WO2013046443A1 - 全固体電池およびその製造方法 - Google Patents
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- WO2013046443A1 WO2013046443A1 PCT/JP2011/072594 JP2011072594W WO2013046443A1 WO 2013046443 A1 WO2013046443 A1 WO 2013046443A1 JP 2011072594 W JP2011072594 W JP 2011072594W WO 2013046443 A1 WO2013046443 A1 WO 2013046443A1
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- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
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- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
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- H01M10/052—Li-accumulators
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
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- H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
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- H—ELECTRICITY
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
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- H—ELECTRICITY
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- 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
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
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- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0068—Solid electrolytes inorganic
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- H01M2300/00—Electrolytes
- H01M2300/0088—Composites
- H01M2300/0094—Composites in the form of layered products, e.g. coatings
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- 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
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- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Definitions
- the present invention relates to an all solid state battery capable of suppressing an increase in interfacial resistance between a positive electrode active material and a sulfide solid electrolyte material over time.
- lithium batteries that are commercially available use electrolytes that contain flammable organic solvents, so it is possible to install safety devices that suppress the temperature rise during short circuits and to improve the structure and materials to prevent short circuits. Necessary.
- a lithium battery in which the electrolyte is changed to a solid electrolyte layer to make the battery completely solid does not use a flammable organic solvent in the battery, so the safety device can be simplified, and the manufacturing cost and productivity can be simplified. It is considered excellent.
- Non-Patent Document 1 discloses a material in which the surface of LiCoO 2 that is a positive electrode active material is coated with LiNbO 3 . This technique is to coat the LiNbO 3 on the surface of LiCoO 2, reduce the interfacial resistance of LiCoO 2 and a solid electrolyte material, those which attained higher output of the battery.
- Patent Document 1 discloses a positive electrode active material in which a positive electrode active material is coated with a resistance layer formation suppressing coat having lithium ion conductivity.
- a positive electrode active material is coated with LiNbO 3 .
- a positive electrode active material having a coating state defined by XPS measurement is disclosed. This is intended to suppress an increase in interfacial resistance between the oxide positive electrode active material and the solid electrolyte material at a high temperature by making the thickness of the coated LiNbO 3 uniform.
- LiNbO3-coated LiCoO2 as cathode material for all solid-state lithium secondary batteries
- a positive electrode is formed when an all-solid-state battery is formed by forming a reaction suppressing portion containing a material having excellent ion conductivity on the surface of a positive electrode active material.
- the interface resistance between the active material and the solid electrolyte material can be reduced.
- the interfacial resistance increases, so there is a problem with durability.
- the present invention has been made in view of the above circumstances, and provides an all-solid-state battery capable of lowering the interface resistance between a positive electrode active material and a sulfide solid electrolyte material and suppressing an increase over time. Main purpose.
- a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and between the positive electrode active material layer and the negative electrode active material layer A solid electrolyte layer, wherein at least one of the positive electrode active material layer and the solid electrolyte layer contains a sulfide solid electrolyte material, and is on the surface of the positive electrode active material.
- a reaction suppression unit having two layers is formed in which the lithium ion conductive layer having the first lithium ion conductor is on the active material side and the stabilization layer having the second lithium ion conductor is on the solid electrolyte side.
- Lithium ion conductor is a Li-containing compound having a lithium ion conductivity of 1.0 ⁇ 10 ⁇ 7 S / cm or more at normal temperature, and the second lithium ion conductor includes B, Si, P, Ti , Zr, An all-solid-state battery characterized by being a Li-containing compound having a polyanion structure having at least one of Al and W.
- the lithium ion conductive layer containing the first lithium ion conductor having good Li ion conductivity is coated on the active material side.
- the stabilization layer containing the second lithium ion conductor containing a metal having a high electronegativity so as to be on the solid electrolyte layer side, the oxygen atoms from the reaction suppressing portion are brought into contact with the solid electrolyte layer. Is less likely to be pulled out, deterioration of the reaction suppressing portion is suppressed, and an increase in interfacial resistance with time can be suppressed.
- the first lithium ion conductor is preferably LiNbO 3 .
- the second lithium ion conductor is Li 2 Ti 2 O 5.
- Ti forms an oxide film on the surface and is easily passivated, and a Li-containing compound having a polyanion structure having Ti exhibits high corrosion resistance and high electrochemical stability. For this reason, oxygen atoms in the reaction suppressing portion are hardly extracted when coming into contact with the electrolyte, and deterioration of the all-solid battery can be suppressed.
- a method for producing the above-described all-solid-state battery wherein the first precursor coating liquid containing the first lithium ion conductor material is applied to the surface of the positive electrode active material and subjected to heat treatment.
- the first precursor coating liquid described above is applied to the surface of the positive electrode active material, heat-treated to coat the lithium ion conductive layer, and then the second precursor coating liquid described above.
- the stabilization layer By applying heat treatment and coating the stabilization layer, it is possible to suppress the increase in the interfacial resistance of the positive electrode active material and the sulfide solid electrolyte material over time, and the Li ion conductivity and durability are excellent.
- an all solid state battery can be easily manufactured.
- the first lithium ion conductor is preferably LiNbO 3 .
- the second lithium ion conductor is Li 2 Ti 2 O 5.
- FIG. 4 is a TEM image of a cross section of a positive electrode active material of an all solid state battery obtained in Examples and Comparative Example 3.
- FIG. It is a graph which shows the change of the interface resistance in the 60 degreeC preservation
- the all-solid battery of the present invention is formed between a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and the positive electrode active material layer and the negative electrode active material layer.
- a solid electrolyte layer wherein at least one of the positive electrode active material layer and the solid electrolyte layer contains a sulfide solid electrolyte material, and on the surface of the positive electrode active material,
- a reaction suppression unit having two layers is formed in which the lithium ion conductive layer having one lithium ion conductor is the active material side, and the stabilization layer having the second lithium ion conductor is the solid electrolyte layer side.
- the lithium ion conductor is a Li-containing compound having a lithium ion conductivity at room temperature of 1.0 ⁇ 10 ⁇ 7 S / cm or more, and the second lithium ion conductor includes B, Si, P, Ti, Zr, Al, Oh Is characterized in that a Li-containing compound having a polyanionic structure having at least one fine-W.
- FIGS. 1A and 1B are explanatory views showing an example of the power generation element of the all solid state battery of the present invention.
- a power generation element 10 of an all-solid battery illustrated in FIGS. 1A and 1B is formed between a positive electrode active material layer 1, a negative electrode active material layer 2, a positive electrode active material layer 1, and a negative electrode active material layer 2.
- the solid electrolyte 3 is provided.
- the positive electrode active material layer 1 has the positive electrode active material 4 in which the reaction suppression part 6 was formed in the surface.
- the sulfide solid electrolyte material 5 is contained in at least one of the positive electrode active material layer 1 and the solid electrolyte layer 3 and is in contact with the positive electrode active material 4 through the reaction suppression unit 6.
- the sulfide solid electrolyte material 5 may be contained in the positive electrode active material layer 1 as shown in FIG. 1A, or contained in the solid electrolyte layer 3 as shown in FIG. Although not shown, the positive electrode active material layer 1 and the solid electrolyte layer 3 may be contained in both layers.
- the surface of the lithium ion conductive layer is electrochemically stable.
- a stabilizing layer containing a second high lithium ion conductor because the reaction suppressor having two layers is formed, the reaction suppressing portion formed from only the conventional niobium oxide (e.g., LiNbO 3)
- the reaction suppressing portion formed from only the conventional niobium oxide (e.g., LiNbO 3)
- a change in the structure of the first lithium ion conductor that occurs when contacting the sulfide solid electrolyte material can be suppressed, and a highly electrochemically stable reaction suppressing portion can be obtained.
- the second lithium ion conductor includes a polyanion structure having at least one of B, Si, P, Ti, Zr, Al, and W, and has electrochemical stability as described later. high.
- the all solid state battery of the present invention will be described for each configuration.
- the positive electrode active material layer used in the present invention is a layer containing at least a positive electrode active material.
- the positive electrode active material layer in the present invention may contain at least one of a solid electrolyte material and a conductive material, if necessary.
- the positive electrode active material used for this invention is demonstrated.
- the positive electrode active material in the present invention is not particularly limited as long as the charge / discharge potential becomes a noble potential as compared with the charge / discharge potential of the negative electrode active material contained in the negative electrode active material layer described later.
- a positive electrode active material for example, an oxide positive electrode active material is preferable from the viewpoint of forming a high resistance layer by reacting with a sulfide solid electrolyte material described later. Further, by using an oxide positive electrode active material, an all-solid battery having a high energy density can be obtained.
- M is preferably at least one selected from the group consisting of Co, Mn, Ni, V, Fe and Si, and is at least one selected from the group consisting of Co, Ni and Mn. It is more preferable.
- the oxide positive electrode active material is a general formula Li 1 + x Mn 2- xy My O 4 (M is at least one selected from the group consisting of Al, Mg, Co, Fe, Ni, and Zn).
- an oxide positive electrode active material specifically, LiCoO 2 , LiMnO 2 , LiNiO 2 , LiVO 2 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 , LiMn 2 O 4 , Li ( Ni 0.5 Mn 1.5) O 4, Li 2 FeSiO 4, Li 2 MnSiO 4 , and the like.
- the shape of the positive electrode active material examples include particle shapes such as a true sphere and an elliptic sphere, and a thin film shape, among which a particle shape is preferable. Further, when the positive electrode active material has a particle shape, the average particle diameter is preferably in the range of 0.1 ⁇ m to 50 ⁇ m, for example.
- the content of the positive electrode active material in the positive electrode active material layer is preferably in the range of 10% by weight to 99% by weight, for example, and more preferably in the range of 20% by weight to 90% by weight.
- the reaction suppression part in this invention is demonstrated.
- the reaction suppression unit used in the present invention is formed on the surface of the positive electrode active material, has a lithium ion conductive layer having a first lithium ion conductor as an active material side, and has a second lithium ion conductor. It has two layers which make a stabilization layer the solid electrolyte layer side.
