, and calcium is detected in the amorphous layer 12 by EDX.
  • aluminum is also detected in the thin amorphous layer 12 by EDX.
  • the center of the primary particle 10d aluminum and calcium were not detected by EDX, that is, at the lower limit of detection.
  • FIG. 7C shows an enlarged photograph of the surface layer portion of one primary particle 10d among the adjacent primary particles 10c and 10d, which is the dotted line in FIG. 7B.
  • the inside was at the lower limit of detection.
  • the layer containing aluminum (dark area) was confirmed to be NCM containing aluminum, and no aluminum was detected in the inner NCM portion.
  • FIG. 7B is different from the location in FIG. 1C, and at least two thin amorphous layers are present. Note that the location in FIG. 7B is close to the outermost surface of the secondary particle, and the location in FIG. 1C is close to the center of the secondary particle.
  • the thin amorphous layer contributes to increasing the adhesion between the primary particles both inside the secondary particles and on the surface of the secondary particles.
  • the protective layer CA or protective layer AL which is like a deposit, is also adhered to the surface of the secondary particles, and as a result, the reliability is improved, that is, the cracking of the secondary particles is reduced or This can contribute to suppressing an increase in resistance (Li diffused resistance).
  • Embodiment 2 In Embodiment 1, a thin amorphous layer between primary particles has been described, but in this embodiment, a manufacturing method for forming a thin amorphous layer between primary particles will be described below. The figure shows an example of the manufacturing flow for forming a thin amorphous layer between primary particles.
  • raw materials are prepared depending on the type of positive electrode active material.
  • an aqueous solution in which at least a transition metal salt is dissolved is prepared.
  • An aqueous solution in which a transition metal salt is dissolved can be referred to as a transition metal source.
  • the pH value of the aqueous solution in which the transition metal salt is dissolved is less than 7, preferably when the pH value is 1 or more and 6 or less, the aqueous solution exhibits acidity and can be described as an acidic aqueous solution.
  • the transition metal may be one or more selected from manganese, cobalt, and nickel. Specifically, as the transition metal, only cobalt, only nickel, two types of cobalt and manganese, two types of cobalt and nickel, or cobalt, manganese, and nickel are used. Three types may be used.
  • the above X, Y, and Z may be expressed as the mixing ratio of nickel, cobalt, and manganese, and when the mixing ratios described above as X, Y, and Z are satisfied, a layered rock salt type crystal structure can be obtained.
  • the above mixing ratio can be measured by analysis using X-ray photoelectron spectroscopy (XPS), inductively coupled plasma mass spectrometry (ICP-MS), or energy dispersive X-ray spectroscopy (TEM-EDX).
  • XPS X-ray photoelectron spectroscopy
  • ICP-MS inductively coupled plasma mass spectrometry
  • TEM-EDX energy dispersive X-ray spectroscopy
  • the proportion of nickel among the transition metals is high, since it is possible to form an inexpensive and high-capacity positive electrode active material.
  • the number of atoms of nickel is preferably 33 or more, more preferably 50 or more, and 80 or more. and even more preferable.
  • the proportion of nickel is too high, chemical stability and heat resistance may decrease. Therefore, when the sum of the numbers of atoms of nickel, cobalt, and manganese contained in the positive electrode active material is 100, it is preferable that the number of atoms of nickel is 95 or less.
  • cobalt When cobalt is included as the transition metal, the average discharge voltage is high, and since cobalt contributes to stabilizing the layered rock-salt structure, a highly reliable secondary battery can be obtained.
  • cobalt is more expensive than nickel and manganese and is unstable, so if the proportion of cobalt is too high, production costs may increase. Therefore, for example, when the sum of the numbers of atoms of nickel, cobalt, and manganese contained in the positive electrode active material is 100, it is preferable that the number of cobalt atoms is 2.5 or more and 34 or less.
  • manganese as the transition metal because heat resistance and chemical stability are improved. However, if the proportion of manganese is too high, the discharge voltage and discharge capacity tend to decrease. Therefore, for example, when the sum of the numbers of atoms of nickel, cobalt, and manganese contained in the positive electrode active material is 100, it is preferable that the number of atoms of manganese is 2.5 or more and 33 or less.
  • an aqueous solution in which a transition metal salt is dissolved will be explained.
  • an aqueous solution in which the transition metal salt is dissolved an aqueous solution in which the above-mentioned nickel salt is dissolved, or an aqueous solution containing a water-soluble salt of nickel can be used.
  • an aqueous solution in which nickel sulfate or nickel nitrate is dissolved in water is used. I can do it.
  • nickel ions may be present, and nickel may be present as a complex.
  • an aqueous solution in which the transition metal salt is dissolved an aqueous solution in which a cobalt salt is dissolved or an aqueous solution containing a water-soluble salt of cobalt can be used.
  • an aqueous solution in which cobalt sulfate or cobalt nitrate is dissolved in water is used. be able to.
  • Cobalt ions may be present in the aqueous solution, and cobalt may be present as a complex.
  • an aqueous solution in which a manganese salt is dissolved or an aqueous solution containing a water-soluble salt of manganese can be used, and an aqueous solution in which manganese sulfate or manganese nitrate is dissolved in water can be used.
  • Manganese ions may be present in the aqueous solution, and manganese may be present as a complex.
  • the aqueous solution in which the transition metal salt is dissolved has high purity, and it is preferable to use pure water as the aqueous solution.
  • the concentration of transition metal ions in the aqueous solution in which the transition metal salt is dissolved is 1 mol/L or more and 5 mol/L or less, preferably 2 mol/L or more and 3 mol/L or less.
  • the aqueous solution contains a plurality of transition metal salts, it is sufficient that the total concentration of transition metal ions satisfies the above range.
  • an aqueous solution in which cobalt salt, manganese salt, and nickel salt are dissolved can be used as the aqueous solution in which transition metal salts are dissolved.
  • an aqueous solution in which nickel sulfate, cobalt sulfate, and manganese sulfate are dissolved can be used as an aqueous solution in which a transition metal salt is dissolved.
  • Sulfide may be used to add sulfur to the amorphous layer that is formed later. Furthermore, in order to add silicon to the amorphous layer that will be formed later, a material containing a small amount of silicon may be used as a raw material.
  • an aqueous solution exhibiting alkalinity (referred to as an alkaline aqueous solution) is prepared.
  • the alkaline aqueous solution refers to an aqueous solution having a pH value of greater than 7, preferably an aqueous solution having a pH value of 8 or more.
  • an aqueous solution containing sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia can be used as the alkaline aqueous solution.
  • an aqueous solution of sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia dissolved in water can be used.
  • An aqueous solution in which a plurality of selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia are dissolved in water may be used. It is preferable to use pure water as the water.
  • the alkali concentration of the alkaline aqueous solution is 1 mol/L or more and 10 mol/L or less, preferably 3 mol/L or more and 7 mol/L or less. When the aqueous solution contains a plurality of alkalis, the total concentration of the alkalis should just satisfy the above range.
  • the pure water used for the aqueous solution in which the transition metal salt is dissolved and the alkaline aqueous solution is water with a specific resistance of 1 M ⁇ cm or more, more preferably water with a specific resistance of 10 M ⁇ cm or more, and still more preferably 15 M ⁇ cm or more. water is preferred. Water that satisfies the specific resistance has high purity and contains very few impurities.
  • Step S203 Mixing step> Next, the above two aqueous solutions are mixed to produce a mixed aqueous solution (referred to as a mixed solution or coprecipitation mixed solution).
  • a mixed solution or coprecipitation mixed solution the aqueous solution in which the transition metal salt is dissolved can be reacted with the alkaline aqueous solution.
  • the reaction may be referred to as a neutralization reaction, an acid-base reaction, or a coprecipitation reaction.
  • a coprecipitate is precipitated.
  • a hydroxide is formed as a coprecipitate.
  • the temperature of the mixed liquid and the pH value of the mixed liquid may be kept constant, and the mixed liquid may be further stirred.
  • the above temperature is preferably 40°C or more and 90°C or less, preferably 45°C or more and 70°C or less.
  • the pH value is preferably 9.0 or more and 13.0 or less, preferably 10.5 or more and 11.5 or less.
  • the rotational speed of the stirring is preferably 800 rpm or more and 1200 rpm or less, preferably 900 rpm or more and 1100 rpm or less.
  • a coprecipitate is precipitated in the mixed liquid as a reaction product.
