WO2015152215A1 - 全固体電池用負極電極の製造方法及び全固体電池用負極電極 - Google Patents
全固体電池用負極電極の製造方法及び全固体電池用負極電極 Download PDFInfo
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- WO2015152215A1 WO2015152215A1 PCT/JP2015/060075 JP2015060075W WO2015152215A1 WO 2015152215 A1 WO2015152215 A1 WO 2015152215A1 JP 2015060075 W JP2015060075 W JP 2015060075W WO 2015152215 A1 WO2015152215 A1 WO 2015152215A1
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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
- H01M4/139—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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- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- 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
- H01M10/0562—Solid materials
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- H01M4/043—Processes of manufacture in general involving compressing or compaction
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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
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0068—Solid electrolytes inorganic
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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
Definitions
- the present invention relates to a method for producing a negative electrode for an all solid state battery and a negative electrode for an all solid state battery. According to the present invention, a negative electrode in which the gap between the negative electrode material and the solid electrolyte is controlled can be manufactured.
- Graphite materials or carbonaceous materials with a developed graphite structure are prone to breakage due to expansion and contraction of crystals due to repeated lithium doping and undoping, and inferior charge / discharge cycle performance, and therefore high cycle durability is required. It is not suitable as a negative electrode material for lithium ion secondary batteries.
- the turbostratic carbon which does not have a graphite structure and has a structure in which the carbon hexagonal plane is not three-dimensionally regular, has a smaller particle expansion and contraction due to lithium doping and dedoping reactions than graphite. From the viewpoint of having high cycle durability, it is suitable for use in automobile applications (Patent Document 1).
- turbostratic carbon when compared to graphite materials, turbostratic carbon has a gentle charge / discharge curve, and the potential difference from the charge regulation is larger even when charging more rapidly than when graphite material is used as the negative electrode active material. It is characterized by being capable of rapid charging. Further, since there are many sites that have low crystallinity and can contribute to charge / discharge compared with the graphite material, there is a feature that rapid charge / discharge (input / output) characteristics are also excellent.
- a lithium battery using non-graphitizable carbon currently on the market uses a non-aqueous electrolyte containing a flammable organic solvent. Therefore, there is a fear of abnormal heat generation due to temperature rise at the time of short circuit and ignition due to heat generation, and it cannot be said that safety is high.
- an all-solid battery in which the electrolyte solution is changed to a solid electrolyte layer to make the battery all solid does not use a flammable organic electrolyte solution, so the possibility of ignition is reduced and it is excellent in terms of safety.
- patent document 2 is disclosing the manufacturing method of the negative mix for lithium batteries which mixes a carbon material and a solid electrolyte by a mechanochemical process.
- Patent Document 3 discloses that graphite and amorphous carbon are used as a negative electrode active material in an all-solid battery.
- the inventors of the present invention tried to make a negative electrode by using a turbostratic carbon and a solid electrolyte.
- a negative electrode for an all-solid battery is prepared by simply mixing the turbulent structure carbon and the solid electrolyte, the negative electrode is deformed by the repulsion of the turbulent structure carbon after pressure molding.
- the objective of this invention is providing the manufacturing method which suppresses a deformation
- the turbulent layer carbon is coated with a solid electrolyte
- the turbulent layer is coated with the solid electrolyte. It has been found that a negative electrode manufactured by pressure molding using structural carbon has a reduced deformation rate of the negative electrode.
- the present invention is based on these findings.
- the present invention [1] (1) true density determined by butanol method carbonaceous material is 1.30g / cm 3 ⁇ 2.10g / cm 3, the step of coating the solid electrolyte, and (2) the solid electrolyte coated carbon A method for producing a negative electrode for an all-solid battery, comprising a step of pressure-molding a porous material, [2] The method for producing a negative electrode for an all solid state battery according to [1], wherein the volume ratio of the carbonaceous material to the solid electrolyte is 20:80 to 99: 1.
- the average plane spacing of 002 planes determined by powder X-ray diffraction method is 0.340 to 0.400 nm
- L c (002) is 0.5 to 10 nm
- average particle diameter D v50 The method for producing a negative electrode for an all-solid battery according to [1] or [2], wherein is 1 to 50 ⁇ m
- the carbonaceous material has a combustion peak T (° C.) by differential thermal analysis and a butanol true density ⁇ Bt (g / cm 3 ) expressed by the following formula (1) 300 ⁇ T ⁇ 100 ⁇ ⁇ Bt ⁇ 650 ( [1]
- the method for producing a negative electrode for an all-solid-state battery of the present invention in the negative electrode using the turbulent structure carbon and the solid electrolyte, the repulsion of the turbulent structure carbon after pressure molding is suppressed, and the deformation rate of the negative electrode is reduced. Can be obtained.
- the negative electrode with a low deformation rate suppresses separation between the turbulent structure carbon and the solid electrolyte, and also suppresses the formation of voids. Therefore, the deterioration of the input / output characteristics caused by the gap between the turbostratic structure carbon and the solid electrolyte is suppressed.
- the all-solid battery using the all-solid battery negative electrode obtained by the method for producing the all-solid battery negative electrode of the present invention exhibits excellent input / output characteristics.
- Method for producing negative electrode for all solid state battery is as follows: (1) True density determined by butanol method is 1.30 g / cm 3 to 2.10 g / cm 3. And (2) a step of pressure-molding the solid electrolyte-covered carbonaceous material.
- the carbonaceous material used in the production method of the present invention is turbostratic carbon, and is not limited as long as the true density obtained by the butanol method is 1.30 g / cm 3 to 2.10 g / cm 3.
- the non-graphitizable carbon has a true density obtained by a butanol method of 1.30 g / cm 3 or more and 1.70 g / cm 3 or less, or in a preferred embodiment, a true density obtained by the butanol method. density of the graphitizable carbon is increased 2.10 g / cm 3 or less than 1.70 g / cm 3.
- the carbon source of non-graphitizable carbon or graphitizable carbon is not limited as long as non-graphitizable carbon or graphitizable carbon can be produced.
- Thermoplastic resin eg, ketone resin, polyvinyl alcohol, polyethylene terephthalate, polyacetal, polyacrylonitrile, styrene / divinylbenzene copolymer, polyimide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyarylate, polysulfone, polyphenylene sulfide, polyimide resin , Fluororesin, polyamideimide, aramid resin, or polyetheretherketone), thermosetting resin (eg, epoxy resin, urethane resin, urea resin, diallyl phthalate resin, polyester resin, polycarbonate resin) Boneto resins, silicone resins, and polyacetal resin, nylon resin, furan resin, or aldehyde
- Thermoplastic resin e
- the average interplanar spacing of the (002) plane of the carbonaceous material shows a smaller value as the crystal perfection is higher, and that of an ideal graphite structure shows a value of 0.3354 nm, and the value increases as the structure is disturbed. Tend. Therefore, the average spacing is effective as an index indicating the carbon structure.
- the average interplanar spacing of the (002) plane measured by the X-ray diffraction method of the carbonaceous material used in the production method of the present invention is not limited, but is preferably 0.340 to 0.400 nm, more preferably It is 0.350 nm or more and 0.400 nm or less, and particularly preferably 0.355 nm or more and 0.400.
- a carbonaceous material of less than 0.340 nm may have poor cycle characteristics.
- the crystallite thickness L c (002) in the c-axis direction of the carbonaceous material used in the production method of the present invention is not limited, but is preferably 0.5 to 10.0 nm.
- the upper limit of L c (002) is preferably 8.0 nm or less, and more preferably 5.0 nm or less.
- the specific surface area can be obtained by an approximate expression derived from the BET expression by nitrogen adsorption.
- the specific surface area of the carbonaceous material used for the all-solid battery negative electrode of the present invention is not limited, but is preferably 0.5 to 50 m 2 / g.
- the upper limit of the BET specific surface area is preferably not more than 45 m 2 / g, more preferably not more than 40 m 2 / g, still more preferably not more than 35m 2 / g.
- the lower limit of the BET specific surface area is preferably 1 m 2 / g or more.
- the specific surface area exceeds 50 m 2 / g or less, the decomposition reaction with the solid electrolyte increases, leading to an increase in irreversible capacity, and thus battery performance may be reduced. Further, when the BET specific surface area is less than 0.5 m 2 / g, when used as a negative electrode of an all-solid battery, there is a possibility that the input / output characteristics may be lowered due to a reduction in the reaction area with the solid electrolyte.
- the true density of the graphite material having an ideal structure is 2.27 g / cm 3 , and the true density tends to decrease as the crystal structure is disturbed. Therefore, the true density can be used as an index representing the structure of carbon.
- the true density of the carbonaceous material used in the negative electrode for an all solid state battery of the present invention is 1.30 g / cm 3 to 2.10 g / cm 3 .
- the upper limit of the true density is preferably not 2.05 g / cm 3 or less, more preferably 2.00 g / cm 3 or less.
- the lower limit of the true density is preferably 1.31 g / cm 3 or more, more preferably 1.32 g / cm 3 or more, further preferably 1.33 g / cm 3 or more. Further, the lower limit of the true density may be 1.40 g / cm 3 or more.