- FIG. 2 is a schematic cross-sectional view showing an example of the reaction suppression unit in the present invention. As illustrated in FIG. 2, a reaction suppression unit 6 having a lithium ion conductive layer 8 and a stabilization layer 7 is formed on the surface of the positive electrode active material 4.
- the lithium ion conductive layer 8 covers the surface of the positive electrode active material 4, and the stabilization layer 7 covers the surface of the lithium ion conductive layer 8.
- the first lithium ion conductor contained in the lithium ion conductive layer has a lithium ion conductivity at room temperature of 1.0 ⁇ 10 ⁇ 7 S / cm or more.
- the second lithium ion conductor contained in the stabilization layer includes a polyanion structure having at least one of B, Si, P, Ti, Zr, Al, and W. A compound.
- the reaction suppression unit has a function of suppressing the reaction between the positive electrode active material and the sulfide solid electrolyte material that occurs when the all solid state battery is used.
- the reaction suppression unit has a structure in which the surface of the lithium ion conductive layer as described above is covered with a stabilization layer.
- a reaction suppressing portion formed only from a conventional niobium oxide (for example, LiNbO 3 ). Can do.
- a conventional niobium oxide for example, LiNbO 3
- the lithium ion conductive layer in the present invention is made of a material having a first lithium ion conductor having good conductivity as described later, and is formed on the surface of the positive electrode active material. It is characterized in that the interface resistance generated between the substance layer and the sulfide solid electrolyte material is reduced, and the decrease in output is suppressed.
- the form of the lithium ion conductive layer in the present invention is not particularly limited as long as it is formed on the surface of the positive electrode active material described above.
- the shape of the positive electrode active material described above is a particle shape
- the lithium ion conductive layer preferably covers a larger area of the positive electrode active material particles (hereinafter sometimes referred to simply as “particles”). % Or more is preferable, and 95% or more is more preferable. Moreover, you may cover all the particle
- TEM transmission electron microscope
- XPS X-ray photoelectron spectroscopy
- the thickness of the lithium ion conductive layer in the present invention is not particularly limited as long as the positive electrode active material and the sulfide solid electrolyte material do not cause a reaction.
- the thickness is in the range of 1 nm to 100 nm. Preferably, it is in the range of 1 nm to 20 nm. This is because when the thickness of the lithium ion conductive layer is less than the above range, the positive electrode active material and the sulfide solid electrolyte may react. On the other hand, if the thickness of the lithium ion conductive layer exceeds the above range, the Li ion conductivity may be lowered.
- the image analysis etc. which use a transmission electron microscope (TEM) etc. can be mentioned, for example.
- the conductivity of the lithium ion conductive layer in the present invention is described in the section of “(a) first lithium ion conductor” to be described later. Preferably it is in the range of degrees.
- the conductivity of the lithium ion conductive layer is in the range described later, when the surface of the positive electrode active material is coated, a decrease in lithium ion conductivity can be suppressed, and a decrease in output in the all solid state battery can be suppressed.
- the method for forming the lithium ion conductive layer in the present invention is not particularly limited as long as it is a method capable of forming the coating as described above.
- a method for forming the lithium ion conductive layer when the shape of the positive electrode active material is a granular shape, the positive electrode active material is brought into a rolling / flowing state, and a coating liquid containing the material for forming the lithium ion conductive layer is applied. And a method of performing heat treatment.
- the shape of a positive electrode active material is a thin film shape, the method etc. which apply
- Heat treatment in this case refers to drying and firing the coated positive electrode active material.
- the method described in the section “B. Manufacturing method of all-solid battery” described later can be suitably used.
- each component of the lithium ion conductive layer will be described.
- the first lithium ion conductor in the present invention is usually a Li-containing compound having a lithium ion conductivity at normal temperature of 1.0 ⁇ 10 ⁇ 7 S / cm or more.
- the first lithium ion conductor preferably has a lithium ion conductivity at room temperature of 1.0 ⁇ 10 ⁇ 6 S / cm or more. Since the 1st lithium ion conductor shows the lithium ion conductivity which becomes the range mentioned above, when a reaction suppression part is formed in the surface of a positive electrode active material, the fall of Li ion conductivity can be suppressed.
- the method for measuring lithium ion conductivity is not particularly limited as long as it is a method capable of measuring the lithium ion conductivity at room temperature of the first lithium ion conductor in the present invention.
- the measuring method using can be mentioned.
- the first lithium ion conductor is not particularly limited as long as it has lithium ion conductivity in the above range.
- Li-containing oxides such as LiNbO 3 and LiTaO 3 , NASICON type phosphoric acid compounds and the like can be used. Can be mentioned. Among these, Li-containing oxides are preferable, and LiNbO 3 is particularly preferable. It is because the effect of the present invention can be exhibited more.
- the Nasicon-type phosphate compound include Li 1 + x Al x Ti 2-x (PO 4 ) 3 (0 ⁇ x ⁇ 2) (LATP), Li 1 + x Al x Ge 2-x (PO 4). ) 3 (0 ⁇ x ⁇ 2) (LAGP) and the like.
- the range of x may be 0 or more, more preferably greater than 0, and particularly preferably 0.3 or more.
- the range of x should just be 2 or less, and it is preferable that it is 1.7 or less especially, and it is especially preferable that it is 1 or less.
- Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 is preferable.
- the range of x may be 0 or more, more preferably greater than 0, and particularly preferably 0.3 or more.
- the range of x may be 2 or less, more preferably 1.7 or less, and particularly preferably 1 or less.
- a material that becomes Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 can be suitably used.
- the lithium ion conductive layer in the present invention includes a conductive material and a binder that are not reactive with the positive electrode active material and the solid electrolyte material. It may contain.
- the conductive material include acetylene black, ketjen black, and carbon fiber.
- the binder include fluorine-containing binders such as PTFE and PVDF.
- the stabilization layer in the present invention is made of a material having a second lithium ion conductor having a high electronegativity as described later, and is particularly preferably made of a Li-containing compound having a polyanion structure.
- the stabilization layer is formed on the surface of the lithium ion conductive layer, thereby increasing the electrochemical stability of the positive electrode active material layer and suppressing deterioration.
- the lithium ion conductive layer is coated on the surface of the positive electrode active material, the lithium ion conductive layer is prevented from coming into direct contact with the sulfide solid electrolyte layer by coating the stabilization layer, Deterioration of the positive electrode active material layer caused by contact with the sulfide solid electrolyte layer material can be suppressed.
- the form of the stabilization layer in the present invention is not particularly limited as long as it is formed on the surface of the above-described lithium ion conductive layer.
- the shape of the positive electrode active material is a particle shape
- the positive electrode active material particles coated with a lithium ion conductive layer (hereinafter simply referred to as coated particles). It is preferable that the surface be coated on the surface.
- the specific coverage with respect to the surface of the coated particles is preferably 80% or more, and more preferably 95% or more. Moreover, you may cover all the said covering particle
- TEM transmission electron microscope
- XPS X-ray photoelectron spectroscopy
- the thickness of the stabilization layer in the present invention is not particularly limited as long as the positive electrode active material and the sulfide solid electrolyte material do not cause a reaction.
- it is preferably in the range of 1 nm to 100 nm, and more preferably in the range of 1 nm to 20 nm. If the thickness of the stabilization layer is less than the above range, the electrochemical stability effect of the second lithium ion conductor is reduced, and the improvement in the durability of the reaction suppression unit may be suppressed. It is. On the other hand, if the thickness of the stabilization layer exceeds the above range, the initial interface resistance between the positive electrode active material layer and the sulfide solid electrolyte material may be increased.
- the image analysis etc. which use a transmission electron microscope (TEM) etc. can be mentioned, for example.
- the formation method of the stabilization layer in this invention will not be specifically limited if it is a method which can form a coating as mentioned above.
- the shape of the positive electrode active material is a particle shape
- the stabilization layer is formed in a state where the positive electrode active material is in a rolling / flowing state, and a coating liquid containing the stabilization layer forming material is applied and heat-treated.
- a method can be mentioned.
- the shape of the positive electrode active material is a thin film shape
- a method of applying the above-described heat treatment by applying a coating liquid containing the stabilizing layer forming material onto the positive electrode active material can be exemplified.
- the method described in the section “B. Manufacturing method of all-solid battery” described later can be suitably used.
- each component of the stabilization layer will be described.
- the second lithium ion conductor in the present invention is usually a Li-containing compound comprising a polyanion structure having at least one of B, Si, P, Ti, Zr, Al, and W. It is.
- the second lithium ion conductor has high electrochemical stability and can suppress structural changes that occur when it is in contact with the sulfide solid electrolyte material. The reason why the second lithium ion conductor has high electrochemical stability is as follows.
- the second lithium ion conductor is a Li-containing compound having a polyanion structure having at least one of B, Si, P, Al, and W
- it is used for a conventional reaction suppression unit in Pauling's electronegativity
- the electronegativity of each element of B, Si, P, Al, and W is increased.
- the difference from the electronegativity (3.44) is smaller than that of Nb, and a more stable covalent bond can be formed. As a result, the electrochemical stability is increased.
- the second lithium ion conductor is a Li-containing compound including a polyanion structure portion having at least one of Ti and Zr
- the electrochemical stability is increased because of excellent corrosion resistance.
- Ti and Zr are elements that form an oxide coating on the surface and are easily passivated, so-called valve metals. Therefore, it is considered that a Li-containing compound having a polyanion structure having these elements exhibits high corrosion resistance and has high electrochemical stability.
- the second lithium ion conductor in the present invention is not particularly limited as long as it has a polyanion structure portion composed of at least one element among the above-described elements and a plurality of oxygen elements.
- a polyanion structure portion composed of at least one element among the above-described elements and a plurality of oxygen elements.
- the second lithium ion conductor is more preferably a Li-containing compound having a polyanion structure having any one of Ti and Zr, and more preferably Li 2 Ti 2 O 5 .
- the stabilizing layer in the present invention is made of a conductive material and a binder that are not reactive with the positive electrode active material and the solid electrolyte material. You may contain.