  • a coprecipitate may precipitate in a mixed solution and is sometimes referred to as a precipitate.
  • the mixture may become a suspension.
  • a suspension refers to a liquid in which coprecipitate particles are dispersed in a liquid.
  • Step S205 Filtration step> Next, the mixture is filtered to obtain a coprecipitate from the mixture. Specifically, a coprecipitate is taken out from the mixed solution. It is recommended to use suction filtration for filtration.
  • the coprecipitate has a size (long axis) of 1 ⁇ m or more and 20 ⁇ m or less. Further, an ordinal number may be attached to the coprecipitate obtained by filtration to distinguish it from the coprecipitate present in the mixed solution, and this may be referred to as a filtered powder.
  • a hydroxide containing a transition metal is obtained as a coprecipitate.
  • a hydroxide containing cobalt, manganese, and nickel is produced as a coprecipitate (composite hydroxide containing cobalt, manganese, and nickel). ) is obtained.
  • the coprecipitate obtained by filtration typically hydroxide, contains impurities such as water.
  • the hydroxide obtained as a coprecipitate may become secondary particles in which primary particles are aggregated.
  • the primary particles refer to the smallest unit particles (agglomerates) that are observed when observed at a magnification of, for example, 20,000 times using a SEM (scanning electron microscope). In other words, primary particles are the smallest unit particles.
  • secondary particles refers to particles (particles that are independent from others) that are aggregated so that the primary particles share a part of the grain boundary (the outer periphery of the primary particles) and are not easily separated.
  • Step S207 Cleaning process>
  • the coprecipitate is washed to obtain a hydroxide from which impurities have been removed.
  • Cleaning using water can be applied to the cleaning in the main cleaning step. Cleaning using water is sometimes referred to as water washing. Note that washing with water can be repeated once or multiple times. Impurities can be removed to some extent from the coprecipitate by washing with water. Distilled water or pure water may be used as the water.
  • suction filtration may be performed after washing the coprecipitate with water. Furthermore, when washing with water is repeated multiple times, it is advisable to perform suction filtration after washing with water.
  • cleaning using an organic solvent can be applied to the above-mentioned cleaning.
  • cleaning using an organic solvent can be repeated once or multiple times.
  • the coprecipitate can be dried by washing with an organic solvent. The drying process includes removing water or moisture adhering from the previous washing.
  • acetone or alcohol such as isopropanol (typically isopropyl alcohol) may be used.
  • suction filtration may be performed after washing the coprecipitate with an organic solvent. Further, when washing with an organic solvent is repeated multiple times, it is preferable to perform suction filtration after washing with the organic solvent.
  • the above-mentioned cleaning can be applied in combination of washing with water and washing using an organic solvent. If suction filtration is used, a step of washing with water and then suction filtration can be carried out, and then a step of washing with an organic solvent and then suction filtration can be carried out. At this time, it is preferable that the number of times of washing with water is greater than the number of times of washing with an organic solvent.
  • the heating step is a step of heating the coprecipitate, resulting in a precursor from which sufficient impurities have been removed. That is, the precursor can be obtained through the main heating step.
  • an oxide is generated as the positive electrode active material, among the hydroxides in the pre-generation stage, impurities are sufficiently removed through the heating step of one embodiment of the present invention.
  • the precursor can also be called a nickel compound if the proportion of nickel is high.
  • the main heating step includes a dehydration step.
  • water or moisture contained in the coprecipitate can be removed by this heating step.
  • the main heating step includes a drying step.
  • impurities can also be gasified and removed in this heating step.
  • the organic solvent used in the cleaning step can also be removed by the main heating step.
  • the upper limit of the heating temperature in this step is preferably lower than the temperature at which hydroxide, which is a coprecipitate, begins to change into an oxide. That is, it is preferable that the hydroxide is not changed into the oxide in the main heating step.
  • the temperature at which hydroxide changes to oxide can be determined by thermogravimetry-differential thermal analysis (TG-DTA).
  • the curve showing TG shows weight loss in the region
  • the curve showing DTA shows a range of 210°C to 230°C, typical Generally, the temperature starts to decrease at or around 220°C, and the maximum endothermic peak is observed at or around 260°C. From this result, 220°C is derived as the temperature at which hydroxide begins to decompose, dehydrate, or reduce, that is, the temperature at which hydroxide begins to change to oxide, and 220°C can be set as the upper limit of the temperature for heat treatment. .
  • the temperature of the heat treatment is higher because the treatment progresses more easily, the treatment time is shorter, and the productivity is higher.
  • the lower limit of the heat treatment temperature may be at least a temperature that can remove water or moisture from the hydroxide.
  • the removal of water or moisture is also called drying.
  • the specific temperature of the heat treatment is preferably 130°C or more and 220°C or less, preferably 150°C or more and 220°C or less, and more preferably 180°C or more and 220°C or less.
  • the heat treatment time in this heating step is preferably 3 hours or more and 15 hours or less, preferably 8 hours or more and 15 hours or less, preferably 10 hours or more and 13 hours or less, and more preferably 11 hours or more and 12 hours or less.
  • the atmosphere for the heat treatment in the main heating step is preferably an atmosphere that does not contain oxygen.
  • An atmosphere that does not contain oxygen is referred to as a non-oxygen atmosphere.
  • a dry atmosphere, a vacuum atmosphere, or an inert atmosphere typically a nitrogen atmosphere or an argon atmosphere
  • the dew point inside the container is preferably -40°C or lower, preferably -80°C or lower.
  • a bell jar type vacuum device can be used that includes a container (referred to as a bell jar) that can evacuate the inside and a vacuum pump connected to the bell jar.
  • a vacuum drying furnace when heating is performed in a vacuum atmosphere, a vacuum drying furnace may be used, and the vacuum drying furnace has a vacuum pump connected to the drying furnace.
  • a dry pump, a turbo molecular pump, an oil rotary pump, a cryopump, or a mechanical booster pump can be used as the vacuum pump included in the bell jar type vacuum device and the vacuum drying furnace.
  • the vacuum atmosphere in the bell jar type vacuum device and the vacuum drying furnace includes an atmosphere in which the pressure is reduced so that the differential pressure gauge of each device is ⁇ 0.1 MPa or more and less than ⁇ 0.08 MPa.
  • a gas containing nitrogen may be flowed into a container included in a bell jar type vacuum device and a vacuum drying furnace.
  • the heat treatment in the main heating step may be performed in multiple stages. For example, it can be carried out at a first temperature for a first time and then at a second temperature for a second time. It is sufficient that the second temperature satisfies the temperature range of the heat treatment described above.
  • the first temperature is lower than the second temperature, for example, in a range of 80°C or higher and lower than 90°C.
  • the second time may satisfy the range of the heat treatment time described above.
  • the first time is shorter than the second time, for example, 0.5 hours or more and 1 hour or less. Multi-stage treatment is preferred because impurities can be easily removed from the precursor.
  • the method for producing the precursor may include up to the main heating step. That is, the precursor can be obtained through the main heating step.
  • an amorphous layer may be formed between the primary particles after the main heating step.
  • the amorphous layer in this case is presumed to be silicon or an oxide containing sulfur.
  • the precursor after the main heating step is a powder, and a plurality of primary particles are aggregated to form secondary particles having voids inside.
  • the voids in the secondary particles do not exist as hollow structures, and when a liquid is brought into contact with the powder, the liquid enters from the outside and fills the voids in the secondary particles.
  • a lithium source is provided.
  • the ratio of the lithium source to the precursor (lithium source/precursor) is set to be 0.90 or more and 1.05 or less, preferably 0.92 or more and 1.01 or less.
  • a lithium compound can be used as the lithium source.
  • Lithium compounds include lithium hydroxide, lithium carbonate, or lithium nitrate. It is preferable that the lithium source has high purity. Further, it is preferable that the lithium source is pulverized so that the solid phase reaction can proceed easily. In order to prevent the particle size of the lithium source from being too large compared to the particle size of the precursor, it is preferable to adjust the particle size by pulverizing the lithium source before mixing, which is a subsequent step.
  • lithium hydroxide has a melting point of 462° C., which is the lowest among lithium compounds.
  • a lithium compound with a low melting point such as lithium hydroxide, is preferably used when producing a positive electrode active material containing a high proportion of nickel.
  • Step S211 Mixing process> The precursor is then processed using solid phase methods. Specifically, in step S211 of FIG. 9, a lithium source is mixed with a precursor to produce a mixture. When distinguishing from the previous mixing step, this mixing step may be given an ordinal number. In the present invention, the mixing in this step may be carried out in a dry or wet manner.