- a carbonaceous material having a true density exceeding 2.10 g / cm 3 is not preferable because it has few pores of a size that can store lithium and the doping and dedoping capacities are small. Further, since the increase in true density is accompanied by selective orientation of the carbon hexagonal plane, it is not preferable because the carbonaceous material often involves expansion and contraction during lithium doping / dedoping.
- non-graphitizable carbon is a general term for non-graphitic carbon that does not change to a graphite structure even when heat-treated at an extremely high temperature of about 3000 ° C.
- a carbonaceous material having a density of 1.30 g / cm 3 or more and 1.70 g / cm 3 or less is called non-graphitizable carbon.
- graphitizable carbon is a general term for non-graphitic carbon that changes into a graphite structure by heat treatment at a high temperature of 2000 ° C. or higher.
- the large 2.10 g / cm 3 or less of carbonaceous material than 1.70 g / cm 3 is referred to as the graphitizable carbon.
- the average particle diameter (D v50 ) of the carbonaceous material used in the production method of the present invention is 1 to 50 ⁇ m.
- the lower limit of the average particle diameter is preferably 1 ⁇ m or more, more preferably 1.5 ⁇ m or more, and particularly preferably 2.0 ⁇ m or more.
- the upper limit of the average particle diameter is preferably 40 ⁇ m or less, more preferably 35 ⁇ m or less.
- the carbonaceous material used for the negative electrode for an all solid state battery of the present invention is not limited, but preferably has a combustion peak T (° C.) by differential thermal analysis and a butanol true density ⁇ Bt (g / cm 3 ).
- the following formula (1) 300 ⁇ T-100 ⁇ ⁇ Bt ⁇ 650 (1) It is a carbonaceous material that satisfies the requirements.
- the combustion peak generally shows a change depending on the size of the carbon hexagonal plane of the carbonaceous material and their three-dimensional order. Generally, the carbon hexagonal plane is large and the three-dimensional order is large.
- a peak tends to appear on the high temperature side. Since such a carbonaceous material has high three-dimensional order, the true density ⁇ Bt measured by the butanol method is also high.
- a graphite material having a large carbon hexagonal plane and an interplanar spacing of 0.3354 nm exhibits a combustion peak temperature close to 800 ° C.
- Such a carbonaceous material is liable to break down due to expansion and contraction of crystals due to repeated lithium doping and dedoping, and is inferior in charge / discharge repetition performance.
- the carbon hexagonal plane is smaller and the three-dimensional order is lower, a peak tends to appear on the low temperature side.
- Such a carbonaceous material exhibits a high cycle durability since the expansion and contraction of crystals due to repeated lithium doping and dedoping is smaller than that of graphite.
- the combustion peak appears excessively on the low temperature side, the amount of pores and the pore diameter are excessively large and the specific surface area is high, which increases the irreversible capacity.
- the true density ⁇ Bt measured by the butanol method becomes excessively low, which is not preferable from the viewpoint of volume energy density.
- the carbonaceous material is 300 ⁇ T ⁇ 100 ⁇ ⁇ Bt ⁇ 650. It was found that when the combustion peak T satisfying the above relationship and the true density ⁇ Bt measured by the butanol method are present, the expansion and shrinkage of the crystal is smaller than that of graphite, and high cycle durability can be expected.
- the carbonaceous material of the present invention preferably has a combustion peak T satisfying 305 ⁇ T ⁇ 100 ⁇ ⁇ Bt ⁇ 650, more preferably 310 ⁇ T ⁇ 100 ⁇ ⁇ Bt ⁇ 650 and a true density ⁇ Bt measured by the butanol method. Is to have. Further, the lower limit of T-100 ⁇ ⁇ Bt of the carbonaceous material of the present invention may be 430.
- the solid electrolyte material used in the method for producing a negative electrode for an all-solid battery of the present invention can be used without limitation to those used in the field of lithium ion secondary batteries, and can be an organic compound, an inorganic compound, or those A solid electrolyte material made of a mixture of the above can be used.
- the solid electrolyte material has ion conductivity and insulating properties, and specifically includes a polymer electrolyte (for example, intrinsic polymer electrolyte), a sulfide solid electrolyte material, or an oxide solid electrolyte material. Solid electrolyte materials are preferred.
- the intrinsic polymer electrolyte examples include a polymer having an ethylene oxide bond, a crosslinked product or copolymer thereof, polyacrylonitrile, a polycarbonate-based polymer, and the like, and examples thereof include polyethylene oxide, polyethylene carbonate, and polypropylene carbonate.
- a sulfide solid electrolyte material a combination of Li 2 S and Al 2 S 3 , SiS 2 , GeS 2 , P 2 S 3 , P 2 S 5 , As 2 S 3 , Sb 2 S 3 or a mixture thereof. Can be mentioned.
- Li 2 S—Al 2 S 3 material, Li 2 S—SiS 2 material, Li 2 S—GeS 2 material, Li 2 S—P 2 S 3 material, Li 2 S—P 2 S 5 material, Li 2 S—As 2 S 3 material, Li 2 S—Sb 2 S 3 material, and Li 2 S—material can be mentioned, and Li 2 S—P 2 S 5 material is particularly preferable.
- Li 3 PO 4 , halogen, or a halogen compound can be added to these solid electrolyte materials and used as a solid electrolyte material.
- oxide solid electrolyte material examples include oxide solid electrolyte materials having a perovskite type, NASICON type, or garnet type structure.
- oxide solid electrolyte materials having a perovskite type, NASICON type, or garnet type structure.
- La 0.51 LiTiO 2.94 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , Li 7 La 3 Zr 2 O 12 or the like can be given.
- the shape of the solid electrolyte material is not limited as long as it functions as an electrolyte.
- the average particle size of the solid electrolyte material is not particularly limited, but is preferably 0.1 ⁇ m to 50 ⁇ m.
- the lithium ion conductivity of the solid electrolyte material is not limited as long as the effect of the present invention is obtained, but is preferably 1 ⁇ 10 ⁇ 6 S / cm or more, more preferably 1 ⁇ 10 ⁇ 5. S / cm or more.
- the Li 2 S—P 2 S 5 material can be produced from Li 2 S and P 2 S 5 , or can be produced using Li 2 S, simple phosphorus and simple sulfur.
- Li 2 S may be industrially produced and sold, but can also be produced by the following method. Specifically, lithium hydroxide and hydrogen sulfide are reacted at 0 to 150 ° C. in an aprotic organic solvent to produce water Li 2 S, and then this reaction solution is dehydrogenated at 150 to 200 ° C. (Refer to JP-A-7-330312); a method in which lithium hydroxide and hydrogen sulfide are reacted at 150 to 200 ° C.
- a Li 2 S—P 2 S 5 material can be produced by a melt quenching method or a mechanical milling method.
- the electrolyte material obtained by these methods is a sulfide glass and is made amorphous.
- a solid electrolyte can be produced by mixing P 2 S 5 and Li 2 S in a molar ratio of, for example, 50:50 to 80:20, preferably 60:40 to 75:25.
- the melt quenching method the mixture in the form of pellets in a mortar is placed in a carbon-coated quartz tube and vacuum-sealed. Then, the reaction is carried out at 400 to 1000 ° C. for 0.1 to 12 hours.
- An amorphous solid electrolyte can be obtained by putting the obtained reaction product into ice and rapidly cooling it.
- the reaction can be performed at room temperature.
- an amorphous solid electrolyte can be obtained by performing a treatment for 0.5 to 100 hours at a rotational speed of several tens to several hundreds of revolutions / minute using a planetary ball mill.
- the production method of the present invention includes a step of coating the carbonaceous material with a solid electrolyte.
- the volume ratio between the carbonaceous material and the solid electrolyte is not limited as long as the effect of the present invention is obtained, but is 20:80 to 99: 1, more preferably 30:70 to 97: 3. It is.
- the amount of the solid electrolyte added to the carbonaceous material is not limited as long as the effect of the present invention is obtained, but is preferably 400% by volume to 1% by volume with respect to the volume of the carbonaceous material. More preferably, it is 300 volume% to 3 volume%, more preferably 250 volume% to 5 volume%, still more preferably 200 volume% to 10 volume%.
- the coating method in the coating process is not limited.
- the solid electrolyte is dissolved or dispersed in a solvent, mixed with a carbonaceous material, and then coated by heating and / or drying, or by using a sol-gel method.
- examples thereof include a method, a coating method using a ball mill or a bead mill, a coating method using a kneader such as a pressure kneader or a kneader, a coating method using a vibration mill, or a coating method using a jet mill.
- a method in which a solid electrolyte is dissolved or dispersed in a solvent and mixed with a carbonaceous material and then coated by heating and / or drying a method using a ball mill or a bead mill, or a sol-gel method is preferred.
- a method in which a solid electrolyte is dissolved or dispersed in a solvent, mixed with a carbonaceous material, and then coated by heating and / or drying is performed by mixing and dispersing the carbonaceous material and the solid electrolyte in a solvent and removing the solvent.
- the surface of the carbonaceous material is coated with a solid electrolyte.
- the solvent to be used is not particularly limited as long as it can dissolve or disperse the solid electrolyte, but water, methanol, ethanol, n-propanol, n-butanol, acetone, heptane, N-methylformamide (NMF) ), Dimethylformamide (DMF), dimethylsulfoxide (DMSO), or N-methylpyrrolidone (NMP). From the viewpoint of the solubility of the solid electrolyte, water, methanol, ethanol, heptane, N-methylformamide (NMF) Or N-methylpyrrolidone (NMP).