- the conductive material include acetylene black, ketjen black, and carbon fiber.
- the binder include fluorine-containing binders such as PTFE and PVDF.
- the ratio of the thickness of the lithium ion conductive layer including the first lithium ion conductor and the thickness of the stabilization layer including the second lithium ion conductor that constitutes the reaction suppression part in the present invention is
- the ratio of the thickness of the lithium ion conductive layer to the thickness of the stabilization layer is 0.01 to 1 when the thickness of the stabilization layer is 1. It is preferably in the range of 100, more preferably in the range of 1 to 100. If the thickness of the lithium ion layer is too thick relative to the thickness of the stabilization layer, the first lithium ion conductor is likely to come into contact with the sulfide solid electrolyte material, and the interface resistance may increase over time. It is because it has.
- the lithium ion conductivity may be lowered.
- the image analysis etc. which use a transmission electron microscope (TEM) etc. can be mentioned, for example.
- the form of the reaction suppressing portion in the present invention is not particularly limited as long as it is formed on the surface of the positive electrode active material described above.
- the reaction suppression portion when the shape of the positive electrode active material described above is a particle shape, the reaction suppression portion is configured to cover the surface of the positive electrode active material particles.
- the portion where the lithium ion conductive layer and the stabilization layer are laminated preferably covers a larger area of the particle surface of the positive electrode active material.
- the specific coverage of the laminated portion is preferably 80% or more, and more preferably 95% or more. Moreover, you may cover all the particle
- TEM transmission electron microscope
- XPS X-ray photoelectron spectroscopy
- the thickness of the reaction suppressing part in the present invention is not particularly limited as long as the positive electrode active material and the sulfide solid electrolyte material do not cause a reaction, and are, for example, in the range of 1 nm to 500 nm. Preferably, it is in the range of 2 nm to 100 nm, and when the thickness of the reaction suppression portion is less than the upper range, there is a possibility that the positive electrode active material and the sulfide solid electrolyte material react. It is. On the other hand, if the thickness of the reaction suppression part exceeds the above range, the ion conductivity may be lowered.
- the method for forming the reaction suppression unit in the present invention is not particularly limited as long as it is a method capable of forming the reaction suppression unit as described above.
- the method described in the section “B. Manufacturing method of all-solid battery” described later can be suitably used.
- the positive electrode active material layer in this invention contains sulfide solid electrolyte material. This is because the ion conductivity of the positive electrode active material layer can be improved. Since the sulfide solid electrolyte material has high reactivity, it easily reacts with the above-described positive electrode active material and easily forms a high resistance layer with the positive electrode active material. On the other hand, in the present invention, since the above-described reaction suppression portion is formed on the surface of the positive electrode active material, the increase in the interfacial resistance between the positive electrode active material and the sulfide solid electrolyte material is effectively suppressed over time. can do.
- Examples of the sulfide solid electrolyte material include Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiI, Li 2 S—P 2 S 5 —Li 2 O, and Li 2 S—P 2 S. 5 -Li 2 O—LiI, Li 2 S—SiS 2 , Li 2 S—SIS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 -LiI, Li 2 S -SiS 2 -P 2 S 5 -LiI, Li 2 S-B 2 S 3, Li 2 S-P 2 S 5 -Z m S n ( however, m, n are positive Z is one of Ge, Zn, and Ga.), Li 2 S—GeS 2 , Li 2 S—SiS 2 —Li 3 PO 4 , Li 2 S—SiS 2 —Li
- the sulfide solid electrolyte material if it is made by using the raw material composition containing Li 2 S and P 2 S 5, the proportion of Li 2 S to the total of Li 2 S and P 2 S 5 is For example, it is preferably in the range of 70 mol% to 80 mol%, more preferably in the range of 72 mol% to 78 mol%, and still more preferably in the range of 74 mol% to 76 mol%. This is because a sulfide solid electrolyte material having an ortho composition or a composition in the vicinity thereof can be obtained, and a sulfide solid electrolyte material having high chemical stability can be obtained.
- ortho generally refers to one having the highest degree of hydration among oxo acids obtained by hydrating the same oxide.
- the crystal composition in which Li 2 S is added most in the sulfide is called the ortho composition.
- Li 2 S—P 2 S 5 system Li 3 PS 4 corresponds to the ortho composition.
- P 2 S 5 in the raw material composition, even when using the Al 2 S 3, or B 2 S 3, a preferred range is the same.
- Li 3 AlS 3 corresponds to the ortho composition
- Li 3 BS 3 corresponds to the ortho composition.
- the sulfide solid electrolyte material if it is made by using the raw material composition containing Li 2 S and SiS 2, the ratio of Li 2 S to the total of Li 2 S and SiS 2, for example 60 mol% ⁇ It is preferably within the range of 72 mol%, more preferably within the range of 62 mol% to 70 mol%, and even more preferably within the range of 64 mol% to 68 mol%. This is because a sulfide solid electrolyte material having an ortho composition or a composition in the vicinity thereof can be obtained, and a sulfide solid electrolyte material having high chemical stability can be obtained. In the Li 2 S—SiS 2 system, Li 4 SiS 4 corresponds to the ortho composition.
- SiS 2 instead of SiS 2 in the raw material composition, even when using a GeS 2, the preferred range is the same.
- Li 4 GeS 4 corresponds to the ortho composition.
- the ratio of LiX is, for example, in the range of 1 mol% to 60 mol%. Preferably, it is in the range of 5 mol% to 50 mol%, more preferably in the range of 10 mol% to 40 mol%.
- the sulfide solid electrolyte material if it is made by using the raw material composition containing Li 2 O, the ratio of Li 2 O is, for example, is preferably in the range of 1 mol% ⁇ 25 mol%, More preferably, it is in the range of 3 mol% to 15 mol%.
- the sulfide solid electrolyte material may be sulfide glass, crystallized sulfide glass, or a crystalline material obtained by a solid phase method.
- the sulfide glass can be obtained, for example, by performing mechanical milling (ball mill or the like) on the raw material composition.
- Crystallized sulfide glass can be obtained, for example, by subjecting sulfide glass to a heat treatment at a temperature equal to or higher than the crystallization temperature.
- the lithium ion conductivity of the sulfide solid electrolyte material at room temperature is, for example, preferably 1 ⁇ 10 ⁇ 5 S / cm or more, and more preferably 1 ⁇ 10 ⁇ 4 S / cm or more.
- the shape of the sulfide solid electrolyte material in the present invention examples include a particle shape such as a true sphere and an oval sphere, and a thin film shape.
- the average particle diameter (D 50 ) is not particularly limited, but is preferably 40 ⁇ m or less, more preferably 20 ⁇ m or less, and more preferably 10 ⁇ m. More preferably, it is as follows. This is because it is easy to improve the filling rate in the positive electrode active material layer.
- the average particle diameter is preferably 0.01 ⁇ m or more, and more preferably 0.1 ⁇ m or more.
- the said average particle diameter can be determined with a particle size distribution meter, for example.
- the positive electrode active material layer in the present invention further contains at least one of a conductive material and a binder in addition to the above-described positive electrode active material, reaction inhibitor and sulfide solid electrolyte material. Also good.
- the conductive material include acetylene black, ketjen black, and carbon fiber.
- the binder include fluorine-containing binders such as PTFE and PVDF.
- the thickness of the positive electrode active material layer varies depending on the intended configuration of the all-solid battery, but is preferably in the range of 0.1 ⁇ m to 1000 ⁇ m, for example.
- the solid electrolyte layer in the present invention is a layer containing at least a solid electrolyte material, and is a layer formed between the positive electrode active material layer and the negative electrode active material layer.
- the solid electrolyte material contained in the solid electrolyte layer is not particularly limited as long as it has lithium ion conductivity. Solid electrolyte materials may be used, and other solid electrolyte materials may be used.
- the solid electrolyte layer contains a sulfide solid electrolyte material.
- both the positive electrode active material layer and the solid electrolyte layer contain a sulfide solid electrolyte material. This is because the effects of the present invention can be sufficiently exhibited.
- the solid electrolyte material used for the solid electrolyte layer is composed only of a sulfide solid electrolyte material.
- the sulfide solid electrolyte material is the same as that described in the above section “1. Positive electrode active material layer”. Moreover, about solid electrolyte materials other than sulfide solid electrolyte material, the material similar to the solid electrolyte material used for a general all-solid-state battery can be used.
- the thickness of the solid electrolyte layer in the present invention is, for example, preferably in the range of 0.1 ⁇ m to 1000 ⁇ m, and more preferably in the range of 0.1 ⁇ m to 300 ⁇ m.
- the negative electrode active material layer in the present invention is a layer containing at least a negative electrode active material, and may contain at least one of a solid electrolyte material and a conductive agent as required.
- the negative electrode active material is not particularly limited as long as the charge / discharge potential becomes a base potential as compared with the charge / discharge potential of the positive electrode active material contained in the positive electrode active material layer described above.
- a metal active material, a carbon active material, etc. can be mentioned. Examples of the metal active material include Li alloy, In, Al, Si, and Sn.
- examples of the carbon active material include mesocarbon microbeads (MCMB), highly compoundable graphite (HOPG), hard carbon, and soft carbon.
- MCMB mesocarbon microbeads
- HOPG highly compoundable graphite
- hard carbon hard carbon
- soft carbon soft carbon.
- the solid electrolyte material and the conductive agent used in the negative electrode active material layer are the same as those in the positive electrode active material layer described above.
- the thickness of the negative electrode active material layer is, for example, in the range of 0.1 ⁇ m to 1000 ⁇ m.
- the all solid state battery of the present invention has at least the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer described above. Furthermore, it usually has a positive electrode current collector for collecting current of the positive electrode active material layer and a negative electrode current collector for collecting current of the negative electrode active material layer.
- the material for the positive electrode current collector include SUS, aluminum, nickel, iron, titanium, and carbon. Among them, SUS is preferable.
- examples of the material for the negative electrode current collector include SUS, copper, nickel, and carbon. Among them, SUS is preferable.