  • a ball mill, bead mill, or kneader can be used for mixing.
  • a ball mill it is preferable to use zirconia balls as the media, for example.
  • Step S213 Heating process> The mixture is then heated.
  • an ordinal number may be given to the heating step of this step.
  • the heating conditions for this step are preferably heating at a first temperature and then heating at a second temperature. Heating at the first temperature may be referred to as first firing, and heating at the second temperature may be referred to as second firing. Note that the second firing may be performed without performing the first firing. That is, this step may be performed only once.
  • the second temperature is preferably higher than the first temperature.
  • heating at the first temperature may be referred to as preliminary firing
  • heating at the second temperature may be referred to as main firing. Note that main firing may be performed without performing preliminary firing. However, when lithium hydroxide is used as a lithium source, it is preferable to perform temporary calcination.
  • the first temperature is preferably higher than the melting point of the lithium source.
  • the first temperature is preferably 500°C or higher and 700°C or lower.
  • the second temperature is preferably higher than 500°C and lower than 1050°C, and when the second temperature is higher than the first temperature, the second temperature is preferably higher than 700°C and lower than 1050°C.
  • the heating time at the first temperature and the heating time at the second temperature are preferably 1 hour or more and 20 hours or less, respectively. Heating at the first temperature may be equal to, longer than, or shorter than the time of heating at the second temperature.
  • the heating at the first temperature and the heating at the second temperature are preferably performed in an oxygen atmosphere, and particularly preferably performed while supplying oxygen.
  • the flow rate may be set to 2 L/min or more and 15 L/min or less, preferably 5 L/min or more and 10 L/min or less per 1 L of internal volume of the furnace.
  • the heating atmosphere at the first temperature may be the same as or different from the heating atmosphere at the second temperature.
  • an electric furnace or a rotary kiln furnace can be used as the firing device used for heating at the first temperature and the second temperature.
  • the firing device used for heating at the first temperature may be the same as or different from the firing device used for heating at the second temperature.
  • the mixture may be placed in a crucible or pod.
  • a crucible made of aluminum oxide with a purity of 99.9% is used.
  • the lid may be placed so that the inside of the crucible is isolated from the air inside the furnace, or it may be placed so that it is partially open so that the inside of the crucible can come into contact with the inside air of the furnace.
  • a state where the mixtures are stuck to each other or agglomerated between the mixtures can be loosened by crushing or crushing. If the mixture sticks to each other during heating, the contact area with oxygen in the atmosphere may decrease, so it is preferable to crush or crush the mixture as described above. Furthermore, after pulverization or crushing, it may be classified using a sieve.
  • the mortar is also preferably made of a material that does not easily release impurities.
  • an amorphous layer may be formed between the primary particles after the main heating step.
  • the amorphous layer in this case is presumed to be an oxide containing lithium, silicon, or sulfur.
  • an additive element source is prepared.
  • the source of the additional element aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum nitrate, calcium oxide, calcium carbonate, calcium hydroxide, or calcium sulfate can be used.
  • the additive element source is weighed so that the additive element is 0.1 atm % or more and 5 atm % or less of the composite oxide (for example, NCM).
  • a plurality of additive elements may be included. When a plurality of additive elements are included, the total concentration of the additive elements may be 0.1 atm % or more and 5 atm % or less of the composite oxide (for example, NCM).
  • two types of particles are used: calcium carbonate with a reduced particle size and aluminum hydroxide with a reduced particle size so as to be smaller than the size of the secondary particles of NCM.
  • Step S216 Mixing step>
  • the composite oxide and the additive element source are mixed to produce a mixture.
  • the mixing in this step is similar to step S211 in manufacturing method 1.
  • Step S217 Heating process>
  • the mixture is heated. Heating in this step is similar to step S213 described above.
  • calcium is not detected inside or on the surface of the primary particles after the heating step. Therefore, although calcium is scattered inside the secondary particles, that is, between the primary particles, it is not present inside or on the surface of the primary particles.
  • Calcium exists so as to surround each primary particle inside the secondary particles, and contributes to suppressing the amount of change in the a-axis or c-axis of the plurality of crystals constituting the primary particle.
  • calcium exists surrounding each primary particle inside the secondary particles, which contributes to suppressing oxygen desorption, and the effect of suppressing oxygen desorption is particularly strong under high temperatures or high charging voltages. big.
  • the primary particles have a core-shell structure, that is, a structure in which the surface layer portion contains aluminum and the inside does not contain aluminum.
  • the secondary particles have a spherical shape with a D50 of 5 ⁇ m or more and 15 ⁇ m or less.
  • D50 refers to the particle diameter when the cumulative distribution of secondary particles is 50%, which is calculated from a particle size distribution analyzer (SALD-2200 manufactured by Shimadzu Corporation) using a laser diffraction/scattering method. Measurement of particle size is not limited to laser diffraction particle size distribution measurement, and the major axis of a particle cross section may be measured by analysis using SEM or TEM (Transmission Electron Microscope).
  • SEM Transmission Electron Microscope
  • an integrated particle amount curve is created, and the particle diameter when the integrated amount accounts for 50% is defined as D50. be able to.
  • NCM also referred to as nickel-cobalt-manganese composite oxide
  • NCM nickel-cobalt-manganese composite oxide
  • the manufactured positive electrode active material is a powder, and a plurality of primary particles are aggregated to form secondary particles having voids inside.
  • the electrolytic solution has entered this gap at the stage of fabricating the secondary battery.
  • an amorphous layer may be formed between the primary particles.
  • the primary particles are fixed by forming an amorphous layer between the primary particles.
  • the amorphous layer in this case is presumed to be an oxide containing calcium, aluminum, lithium, silicon, or sulfur. Therefore, the amorphous layer has high lithium ion conductivity and has the effect of promoting the movement of lithium ions during charging and discharging of the secondary battery. Furthermore, since a portion of the amorphous layer comes into contact with the electrolyte and can serve as a conduction path for lithium ions, the overall reaction resistance of the positive electrode active material layer can be reduced and the output characteristics can be improved.
  • a calcium compound or an aluminum compound adheres or adheres to the surface of the secondary particles, covers a part of the surface of the secondary particles, and functions as a protective layer or a barrier layer.
  • calcium compounds or aluminum compounds are formed on the entire surface of the secondary particles, they may inhibit the movement of lithium ions during charging and discharging, so it is important that there are no calcium compounds on the entire surface of the secondary particles. preferable.
  • FIG. 12A is an exploded perspective view of a coin-shaped (single-layer flat type) secondary battery
  • FIG. 12B is an external view
  • FIG. 12C is a cross-sectional view thereof.
  • Coin-shaped secondary batteries are mainly used in small electronic devices.
  • FIG. 12A is a schematic diagram so that the overlapping (vertical relationship and positional relationship) of members can be seen. Therefore, FIGS. 12A and 12B are not completely identical corresponding views.
  • a positive electrode 304, a separator 310, a negative electrode 307, a spacer 322, and a washer 312 are stacked. These are sealed with a negative electrode can 302 and a positive electrode can 301 with a gasket. Note that in FIG. 12A, a gasket for sealing is not shown.
  • the spacer 322 and the washer 312 are used to protect the inside or fix the position inside the can when the positive electrode can 301 and the negative electrode can 302 are crimped together.
  • the spacer 322 and washer 312 are made of stainless steel or an insulating material.
  • a positive electrode 304 has a laminated structure in which a positive electrode active material layer 306 is formed on a positive electrode current collector 305 .
  • FIG. 12B is a perspective view of the completed coin-shaped secondary battery.
  • a positive electrode can 301 that also serves as a positive electrode terminal and a negative electrode can 302 that also serves as a negative electrode terminal are insulated and sealed with a gasket 303 made of polypropylene.
  • the positive electrode 304 is formed by a positive electrode current collector 305 and a positive electrode active material layer 306 provided in contact with the positive electrode current collector 305 .
  • the negative electrode 307 is formed of a negative electrode current collector 308 and a negative electrode active material layer 309 provided in contact with the negative electrode current collector 308. Further, the negative electrode 307 is not limited to a laminated structure, and lithium metal foil or lithium-aluminum alloy foil may be used.
  • the positive electrode 304 and the negative electrode 307 used in the coin-shaped secondary battery 300 may each have an active material layer formed only on one side.