- the method of coating using a ball mill or a bead mill is a method of coating a solid electrolyte on the surface of a carbonaceous material by mixing, mixing and dispersing, or mixing, dispersing and pulverizing a carbonaceous material and a solid electrolyte with a ball mill or bead mill.
- those which can be mixed and dispersed, or mixed, dispersed and pulverized are preferable.
- the setting conditions of the ball mill or bead mill are not particularly limited as long as the effects of the present invention can be obtained.
- the rotation speed of the ball mill or the bead mill can be performed, for example, at 200 to 1000 rpm, preferably 300 to 800 rpm.
- the set time of the ball mill or the bead mill can be performed, for example, in 30 to 600 minutes, and preferably in 60 to 480 minutes.
- the setting conditions in the sol-gel method are not particularly limited as long as the effects of the present invention can be obtained.
- the production method of the present invention includes a step of pressure forming the carbonaceous material coated with the solid electrolyte.
- a conventionally known method can be used for the pressure molding operation, and it is not particularly limited.
- the pressure for the pressure molding is not particularly limited, but can be, for example, 0.5 to 600 MPa, preferably 1.0 to 600 MPa, and more preferably 2.0 to 600 MPa.
- the all-solid-state battery negative electrode obtained in the production method of the present invention can contain a negative electrode material other than the carbonaceous material, a conductive additive, and / or a binder as long as the effects of the present invention are obtained.
- a negative electrode material, a conductive support agent, and / or a binder can be added in the production method of the present invention.
- the carbonaceous material is coated with a solid electrolyte, so that the repulsion of the carbonaceous material after pressure molding is suppressed, and the deformation rate of the negative electrode is increased.
- a small number of negative electrodes can be obtained.
- the reason why the negative electrode having a low deformation rate of the negative electrode can be obtained in the production method of the present invention has not been completely clarified, but can be considered as follows.
- the present invention is not limited by the following description. As shown in FIG.
- the carbonaceous material used in the present invention has a high particle strength
- the carbonaceous material has a contact between the particles of the carbonaceous material (a contact between the particles of the carbonaceous material (a reaction force is generated in the vertical direction during pressure molding (as shown in FIG. 1 (ii)).
- the particles forming the contact point release the reaction force and attempt to have a stable structure. Therefore, the electrode is deformed in the direction opposite to the load direction and the electrode thickness is increased (FIG. 1 (iii)).
- Negative electrode for all solid state battery The negative electrode for all solid state battery of the present invention is obtained by the above production method. That is, the negative electrode for an all-solid battery of the present invention includes a carbonaceous material and a solid electrolyte having a true density determined by a butanol method of 1.30 g / cm 3 to 2.10 g / cm 3 . Specifically, the carbonaceous material and the solid electrolyte include the carbonaceous material and the solid electrolyte described in “[1] Method for producing negative electrode for all-solid battery”. The negative electrode for an all-solid battery of the present invention has little peeling between the carbonaceous material and the solid electrolyte. Therefore, there is no space between the carbonaceous materials, and input / output characteristics are improved.
- the all-solid-state battery of the present invention includes the negative electrode for an all-solid-state battery. More specifically, a negative electrode active material layer, a positive electrode active material layer, and a solid electrolyte layer are included, and the negative electrode for an all-solid battery of the present invention can be used as the negative electrode active material layer.
- a negative electrode active material layer contains the said negative electrode for all-solid-state batteries. That is, the carbonaceous material and the solid electrolyte material are included, but a conductive additive, a binder, or both may be further included.
- the volume of the carbonaceous material relative to the total volume of the negative electrode active material layer is preferably 20% by volume to 80% by volume, more preferably 30% by volume to 70% by volume.
- the carbonaceous material is coated with a solid electrolyte at a volume ratio of 99: 1, the solid electrolyte or the like is added so that the volume of the carbonaceous material is 20% by volume to 80% by volume with respect to the total volume of the negative electrode active material layer.
- the negative electrode active material layer can contain a negative electrode material other than the carbonaceous material as long as the effect of the present invention is obtained.
- Examples of the conductive assistant include acetylene black, ketjen black, carbon nanofiber, carbon naotube, and carbon fiber.
- the content of the conductive assistant is not limited, but is, for example, 0.5 to 15% by weight.
- fluorine-containing binders such as PTFE or PVDF, can be mentioned, for example.
- the content of the conductive assistant is not limited, but is, for example, 0.5 to 15% by weight.
- the thickness of the negative electrode active material layer is not limited, but is, for example, in the range of 0.1 ⁇ m to 1000 ⁇ m.
- the negative electrode active material layer usually has a current collector.
- As the negative electrode current collector for example, SUS, copper, nickel, or carbon can be used, and among them, Cu or SUS is preferable.
- the positive electrode active material layer includes a positive electrode active material and a solid electrolytic material, and may further include a conductive additive, a binder, or both.
- the mixing ratio of the positive electrode active material and the solid electrolyte in the positive electrode active material layer is not limited as long as the effect of the present invention is obtained, and can be determined as appropriate.
- the positive electrode active material can be used without limiting the positive electrode active material used in all solid state batteries.
- a layered oxide system (expressed as LiMO 2 , where M is a metal: for example, LiCoO 2 , LiNiO 2 , LiMnO 2 , or LiNi x Co y Mn z O 2 (where x, y, z are composition ratios)
- Olivine-based represented by LiMPO 4 , M is a metal: for example LiFePO 4
- spinel-based represented by LiM 2 O 4 , M is a metal: for example LiMn 2 O 4
- Compounds may be mentioned, and these chalcogen compounds may be mixed as necessary.
- the positive electrode active material layer can further contain a conductive additive and / or a binder.
- a conductive support agent acetylene black, ketjen black, or carbon fiber can be mentioned, for example.
- the content of the conductive assistant is not limited, but is, for example, 0.5 to 15% by weight.
- a binder fluorine-containing binders, such as PTFE or PVDF, can be mentioned, for example.
- the content of the conductive assistant is not limited, but is, for example, 0.5 to 15% by weight.
- the thickness of the positive electrode active material layer is not limited, but is, for example, in the range of 0.1 ⁇ m to 1000 ⁇ m.
- the method for preparing the positive electrode active material layer is not particularly limited, and the positive electrode active material, the solid electrolyte material, and further, if necessary, a conductive additive and / or binder are mixed and pressure-molded. Can be manufactured. It can also be produced by mixing a positive electrode active material, a solid electrolyte material, and a conductive aid and / or binder as necessary in a specific solvent, applying a slurry, and drying, followed by pressure molding. .
- the positive electrode active material layer usually has a current collector.
- As the negative electrode current collector for example, SUS, aluminum, nickel, iron, titanium, and carbon can be used, and among these, aluminum or SUS is preferable.
- the solid electrolyte layer contains the solid electrolyte described in the above-mentioned section “[1] Method for producing negative electrode for all solid state battery”.
- the content of the solid electrolyte in the solid electrolyte layer is not particularly limited, but is, for example, 10% to 100% by volume, preferably 50% to 100% by volume.
- the thickness of the solid electrolyte layer is not particularly limited, but is, for example, 0.1 ⁇ m to 1000 ⁇ m, preferably 0.1 ⁇ m to 300 ⁇ m.
- the method for preparing the solid electrolyte layer is not particularly limited, but can be prepared by a gas phase method or a pressure forming method.
- Examples of the vapor phase method include, but are not limited to, a vacuum vapor deposition method, a pulse laser deposition method, a laser ablation method, an ion plating method, and a sputtering method.
- a pressure molding method it can manufacture by mixing a solid electrolyte and also a conductive support agent and / or a binder as needed, and pressure-molding.
- it can manufacture also by mixing a solid electrolyte material and a conductive support agent and / or a binder as needed in a specific solvent, applying what was made into the slurry state, drying, and pressure-molding after that.
- the manufacturing method of an all-solid battery is not particularly limited, and a known manufacturing method of an all-solid battery can be used.
- a known manufacturing method of an all-solid battery can be used as the negative electrode active material layer.
- compression molding of the negative electrode for an all-solid battery of the present invention a mixture of materials constituting the positive electrode active material layer, and a mixture of materials constituting the solid electrolyte layer
- an all-solid battery can be obtained.
- the order of compression molding is not particularly limited, but the order of negative electrode active material layer, solid electrolyte layer, and positive electrode active material layer, order of positive electrode active material layer, solid electrolyte layer, and negative electrode active material layer, solid electrolyte layer, negative electrode
- the order of the active material layer and the positive electrode active material layer, or the order of the solid electrolyte layer, the positive electrode active material layer, and the negative electrode active material layer can be given. Further, as described above, after forming the solid electrolyte layer by the vapor phase method, each layer can be compression-molded.
- the physical property values of the carbonaceous material for nonaqueous electrolyte secondary batteries of the present invention (“average surface spacing d (002) of (002) plane by X-ray diffraction method and crystallite thickness L c ( 002) ”,“ specific surface area ”,“ true density determined by butanol method ”,“ average particle diameter by laser diffraction method ”, and“ differential thermal analysis measurement ”).
- the physical property values described in the present specification are based on values obtained by the following method.