- the thickness and shape of the positive electrode current collector and the negative electrode current collector are preferably appropriately selected according to the use of the all solid state battery.
- the battery case used for a general all-solid-state battery can be used for the battery case used for this invention,
- the battery case made from SUS etc. can be mentioned.
- the all solid state battery of the present invention may be one in which the power generating element is formed inside the insulating ring.
- All-solid battery The all-solid battery of the present invention may be a primary battery or a secondary battery, and among these, a secondary battery is preferred. This is because it can be repeatedly charged and discharged and is useful, for example, as an in-vehicle battery.
- Examples of the shape of the all solid state battery of the present invention include a coin type, a laminate type, a cylindrical type, and a square type.
- the method for producing an all solid state battery of the present invention is not particularly limited as long as it is a method capable of obtaining the all solid state battery described above. For example, the method for producing an all solid state battery described later can be suitably used. .
- the all-solid battery manufacturing method of the present invention is the above-described all-solid battery manufacturing method, wherein the first precursor coating liquid containing the first lithium ion conductor material is applied to the surface of the positive electrode active material.
- a positive ion active material was coated with a lithium ion conductive layer forming step of forming a lithium ion conductive layer by coating and heat treatment, and a second precursor coating liquid containing the second lithium ion conductor raw material.
- the “heat treatment” in this case is not particularly limited as long as it is a treatment for applying heat to each layer to solidify, but usually means drying and firing.
- FIG. 3 is a flowchart for explaining an example of the method for producing an all solid state battery of the present invention.
- the manufacturing method of a positive electrode active material layer is a method of performing a lithium ion conductive layer forming step and a stabilizing layer forming step on a positive electrode active material.
- a lithium ion conductive layer forming step is performed.
- the first precursor coating liquid containing the first lithium ion conductor material is applied to the surface of the positive electrode active material (coating process), the coated surface is dried (drying process), and finally fired ( Firing step).
- the lithium ion conductive layer is formed by performing the coating step and the heat treatment step of the drying step and the firing step.
- a stabilization layer forming step is performed.
- the positive electrode active material that has undergone the lithium ion conductive layer formation step is coated with a second precursor coating solution containing a raw material for the second lithium ion conductor (coating step), and the coated surface is dried (drying step). ) And finally firing (firing step).
- the stabilizing layer is formed by performing the coating process and the heat treatment process of the drying process and the baking process.
- the lithium ion conductive layer and the stabilization layer are separated from each other by performing a heat treatment step after coating in each coating step.
- the reaction suppression part which is formed as this and has a two-layer structure can be formed.
- the surface of the lithium ion conductive layer is coated with the stabilizing layer, the deterioration of the first lithium conductor due to contact with the sulfide solid electrolyte material is suppressed, whereby the positive electrode active material and the sulfide solid electrolyte are suppressed.
- An increase in the interfacial resistance of the material over time can be suppressed, and an all-solid battery excellent in Li ion conductivity and durability can be easily produced.
- the lithium ion conductive layer forming step in the present invention will be described.
- the first precursor coating liquid containing the raw material of the first lithium ion conductor is applied to the surface of the positive electrode active material so as to have a thickness described later.
- the heat treatment step is usually a drying step for drying the coated positive electrode active material.
- Coating process The coating process in a lithium ion conductive layer formation process is a process of coating the 1st precursor coating liquid mentioned later on the surface of a positive electrode active material.
- the 1st precursor coating liquid in this process contains a 1st lithium ion conductor.
- the raw material of the first lithium ion conductor contained in the first precursor coating liquid in this step is not particularly limited as long as the target first lithium ion conductor can be formed.
- Examples of the first lithium ion conductor include the same ones as described in the above section “A. All-solid battery”, and in the present invention, the first lithium ion conductor is LiNbO 3 . It is preferable.
- a raw material for LiNbO 3 an Li supply compound and an Nb supply compound can be used.
- Li supply compound examples include Li alkoxides such as lithium ethoxide and lithium methoxide, lithium salts such as lithium hydroxide and lithium acetate.
- Nb supply compound examples include Nb alkoxides such as pentaethoxyniobium and pentamethoxyniobium, niobium salts such as niobium hydroxide and niobium acetate.
- concentration of the raw material of the 1st lithium ion conductor contained in a 1st precursor coating liquid it sets suitably according to the composition etc. of the target reaction suppression part.
- the first precursor coating liquid described above can be usually obtained by dissolving or dispersing the raw material of the first lithium ion conductor in a solvent.
- the solvent used in the first precursor coating liquid is particularly limited as long as it can dissolve or disperse the raw material of the first lithium ion conductor and does not degrade the raw material of the first lithium ion conductor. Is not to be done.
- methanol, ethanol, propanol, etc. can be mentioned.
- the said solvent is a thing with little moisture content from a viewpoint etc. which suppress deterioration of the said raw material.
- sol-gel solution that becomes a sol state by hydrolysis and polycondensation reaction of a compound that is a raw material of the ionic conductor to be contained, and further becomes a gel state by progressing polycondensation reaction and aggregation.
- the 1st precursor coating liquid used for this process may contain arbitrary additives, such as a electrically conductive material and a binder, as needed, as an electrically conductive material, for example, acetylene black , Ketjen black, carbon fiber and the like.
- a binder include fluorine-containing binders such as PTFE and PVDF.
- Positive electrode active material The positive electrode active material in this step reacts with the sulfide solid electrolyte material to form a high-resistance layer, and is the same as the content described in the above section “A. All-solid battery”. Therefore, the description here is omitted.
- the method of applying the first precursor coating solution described above is preferably a coating method capable of uniformly applying the coating solution, for example, spin coating. Method, dip coating method, spray coating method, impregnation method and the like. Especially, it is preferable to apply using a spin coat method. This is because a thin film can be generated efficiently.
- the coating atmosphere is not particularly limited as long as the target lithium ion conductive layer can be formed and the atmosphere does not deteriorate the lithium ion conductive layer and the positive electrode active material.
- the thickness of the coating layer of the first precursor coating liquid described above is appropriately set according to the thickness of the target reaction suppression portion, etc. It is preferable to satisfy the thickness range of the lithium ion conductive layer described in the section “Battery”.
- the heat treatment step in the lithium ion conductive layer forming step is a step of applying heat to the positive electrode active material coated with the first precursor coating solution and solidifying it, and usually the coating is performed. It has a drying process for drying the positive electrode active material, and a baking process for subsequent baking.
- Drying step The drying step in this step is to remove the solvent contained in the coated first precursor coating solution and dry the positive electrode active material.
- the drying method in this step is not particularly limited as long as it is a method capable of removing the solvent of the first precursor coating liquid and drying the positive electrode active material layer, and the method can be appropriately selected. Is. Examples thereof include a hot air drying method, a vacuum drying method, an evaporation to dryness method, a freeze drying method, a spray drying method, and a reduced pressure drying method.
- the drying temperature in this step can be appropriately selected according to the volatility of the solvent used in the first precursor coating liquid, and the solvent contained in the coating liquid can be removed. There is no particular limitation as long as it is a temperature at which the active material can be dried. Further, the drying time in this step can be appropriately selected according to the volatility of the solvent used in the coating solution, and the solvent contained in the coated first precursor coating solution can be selected. There is no particular limitation as long as it can be removed and the positive electrode active material can be dried.
- (Ii) Firing step In the firing step in this step, the positive electrode active material coated with the first precursor coating liquid is heated to solidify the lithium ion conductive layer formed on the surface of the positive electrode active material. It is.
- the firing method in this step is not particularly limited as long as it does not degrade the lithium ion conductive layer and the positive electrode active material, and examples thereof include a reaction firing method, an atmosphere firing method, and a thermal plasma method. .
- the firing atmosphere in this step is not particularly limited as long as the lithium ion conductive layer can be solidified and the lithium ion conductive layer and the positive electrode active material are not deteriorated.
- an air atmosphere a nitrogen atmosphere
- an inert gas atmosphere such as an argon atmosphere
- a reducing atmosphere such as an ammonia atmosphere, a hydrogen atmosphere, and a carbon monoxide atmosphere
- a vacuum etc.
- the firing temperature in this step is not particularly limited as long as it can solidify the lithium ion conductive layer and does not deteriorate the lithium ion conductive layer and the positive electrode active material.
- the temperature is preferably in the range of 600 ° C, more preferably in the range of 200 ° C to 500 ° C, and particularly preferably in the range of 300 ° C to 400 ° C. This is because when the firing temperature is less than the above range, the lithium ion conductive layer may not be sufficiently formed. On the other hand, when the said baking temperature exceeds the said range, it is because there exists a possibility that a lithium ion conductive layer and a positive electrode active material may deteriorate.
- the firing time in this step is not particularly limited as long as it is a time obtained in a state in which the lithium ion conductive layer is solidified.
- it is preferably in the range of 0.5 hours to 10 hours, More preferably, it is within the range of 3 hours to 7 hours. This is because if the firing time is less than the above range, the lithium ion conductive layer may not be sufficiently formed.
- the firing time exceeds the above range, the lithium ion conductive layer and the positive electrode active material may be deteriorated by excessive heat treatment.
- a second precursor coating liquid containing a raw material for the second lithium ion conductor on the surface of the lithium ion conductive layer coated with the positive electrode active material described above has a thickness described later.
- a heat treatment step for applying heat to the coated positive electrode active material to solidify, and the heat treatment step is usually the above-mentioned coating step. It has a drying step for drying the positive electrode active material and a firing step for firing thereafter.
- Coating process is a process of coating the surface of the lithium ion conductive layer coat
- the 2nd precursor coating liquid in this process contains the raw material of a 2nd lithium ion conductor.
- the raw material for the second lithium ion conductor contained in the second precursor coating liquid used in this step is not particularly limited as long as the second lithium ion conductor can be formed.
- the raw material for the second lithium ion conductor is not particularly limited as long as the target Li-containing compound can be formed.
- hydroxide, oxide, metal salt, metal alkoxide, A metal complex etc. can be mentioned.
- a pre-synthesized compound may be used as a raw material for the second lithium ion conductor.