  • the positive electrode can 301 and the negative electrode can 302 metals such as nickel, aluminum, and titanium, which are corrosion resistant to electrolyte, or alloys thereof, or alloys of these and other metals (for example, stainless steel) can be used. Further, in order to prevent corrosion caused by electrolyte, it is preferable to coat with nickel or aluminum.
  • the positive electrode can 301 is electrically connected to the positive electrode 304, and the negative electrode can 302 is electrically connected to the negative electrode 307.
  • negative electrode 307, positive electrode 304, and separator 310 are immersed in an electrolytic solution, and as shown in FIG. 12C, the positive electrode 304, separator 310, negative electrode 307, and negative electrode can 302 are stacked in this order with the positive electrode can 301 facing down. 301 and a negative electrode can 302 are crimped together via a gasket 303 to produce a coin-shaped secondary battery 300.
  • the cylindrical secondary battery 616 has a positive electrode cap (battery lid) 601 on the top surface and a battery can (exterior can) 602 on the side and bottom surfaces. These positive electrode cap 601 and battery can (exterior can) 602 are insulated by a gasket (insulating packing) 610.
  • FIG. 13B is a diagram schematically showing a cross section of a cylindrical secondary battery.
  • the cylindrical secondary battery shown in FIG. 13B has a positive electrode cap (battery lid) 601 on the top surface and a battery can (exterior can) 602 on the side and bottom surfaces.
  • These positive electrode cap 601 and battery can (exterior can) 602 are insulated by a gasket (insulating packing) 610.
  • a battery element is provided inside the hollow cylindrical battery can 602, in which a band-shaped positive electrode 604 and a negative electrode 606 are wound with a separator 605 in between.
  • the battery element is wound around a central axis.
  • the battery can 602 has one end closed and the other end open.
  • metals such as nickel, aluminum, and titanium, which are corrosion resistant to electrolyte, or alloys thereof, or alloys of these and other metals (for example, stainless steel) can be used. Further, in order to prevent corrosion caused by the electrolyte, it is preferable to coat the battery can 602 with nickel and aluminum.
  • a battery element in which a positive electrode, a negative electrode, and a separator are wound is sandwiched between a pair of opposing insulating plates 608 and 609. Furthermore, a non-aqueous electrolyte (not shown) is injected into the inside of the battery can 602 in which the battery element is provided.
  • the non-aqueous electrolyte the same one as a coin-type secondary battery can be used.
  • the positive electrode and negative electrode used in a cylindrical storage battery are wound, it is preferable to form an active material on both sides of the current collector.
  • a positive electrode terminal (positive electrode current collector lead) 603 is connected to the positive electrode 604, and a negative electrode terminal (negative electrode current collector lead) 607 is connected to the negative electrode 606.
  • Both the positive electrode terminal 603 and the negative electrode terminal 607 can be made of a metal material such as aluminum.
  • the positive terminal 603 and the negative terminal 607 are resistance welded to the safety valve mechanism 613 and the bottom of the battery can 602, respectively.
  • the safety valve mechanism 613 is electrically connected to the positive electrode cap 601 via a PTC element (Positive Temperature Coefficient) 611. The safety valve mechanism 613 disconnects the electrical connection between the positive electrode cap 601 and the positive electrode 604 when the increase in the internal pressure of the battery exceeds a predetermined threshold value.
  • the PTC element 611 is a heat-sensitive resistance element whose resistance increases when the temperature rises, and the increase in resistance limits the amount of current to prevent abnormal heat generation.
  • Barium titanate (BaTiO 3 )-based semiconductor ceramics can be used for the PTC element.
  • FIG. 13C shows an example of the power storage system 615.
  • Power storage system 615 includes a plurality of secondary batteries 616.
  • the positive electrode of each secondary battery contacts a conductor 624 separated by an insulator 625 and is electrically connected.
  • the conductor 624 is electrically connected to the control circuit 620 via the wiring 623.
  • the negative electrode of each secondary battery is electrically connected to the control circuit 620 via a wiring 626.
  • As the control circuit 620 a charge/discharge control circuit or a protection circuit that prevents overcharging and/or overdischarging can be applied.
  • FIG. 13D shows an example of the power storage system 615.
  • the power storage system 615 includes a plurality of secondary batteries 616, and the plurality of secondary batteries 616 are sandwiched between a conductive plate 628 and a conductive plate 614.
  • the plurality of secondary batteries 616 are electrically connected to a conductive plate 628 and a conductive plate 614 by wiring 627.
  • the plurality of secondary batteries 616 may be connected in parallel, connected in series, or connected in parallel and then further connected in series.
  • the plurality of secondary batteries 616 may be connected in parallel and then further connected in series.
  • a temperature control device may be provided between the plurality of secondary batteries 616.
  • the secondary battery 616 When the secondary battery 616 is overheated, it can be cooled by the temperature control device, and when the secondary battery 616 is too cold, it can be heated by the temperature control device. Therefore, the performance of power storage system 615 is less affected by outside temperature.
  • the power storage system 615 is electrically connected to the control circuit 620 via wiring 621 and wiring 622.
  • the wiring 621 is electrically connected to the positive electrodes of the plurality of secondary batteries 616 via the conductive plate 628
  • the wiring 622 is electrically connected to the negative electrodes of the plurality of secondary batteries 616 via the conductive plate 614.
  • a secondary battery 913 having a wound body 950a as shown in FIG. 14A may be used.
  • a wound body 950a shown in FIG. 14A includes a negative electrode 931, a positive electrode 932, and a separator 933.
  • the negative electrode 931 has a negative electrode active material layer 931a.
  • the positive electrode 932 has a positive electrode active material layer 932a.
  • the separator 933 has a width wider than the negative electrode active material layer 931a and the positive electrode active material layer 932a, and is wound so as to overlap with the negative electrode active material layer 931a and the positive electrode active material layer 932a. Further, from the viewpoint of safety, it is preferable that the width of the negative electrode active material layer 931a is wider than that of the positive electrode active material layer 932a. Further, the wound body 950a having such a shape is preferable because it has good safety and productivity.
  • the separator 933 has a width wider than the negative electrode active material layer 931a and the positive electrode active material layer 932a, and is wound so as to overlap with the negative electrode active material layer 931a and the positive electrode active material layer 932a. Further, from the viewpoint of safety, it is preferable that the width of the negative electrode active material layer 931a is wider than that of the positive electrode active material layer 932a. Further, the wound body 950a having such a shape is preferable because it has good safety and productivity.
  • the negative electrode 931 is electrically connected to the terminal 951 by ultrasonic bonding, welding, or crimping.
  • Terminal 951 is electrically connected to terminal 911a.
  • the positive electrode 932 is electrically connected to the terminal 952 by ultrasonic bonding, welding, or crimping.
  • Terminal 952 is electrically connected to terminal 911b.
  • the wound body 950a and the electrolyte are covered by the casing 930, forming a secondary battery 913.
  • the housing 930 be provided with a safety valve and an overcurrent protection element.
  • a metal material for example, aluminum
  • a resin material can be used as the housing 930.
  • the safety valve is a valve that opens the inside of the casing 930 at a predetermined internal pressure in order to prevent the battery from exploding.
  • the secondary battery 913 may have a plurality of wound bodies 950a. By using a plurality of wound bodies 950a, the secondary battery 913 can have a larger discharge capacity.
  • FIGS. 15A and 15B an example of an external view of an example of a laminate type secondary battery is shown in FIGS. 15A and 15B.
  • 15A and 15B have a positive electrode 503, a negative electrode 506, a separator 507, an exterior body 509, a positive lead electrode 510, and a negative lead electrode 511.
  • FIG. 16A shows an external view of the positive electrode 503 and the negative electrode 506.
  • the positive electrode 503 has a positive electrode current collector 501 , and the positive electrode active material layer 502 is formed on the surface of the positive electrode current collector 501 . Further, the positive electrode 503 has a region (hereinafter referred to as a tab region) where the positive electrode current collector 501 is partially exposed.
  • the negative electrode 506 has a negative electrode current collector 504 , and the negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504 . Further, the negative electrode 506 has a region where the negative electrode current collector 504 is partially exposed, that is, a tab region. Note that the area or shape of the tab regions of the positive electrode and the negative electrode is not limited to the example shown in FIG. 16A.
  • FIG. 16B shows a stacked negative electrode 506, separator 507, and positive electrode 503.