- the diffraction pattern was corrected using the diffraction line on the (111) plane of the high-purity silicon powder for the standard substance without correcting the Lorentz changing factor, absorption factor, atomic scattering factor, and the like.
- the sample tube is filled with a carbon material, and the sample tube is cooled to ⁇ 196 ° C. while flowing a helium gas containing nitrogen gas at a concentration of 20 mol%, and nitrogen is adsorbed on the carbon material.
- the test tube is then returned to room temperature. At this time, the amount of nitrogen desorbed from the sample was measured with a thermal conductivity detector, and the amount of adsorbed gas v was obtained.
- distilled water excluding the gas that has been boiled and dissolved immediately before use is placed in a specific gravity bottle, immersed in a constant temperature water bath as before, and the mass (m 5 ) is measured after aligning the marked lines.
- the true density ( ⁇ Bt ) is calculated by the following formula. (Where d is the specific gravity of water at 30 ° C. (0.9946))
- ⁇ Average particle size Three drops of a dispersing agent (cationic surfactant “SN Wet 366” (manufactured by San Nopco)) are added to about 0.1 g of the sample, and the sample is made to conform to the dispersing agent. Next, after adding 30 mL of pure water and dispersing with an ultrasonic cleaner for about 2 minutes, particles with a particle size distribution measuring device (“SALD-3000J” manufactured by Shimadzu Corporation) with a particle size in the range of 0.05 to 3000 ⁇ m are used. The diameter distribution was determined. From the obtained particle size distribution, the average particle size D v50 ( ⁇ m) was defined as the particle size with a cumulative volume of 50%.
- SALD-3000J particle size distribution measuring device
- the string-like molded body was pulverized so that the ratio (L / D) of the diameter (D) to the length (L) was about 1.5 to 2.0, and the obtained pulverized product was heated to 93 ° C.
- the solution was charged into an aqueous solution in which 0.53% by mass of polyvinyl alcohol (saponification degree: 88%) was dissolved, stirred and dispersed, and cooled to obtain a spherical pitch molded body slurry. After most of the water was removed by filtration, naphthalene in the pitch molding was extracted and removed with n-hexane, which was about 6 times the weight of the spherical pitch molding.
- the porous spherical pitch obtained in this way was heated to 260 ° C. while passing through heated air using a fluidized bed, oxidized at 260 ° C. for 1 hour, and insoluble to heat. Spherical oxidized pitch was obtained.
- an oxidation pitch of 100 g was put into a vertical tubular furnace having an inner diameter of 50 mm and a height of 900 mm, and the temperature was raised to 550 ° C. while flowing normal pressure nitrogen gas from the lower part of the apparatus at a flow rate of 5 NL / min.
- the carbonaceous precursor was obtained by carrying out temporary baking while maintaining the time.
- 200 g of the obtained carbonaceous precursor was pulverized with a jet mill (AIR JET MILL; MODEL 100AFG) at a pulverization pressure of 4.0 kgf / cm 2 and a rotor rotation speed of 4500 rpm for 20 minutes. did.
- the used jet mill is equipped with a classifier.
- 10 g of the pulverized carbonaceous precursor is placed in a horizontal tubular furnace having a diameter of 100 mm, heated to 1200 ° C. at a heating rate of 250 ° C./h, held at 1200 ° C. for 1 hour, and subjected to main firing, and carbon Material 1 was prepared.
- the main firing was performed in a nitrogen atmosphere with a flow rate of 10 L / min.
- the obtained carbonaceous material 1 has physical properties of a specific surface area of 2.9 m 2 / g, an average particle diameter of 21.0 ⁇ m, d (002) of 0.386 nm, L c (002) of 1.1 nm, ⁇ Bt Is 1.52 g / cm 3 , the combustion peak T is 654 ° C., and T-100 ⁇ ⁇ Bt is 502.
- the obtained carbonaceous material 2 has physical properties of a specific surface area of 0.3 m 2 / g, an average particle diameter of 22.8 ⁇ m, d (002) of 0.393 nm, Lc (002) of 1.1 nm, and ⁇ Bt of 1.41 g / cm 3 , combustion peak T is 639 ° C., and T-100 ⁇ ⁇ Bt is 498.
- ⁇ Production Example 3 In the oxidation of the porous spherical pitch, the operation of Production Example 1 was repeated to obtain the carbonaceous material 3 except that the temperature of the heated air was set to 165 ° C. and held for 1 hour.
- the obtained carbonaceous material 3 has physical properties of a specific surface area of 3.9 m 2 / g, an average particle diameter of 19.5 ⁇ m, d (002) of 0.357 nm, L c (002) of 1.8 nm, ⁇ Bt Is 1.97 g / cm 3 , the combustion peak T is 748 ° C., and T-100 ⁇ ⁇ Bt is 551.
- Example 1 the carbonaceous material 2 was coated with polyethylene glycol as a solid electrolyte substitute by a sol-gel method to produce a negative electrode for an all-solid battery. Specifically, the carbonaceous material 2 and polyethylene glycol were weighed so that the weight ratio was 90:10 and the volume ratio was 84:16. The weighed polyethylene glycol was dissolved in 10 g of a mixed solvent of methanol and water. Next, the carbonaceous material 2 was dispersed in a solvent, and methanol was removed using a rotary evaporator. The obtained powder was dried at 60 ° C. in a vacuum for 8 hours to obtain a negative electrode 1. Table 1 shows the electrode deformation rate and the physical properties of only the carbonaceous material 2 obtained by removing the coating after the coating treatment.
- Example 2 The negative electrode 2 was obtained by repeating the operation of Example 1 except that the weight ratio of the carbonaceous material 2 and the solid electrolyte substitute was 70:30 and the volume ratio was 65:35. Table 1 shows the electrode deformation rate and the physical properties of only the carbonaceous material 2 obtained by removing the coating after the coating treatment.
- Example 3 Using potassium bromide (KBr) as the solid electrolyte substitute, and using the carbonaceous material 1 obtained in Production Example 1 as the carbonaceous material, and the weight ratio between the carbonaceous material 1 and the solid electrolyte substitute The negative electrode 3 was obtained by repeating the operation of Example 1 except that the volume ratio was set to 50:50 and 65:35. Table 2 shows the electrode deformation rate and the physical properties of only the carbonaceous material 1 obtained by removing the coating after the coating treatment.
- KBr potassium bromide
- Example 4 In this example, KBr as a solid electrolyte substitute was mixed with the base material 1 obtained in Production Example 1 using a ball mill to produce a negative electrode for an all-solid battery. Specifically, the carbonaceous material 1 and KBr were weighed so that the weight ratio was 50:50 and the volume ratio was 65:35. 4 mL of zirconia balls having a diameter of 2 mm were put into a zirconia pot having a volume of 12 mL. Next, the weighed powder was put into a container and mixed for 1 hour at a rotation speed of 600 rpm using a ball mill (P-6 manufactured by FRITSCH) to obtain the negative electrode 4. Table 2 shows the electrode deformation rate and the physical properties of only the carbonaceous material 1 obtained by removing the coating after the coating treatment.
- Example 5 The negative electrode 5 was obtained by repeating the operation of Example 4 except that the mixing time in the ball mill was 3 hours.
- Table 2 shows the electrode deformation rate and the physical properties of only the carbonaceous material 1 obtained by removing the coating after the coating treatment.
- Example 6 The negative electrode 6 was obtained by repeating the operation of Example 4 except that the mixing time in the ball mill was 5 hours.
- Table 2 shows the electrode deformation rate and the physical properties of only the carbonaceous material 1 obtained by removing the coating after the coating treatment.
- Example 7 In this example, the operation of Example 4 was repeated except that the carbonaceous material 3 obtained in Production Example 3 was used, and the negative electrode 7 was obtained.
- Table 3 shows the electrode deformation rate and the physical properties of only the carbonaceous material 3 obtained by removing the coating after the coating treatment.
- Comparative Example 1 Polyethylene glycol was mixed with the carbonaceous material 2 obtained in Production Example 2 as a solid electrolyte substitute using a ball mill to produce a negative electrode for an all-solid battery. Specifically, the carbonaceous material 2 and polyethylene glycol were weighed so that the weight ratio was 90:10 and the volume ratio was 84:16. 4 mL of zirconia balls having a diameter of 2 mm were put into a zirconia pot having a volume of 12 mL. Next, the weighed powder was put in a container and mixed for 20 minutes at a rotation speed of 150 rpm using a ball mill (P-6 manufactured by FRITSCH) to obtain a comparative negative electrode 1. Table 1 shows the electrode deformation rate and the physical properties of the carbonaceous material 2 obtained after the treatment.
- Comparative Example 2 The comparative negative electrode 2 was obtained by repeating the operation of Comparative Example 1 except that the weight ratio of the carbonaceous material 2 and the solid electrolyte substitute was 70:30 and the volume ratio was 65:35. Table 1 shows the electrode deformation rate and the physical properties of the carbonaceous material 2 obtained after the treatment.
- Comparative Example 3 The use of potassium bromide (KBr) as the solid electrolyte substitute, and the use of the carbonaceous material 1 obtained in Production Example 1 as the carbonaceous material, and the weight of the carbonaceous material 1 and the solid electrolyte substitute
- the comparative negative electrode 3 was obtained by repeating the operation of Comparative Example 1 except that the ratio was 50:50 and the volume ratio was 65:35.