- the second lithium ion conductor is a polyanion structure having at least one of B, Si, P, Ti, Zr, Al, and W. Li-containing compound having a part.
- the polyanion structure part is composed of at least one element and a plurality of oxygen elements among the elements described above.
- the second lithium ion conductor is, for example, a general formula Li x AO y (A is at least one of B, Si, P, Ti, Zr, Al, and W, and x and y are positive numbers) There is.)
- the second lithium ion conductor is preferably Li 2 Ti 2 O 5 .
- a Li-supplying compound for example, ethoxy lithium, Li etc. methoxy lithium Lithium salts such as alkoxide, lithium hydroxide, and lithium acetate are used, and the above-described metal oxide, metal salt, metal complex, and the like containing A are used as the A supply compound.
- the Li-containing compound is Li 2 Ti 2 O 5
- ethoxy lithium as a Li supply compound and tetraisopropoxy titanium as a Ti supply compound can be used as raw materials.
- the target Li-containing compound when the element A is a nonmetal, for example, the target Li-containing compound can be used as it is.
- the Li-containing compound when the Li-containing compound is Li 3 PO 4 , Li 3 PO 4 can be used as a raw material for the second lithium ion conductor.
- A when A is B (boron), the above-described Li supply compound and boric acid as the B supply compound are used as the raw material for the second lithium ion conductor. Can do.
- the raw material of a 2nd lithium ion conductor may be sufficient, and the water contained in the 2nd precursor coating liquid in this invention may be sufficient.
- Content of the raw material of the 2nd lithium ion conductor contained in the 2nd precursor coating liquid in this process is suitably selected according to the target reaction suppression part.
- the second precursor coating liquid can be obtained by dissolving or dispersing the raw material of the second lithium ion conductor in a solvent, similarly to the first precursor coating liquid described above.
- the solvent used in the second precursor coating liquid is not particularly limited as long as it can dissolve or disperse the raw material of the second lithium ion conductor and does not degrade the above-described compound. Mention may be made of methanol, ethanol, propanol and the like. Moreover, it is preferable that the said solvent is a thing with little moisture content from a viewpoint etc. which suppress deterioration of the said raw material.
- sol-gel solution that becomes a sol state by hydrolysis and polycondensation reaction of a compound that is a raw material of the ionic conductor to be contained, and further becomes a gel state by progressing polycondensation reaction and aggregation.
- a binder include fluorine-containing binders such as PTFE and PVDF.
- Positive electrode active material and coated lithium ion conductive layer are the same as those described in the section “1. Lithium ion conductive layer forming step” above. Since it is the same, description here is abbreviate
- (Iii) Coating step In this step, the method of applying the second precursor coating solution described above is the same as the coating method described in the above "1. Lithium ion conductive layer forming step". The description in is omitted. Further, the thickness of the stabilization layer formed by this step is appropriately set according to the thickness of the target reaction suppressing portion, etc., but is described in the above section “A. All-solid battery”. It is preferable to satisfy the range of the thickness of the stabilized layer.
- the heat treatment step in the stabilization layer forming step is a step in which the positive electrode active material coated with the second precursor coating liquid is heated and solidified, and usually the coated positive electrode. It has a drying step for drying the active material and a firing step for firing thereafter. Since the drying step and the firing step in the stabilization layer forming step are the same as the contents described in the above “1. Lithium ion conductive layer forming step”, the description thereof is omitted here.
- Step 3 there is no particular limitation as long as it has the above-described steps.
- the reaction is suppressed on the surface by the above-described steps.
- the material forming the positive electrode active material layer such as the positive electrode active material formed with a portion, is pressed with a press to form the positive electrode active material layer, and the material forming the solid electrolyte material is pressed in the same manner. Examples thereof include a solid electrolyte layer forming step for forming a solid electrolyte layer and a negative electrode active material layer forming step for forming a negative electrode active material layer by similarly pressing the material constituting the negative electrode active material layer.
- a solid electrolyte layer forming step of laminating a material constituting the solid electrolyte material on the positive electrode active material having a reaction suppressing portion formed on the surface by the above-described steps, and a solid Examples include a negative electrode active material forming step of laminating a material constituting the negative electrode active material layer on the electrolyte layer.
- the negative electrode active material layer and the solid electrolyte layer in the present invention are the same as the contents described in the above-mentioned section “A. All-solid battery”, the description thereof is omitted here.
- a step of disposing a positive electrode current collector on the surface of the positive electrode active material layer, a step of disposing a negative electrode current collector on the surface of the negative electrode active material layer, and a power generation element as a battery You may have the process etc. which are accommodated in a case.
- the positive electrode current collector, the negative electrode current collector, the battery case, and the like are the same as those described in the section “A. All-solid-state battery”, and thus the description thereof is omitted here.
- the present invention is not limited to the above embodiment.