  • an example is shown in which five sets of negative electrodes and four sets of positive electrodes are used. It can also be called a laminate consisting of a negative electrode, a separator, and a positive electrode.
  • the tab regions of the positive electrodes 503 are joined together, and the positive lead electrode 510 is joined to the tab region of the outermost positive electrode. For example, ultrasonic welding may be used for joining.
  • the tab regions of the negative electrodes 506 are bonded to each other, and the negative lead electrode 511 is bonded to the tab region of the outermost negative electrode.
  • a negative electrode 506, a separator 507, and a positive electrode 503 are placed on the exterior body 509.
  • the exterior body 509 is bent at the portion indicated by the broken line. After that, the outer peripheral portion of the exterior body 509 is joined. For example, thermocompression bonding may be used for bonding. At this time, a region (hereinafter referred to as an inlet) that is not joined is provided in a part (or one side) of the exterior body 509 so that the electrolyte can be introduced later.
  • an inlet a region (hereinafter referred to as an inlet) that is not joined is provided in a part (or one side) of the exterior body 509 so that the electrolyte can be introduced later.
  • the electrolytic solution is introduced into the interior of the exterior body 509 through an inlet provided in the exterior body 509 .
  • the electrolytic solution is preferably introduced under a reduced pressure atmosphere or an inert atmosphere. Finally, connect the inlet. In this way, a laminate type secondary battery 500 can be manufactured.
  • a secondary battery can typically be applied to an automobile.
  • automobiles include next-generation clean energy vehicles such as hybrid vehicles (HVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHEVs or PHVs).
  • HVs hybrid vehicles
  • EVs electric vehicles
  • PHEVs or PHVs plug-in hybrid vehicles
  • the following batteries can be applied.
  • Vehicles are not limited to automobiles. Examples of vehicles include trains, monorails, ships, submersibles (deep-sea exploration vehicles, unmanned submarines), flying vehicles (helicopters, unmanned aerial vehicles (drones), airplanes, rockets, artificial satellites), electric bicycles, and electric motorcycles. Therefore, the secondary battery of one embodiment of the present invention can be applied to these vehicles.
  • the electric vehicle is installed with first batteries 1301a and 1301b as main secondary batteries for driving, and a second battery 1311 that supplies power to an inverter 1312 that starts a motor 1304.
  • the second battery 1311 is also called a cranking battery (also called a starter battery).
  • the second battery 1311 only needs to have a high output, and a large capacity is not required, and the capacity of the second battery 1311 is smaller than that of the first batteries 1301a and 1301b.
  • the internal structure of the first battery 1301a may be the wound type shown in FIG. 14A, or the stacked type shown in FIG. 15A or 15B.
  • first batteries 1301a and 1301b are connected in parallel, but three or more may be connected in parallel. Furthermore, if the first battery 1301a can store sufficient power, the first battery 1301b may not be necessary.
  • a battery pack that includes a plurality of secondary batteries, a large amount of electric power can be extracted.
  • a plurality of secondary batteries may be connected in parallel, may be connected in series, or may be connected in parallel and then further connected in series.
  • a plurality of secondary batteries is also called an assembled battery.
  • the first battery 1301a has a service plug or circuit breaker that can cut off high voltage without using tools. provided.
  • the electric power of the first batteries 1301a and 1301b is mainly used to rotate the motor 1304, but is also used to supply 42V in-vehicle components (electric power steering 1307, heater 1308, defogger 1309) via a DCDC circuit 1306. Supply electricity. Even when the rear motor 1317 is provided on the rear wheel, the first battery 1301a is used to rotate the rear motor 1317.
  • the second battery 1311 supplies power to 14V vehicle components (audio 1313, power window 1314, lamps 1315) via the DCDC circuit 1310.
  • FIG. 17A shows an example in which nine square secondary batteries 1300 are used as one battery pack 1415. Further, nine prismatic secondary batteries 1300 are connected in series, one electrode is fixed by a fixing part 1413 made of an insulator, and the other electrode is fixed by a fixing part 1414 made of an insulator.
  • this embodiment shows an example in which the battery is fixed using the fixing parts 1413 and 1414, it may also be configured to be housed in a battery housing box (also referred to as a housing). Since it is assumed that the vehicle is subjected to vibrations or shaking from the outside (road surface or motor), it is preferable to fix the plurality of secondary batteries using fixing parts 1413, 1414, a battery housing box, or the like.
  • one electrode is electrically connected to the control circuit section 1320 by a wiring 1421.
  • the other electrode is electrically connected to the control circuit section 1320 by a wiring 1422.
  • FIG. 17B shows an example of a block diagram of the battery pack 1415 shown in FIG. 17A.
  • the control circuit section 1320 includes a switch section 1324 including at least a switch for preventing overcharging and a switch for preventing overdischarge, a control circuit 1322 for controlling the switch section 1324, and a voltage measuring section for the first battery 1301a. has.
  • the control circuit section 1320 has an upper limit voltage and a lower limit voltage set for the secondary battery to be used, and limits the upper limit of the current from the outside or the upper limit of the output current to the outside.
  • the range of the secondary battery's lower limit voltage to upper limit voltage is within the recommended voltage range, and when the voltage is outside of that range, the switch section 1324 is activated and functions as a protection circuit.
  • control circuit section 1320 can also be called a protection circuit because it controls the switch section 1324 to prevent over-discharging and/or over-charging. For example, when the control circuit 1322 detects a voltage that is likely to cause overcharging, the switch section 1324 is turned off to cut off the current. Furthermore, a PTC element may be provided in the charging/discharging path to provide a function of cutting off the current in response to a rise in temperature. Further, the control circuit section 1320 has an external terminal 1325 (+IN) and an external terminal 1326 (-IN).
  • the switch portion 1324 can be configured by combining n-channel transistors or p-channel transistors.
  • the first batteries 1301a and 1301b mainly supply power to 42V system (high voltage system) in-vehicle equipment, and the second battery 1311 supplies power to 14V system (low voltage system) in-vehicle equipment.
  • the second battery 1311 a lead-acid battery is often used because it is advantageous in terms of cost.
  • the second battery 1311 that starts the inverter becomes inoperable, the second battery 1311 is powered by a lead-acid In the case of a storage battery, power is supplied from the first battery to the second battery, and the battery is charged so as to always maintain a fully charged state.
  • the second battery 1311 may be a lead-acid battery, an all-solid-state battery, or an electric double layer capacitor.
  • regenerated energy due to the rotation of the tire 1316 is sent to the motor 1304 via the gear 1305 and charged to the second battery 1311 from the motor controller 1303 or the battery controller 1302 via the control circuit section 1321.
  • the first battery 1301a is charged from the battery controller 1302 via the control circuit section 1320.
  • the first battery 1301b is charged from the battery controller 1302 via the control circuit unit 1320. In order to efficiently charge the regenerated energy, it is desirable that the first batteries 1301a and 1301b can be rapidly charged.
  • the battery controller 1302 can set the charging voltage, charging current, etc. of the first batteries 1301a and 1301b.
  • the battery controller 1302 can set charging conditions according to the charging characteristics of the secondary battery to be used and perform rapid charging.
  • the outlet of the charger or the connection cable of the charger is electrically connected to the battery controller 1302.
  • Power supplied from an external charger charges the first batteries 1301a and 1301b via the battery controller 1302.
  • a control circuit is provided and the function of the battery controller 1302 is not used in some cases, but in order to prevent overcharging, the first batteries 1301a and 1301b are charged via the control circuit section 1320. It is preferable.
  • the connecting cable or the connecting cable of the charger is provided with a control circuit.
  • the control circuit section 1320 is sometimes called an ECU (Electronic Control Unit).
  • the ECU is connected to a CAN (Controller Area Network) provided in the electric vehicle.
  • CAN is one of the serial communication standards used as an in-vehicle LAN.
  • the ECU includes a microcomputer. Further, the ECU uses a CPU or a GPU.
  • External chargers installed at the charging stand include 100V outlet-200V outlet, or 3-phase 200V and 50kW. It can also be charged by receiving power from an external charging facility using a non-contact power supply method.
  • the capacity decrease is suppressed even when the electrode layer is made thicker and the loading amount is increased, and the synergistic effect of maintaining high capacity has resulted in a secondary battery with significantly improved electrical characteristics.
  • It is particularly effective for secondary batteries used in vehicles, and provides a vehicle with a long cruising range, specifically a cruising range of 500 km or more on one charge, without increasing the weight ratio of the secondary battery to the total vehicle weight. be able to.