- Table 2 shows the electrode deformation rate and the physical properties of the carbonaceous material 1 obtained after the treatment.
- Comparative Example 4 The use of the carbonaceous material 3 obtained in Production Example 3 as the carbonaceous material, the use of potassium bromide (KBr) as the solid electrolyte substitute, and the carbonaceous material 3 and the solid electrolyte substitute A comparative negative electrode 4 was obtained by repeating the operation of Comparative Example 1 except that the weight ratio was 50:50 and the volume ratio was 65:35. Table 3 shows the electrode deformation rate and the physical properties of only the carbonaceous material 3 obtained after the treatment.
- Electrode deformation rate [(B / A) ⁇ 100] ⁇ 100
- a negative electrode for an all solid state battery exhibiting excellent battery performance can be obtained.
- the negative electrode for all-solid-state batteries of this invention and the all-solid-state battery containing the same can be used suitably for a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), and an electric vehicle (EV).
- HEV hybrid vehicle
- PHEV plug-in hybrid vehicle
- EV electric vehicle
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Abstract
Description
例えば、特許文献2は、炭素材料と固体電解質とをメカノケミカル処理にて混合するリチウム電池用負極合材の製造方法を開示している。また、特許文献3は、全固体電池において、負極活物質として、黒鉛及びアモルファスカーボンを用いることを開示している。
本発明者らは乱層構造炭素及び固体電解質を用いて、負極電極の作成を試みた。しかしながら、乱層構造炭素及び固体電解質を単に混合して全固体電池用負極電極を作成した場合、加圧成形後に、乱層構造炭素の反発により、負極電極が変形することが分かった。
本発明の目的は、乱層構造炭素及び固体電解質を用いた全固体電池用負極電極の製造において、負極電極の変形を抑制する製造方法を提供することである。
本発明は、こうした知見に基づくものである。
従って、本発明は、
[1](1)ブタノール法により求めた真密度が1.30g/cm3~2.10g/cm3である炭素質材料に、固体電解質を被覆する工程、及び(2)前記固体電解質被覆炭素質材料を加圧成形する工程を含む全固体電池用負極電極の製造方法、
[2]炭素質材料と、固体電解質との体積比が20:80~99:1である、[1]に記載の全固体電池用負極電極の製造方法、
[3]前記炭素質材料が、粉末X線回折法により求められる002面の平均面間隔が0.340~0.400nm、Lc(002)が0.5~10nm、及び平均粒子径Dv50が1~50μmである、[1]又は[2]に記載の全固体電池用負極電極の製造方法、
[4]前記炭素質材料が、示差熱分析による燃焼ピークT(℃)とブタノール真密度ρBt(g/cm3)とが、下記式(1)300≦T-100×ρBt≦650 (1)を満たす炭素質材料である[1]~[3]のいずれかに記載の全固体電池用負極電極の製造方法、
[5][1]~[4]のいずれかに記載の製造方法により得られる全固体電池用負極電極、又は
[6][5]に記載の全固体電池用負極電極を含む全固体電池、
に関する。
本発明の全固体電池用負極電極の製造方法は、(1)ブタノール法により求めた真密度が1.30g/cm3~2.10g/cm3である炭素質材料に、固体電解質を被覆する工程、及び(2)前記固体電解質被覆炭素質材料を加圧成形する工程、を含む。
(炭素質材料の原料)
本発明の製造方法に用いる炭素質材料は乱層構造炭素であり、ブタノール法により求めた真密度が1.30g/cm3~2.10g/cm3である限りにおいて限定されるものではないが、ある好ましい態様においてはブタノール法により求めた真密度が1.30g/cm3以上1.70g/cm3以下である難黒鉛化性炭素であり、又はある好ましい態様においてはブタノール法により求めた真密度が1.70g/cm3より大きく2.10g/cm3以下である易黒鉛化性炭素である。
難黒鉛化性炭素、又は易黒鉛化性炭素の炭素源は、難黒鉛化性炭素、又は易黒鉛化性炭素が製造できる限りにおいて限定されるものではなく、例えば石油系ピッチ、石炭系ピッチ、熱可塑性樹脂(例えば、ケトン樹脂、ポリビニルアルコール、ポリエチレンテレフタレート、ポリアセタール、ポリアクリロニトリル、スチレン/ジビニルベンゼン共重合体、ポリイミド、ポリカーボネート、変性ポリフェニレンエーテル、ポリブチレンテレフタレート、ポリアリレート、ポリスルホン、ポリフェニレンスルフィド、ポリイミド樹脂、フッ素樹脂、ポリアミドイミド、アラミド樹脂、又はポリエーテルエーテルケトン)、熱硬化性樹脂(例えば、エポキシ樹脂、ウレタン樹脂、ユリア樹脂、ジアリルフタレート樹脂、ポリエステル樹脂、ポリカーボネート樹脂、シリコン樹脂、ポリアセタール樹脂、ナイロン樹脂、フラン樹脂、又はアルデヒド樹脂(例えば、フェノール樹脂、メラミン樹脂、アミノ樹脂及びアミド樹脂))を挙げることができる。なお、石油系ピッチ、石炭系ピッチ、又は熱可塑性樹脂は、酸化処理などにより不融化することによっても、難黒鉛化性炭素の炭素源として用いることができる。
炭素質材料の(002)面の平均面間隔は、結晶完全性が高いほど小さな値を示し、理想的な黒鉛構造のそれは、0.3354nmの値を示し、構造が乱れるほどその値が増加する傾向がある。従って、平均面間隔は、炭素の構造を示す指標として有効である。
本発明の製造方法に用いる炭素質材料のX線回折法により測定した(002)面の平均面間隔は限定されるものではないが、好ましくは0.340~0.400nmであり、更に好ましくは0.350nm以上0.400nm以下であり、特に好ましくは、0.355nm以上0.400である。0.340nm未満の炭素質材料はサイクル特性が悪くなることがある。
本発明の製造方法に用いるに用いる炭素質材料のc軸方向の結晶子厚みLc(002)は、限定されるものではないが、好ましくは0.5~10.0nmである。Lc(002)の上限は、好ましくは8.0nm以下であり、より好ましくは5.0nm以下である。Lc(002)が10.0nmを超えると、リチウムのドープ、脱ドープに伴う体積膨張収縮が大きくなる。これにより、炭素構造を破壊し、リチウムのドープ、脱ドープが遮断され、繰り返し特性に劣ることがある。
比表面積は、窒素吸着によるBETの式から誘導された近似式で求めることができる。本発明の全固体電池用負極に用いる炭素質材料の比表面積は、限定されるものではないが、好ましくは0.5~50m2/gである。BET比表面積の上限は、好ましくは45m2/g以下であり、より好ましくは40m2/g以下であり、更に好ましくは35m2/g以下である。BET比表面積の下限は、好ましくは1m2/g以上である。比表面積が、50m2/g以下を超えると固体電解質との分解反応が増加し、不可逆容量の増加に繋がり、従って電池性能が低下する可能性がある。また、BET比表面積が0.5m2/g未満であると、全固体電池の負極として用いた場合に、固体電解質との反応面積が低下することにより入出力特性が低下する可能性がある。
理想的な構造を有する黒鉛質材料の真密度が2.27g/cm3であり、結晶構造が乱れるに従い真密度が小さくなる傾向がある。従って、真密度は炭素の構造を表す指標として用いることができる。
本発明の全固体電池用負極に用いる炭素質材料の真密度は、1.30g/cm3~2.10g/cm3である。真密度の上限は、好ましくは2.05g/cm3以下であり、より好ましくは2.00g/cm3以下である。真密度の下限は、好ましくは1.31g/cm3以上であり、より好ましくは1.32g/cm3以上であり、更に好ましくは1.33g/cm3以上である。更に、真密度の下限は1.40g/cm3以上であってもよい。真密度が2.10g/cm3を超える炭素質材料は、リチウムを格納できるサイズの細孔が少なくドープ及び脱ドープ容量が小さくなるため好ましくない。また、真密度の増加は炭素六角平面の選択的配向性を伴うため、リチウムのドープ・脱ドープ時に炭素質材料が膨張収縮を伴う場合が多いため好ましくない。一方、1.30g/cm3未満の炭素材料は、閉孔が多くなる場合があり、ドープ及び脱ドープ容量が小さくなることがあるので好ましくない。更に、電極密度が低下するため体積エネルギー密度の低下をもたらすので好ましくない。