- the above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. It is included in the technical scope.
- a lithium cobaltate thin film (positive electrode active material) was obtained by sputtering on an Au substrate.
- the first precursor coating solution was applied at 5000 rpm for 10 seconds using a spin coater (MS-A100, manufactured by Mikasa Co., Ltd.), and after drying, at 350 ° C. for 0.5 hour. Baking was performed to obtain a lithium ion conductive layer having a thickness of 5 nm.
- the second precursor coating solution was applied at 5000 rpm for 10 seconds using a spin coater (MS-A100, manufactured by Mikasa Co., Ltd.), dried, 350 ° C., 0.5 Firing was performed over time to obtain a stabilization layer having a thickness of 5 nm.
- reaction suppression part By the formation process of the above-described lithium ion conductive layer and the above-described stabilization layer, a reaction suppression unit having two layers on the surface of the positive electrode active material, the active material side being a lithium ion conductive layer and the solid electrolyte side being a stabilization layer An electrode having a positive electrode active material formed and having a reaction suppression portion formed on the surface was obtained.
- the reaction suppression unit includes a lithium ion conductive layer having LiNbO 3 as the first lithium ion conductor and a stabilization having Li 2 Ti 2 O 5 as the second lithium ion conductor.
- a lithium ion conductive layer having LiNbO 3 as the first lithium ion conductor and a stabilization having Li 2 Ti 2 O 5 as the second lithium ion conductor.
- the structure of the positive electrode active material by the suppression of the initial interface resistance by the first lithium ion conductor and the contact with the sulfide solid electrolyte material by the second lithium ion conductor It is presumed that the change of the initial interface resistance and the interfacial resistance over time can be suppressed because it has two characteristics of the change suppression.
- the surface of the lithium ion conductive layer is covered with a stabilization layer, and LiNbO 3 is not in direct contact with the sulfide solid electrolyte layer. As a result, it is considered that an increase in the interfacial resistance with time is also suppressed.
Abstract
Description
本発明の全固体電池は、正極活物質を含有する正極活物質層と、負極活物質を含有する負極活物質層と、上記正極活物質層および上記負極活物質層の間に形成された固体電解質層と、を有する全固体電池であって、上記正極活物質層および上記固体電解質層の少なくとも一方が、硫化物固体電解質材料を含有し、上記正極活物質の表面上に、第1リチウムイオン伝導体を有するリチウムイオン伝導層を活物質側とし、第2リチウムイオン伝導体を有する安定化層を固体電解質層側とする、2層を有する反応抑制部が形成され、上記第1リチウムイオン伝導体は、常温でのリチウムイオン伝導度が、1.0×10-7S/cm以上のLi含有化合物であり、上記第2リチウムイオン伝導体は、B、Si、P、Ti、Zr、Al、およびWの少なくとも一つを有するポリアニオン構造部を備えるLi含有化合物であることを特徴とするものである。
以下、本発明の全固体電池について、構成ごとに説明する。
まず、本発明における正極活物質層について説明する。本発明に用いられる正極活物質層は、少なくとも正極活物質を含有する層である。また、本発明における正極活物質層は、必要に応じて、固体電解質材料および導電化材の少なくとも一方を含有していても良い。本発明においては硫化物固体電解質材料を含有することが特に好ましい。正極活物質層のイオン伝導性を向上させることができるからである。
本発明に用いられる正極活物質について説明する。本発明における正極活物質は、後述する負極活物質層に含有される負極活物質の充放電電位と比較して、充放電電位が貴な電位となるものであれば特に限定されるものではない。このような正極活物質としては、後述する硫化物固体電解質材料と反応し高抵抗層を形成するという観点から、例えば、酸化物正極活物質であることが好ましい。また酸化物正極活物質を用いることにより、エネルギー密度の高い全固体電池とすることができる。
本発明における反応抑制部について説明する。本発明に用いられる反応抑制部は、上記正極活物質の表面に形成されるものであり、第1リチウムイオン伝導体を有するリチウムイオン伝導層を活物質側とし、第2リチウムイオン伝導体を有する安定化層を固体電解質層側とする2つの層を有するものである。図2は、本発明における反応抑制部の一例を示す概略断面図である。図2に例示するように、正極活物質4の表面に、リチウムイオン伝導層8と安定化層7を有する反応抑制部6が形成される。リチウムイオン伝導層8は正極活物質4の表面を被覆し、安定化層7は上記リチウムイオン伝導層8の表面を被覆する。反応抑制部を構成する上記2つの層のうち、上記リチウムイオン伝導層に含有される第1リチウムイオン伝導体は、常温でのリチウムイオン伝導度が、1.0×10-7S/cm以上のLi含有化合物であり、上記安定化層に含有される第2リチウムイオン伝導体は、B、Si、P、Ti、Zr、Al、およびWの少なくとも一つを有するポリアニオン構造部を備えるLi含有化合物である。反応抑制部は、全固体電池使用時に生じる、正極活物質と硫化物固体電解質材料との反応を抑制する機能を有する。本発明においては、反応抑制部は上述したようなリチウムイオン伝導層の表面を安定化層で被覆した構造をとる。これにより第1リチウムイオン伝導体と硫化物固体電解質材料との接触による劣化が抑制され、従来のニオブ酸化物(例えばLiNbO3)のみから形成される反応抑制部と比較して耐久性を高めることができる。
以下、反応抑制部の各構成について説明する。
本発明におけるリチウムイオン伝導層は、後述のとおり伝導性の良い第1リチウムイオン伝導体を有する材料からなり、上記正極活物質の表面に形成されることで、正極活物質層と硫化物固体電解質材料との間で生じる界面抵抗を低減し、出力の低下を抑制することを特徴とするものである。
以下、リチウムイオン伝導層の各構成要素について説明する。
本発明における第1リチウムイオン伝導体は、通常、常温でのリチウムイオン伝導度が1.0×10-7S/cm以上のLi含有化合物である。第1リチウムイオン伝導体は、中でも常温でのリチウムイオン伝導度が、1.0×10-6S/cm以上であることがより好ましい。第1リチウムイオン伝導体が上述した範囲となるリチウムイオン伝導度を示すことから、正極活物質の表面に反応抑制部を形成した際に、Liイオン伝導性の低下を抑制することができる。そのため表面に反応抑制部が形成された正極活物質を含有する正極活物質層を用いた全固体電池において出力特性が低下することを抑制できる。なお、リチウムイオン伝導度の測定方法としては、本発明における第1リチウムイオン伝導体の常温でのリチウムイオン伝導度が測定できる方法であれば特に限定されるものではないが、例えば、交流インピーダンス法を用いた測定方法を挙げることができる。
本発明におけるリチウムイオン伝導層は、上述した第1リチウムイオン伝導体の他に、上記正極活物質および固体電解質材料と反応性を有さない導電化材および結着材を含有していても良い。導電化材としては、例えば、アセチレンブラック、ケッチェンブラック、カーボンファイバー等を挙げることができる。結着材としては、例えば、PTFE、PVDF等のフッ素含有結着材を挙げることができる。
本発明における安定化層は、後述のとおり電気陰性度の高い第2リチウムイオン伝導体を有する材料からなり、特にポリアニオン構造部を備えるLi含有化合物からなることが好ましい。安定化層は上記リチウムイオン伝導層の表面に形成されることで、正極活物質層の電気化学的安定性を高め、劣化を抑制することを特徴とするものである。本発明によれば、正極活物質の表面に上記リチウムイオン伝導層を被覆させた後に、安定化層を被覆させることで、リチウムイオン伝導層が硫化物固体電解質層に直接接触することを防ぎ、硫化物固体電解質層材料との接触により生じる正極活物質層の劣化を抑制することができる。
以下、安定化層の各構成要素について説明する。
本発明における第2リチウムイオン伝導体は、通常、B、Si、P、Ti、Zr、Al、およびWの少なくとも一つを有するポリアニオン構造部を備えるLi含有化合物である。第2リチウムイオン伝導体は電気化学的安定性が高く、硫化物固体電解質材料と接触した際に生じる構造変化を抑制することができる。第2リチウムイオン伝導体の電気化学的安定性が高い理由は、以下の通りである。
本発明における安定化層は、上述した第2リチウムイオン伝導体の他に、上記正極活物質および固体電解質材料と反応性を有さない導電化材および結着材を含有していても良い。導電化材としては、例えば、アセチレンブラック、ケッチェンブラック、カーボンファイバー等を挙げることができる。結着材としては、例えば、PTFE、PVDF等のフッ素含有結着材を挙げることができる。
本発明における反応抑制部を構成する、第1リチウムイオン伝導体を含むリチウムイオン伝導層の厚さと第2リチウムイオン伝導体を含む安定化層の厚さの比率は、全固体電池に応じて適宜設定されるものであり、例えば、リチウムイオン伝導層の厚さの、安定化層の厚さに対する比率は、安定化層の厚さを1とした場合、0.01~100の範囲内であることが好ましく、1~100の範囲内であることがより好ましい。リチウムイオン層の厚さが、安定化層の厚さに対して厚すぎる場合、第1リチウムイオン伝導体が硫化物固体電解質材料と接触しやすくなり、界面抵抗が経時的に増加する可能性を有するからである。また一方、リチウムイオン層の厚さが、安定化層の厚さに対して薄すぎる場合、リチウムイオン伝導性が低下する可能性を有するからである。なお、本発明における反応抑制部を構成する各層の厚さの比率を求める方法としては、例えば透過型電子顕微鏡(TEM)等を用いる画像解析等を挙げることができる。
本発明における正極活物質層は、硫化物固体電解質材料を含有することが好ましい。正極活物質層のイオン伝導性を向上させることができるからである。硫化物固体電解質材料は、反応性が高いため、上述した正極活物質と反応しやすく、正極活物質との間に高抵抗層を形成しやすい。これに対して、本発明においては、正極活物質の表面に上述した反応抑制部が形成されることから、正極活物質および硫化物固体電解質材料の界面抵抗の経時的な増加を効果的に抑制することができる。
本発明における正極活物質層は、上述した正極活物質、反応抑制部および硫化物固体電解質材料の他に、導電化材および結着材の少なくとも一つをさらに含有しても良い。導電化材としては、例えば、アセチレンブラック、ケッチェンブラック、カーボンファイバー等を挙げることができる。結着材としては、例えば、PTFE、PVDF等のフッ素含有結着材を挙げることができる。上記正極活物質層の厚さは、目的とする全固体電池の構成によって異なるものであるが、例えば、0.1μm~1000μmの範囲内であることが好ましい。