  • the secondary battery of this embodiment described above can provide a secondary battery for vehicles with excellent cycle characteristics by using the positive electrode active material described in Embodiment 2 for the positive electrode.
  • the secondary battery shown in any one of FIG. 12D, FIG. 14C, and FIG. 17A When the secondary battery shown in any one of FIG. 12D, FIG. 14C, and FIG. 17A is installed in a vehicle, it becomes a next-generation clean energy vehicle such as a hybrid vehicle (HV), electric vehicle (EV), or plug-in hybrid vehicle (PHV). can be realized.
  • HV hybrid vehicle
  • EV electric vehicle
  • PHS plug-in hybrid vehicle
  • secondary batteries in agricultural machinery, motorized bicycles including electric assist bicycles, motorcycles, electric wheelchairs, electric carts, ships, submarines, aircraft, rockets, artificial satellites, space probes, planetary probes, or spacecraft. It can also be installed.
  • a high-capacity secondary battery can be obtained.
  • a car 2001 shown in FIG. 18A is an electric car that uses an electric motor as a power source for driving. Alternatively, it is a hybrid vehicle that can appropriately select and use an electric motor and an engine as a power source for driving.
  • a secondary battery is mounted on a vehicle, the example of the secondary battery shown in Embodiment 3 is installed at one location or multiple locations.
  • a car 2001 shown in FIG. 18A includes a battery pack 2200, and the battery pack includes a secondary battery module to which a plurality of secondary batteries are connected. Furthermore, it is preferable to include a charging control device electrically connected to the secondary battery module.
  • the automobile 2001 can be charged by receiving power from an external charging facility using a plug-in method or a non-contact power feeding method to a secondary battery of the automobile 2001.
  • a predetermined charging method or connector standard such as CHAdeMO (registered trademark) or Combo may be used as appropriate.
  • the charging device may be a charging station provided at a commercial facility or may be a home power source.
  • plug-in technology it is possible to charge the power storage device mounted on the vehicle 2001 by supplying power from the outside. Charging can be performed by converting AC power into DC power via an ACDC converter.
  • a power receiving device can be mounted on a vehicle and electrical power can be supplied from a ground power transmitting device in a non-contact manner for charging.
  • this non-contact power supply method by incorporating a power transmission device into the road or outside wall, charging can be performed not only while the vehicle is stopped but also while the vehicle is running. Further, electric power may be transmitted and received between two vehicles using this contactless power supply method.
  • a solar cell may be provided on the exterior of the vehicle, and the secondary battery may be charged when the vehicle is stopped or traveling.
  • an electromagnetic induction method or a magnetic resonance method can be used.
  • FIG. 18B shows a large transport vehicle 2002 having an electrically controlled motor as an example of a transport vehicle.
  • the secondary battery module of the transport vehicle 2002 has a maximum voltage of 170V, for example, in which four secondary batteries with a nominal voltage of 3.0 V or more and 5.0 V or less are connected in series, and 48 cells are connected in series. Except for the difference in the number of secondary batteries constituting the secondary battery module of the battery pack 2201, it has the same functions as those in FIG. 18A, so a description thereof will be omitted.
  • FIG. 18C shows, by way of example, a large transport vehicle 2003 with an electrically controlled motor.
  • the secondary battery module of the transportation vehicle 2003 has a maximum voltage of 600 V, for example, by connecting in series one hundred or more secondary batteries with a nominal voltage of 3.0 V or more and 5.0 V or less. Therefore, a secondary battery with small variations in characteristics is required.
  • a secondary battery in which the positive electrode active material described in Embodiment 2 is used as a positive electrode a secondary battery having stable battery characteristics can be manufactured, and mass production can be performed at low cost from the viewpoint of yield. It is.
  • it since it has the same functions as those in FIG. 20A except for the difference in the number of secondary batteries that constitute the secondary battery module of the battery pack 2202, a description thereof will be omitted.
  • FIG. 18D shows an example aircraft 2004 with an engine that burns fuel. Since the aircraft 2004 shown in FIG. 18D has wheels for takeoff and landing, it can be said to be part of a transportation vehicle, and a secondary battery module is configured by connecting a plurality of secondary batteries, and the aircraft 2004 is connected to a secondary battery module and charged.
  • the battery pack 2203 includes a control device.
  • the secondary battery module of the aircraft 2004 has a maximum voltage of 32V, for example, by connecting eight 4V secondary batteries in series. Except for the difference in the number of secondary batteries that constitute the secondary battery module of the battery pack 2203, it has the same functions as those in FIG. 18A, so a description thereof will be omitted.
  • FIG. 18E shows an artificial satellite 2005 equipped with a secondary battery 2204 as an example. Since the artificial satellite 2005 is used in extremely low temperature outer space, it is preferable to include a secondary battery 2204 having excellent low temperature resistance. Furthermore, it is more preferable that the secondary battery 2204 is mounted inside the artificial satellite 2005 while being covered with a heat insulating member.
  • FIG. 19A is an example of an electric bicycle using a lithium ion battery according to one embodiment of the present invention.
  • the lithium ion battery of one embodiment of the present invention can be applied to an electric bicycle 8700 shown in FIG. 19A.
  • a power storage device includes a plurality of lithium ion batteries according to one embodiment of the present invention and a protection circuit.
  • Electric bicycle 8700 includes a power storage device 8702.
  • the power storage device 8702 can supply electricity to a motor that assists the driver. Further, the power storage device 8702 is portable, and FIG. 19B shows a state in which it has been removed from the bicycle. Further, the power storage device 8702 includes a plurality of built-in storage batteries 8701 each including a positive electrode active material according to one embodiment of the present invention, and can display the remaining battery power on a display portion 8703.
  • the power storage device 8702 also includes a control circuit 8704 that can control charging of the secondary battery or detect an abnormality.
  • the control circuit 8704 is electrically connected to the positive and negative electrodes of the storage battery 8701.
  • the secondary battery and control circuit 8704 using the positive electrode active material obtained in Embodiment 2 as the positive electrode can greatly contribute to eradicating fire accidents caused by secondary batteries.
  • FIG. 19C is an example of a two-wheeled vehicle using the power storage device of one embodiment of the present invention.
  • a scooter 8600 shown in FIG. 19C includes a power storage device 8602, a side mirror 8601, and a direction indicator light 8603.
  • the power storage device 8602 can supply electricity to the direction indicator light 8603.
  • the power storage device 8602 that houses a plurality of secondary batteries in which the positive electrode active material obtained in Embodiment 2 is used as a positive electrode can have a high capacity and can contribute to miniaturization.
  • the scooter 8600 shown in FIG. 19C can store a power storage device 8602 in an under-seat storage 8604.
  • the power storage device 8602 can be stored in the under-seat storage 8604 even if the under-seat storage 8604 is small.
  • FIG. 20A shows a schematic diagram of a station 1500 where secondary batteries can be replaced.
  • the station 1500 has a mechanism 1503 for lifting the car, a mechanism for attaching and removing the secondary battery, a mechanism for charging the secondary battery, and a mechanism for storing the secondary battery.
  • the station 1500 has a shutter 1505, and can open and close the entrance/exit of the car.
  • a shutter 1505 When replacing the secondary battery, it is preferable to close the shutter 1505 to close the entrance and exit of the vehicle, since there is a risk of electric shock.
  • the driver or worker After the driver or worker stops the car 1501 at a predetermined position in the station 1500, the driver or worker gets out of the car, operates the car lifting mechanism 1503 inside the station 1500, and lifts the car 1501. Then, the driver or worker removes the secondary battery of the vehicle 1501 using the secondary battery attachment/removal mechanism. The removed secondary battery is moved to be stored, and charged using a mechanism that stores the secondary battery. Then, the driver or worker attaches a new, already charged secondary battery to the car 1501 using a secondary battery attachment/detachment mechanism.
  • FIG. 20B is a schematic diagram showing a state immediately before a new secondary battery 1502 is attached to a car 1501 using a secondary battery attachment/removal mechanism. Note that partition plates 1504 are provided on both sides.
  • FIGS. 20A and 20B show a mechanism for raising and lowering tires as the mechanism 1503 for lifting the car, this is not particularly limited, and a mechanism for raising and lowering the lower part of the vehicle body of the car 1501 may also be used.
  • a mechanism to raise and lower the tires there is a suspension between the tires and the vehicle body, so if you use the secondary battery installation/removal mechanism to push from below, the vehicle body may also lift up, making installation difficult. be.