なお、本明細書において、「難黒鉛化性炭素」とは、一般的には3000℃程度の超高温で熱処理しても黒鉛構造に変化しない非黒鉛質炭素の総称であるが、ここでは真密度が1.30g/cm3以上1.70g/cm3以下の炭素質材料を難黒鉛化性炭素と呼ぶ。
また本明細書において、「易黒鉛化性炭素」とは、一般的には2000℃以上の高温で熱処理することにより黒鉛構造に変化する非黒鉛質炭素の総称であるが、ここでは真密度が1.70g/cm3より大きく2.10g/cm3以下の炭素質材料を易黒鉛化性炭素と呼ぶ。
本発明の製造方法に用いる炭素質材料の平均粒子径(Dv50)は、1~50μmである。平均粒子径の下限は、好ましくは1μm以上であり、更に好ましくは1.5μm以上であり、特に好ましくは2.0μm以上である。平均粒子径が1μm未満の場合、微粉が増加し比表面積が増加し、固体電解質との反応性が高くなり充電しても放電しない容量である不可逆容量が増加し、正極の容量が無駄になる割合が増加するため、好ましくない。平均粒子径の上限は、好ましくは40μm以下であり、更に好ましくは35μm以下である。平均粒子径が50μmを超えると、粒子内でのリチウムの拡散自由行程が増加するため、急速な充放電が困難となる。
本発明の全固体電池用負極に用いる炭素質材料は、限定されるものではないが、好ましくは、示差熱分析による燃焼ピークT(℃)とブタノール真密度ρBt(g/cm3)とが、下記式(1)
300≦T-100×ρBt≦650(1)
を満たす炭素質材料である。
燃焼ピークは、一般的に炭素質材料の炭素六角平面の大きさとそれらの三次元的な秩序性に応じて変化を示すものであり、一般的に炭素六角平面が大きく、また三次元的な秩序性が高いほど高温側にピークが現れる傾向にある。このような炭素質材料は、三次元的な秩序性が高いため、ブタノール法により測定した真密度ρBtも高い。例えば、炭素六角平面が大きく、面間隔0.3354nmを有する黒鉛材料は、800℃近くの燃焼ピーク温度を示す。このような炭素質材料は、リチウムのドープ、脱ドープの繰り返しによる結晶の膨張収縮による破壊が起きやすく、充放電の繰り返し性能が劣る。
一方で、一般的に炭素六角平面が小さく、また三次元的な秩序性が低いほど低温側にピークが現れる傾向にある。このような炭素質材料は、リチウムのドープ、脱ドープの繰り返しによる結晶の膨張収縮が黒鉛に比して小さく、高いサイクル耐久性を示す。しかしながら、過度に燃焼ピークが低温側に現れる場合、細孔量や細孔径が過度に大きく、比表面積が高いため、不可逆容量の増加を招き好ましくない。また、炭素質材料中の細孔量が大きいため、ブタノール法により測定した真密度ρBtが過度に低くなり、体積エネルギー密度の観点で好ましくない。
これらの燃焼ピークT及びブタノール法により測定した真密度ρBtと、結晶の膨張収縮が小さい炭素質材料との関係において、鋭意研究した結果、炭素質材料が300≦T-100×ρBt≦650の関係を満たす燃焼ピークTとブタノール法により測定した真密度ρBtを有する場合、結晶の膨張収縮が黒鉛に比して小さく、高いサイクル耐久性が期待できることがわかった。本発明の炭素質材料は、好ましくは305≦T-100×ρBt≦650、更に好ましくは310≦T-100×ρBt≦650を満たす燃焼ピークTとブタノール法により測定した真密度ρBtを有することである。また、本発明の炭素質材料のT-100×ρBtの下限は、430であってもよい。
本発明の全固体電池用負極電極の製造方法に用いる固体電解質材料は、リチウムイオン二次電池分野で使用されているものを限定することなく使用することができ、有機化合物、無機化合物、又はそれらの混合物からなる固体電解質材料を用いることができる。固体電解質材料はイオン伝導性および絶縁性を有しており、具体的には、ポリマー電解質(例えば真性ポリマー電解質)、硫化物固体電解質材料、又は酸化物固体電解質材料を挙げることができるが、硫化物固体電解質材料が好ましい。
真性ポリマー電解質としては、エチレンオキシド結合を有するポリマーやその架橋体やその共重合体、ポリアクリロニトリル、ポリカーボネート系ポリマーなどが挙げられ、例えば、ポリエチレンオキシド、ポリエチレンカーボネート、ポリプロピレンカーボネートなどが挙げられる。
硫化物固体電解質材料としては、Li2Sと、Al2S3、SiS2、GeS2、P2S3、P2S5、As2S3、Sb2S3若しくはそれらの混合物との組み合わせを挙げることができる。すなわち、硫化物固体電解質材料として、Li2S-Al2S3材料、Li2S-SiS2材料、Li2S-GeS2材料、Li2S-P2S3材料、Li2S-P2S5材料、Li2S-As2S3材料、Li2S-Sb2S3材料、Li2S-材料を挙げることができ、特にはLi2S-P2S5材料が好ましい。更に、これらの固体電解質材料に、Li3PO4、ハロゲン、又はハロゲン化合物を添加して、固体電解質材料として用いることもできる。
酸化物固体電解質材料としては、ペロブスカイト型、NASICON型、又はガーネット型の構造を有する酸化物固体電解質材料が挙げられ、例えば、La0.51LiTiO2.94、Li1.3Al0.3Ti1.7(PO4)3、又はLi7La3Zr2O12などが挙げられる。
本発明の製造方法は、前記炭素質材料に固体電解質を被覆する工程を含む。炭素質材料と、固体電解質との体積比は、本発明の効果が得られる限りにおいて限定されるものではないが、20:80~99:1であり、より好ましくは30:70~97:3である。
本発明の製造方法は、前記固体電解質が被覆された炭素質材料を加圧成形する工程を含む。加圧成形の操作は、従来公知の方法を用いることができ、特に限定されるものではない。加圧成形の圧力は、特に限定されるものではないが、例えば0.5~600MPaで行うことができ、好ましくは1.0~600MPaであり、より好ましくは2.0~600MPaである。
本発明の製造方法においては、前記工程(1)の被覆工程において、炭素質材料に固体電解質を被覆することによって、加圧成形後の炭素質材料の反発が抑制され、負極電極の変形率が少ない負極電極を得ることができる。本発明の製造方法において、負極電極の変形率が少ない負極電極を得ることができる理由について、完全には解明されていないが、以下のように考えることができる。しかしながら、本発明は以下の記載によって、限定されるものではない。
図1に示すように、本発明に用いる炭素質材料は粒子強度が高いため、炭素質材料と固体電解質とを用いて負極電極を作製する場合に、炭素質材料の粒子間で接点を持ち(ブリッジを組み)、加圧成形時に、垂直方向に反力が生じる(図1(ii))。この加圧による圧力が解放された場合、接点を形成する粒子群が反力を解放し安定な構造となろうとする。従って、荷重方向とは反対方向に変形し、電極厚みが大きくなる(図1(iii))。そして、炭素質材料と固体電解質との間で剥離が生じ、空隙を形成するため、入出力特性が悪化することも考えられる。
前記のように弾性率の異なる炭素質材料と固体電解質とを単純に混合したのみでは、電極内で、炭素質材料がブリッジを組んでしまい、固体電解質の炭素質材料粒子の間隙への回り込みが悪いと考えられる。一方、本発明の製造方法においては、炭素質材料粒子の表面に固体電解質が被覆されているため、炭素質材料がブリッジを組みにくく、粒子間隙に固体電解質が回り込みやすいと考えられる。これによって、加圧成形後の炭素質材料の反力が抑制される。また、炭素質材料よりも弾性率の低い固体電解質が、反力を緩和するため、電極変形率が改善されると考えられる。
本発明の全固体電池用負極電極は、前記製造方法により得られるものである。すなわち、本発明の全固体電池用負極電極は、ブタノール法により求めた真密度が1.30g/cm3~2.10g/cm3である炭素質材料及び固体電解質を含む。具体的には、炭素質材料及び固体電解質としては、前記「[1]全固体電池用負極電極の製造方法」に記載の炭素質材料及び固体電解質を含むものである。
本発明の全固体電池用負極電極は、炭素質材料と固体電解質との間の剥離が少ない。従って、炭素質材料間の空隙がなく、入出力特性が向上する。
本発明の全固体電池は、前記全固体電池用負極電極を含むものである。より具体的には、負極活物質層、正極活物質層、及び固体電解質層を含み、負極活物質層として、本発明の全固体電池用負極電極を用いることができる。
負極活物質層は、前記全固体電池用負極電極を含むものである。すなわち、前記炭素質材料及び固体電解質材料を含むが、更に導電助剤、バインダー、又はその両方を含んでもよい。負極活物質層における、負極活物質層の全体積に対する炭素質材料の体積は、好ましくは20体積%~80体積%であり、より好ましくは30体積%~70体積%である。例えば、炭素質材料に固体電解質を体積比99:1で被覆した場合は、負極活物質層の全体積に対する炭素質材料の体積が20体積%~80体積%となるように、固体電解質などを加えて、負極活物質層を形成することが好ましい。
負極活物質層は、本発明の効果が得られる限りにおいて、前記炭素質材料以外の負極材料を含むことができる。
負極活物質層は、通常集電体を有する。負極集電体としては、例えば、SUS、銅、ニッケル又はカーボンを用いることができ、中でも、Cu又はSUSが好ましい。
正極活物質層は、正極活物質及び固体電解材料を含み、更に導電助剤、バインダー、又はその両方を含んでもよい。正極活物質層における正極活物質と、固体電解質との混合比は、本発明の効果が得られる限りにおいて、限定されるものではなく、適宜決定することができる。
正極活物質層の調製方法は、特に限定されるものではないが、前記正極活物質、及び固体電解質材料、更に必要に応じて導電助剤及び/又はバインダーを混合して、加圧成形することにより、製造することができる。また、特定の溶媒に正極活物質、固体電解質材料、必要に応じて導電助剤及び/又はバインダーを混合し、スラリー状態としたものを塗工、乾燥し、その後加圧成形することでも製造できる。