次に、本発明における固体電解質層について説明する。本発明における固体電解質層は、少なくとも固体電解質材料を含有する層であり、正極活物質層と負極活物質層の間に形成される層である。上述したように、正極活物質層が硫化物固体電解質材料を含有する場合、固体電解質層に含まれる固体電解質材料は、リチウムイオン伝導性を有するものであれば特に限定されるものではなく、硫化物固体電解質材料であっても良く、それ以外の固体電解質材料であっても良い。一方で正極活物質層が、硫化物固体電解質材料を含有しない場合、固体電解質層は硫化物固体電解質材料を含有する。特に、本発明においては、正極活物質層および固体電解質層の両方が、硫化物固体電解質材料を含有することが好ましい。本発明の効果を十分に発揮することができるからである。また、固体電解質層に用いられる固体電解質材料は、硫化物固体電解質材料のみから構成されることが好ましい。
次に本発明の負極活物質層について説明する。本発明における負極活物質層は、少なくとも負極活物質を含有する層であり、必要に応じて固体電解質材料および導電化剤の少なくとも一方を含有していても良い。負極活物質としては、上述した正極活物質層に含有される正極活物質の充放電電位と比較して、充放電電位が卑な電位となるものであれば特に限定されるものではなく、例えば金属活物質およびカーボン活物質等を挙げることができる。金属活物質としては、例えば、Li合金、In、Al、SiおよびSn等を挙げることができる。一方、カーボン活物質としては、例えばメソカーボンマイクロビーズ(MCMB)、高配合性グラファイト(HOPG),ハードカーボン、ソフトカーボン等を挙げることができる。なお、負極活物質層に用いられる固体電解質材料および導電化剤については、上述した正極活物質層における場合と同様である。また、負極活物質層の厚さは、例えば0.1μm~1000μmの範囲内である。
本発明の全固体電池は、上述した正極活物質層、固体電解質層、および負極活物質層を少なくとも有するものである。さらに通常は、正極活物質層の集電を行う正極集電体、および負極活物質層の集電を行う負極集電体を有する。正極集電体の材料としては、例えばSUS、アルミニウム、ニッケル、鉄、チタンおよびカーボン等を挙げられることができ、中でもSUSが好ましい。一方、負極集電体の材料としては、例えば、SUS、銅、ニッケル、およびカーボン等を挙げることができ、なかでもSUSが好ましい。また、正極集電体および負極集電体の厚さや形状等については、全固体電池の用途等に応じて適宜選択することが好ましい。また、本発明に用いられる電池ケースには、一般的な全固体電池に使用される電池ケースを用いることができ、例えば、SUS製電池ケース等を挙げることができる。また、本発明の全固体電池は、発電要素を絶縁リングの内部に形成したものであっても良い。
本発明の全固体電池は、一次電池であっても良く、二次電池であってもよいが、中でも二次電池であることが好ましい。繰り返し充放電でき、例えば車載用電池として有用だからである。本発明の全固体電池の形状としては、例えば、コイン型、ラミネート型、円筒型および角型等を挙げることができる。本発明の全固体電池の製造方法は、上述した全固体電池を得ることができる方法であれば特に限定されるものではないが、例えば後述する全固体電池の製造方法を好適に用いることができる。
次に、本発明の全固体電池の製造方法について説明する。本発明の全固体電池の製造方法は、上述した全固体電池の製造方法であって、上記第1リチウムイオン伝導体の原料を含有する第1前駆体塗工液を、正極活物質の表面に塗工し熱処理を行うことによりリチウムイオン伝導層を形成するリチウムイオン伝導層形成工程と、上記第2リチウムイオン伝導体の原料を含有する第2前駆体塗工液を、正極活物質を被覆したリチウムイオン伝導層の表面に塗工し熱処理を行うことにより安定化層を形成する安定化層形成工程と、を有することを特徴とするものである。この場合の「熱処理」とは、各層に熱を加えて固化させる処理であれば、特に限定されないが、通常は乾燥および焼成させることをいう。
まず、本発明におけるリチウムイオン伝導層形成工程について説明する。本発明におけるリチウムイオン伝導層形成工程は、上記の正極活物質の表面に第1リチウムイオン伝導体の原料を含有する第1前駆体塗工液を、後述する厚さになるように塗工する塗工工程と、上記塗工された正極活物質に熱を加えて固化させる熱処理工程と、を有するものであり、上記熱処理工程とは、通常、上記塗工された正極活物質を乾燥させる乾燥工程と、その後に焼成させる焼成工程と、を有するものである。
リチウムイオン伝導層形成工程における塗工工程は、正極活物質の表面に後述する第1前駆体塗工液を塗工する工程である。
本工程における第1前駆体塗工液は、第1リチウムイオン伝導体を含有するものである。本工程における第1前駆体塗工液に含有される第1リチウムイオン伝導体の原料としては、目的とする第1リチウムイオン伝導体を形成できるものであれば特に限定されるものではない。第1リチウムイオン伝導体としては、上記「A.全固体電池」の項に記載したものと同様のものを挙げることができ、中でも本発明においては、第1リチウムイオン伝導体がLiNbO3であることが好ましい。LiNbO3の原料としては、Li供給化合物およびNb供給化合物を用いることができる。Li供給化合物としては、例えば、リチウムエトキシド、リチウムメトキシド等のLiアルコキシド、リチウム水酸化物、酢酸リチウム等のリチウム塩を挙げることができる。また、Nb供給化合物としては、例えば、ペンタエトキシニオブ、ペンタメトキシニオブ等のNbアルコキシド、ニオブ水酸化物、酢酸ニオブ等のニオブ塩を挙げることができる。なお、第1前駆体塗工液に含有される第1リチウムイオン伝導体の原料の濃度としては、目的とする反応抑制部の組成等に応じて適宜設定されるものである。
本工程における正極活物質は、硫化物固体電解質材料と反応し、高抵抗層を形成するものであり、上記「A.全固体電池」の項に記載した内容と同様であるため、ここでの説明は省略する。
本工程において、上述した第1前駆体塗工液を塗工する方法は、塗工液を均一に塗工することができる塗工法であることが好ましく、例えば、スピンコート法、ディップコート法、スプレーコート法、含浸法等を挙げることができる。中でも、スピンコート法を用いて塗工することが好ましい。薄膜を能率よく生成できるからである。また、塗工雰囲気は、目的とするリチウムイオン伝導層を形成することができ、リチウムイオン伝導層および正極活物質を劣化させる雰囲気でなければ特に限定されるものではない。
リチウムイオン伝導層形成工程における熱処理工程は、上記第1前駆体塗工液が塗工された正極活物質に熱を加えて固化させる工程であり、通常、上記塗工された正極活物質を乾燥させる乾燥工程と、その後焼成させる焼成工程と、を有するものである。
本工程における乾燥工程は、塗工された上記第1前駆体塗工液に含まれる溶媒を除去し、正極活物質を乾燥させるものである。
本工程における焼成工程は、上記第1前駆体塗工液が塗工された正極活物質に熱を加え、正極活物質の表面に形成されたリチウムイオン伝導層を固化させるものである。
次に、本発明における安定化層形成工程について説明する。本発明における安定化層形成工程は、上述の正極活物質に被覆されたリチウムイオン伝導層の表面に第2リチウムイオン伝導体の原料を含有する第2前駆体塗工液を、後述する厚さになるように塗工する塗工工程と、上記塗工された正極活物質に熱を加えて固化させる熱処理工程と、を有するものであり、上記熱処理工程とは、通常、上記塗工された正極活物質を乾燥させる乾燥工程と、その後に焼成させる焼成工程と、を有するものである。
安定化層形成工程における塗工工程は、正極活物質に被覆されたリチウムイオン伝導層の表面に、後述する第2前駆体塗工液を塗工する工程である。
本工程における第2前駆体塗工液は、第2リチウムイオン伝導体の原料を含有するものである。本工程で用いられる第2前駆体塗工液に含有される第2リチウムイオン伝導体の原料としては、第2リチウムイオン伝導体を形成できるものであれば特に限定されるものではない。
本工程における、正極活物質ならびに被覆されたリチウムイオン伝導層については、上記「1.リチウムイオン伝導層形成工程」の項に記載した内容と同様であるため、ここでの説明は省略する。
本工程において、上述した第2前駆体塗工液を塗工する方法は、上記「1.リチウムイオン伝導層形成工程」に記載した塗工方法と同様であるため、ここでの説明は省略する。また、本工程によって形成される安定化層の厚さは、目的とする反応抑制部の厚さ等に応じて適宜設定されるものであるが、上記「A.全固体電池」の項に記載した安定化層の厚さの範囲を満たすことが好ましい。
安定化層形成工程における熱処理工程は、上記第2前駆体塗工液を塗工された正極活物質に熱を加えて固化させる工程であり、通常、上記塗工された正極活物質を乾燥させる乾燥工程と、その後焼成させる焼成工程と、を有するものである。安定化層形成工程における乾燥工程および焼成工程については、上記「1.リチウムイオン伝導層形成工程」に記載した内容と同様であるため、ここでの説明は省略する。
本発明においては、上述した工程を有するものであれば特に限定されるものではなく、例えば、本発明に用いられる正極活物質が粒子形状である場合、上述した工程により表面に反応抑制部が形成された正極活物質等の正極活物質層を構成する材料を、プレス機でプレスして正極活物質層を形成する正極活物質形成工程、固体電解質材料を構成する材料を同様にプレスして固体電解質層を形成する固体電解質層形成工程、および負極活物質層を構成する材料を同様にプレスし、負極活物質層を形成する負極活物質層形成工程等を挙げることができる。また、正極活物質が薄膜形状である場合、上述した工程により、表面に反応抑制部が形成された正極活物質上に、固体電解質材料を構成する材料を積層する固体電解質層形成工程、および固体電解質層上に負極活物質層を構成する材料を積層する負極活物質形成工程等を挙げることができる。なお、本発明における負極活物質層、および固体電解質層は、上記「A.全固体電池」の項に記載した内容と同様であるため、ここでの説明は省略する。
(第1前駆体塗工液の調製)
20mlのエタノール(和光純薬社製)中で、1mmolのリチウムエトキシド(高純度化学社製)および1mmolのペンタエトキシニオブ(高純度化学社製)を混合して第1前駆体塗工液(LiNbO3前駆体ゾルゲル溶液)を得た。
20mlのエタノール(和光純薬社製)中で、1mmolのリチウムエトキシド(高純度化学社製)および1mmolのチタンテトライソプロポキシド(高純度化学社製)を混合し、第2前駆体塗工液(Li2Ti2O5前駆体ゾルゲル溶液)を得た。
Au基板上にスパッタリングによりコバルト酸リチウム薄膜(正極活物質)を得た。コバルト酸リチウム薄膜表面上に、スピンコーター(MS-A100、ミカサ社製)を用いて第1前駆体塗工液を5000rpm、10秒で塗工し、乾燥後に350℃、0.5時間にて焼成し、厚さが5nmのリチウムイオン伝導層を得た。
上述のリチウムイオン伝導層の表面上に、スピンコーター(MS-A100、ミカサ社製)を用いて第2前駆体塗工液を5000rpm、10秒で塗工し、乾燥後に350℃、0.5時間にて焼成し、厚さが5nmの安定化層を得た。
上述のリチウムイオン伝導層と上述の安定化層の形成工程により、正極活物質の表面上に、活物質側がリチウムイオン伝導層とし、固体電解質側が安定化層とする2層を有する反応抑制部を形成し、表面に反応抑制部を形成した正極活物質を有する電極を得た。
小型セル内のシリンダーに、50mgの75Li2S-25P2S5を投入し、スパチュラーで均一にならして上下のピストンによりプレスし(1.0t/cm2、1min)、固体電解質を形成した。次に、固体電解質層上に、上述した電極を同様にプレスし(4t/cm2、1min)、正極活物質層を形成した。続いて、固体電解質層の正極活物質層が形成された面の反対面に、Li-In箔を同様にプレスし(1.0t/cm2、1min)、負極活物質層を形成し、発電要素を得た。次に、小型セルのボルトを締結した後、配線を接続し、ガラスセル内に乾燥材を入れた後に組み立てて、全固体電池を作製した。
10mlのエタノール(和光純薬社製)中で、1mmolのリチウムエトキシド(高純度化学社製)および1mmolのペンタエトキシニオブ(高純度化学社製)を混合し、第1前駆体塗工液(LiNbO3前駆体ゾルゲル溶液)を得た。次に コバルト酸リチウム薄膜表面上に、スピンコーター(MS-A100、ミカサ社製)を用いて第1前駆体塗工液のみを5000rpm、10秒で塗工し、乾燥後に350℃、0.5時間にて焼成し、厚さが5nmのリチウムイオン伝導層を得た。この電極を正極に使用し、負極活物質層にLi-Li箔を用いた全固体電池を得た。
10mlのエタノール(和光純薬社製)中で、1mmolのリチウムエトキシド(高純度化学社製)および1mmolのチタンテトライソプロポキシド(高純度化学社製)を混合し、第2前駆体塗工液(Li2Ti2O5前駆体ゾルゲル溶液)を得た。次にコバルト酸リチウム薄膜表面上に、スピンコーター(MS-A100、ミカサ社製)を用いて第2前駆体塗工液を5000rpm、10秒で塗工し、乾燥後に350℃、0.5時間にて焼成し、厚さが5nmの安定化層を得た。この電極を正極に使用し、負極活物質層にLi-Li箔を用いた全固体電池を得た。
(全固体電池の界面抵抗測定)
実施例、比較例1、2で得られた全固体電池の初期の界面抵抗測定を行った。まず、全固体電池の電位を3.93Vに調整した後、複素インピーダンス測定を行うことにより、全固体電池の界面抵抗を算出した。なお、界面抵抗はインピーダンス曲線の円孤の直径から求めた。その結果を図4に示す。その後、60℃で1カ月保存し、保存後の全固体電池の界面抵抗を算出し、経時での界面抵抗の変化を測定した。その結果を図5に示す。
リチウムイオン伝導層の形成において焼成を実施しないこと以外は、実施例と同様にして全固体電池を得た。
(TEM測定)
実施例と比較例3で得られた全固体電池の電極の断面を透過型電子顕微鏡(TEM)で観察した。その結果を図6に示す。図6に示されるように、実施例と比較例3とでは、共に正極活物質であるコバルト酸リチウム上に反応抑制部の形成が確認された。実施例ではLiNbO3を有するリチウムイオン伝導層とLi2Ti2O5を有する安定化層がそれぞれ別々の層を成して被覆されているのに対し、比較例3ではリチウムイオン伝導層と安定化層に対して一度に焼成を行ったため、LiNbO3およびLi2Ti2Oが分散された単層となって被覆されていることが確認された。