  • the mechanism for raising and lowering the lower part of the car body of the car 1501 if the car body is light, there is a risk that the mechanism will lose its balance and cannot be installed properly. Therefore, it is preferable to precisely control the alignment between the vehicle 1501 and the secondary battery 1502 or the mechanism for attaching and removing the secondary battery.
  • replacing the secondary battery with a new one can save a long charging time, although it takes some time to replace it. Furthermore, even if the secondary battery becomes old and deteriorates, it can be replaced with another charged secondary battery at any time. Therefore, the life of the vehicle 1501 is extended without depending on the deterioration of the secondary battery.
  • the station 1500 where the secondary battery can be replaced can be installed in a private home, a common space, or a car dealership.
  • a system using the station 1500 that can replace secondary batteries is a service in which a used secondary battery is replaced with another charged secondary battery at a station 1500 installed in a private home, a common space, or a car dealer. I will provide a. With such a system, if the capacity of the secondary battery is significantly lost during driving, it becomes difficult to move the car from the charging spot for several hours or half a day to recharge the secondary battery. be able to solve problems. If station 1500 is used, the vehicle can be driven by replacing it with another secondary battery after driving.
  • the positive electrode active material obtained in Embodiment 2 is NCM, and a portion of the secondary particles are covered with a calcium compound, so oxygen desorption is difficult to occur, excellent cycle characteristics are achieved, and the material is optimal. be.
  • This embodiment mode can be freely combined with other embodiment modes.
  • FIG. 24 is an example of a schematic cross-sectional view of the Taylor reactor 80.
  • Tipton Corporation TVF-1 Type
  • a Taylor reactor 80 that includes an outer cylinder 82 and an inner cylinder 81 that rotates within the outer cylinder, and generates a Taylor vortex within a gap space formed between the outer cylinder 82 and the inner cylinder 81.
  • a plurality of types of fluids are allowed to flow in from one of the inflow holes 84a, 84b, and 84c, and the inner cylinder 81 is rotated using the motor 83, different types of fluids are mixed by Taylor vortex flow. It will be done.
  • chemical reactions of different types of fluids also occur simultaneously.
  • the obtained reactant can be obtained from the outlet 85.
  • Each supply line connected to the inflow hole for supplying fluid is provided with an intake control valve to control the flow of the fluid to be supplied. Further, a metering pump is provided on a supply line connected to the inflow hole for supplying fluid, and feeds the liquid from the material supply tank.
  • the line for acquiring the reactant is provided with a withdrawal control valve for controlling the amount of the reactant withdrawn, and the line passing through the withdrawal control valve is provided with a pH meter.
  • the Taylor reactor 90 can provide a method for continuously preparing a mixture by mixing a plurality of fluids by controlling the temperature and pressure, and can efficiently obtain reactants with good uniformity.
  • a mixed solution of glycine and an aqueous sodium hydroxide solution is supplied as a filling liquid from the inflow hole 84c, and after filling the gap space of the Taylor reactor 90 with the filling liquid, the inflow hole is An acid solution is supplied from 84a, and an alkaline solution is supplied from inflow hole 84b. Injection of the acid solution and the alkaline solution is started at the same time, and a precursor is obtained as a reactant from the outlet 85. Since the initial reactant is non-uniform, it is preferable to discard it and recover the reactant after the state has stabilized.
  • the liquid injection rate is set to 1 by each metering pump. It is sufficient to obtain a product with a pH of 11.8 or more and 13 or less as measured by a pH meter.
  • the acid solution used was an aqueous solution in which nickel sulfate, cobalt sulfate, and manganese sulfate were each weighed and dissolved to give 1M NCM811, and a mixed aqueous solution of 0.1M glycine. A mixed aqueous solution of 2.5M sodium hydroxide aqueous solution and 0.1M glycine is used.
  • the temperature is 50° C.
  • the gap between the inner cylinder and the outer cylinder is 2.5 mm
  • the rotation speed is 3000 rpm
  • the residence time is 10 minutes or more and 30 minutes or less.
  • the amount of lithium added is measured in molar ratio so that when Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 is 1, LiOH ⁇ H 2 O is 0.95. - Weighed H 2 O.
  • a first heat treatment was performed at 700°C for 10 hours, then the temperature was returned to room temperature and crushed, and then a second heat treatment was performed at 800°C for 10 hours.
  • Heat treatment was performed.
  • the mixture was placed in an alumina crucible, placed in a muffle furnace with a lid, and oxygen was supplied to the muffle furnace at a flow rate of 5 L/min.
  • the amount of calcium added is determined by weighing CaCO 3 in molar ratio so that when Li 0.95 Ni 0.8 Co 0.1 Mn 0.1 is 1, CaCO 3 is 0.01. did.
  • calcium carbonate which has been pulverized to have a D50 of 0.762 ⁇ m is used.
  • the amount of aluminum added is determined by measuring the molar ratio such that when Li 0.95 Ni 0.8 Co 0.1 Mn 0.1 is 1, Al(OH) 3 is 0.01. (OH) 3 was weighed.
  • aluminum hydroxide that has been pulverized and has a D50 of 0.791 ⁇ m is used.
  • the mixture was transferred to a mortar and crushed, and further sieved to obtain NCM (Li 0.95 Ni 0.8 Co 0.1 Mn 0.1 O 2 ) to which calcium and aluminum were added.
  • NCM Li 0.95 Ni 0.8 Co 0.1 Mn 0.1 O 2
  • the D50 of this NCM was 9.036 ⁇ m.
  • the amounts added to the positive electrode active material in this example are 1 atomic % of calcium and 1 atomic % of aluminum.
  • Figure 1A is an SEM photograph of a part of the interior of the NCM secondary particles added with calcium and aluminum obtained in this example
  • Figure 1C is an enlarged view of the boundary between two primary particles. .
  • FIG. 2 is an enlarged view of the same location as FIG. 1C
  • FIG. 3 shows the results of analysis using electron beam diffraction at three points.
  • FIG. 3A The selected area electron diffraction pattern of point 1-1 in FIG. 2A is shown in FIG. 3A. Some of the bright spots were designated as 1, 2, 3, and O as shown in FIG. 3A. O is transmitted light, and 1, 2, and 3 are diffraction spots.
  • Point 1-1 in FIG. 2A is the surface layer part of the primary particle, and is the inside of the primary particle.
  • point 1-3 in FIG. 2A is a surface layer part of the primary particle different from point 1-1, and is inside the primary particle.
  • FIG. 3B which is the selected area electron diffraction pattern of point 1-2, did not have at least a clear crystal structure and was confirmed to be amorphous.
  • the primary particles shown in Figure 1 are obtained by observing an amorphous layer between the primary particles closer to the inner center than the outermost surface, as shown in Figure 5, which is a schematic diagram of the secondary particles. It is.
  • FIG. 6 shows an SEM observation image of the NCM added with calcium and aluminum obtained in this example.
  • FIG. 7A shows a ZC image of a portion of the NCM secondary particles added with calcium and aluminum obtained in this example.
  • FIG. 7B shows a schematic diagram corresponding to FIG. 7A.
  • FIG. 8 shows the EDX result of the portion corresponding to FIG. 7A.
  • FIG. 8A is a HAADF-STEM image and corresponds to FIG. 7A.
  • 8B is an EDX mapping image of carbon (C) in the same region as FIG. 8A
  • FIG. 8C is an EDX mapping image of oxygen (O) in the same region as FIG. 8A
  • FIG. 8D is an EDX mapping image of aluminum (O) in the same region as FIG. 8A.
  • FIG. 8E shows an EDX mapping image of calcium (Ca) in the same region as FIG. 8A
  • FIG. 8F shows an EDX mapping image of manganese (Mn) in the same region as FIG. 8A.
  • Mn manganese
  • FIG. 7C is a partially enlarged view of FIG. 7A, and the results of EDX analysis of the dark portion that can be seen on the surface layer of the primary particles 10d in FIG. 7C are shown below.
  • FIG. 10 is an enlarged photograph of the vicinity of the boundary between the primary particles 10d and 10c shown in FIG. 7B, and the results of EDX analysis of the thin amorphous layer 12 present in the vicinity of the boundary are shown below.