正極活物質層は、通常集電体を有する。負極集電体としては、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を用いることができ、中でも、アルミニウム又はSUSが好ましい。
固体電解質層は、前記「[1]全固体電池用負極電極の製造方法」の項に記載の固体電解質を含むものである。
固体電解質層に対する固体電解質の含有量は、特に限定されるものではないが、例えば10体積%~100体積%であり、好ましくは50体積%~100体積%である。
固体電解質層の厚さも、特に限定されるものではないが、例えば0.1μm~1000μmであり、好ましくは0.1μm~300μmである。
固体電解質層の調製方法は、特に限定されるものではないが、気相法、又は加圧成形法によって、作製することができる。気相法としては、限定されるものではないが、真空蒸着法、パルスレーザデポジション法、レーザアブレーション法、イオンプレーティング法、又はスパッタリング法を挙げることができる。また、加圧成形法としては、固体電解質、更に必要に応じて導電助剤及び/又はバインダーを混合して、加圧成形することにより、製造することができる。また、特定の溶媒に固体電解質材料、必要に応じて導電助剤及び/又はバインダーを混合し、スラリー状態としたものを塗工、乾燥し、その後加圧成形することでも製造できる。
全固体電池の製造方法は、特に限定されるものではなく、公知の全固体電池の製造方法を用いることができる。例えば、負極活物質層として、本発明の全固体電池用負極電極、前記正極活物質層を構成する材料を混合したもの、及び前記固体電解質層を構成する材料を混合したものを圧縮成形することによって、全固体電池を得ることができる。圧縮成形の順番は、特に限定されないが、負極活物質層、固体電解質層、そして正極活物質層の順番、正極活物質層、固体電解質層、そして負極活物質層の順番、固体電解質層、負極活物質層、そして正極活物質層の順番、又は固体電解質層、正極活物質層、そして負極活物質層の順番を挙げることができる。また、固体電解質層に関しては、前記の通り気相法により、形成した後に、各層を圧縮成形することもできる。
なお、以下に本発明の非水電解質二次電池用炭素質材料の物性値(「X線回折法による(002)面の平均面間隔d(002)及びc軸方向の結晶子厚みLc(002)」、「比表面積」、「ブタノール法により求めた真密度」、「レーザー回折法による平均粒子径」、及び「示差熱分析測定」)の測定法を記載するが、実施例を含めて、本明細書中に記載する物性値は、以下の方法により求めた値に基づくものである。
炭素質材料粉末を試料ホルダーに充填し、PANalytical社製X’Pert PROを用いて、対称反射法にて測定した。走査範囲は8<2θ<50°で印加電流/印加電圧は45kV/40mAの条件で、Niフィルターにより単色化したCuKα線(λ=1.5418Å)を線源とし、X線回折図形を得た。回折図形の補正は、ローレンツ変更因子、吸収因子、及び原子散乱因子などの関する補正を行わず、標準物質用高純度シリコン粉末の(111)面の回折線を用いて、回折角を補正した。CuKα線の波長を0.15418nmとし、Braggの公式d(002)=λ/2・sinθによりd(002)を計算した。また、(002)回折線のピークトップ法(ピークの広がりをピーク強度の半分の所に相当する2θ)により求められた半値幅からシリコン粉末の(111)回折線の半値幅を差し引いた値βより、Scherrerの式Lc(002)=Kλ/(β1/2・cosθ)によりc軸方向の結晶子の厚みLc(002)を計算した。ここでは形状因子K=0.9とし計算した。
JIS Z8830に定められた方法に準拠し、比表面積を測定した。概要を以下に記す。
BETの式から誘導された近似式vm=1/(v(1-x))を用いて液体窒素温度における、窒素吸着による1点法(相対圧力x=0.2)によりvmを求め、次式により試料の比表面積を計算した:比表面積=4.35×vm(m2/g)
(ここで、vmは試料表面に単分子層を形成するに必要な吸着量(cm3/g)、vは実測される吸着量(cm3/g)、xは相対圧力である。)
具体的には、MICROMERITICS社製「Flow Sorb II2300」を用いて、以下のようにして液体窒素温度における炭素質物質への窒素の吸着量を測定した。
炭素材料を試料管に充填し、窒素ガスを20モル%濃度で含有するヘリウムガスを流しながら、試料管を-196℃に冷却し、炭素材に窒素を吸着させる。次に試験管を室温に戻す。このとき試料から脱離してくる窒素量を熱伝導度型検出器で測定し、吸着ガス量vとした。
JIS R7212に定められた方法に準拠し、ブタノールを用いて測定した。概要を以下に記す。
内容積約40mLの側管付比重びんの質量(m1)を正確に量る。次に、その底部に試料を約10mmの厚さになるように平らに入れた後、その質量(m2)を正確に量る。これに1-ブタノールを静かに加えて、底から20mm程度の深さにする。次に比重びんに軽い振動を加えて、大きな気泡の発生がなくなったのを確かめた後、真空デシケーター中に入れ、徐々に排気して2.0~2.7kPaとする。その圧力に20分間以上保ち、気泡の発生が止まった後取り出して、更に1-ブタノールで満たし、栓をして恒温水槽(30±0.03℃に調節してあるもの)に15分間以上浸し、1-ブタノールの液面を標線に合わせる。次に、これを取り出して外部をよくぬぐって室温まで冷却した後、質量(m4)を正確に量る。次に同じ比重びんに1-ブタノールだけを満たし、前記と同じようにして恒温水槽に浸し、標線を合わせた後、質量(m3)を量る。また、使用直前に沸騰させて溶解した気体を除いた蒸留水を比重びんにとり、前と同様に恒温水槽に浸し、標線を合わせた後質量(m5)を量る。真密度(ρBt)は次の式により計算する。
試料約0.1gに対し、分散剤(カチオン系界面活性剤「SNウェット366」(サンノプコ社製))を3滴加え、試料に分散剤を馴染ませる。次に、純水30mLを加え、超音波洗浄機で約2分間分散させたのち、粒径分布測定器(島津製作所製「SALD-3000J」)で、粒径0.05~3000μmの範囲の粒径分布を求めた。
得られた粒径分布から、累積容積が50%となる粒径をもって平均粒径Dv50(μm)とした。
島津製作所製DTG-60Hを使用し、乾燥空気気流下で示差熱分析を行った。分析条件は、試料2mg、100mL/minの空気気流下、昇温速度10℃/minで行った。示差熱曲線から発熱ピーク温度を読み取った。
軟化点205℃、H/C原子比0.65、キノリン不溶分0.4%の石油系ピッチ70kgと、ナフタレン30kgとを、撹拌翼及び出口ノズルのついた内容積300リットルの耐圧容器に仕込み、190℃で1~2時間加熱溶融混合を行った。その後、加熱溶融混合した石油系ピッチを100℃程度まで冷却し、耐圧容器内を窒素ガスにより加圧して、内容物を出口ノズルから押し出すことで、直径約500μmの紐状成型体を得た。次いで、この紐状成型体を直径(D)と長さ(L)の比(L/D)が約1.5~2.0になるように粉砕し、得られた粉砕物を93℃に加熱した0.53質量%のポリビニルアルコール(ケン化度88%)を溶解した水溶液中に投入し、攪拌分散し、冷却して球状ピッチ成型体スラリーを得た。大部分の水をろ過により取り除いた後に、球状ピッチ成型体の約6倍量の重量のn-ヘキサンでピッチ成型体中のナフタレンを抽出除去した。このようにして得た多孔性球状ピッチを、流動床を用いて、加熱空気を通じながら、260℃まで昇温し、260℃で1時間保持して酸化し、熱に対して不融性の多孔性球状酸化ピッチを得た。
次に、内径50mm、高さ900mmの縦型管状炉に酸化ピッチ100gを入れて、装置下部から常圧の窒素ガスを5NL/minの流量で流しながら550℃まで昇温し、550℃で1時間保持して仮焼成を実施し、炭素質前駆体を得た。得られた炭素質前駆体200gをジェットミル(ホソカワミクロン社AIR JET MILL;MODEL 100AFG)により、粉砕圧4.0kgf/cm2、ローターの回転数4500rpmで、20分間粉砕し、粉砕炭素質前駆体とした。なお、使用したジェットミルは、分級機を備えたものである。次に、粉砕炭素質前駆体10gを直径100mmの横型管状炉に入れ、250℃/hの昇温速度で1200℃まで昇温し、1200℃で1時間保持して、本焼成を行い、炭素質材料1を調製した。なお、本焼成は、流量10L/minの窒素雰囲気下で行った。
得られた炭素質材料1の物性は、比表面積が2.9m2/g、平均粒子径が21.0μm、d(002)が0.386nm、Lc(002)が1.1nm、ρBtが1.52g/cm3、燃焼ピークTが654℃、T-100×ρBtが502である。
(1)フェノール樹脂の製造
オルトクレゾール108gにパラホルムアルデヒド32g、エチルセロソルブ242g及び硫酸10gを添加し115℃で3時間反応させたのち、炭酸水素ナトリウム17g及び水30gを加え反応液を中和した。得られた反応溶液は高速で撹拌した2リットルの水中投入しノボラック樹脂を得た。次に、ノボラック樹脂17.3gとヘキサミン2.0gを120℃で混練し、窒素ガス雰囲気中250℃で2時間加熱し硬化樹脂とした。
(2)炭素質材料の製造
得られた硬化樹脂を粗粉砕したのち、600℃で窒素雰囲気下(常圧)1時間仮焼成し、更にアルゴンガス雰囲気下(常圧)1200℃で1時間熱処理して炭素質材料を得た。得られた炭素質材料を、更に粉砕し、炭素質材料2を得た。
得られた炭素質材料2の物性は、比表面積が0.3m2/g、平均粒子径が22.8μm、d(002)が0.393nm、Lc(002)が1.1nm、ρBtが1.41g/cm3、燃焼ピークTが639℃、T-100×ρBtが498である。
多孔性球状ピッチの酸化において、加熱空気の温度を165℃とし、1時間保持したことを除いては、製造例1の操作を繰り返して炭素質材料3を得た。