(全固体電池の界面抵抗測)
実施例、比較例3で得られた全固体電池の界面抵抗測定を行った。測定方法は上記「評価1」の項に記載した方法と同様である。その結果を図7に示す。実施例は、比較例3に比べて界面抵抗の経時的な増加が抑制されていることが確認された。比較例3ではLiNbO3およびLi2Ti2Oが分散された層が硫化物固体電解質層と接するため、硫化物固体電解質層に直接LiNbO3が接触することにより劣化が進み、界面抵抗の経時的な増加が生じると考えられる。一方で実施例では、リチウムイオン伝導層の表面を安定化層が被覆した構造をとり、LiNbO3は硫化物固体電解質層と直に接触しないことから、比較例3よりも劣化の進行が抑制され、その結果、界面抵抗の経時的な増加も抑制されると考えられる。
2 … 負極活物質層
3 … 固体電解質層
4 … 正極活物質
5 … 硫化物固体電解質材料
6 … 反応抑制部
7 … リチウムイオン伝導層
8 … 安定化層
10 …発電要素
Claims (6)
- 正極活物質を含有する正極活物質層と、負極活物質を含有する負極活物質層と、前記正極活物質層および前記負極活物質層の間に形成された固体電解質層と、を有する全固体電池であって、
前記正極活物質層および前記固体電解質層の少なくとも一方が、硫化物固体電解質材料を含有し、
前記正極活物質の表面上に、第1リチウムイオン伝導体を有するリチウムイオン伝導層を活物質側とし、第2リチウムイオン伝導体を有する安定化層を固体電解質層側とする、2層を有する反応制御部が形成され、
前記第1リチウムイオン伝導体は、常温でのリチウムイオン伝導度が、1.0×10-7S/cm以上のLi含有化合物であり、
前記第2リチウムイオン伝導体は、B、Si、P、Ti、Zr、Al、およびWの少なくとも一つを有するポリアニオン構造部を備えるLi含有化合物であることを特徴とする全固体電池。 - 前記第1リチウムイオン伝導体がLiNbO3であることを特徴とする請求項1に記載の全固体電池。
- 前記第2リチウムイオン伝導体がLi2Ti2O5であることを特徴とする請求項1または請求項2に記載の全固体電池。
- 請求項1から請求項3までのいずれかの請求項に記載の全固体電池の製造方法であって、
前記第1リチウムイオン伝導体の原料を含有する第1前駆体塗工液を、正極活物質の表面に塗工し熱処理を行うことによりリチウムイオン伝導層を形成するリチウムイオン伝導層形成工程と、
前記第2リチウムイオン伝導体の原料を含有する第2前駆体塗工液を、正極活物質を被覆したリチウムイオン伝導層の表面に塗工し熱処理を行うことにより安定化層を形成する安定化層形成工程と、を有することを特徴とする全固体電池の製造方法。 - 前記第1リチウムイオン伝導体がLiNbO3であることを特徴とする請求項4に記載の全固体電池の製造方法。
- 前記第2リチウムイオン伝導体がLi2Ti2O5であることを特徴とする請求項4または請求項5に記載の全固体電池の製造方法。
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Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2015144061A (ja) * | 2014-01-31 | 2015-08-06 | セイコーエプソン株式会社 | 電極複合体の製造方法、電極複合体および電池 |
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JP2017045636A (ja) * | 2015-08-27 | 2017-03-02 | Tdk株式会社 | 安定化リチウム粉末、およびそれを用いた負極およびリチウムイオン二次電池 |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5751235B2 (ja) * | 2012-10-19 | 2015-07-22 | トヨタ自動車株式会社 | 電池用電極の製造方法及び装置 |
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JP6760140B2 (ja) | 2017-03-06 | 2020-09-23 | トヨタ自動車株式会社 | リチウムイオン二次電池用正極材料の製造方法およびリチウムイオン二次電池用正極材料 |
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EP3669416A4 (en) * | 2017-08-14 | 2021-05-19 | Thinika, LLC | SOLID STATE THIN FILM HYBRID ELECTROCHEMICAL CELL |
US10734674B2 (en) * | 2017-08-14 | 2020-08-04 | Thinika, Llc | Solid-state thin film hybrid electrochemical cell |
US10749199B2 (en) | 2017-11-29 | 2020-08-18 | International Business Machines Corporation | Li1+xAlxTi2-x(PO4)3 solid-state thin film electrolyte for 3D microbattery and method of fabrication |
WO2020018002A1 (en) * | 2018-07-18 | 2020-01-23 | Comberry, Llc | Electrochromic material and method of manufacturing thereof |
RU2709487C1 (ru) * | 2018-08-14 | 2019-12-18 | Общество с ограниченной ответственностью "Финика" | Твердотельный тонкопленочный гибридный электрохимический источник тока |
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CN111435735B (zh) * | 2019-12-27 | 2022-10-25 | 蜂巢能源科技有限公司 | 富锂锰基正极材料及其制备方法和应用 |
US20220285726A1 (en) * | 2020-03-13 | 2022-09-08 | Maxell, Ltd. | Electrode for all-solid-state battery and all-solid-state battery |
CN112786840B (zh) * | 2021-01-29 | 2022-04-15 | 蜂巢能源科技(无锡)有限公司 | 一种固态电池用正极片及其制备方法和应用 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001043847A (ja) * | 1999-07-15 | 2001-02-16 | Mitsubishi Chemicals Corp | 表面改質電極を有する電池およびその製造方法 |
JP2010170715A (ja) * | 2009-01-20 | 2010-08-05 | Toyota Motor Corp | 正極活物質材料 |
JP2011159639A (ja) * | 2011-05-23 | 2011-08-18 | Toyota Motor Corp | 電極体及びその製造方法、並びに、リチウムイオン二次電池 |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4982866B2 (ja) * | 2005-07-01 | 2012-07-25 | 独立行政法人物質・材料研究機構 | 全固体リチウム電池 |
KR20080041627A (ko) * | 2005-08-02 | 2008-05-13 | 이데미쓰 고산 가부시키가이샤 | 고체 전해질 시트 |
JP5151692B2 (ja) * | 2007-09-11 | 2013-02-27 | 住友電気工業株式会社 | リチウム電池 |
JP4948510B2 (ja) * | 2008-12-02 | 2012-06-06 | トヨタ自動車株式会社 | 全固体電池 |
JP2010146936A (ja) * | 2008-12-22 | 2010-07-01 | Toyota Motor Corp | 全固体電池 |
JP5158008B2 (ja) * | 2009-04-28 | 2013-03-06 | トヨタ自動車株式会社 | 全固体電池 |
JP2011165467A (ja) * | 2010-02-09 | 2011-08-25 | Toyota Motor Corp | 固体電池 |
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- 2011-09-30 US US14/343,601 patent/US20140227606A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001043847A (ja) * | 1999-07-15 | 2001-02-16 | Mitsubishi Chemicals Corp | 表面改質電極を有する電池およびその製造方法 |
JP2010170715A (ja) * | 2009-01-20 | 2010-08-05 | Toyota Motor Corp | 正極活物質材料 |
JP2011159639A (ja) * | 2011-05-23 | 2011-08-18 | Toyota Motor Corp | 電極体及びその製造方法、並びに、リチウムイオン二次電池 |
Cited By (15)
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CN105556731A (zh) * | 2013-09-02 | 2016-05-04 | 三菱瓦斯化学株式会社 | 全固体电池 |
TWI628826B (zh) * | 2013-09-02 | 2018-07-01 | 三菱瓦斯化學股份有限公司 | 全固體電池 |
CN105556731B (zh) * | 2013-09-02 | 2018-10-02 | 三菱瓦斯化学株式会社 | 全固体电池 |
US9627680B2 (en) | 2013-11-15 | 2017-04-18 | Sumitomo Metal Mining Co., Ltd. | Method for producing surface-treated oxide particles, and oxide particles produced by said production method |
JP2015144061A (ja) * | 2014-01-31 | 2015-08-06 | セイコーエプソン株式会社 | 電極複合体の製造方法、電極複合体および電池 |
JP2017045636A (ja) * | 2015-08-27 | 2017-03-02 | Tdk株式会社 | 安定化リチウム粉末、およびそれを用いた負極およびリチウムイオン二次電池 |
JP7062154B2 (ja) | 2017-07-10 | 2022-05-06 | エルジー エナジー ソリューション リミテッド | リチウム二次電池用正極、この製造方法及びこれを含むリチウム二次電池 |
JP2020526908A (ja) * | 2017-07-10 | 2020-08-31 | エルジー・ケム・リミテッド | リチウム二次電池用正極、この製造方法及びこれを含むリチウム二次電池 |
WO2020090410A1 (ja) * | 2018-10-30 | 2020-05-07 | パナソニックIpマネジメント株式会社 | 二次電池 |
JPWO2020090410A1 (ja) * | 2018-10-30 | 2021-09-16 | パナソニックIpマネジメント株式会社 | 二次電池 |
JP7336680B2 (ja) | 2018-10-30 | 2023-09-01 | パナソニックIpマネジメント株式会社 | 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 |
JP7096197B2 (ja) | 2019-04-23 | 2022-07-05 | トヨタ自動車株式会社 | 被覆正極活物質及び全固体電池 |
US11532813B2 (en) | 2020-02-20 | 2022-12-20 | Samsung Electronics Co., Ltd. | Composite cathode active material, preparation method thereof, cathode layer including the same, and all-solid secondary battery including the cathode layer |
WO2022163584A1 (ja) | 2021-01-29 | 2022-08-04 | 株式会社Gsユアサ | 活物質粒子、電極、蓄電素子、非水電解質二次電池、全固体二次電池、活物質粒子の製造方法及び蓄電装置 |
Also Published As
Publication number | Publication date |
---|---|
US20140227606A1 (en) | 2014-08-14 |
JPWO2013046443A1 (ja) | 2015-03-26 |
JP5737415B2 (ja) | 2015-06-17 |
CN103814472A (zh) | 2014-05-21 |
CN103814472B (zh) | 2016-05-04 |
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