  • the thin amorphous layer 12 had silicon and sulfur at the lower detection limits. From this, it can be confirmed that the secondary particles have at least two types of amorphous layers (amorphous layer 11 and amorphous layer 12) having partially different compositions. In the amorphous layer 12, both silicon and sulfur were at the lower limit of detection, that is, less than 1 atomic %.
  • both the amorphous layer 11 and the amorphous layer 12 contain calcium or aluminum.
  • the compositions of the amorphous layer 11 and the amorphous layer 12 are not particularly limited, but oxides made amorphous by adding an additive element (one or more selected from calcium, aluminum, silicon, and sulfur) It is preferable to have.
  • the materials used for the protective layer AL or CA, which are deposits, and the materials used for the amorphous layer 11 or 12 will be discussed below using calculations.
  • FIG. 11A the relationship between the density of the oxide containing calcium and aluminum and the ratio of the crystal composition is shown in FIG. 11A.
  • the vertical axis represents the density
  • the horizontal axis represents the Ca/Al ratio of the crystal composition.
  • Crystals of CaAl 4 O 7 , CaAl 2 O 4 , Ca 12 Al 14 O 33 , and Ca 9 Al 6 O 18 are listed.
  • Aluminum oxide crystals are used as a comparative example, and the density of aluminum oxide (Al 2 O 3 ) is 3.98 g/cm 3 , but the density is lowered by including calcium.
  • FIG. 11A shows a comparison between crystals, and the density of crystals is higher than that of amorphous.
  • Figure 11B shows that a model is constructed using aluminum oxide as amorphous, quantum molecular dynamics calculations are performed, and the average value of the amorphous density at the time of calculation is calculated, excluding the structural relaxation part at the initial stage of calculation. This is the result.
  • the initial structures include three structures with 80 Al atoms and 120 oxygen atoms, three structures with 78 Al atoms, 120 oxygen atoms, and 3 Ca atoms, and 76 Al atoms, 120 oxygen atoms, and 3 structures with 76 Al atoms, 120 oxygen atoms, and 3 Ca atoms.
  • VASP Version 5.4.4 Functional: GGA-PBE Pseudopotential: PAW K point: Gamma point only Cutoff energy: 600eV Van der Waals force: DFT-D2 Temperature: 300K Time step: 2.0fs Ensemble:NPT
  • the density was calculated from the average value of the volume in 3000 steps after the completion of structural relaxation of the initial structure.
  • the horizontal axis represents the amorphous Ca/Al ratio
  • the vertical axis represents the amorphous density.
  • the models used in the calculations were amorphous aluminum oxide (Al 2 O 3 ), Al 2 O 3 amorphous with approximately 4 at% of Ca added to the number of Al atoms, and On the other hand, three types of Al 2 O 3 amorphous to which Ca was added at about 8 atomic % were prepared from random atomic arrangements.
  • the amorphous layer 11 and the amorphous layer 12 are preferably made of a material with a low density, specifically, a material with a density of 2.0 g/cm 3 or more and less than 3.3 g/cm 3 .
  • the density of the calcium oxide (CaO) crystal is 3.34 g/cm 3 , and it is preferable that the density of the amorphous layer 11 and the amorphous layer 12 is lower than that of the calcium oxide (CaO) crystal.
  • the material used for the protective layer AL or the protective layer CA which is a deposit
  • the material used for the amorphous layer 11 or the amorphous layer 12 contain at least calcium and aluminum, and further contain Ca/ A material having an Al ratio of 0.25 or more and 1.5 or less, preferably 0.5 or more and 0.85 or less may be advantageous in terms of lithium diffusion. It is considered that when the Ca/Al ratio exceeds 1.5 and the number of atoms per unit volume increases, it becomes difficult for lithium ions to move.
  • Figure 11A shows the tendency for crystals, but the fact that when the Ca/Al ratio exceeds 1.5 and the number of atoms per unit volume increases, it becomes difficult for lithium ions to move, which is the same tendency even for amorphous structures. It is thought that.
  • the materials are not limited to these materials, and other elements may be added so as not to increase the density value.
  • the material used for the protective layer AL or the protective layer CA which is a deposit
  • the amorphous layer The material used for the amorphous layer 11 or the amorphous layer 12 may contain silicon oxide or sulfur, which easily combines with lithium.
  • Example 2 two types of positive electrode active materials were produced according to Example 1, a positive electrode active material layer was formed on a current collector, and the cross section thereof was observed.
  • FIG. 21A shows a positive electrode active material layer using NCM containing 1 atomic % of calcium and 1 atomic % of aluminum, which is the same as in Example 1. In the sample shown in FIG. 21A, about two secondary particles with visible cracks can be seen in the photograph.
  • FIG. 21B shows a positive electrode active material layer using NCM containing 1 atomic % of calcium. In the sample shown in FIG. 21B as well, about two secondary particles with visible cracks can be observed in the photograph.
  • FIG. 22 is a comparative example, and is a cross-sectional observation photograph of a sample in which a positive electrode active material layer was formed without adding aluminum or calcium. In the comparative example, about 4 secondary particles with visible cracks can be observed in the photograph.
  • the secondary battery using the positive electrode active material layer of this example has fewer cracks, and thus has improved charge/discharge cycle characteristics.
  • Example 2 a half cell was assembled using the positive electrode active material of Example 2, and the charge/discharge rate characteristics were evaluated.
  • the amount of active material supported on the positive electrode was approximately 7 mg/cm 2 .
  • Lithium metal was prepared as a counter electrode, and a coin-shaped half cell including the above-mentioned positive electrode was formed.
  • Cycle characteristics were measured using the above half cell.
  • the charging voltage was set to 4.6V.
  • the measurement temperature was 45°C.
  • Charging was performed at CC/CV (0.5C, 0.05Ccut), discharging was performed at CC (0.5C, 2.5Vcut), and a 10-minute rest period was provided before the next charge. A 10-minute rest period was also provided after charging.
  • 1C was set to 200 mA/g.
  • FIG. 23 The evaluation results of each cycle characteristic are shown in FIG. 23.
  • the vertical axis represents the discharge capacity.
  • Sample 1 containing 1 atomic % of calcium and 1 atomic % of aluminum and a comparative example are shown.
  • a comparative example is a sample in which a positive electrode active material layer was formed without adding aluminum or calcium.
  • a coin-shaped half cell was used using a positive electrode active material containing 0.5 at% of calcium and 0.5 at% of aluminum. The manufacturing method is the same except for the different amounts of calcium and aluminum.
  • sample 2 exhibits almost the same cycle characteristics as sample 1, and they overlap.

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015026559A (ja) * 2013-07-29 2015-02-05 トヨタ自動車株式会社 非水電解質二次電池の製造方法
WO2020208966A1 (ja) * 2019-04-12 2020-10-15 住友化学株式会社 リチウム金属複合酸化物粉末、リチウム二次電池用正極活物質、正極及びリチウム二次電池
JP2020181643A (ja) * 2019-04-23 2020-11-05 トヨタ自動車株式会社 被覆正極活物質及び全固体電池
JP2020532067A (ja) * 2017-08-22 2020-11-05 エー１２３ システムズ エルエルシーＡ１２３ Ｓｙｓｔｅｍｓ ＬＬＣ 安全性及びサイクル安定性の向上のための正極材料上の四ホウ酸リチウムガラスコーティング
WO2021106324A1 (ja) * 2019-11-29 2021-06-03 パナソニックＩｐマネジメント株式会社 非水電解質二次電池用正極活物質、非水電解質二次電池用正極活物質の製造方法、及び非水電解質二次電池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015026559A (ja) * 2013-07-29 2015-02-05 トヨタ自動車株式会社 非水電解質二次電池の製造方法
JP2020532067A (ja) * 2017-08-22 2020-11-05 エー１２３ システムズ エルエルシーＡ１２３ Ｓｙｓｔｅｍｓ ＬＬＣ 安全性及びサイクル安定性の向上のための正極材料上の四ホウ酸リチウムガラスコーティング
WO2020208966A1 (ja) * 2019-04-12 2020-10-15 住友化学株式会社 リチウム金属複合酸化物粉末、リチウム二次電池用正極活物質、正極及びリチウム二次電池
JP2020181643A (ja) * 2019-04-23 2020-11-05 トヨタ自動車株式会社 被覆正極活物質及び全固体電池
WO2021106324A1 (ja) * 2019-11-29 2021-06-03 パナソニックＩｐマネジメント株式会社 非水電解質二次電池用正極活物質、非水電解質二次電池用正極活物質の製造方法、及び非水電解質二次電池

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