得られた炭素質材料3の物性は、比表面積が3.9m2/g、平均粒子径が19.5μm、d(002)が0.357nm、Lc(002)が1.8nm、ρBtが1.97g/cm3、燃焼ピークTが748℃、T-100×ρBtが551である。
本実施例では、炭素質材料2に、固体電解質代替物として、ポリエチレングリコールをゾルゲル法により被覆し、全固体電池用負極電極を製造した。
具体的には、炭素質材料2とポリエチレングリコールを重量比で90:10、体積比84:16になるように秤量した。秤量したポリエチレングリコールを、10gのメタノールと水の混合溶媒に溶解させた。次に、炭素質材料2を溶媒中に分散させ、ロータリーエバポレータ-を用いて、メタノールを除去した。得られた粉末を、60℃、真空中で、8時間乾燥することにより負極電極1を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料2のみの物性を表1に示す。
炭素質材料2と、固体電解質代替物との重量比を70:30、体積比で65:35とした以外は、実施例1の操作を繰り返して、負極電極2を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料2のみの物性を表1に示す。
固体電解質代替物として臭化カリウム(KBr)を用い、そして炭素質材料として製造例1で得られた炭素質材料1を用いたこと、並びに炭素質材料1と固体電解質代替物との重量比を50:50、体積比で65:35とした以外は、実施例1の操作を繰り返して、負極電極3を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料1のみの物性を表2に示す。
本実施例では、製造例1で得た素質材料1に、固体電解質代替物としてKBrを、ボールミルを用いて混合し、全固体電池用負極電極を製造した。
具体的には、炭素質材料1とKBrを重量比で50:50、体積比で65:35になるように秤量した。容積12mLのジルコニアポットに、直径2mmのジルコニアボールを4mL分、投入した。次に、秤量した粉末を容器に入れ、ボールミル(FRITSCH社製P-6)を用いて、回転数600rpmで1時間混合して、負極電極4を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料1のみの物性を表2に示す。
ボールミルでの混合時間を3時間とした以外は、実施例4の操作を繰り返して、負極電極5を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料1のみの物性を表2に示す。
ボールミルでの混合時間を5時間とした以外は、実施例4の操作を繰り返して、負極電極6を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料1のみの物性を表2に示す。
本実施例では、製造例3で得た炭素質材料3を使用した以外は、実施例4の操作を繰り返して、負極電極7を得た。電極変形率、及び被覆処理後に被覆物を除去して得た炭素質材料3のみの物性を表3に示す。
本比較例では、製造例2で得た炭素質材料2に、固体電解質代替物として、ポリエチレングリコールをボールミルを用いて混合し、全固体電池用負極電極を製造した。
具体的には、炭素質材料2とポリエチレングリコールを重量比で90:10、体積比で84:16になるように秤量した。容積12mLのジルコニアポットに、直径2mmのジルコニアボールを4mL分、投入した。次に、秤量した粉末を容器に入れ、ボールミル(FRITSCH社製P-6)を用いて、回転数150rpmで20分混合して、比較負極電極1を得た。電極変形率、及び処理後に得られた炭素質材料2のみの物性を表1に示す。
炭素質材料2と、固体電解質代替物との重量比を70:30、体積比で65:35とした以外は、比較例1の操作を繰り返して、比較負極電極2を得た。電極変形率、及び処理後に得られた炭素質材料2のみの物性を表1に示す。
固体電解質代替物として、臭化カリウム(KBr)を用い、そして炭素質材料として製造例1で得られた炭素質材料1を用いたこと、並びに炭素質材料1と、固体電解質代替物との重量比を50:50、体積比で65:35とした以外は、比較例1の操作を繰り返して、比較負極電極3を得た。電極変形率、及び処理後に得られた炭素質材料1のみの物性を表2に示す。
炭素質材料に製造例3で得られた炭素質材料3を用いたこと、固体電解質代替物として、臭化カリウム(KBr)を用いたこと、並びに炭素質材料3と、固体電解質代替物との重量比を50:50、体積比で65:35とした以外は、比較例1の操作を繰り返して、比較負極電極4を得た。電極変形率、及び処理後に得られた炭素質材料3のみの物性を表3に示す。
φ10、高さ3cmの筒状容器に、試料0.65mL分を入れ、上部よりφ10の円柱上のロッドで加圧する。加圧は、0から400MPaまで加圧する。その際、400MPa加圧時のロッド上部までの高さをAとする。その後、圧力を徐々に開放し、0MPa時のロッド上部までの高さをBとする。電極変形率は、次の式で算出する。
電極変形率=[(B/A)×100]-100
以上、本発明を特定の態様に沿って説明したが、当業者に自明の変形や改良は本発明の範囲に含まれる。
Claims (6)
- (1)ブタノール法により求めた真密度が1.30g/cm3~2.10g/cm3である炭素質材料に、固体電解質を被覆する工程、及び
(2)前記固体電解質被覆炭素質材料を加圧成形する工程
を含む全固体電池用負極電極の製造方法。 - 炭素質材料と、固体電解質との体積比が20:80~99:1である、請求項1に記載の全固体電池用負極電極の製造方法。
- 前記炭素質材料が、粉末X線回折法により求められる(002)面の平均面間隔が0.340~0.400nm、Lc(002)が0.5~10nm、及び平均粒子径Dv50が1~50μmである、請求項1又は2に記載の全固体電池用負極電極の製造方法。
- 前記炭素質材料が、示差熱分析による燃焼ピークT(℃)とブタノール真密度ρBt(g/cm3)とが、下記式(1)
300≦T-100×ρBt≦650 (1)
を満たす炭素質材料である請求項1~3のいずれか一項に記載の全固体電池用負極電極の製造方法。 - 請求項1~4のいずれか一項に記載の製造方法により得られる全固体電池用負極電極。
- 請求項5に記載の全固体電池用負極電極を含む全固体電池。
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018179580A1 (ja) * | 2017-03-28 | 2018-10-04 | 株式会社村田製作所 | 全固体電池、電子機器、電子カード、ウェアラブル機器および電動車両 |
WO2020116324A1 (ja) * | 2018-12-05 | 2020-06-11 | 昭和電工株式会社 | 全固体リチウムイオン電池および負極合剤 |
WO2020116323A1 (ja) * | 2018-12-05 | 2020-06-11 | 昭和電工株式会社 | 全固体リチウムイオン電池および負極合剤 |
WO2022092055A1 (ja) * | 2020-11-02 | 2022-05-05 | マクセル株式会社 | 全固体二次電池用負極および全固体二次電池 |
Families Citing this family (3)
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FR3083006A1 (fr) * | 2018-06-22 | 2019-12-27 | Institut Polytechnique De Grenoble | Electrolyte polymere solide, son procede de preparation et accumulateur/cellule electrochimique en comprenant |
KR102527861B1 (ko) | 2021-02-01 | 2023-05-02 | 이앤이(주) | 전고체 전지용 음극 및 이의 제조방법 |
CN113363436B (zh) * | 2021-05-14 | 2022-02-18 | 宁波梅山保税港区锂泰企业管理合伙企业(有限合伙) | 一种高能量密度和高循环性能的锂离子电池 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09330717A (ja) * | 1996-06-10 | 1997-12-22 | Hitachi Maxell Ltd | リチウムイオン二次電池 |
JPH10284089A (ja) * | 1997-04-03 | 1998-10-23 | Sony Corp | 非水溶媒系二次電池の電極用炭素質材料及びその製造方法、並びに非水溶媒系二次電池 |
JP2009200014A (ja) * | 2008-02-25 | 2009-09-03 | Sumitomo Bakelite Co Ltd | 二次電池用炭素材、二次電池用電極、および二次電池 |
WO2012099178A1 (ja) * | 2011-01-19 | 2012-07-26 | 住友電気工業株式会社 | 非水電解質電池 |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2949180B2 (ja) * | 1992-03-24 | 1999-09-13 | 工業技術院長 | リチウム二次電池用負極 |
JP3653105B2 (ja) | 1993-02-25 | 2005-05-25 | 呉羽化学工業株式会社 | 二次電池電極用炭素質材料 |
JP3502669B2 (ja) | 1994-08-23 | 2004-03-02 | 呉羽化学工業株式会社 | 二次電池電極用炭素質材料およびその製造法 |
US6884546B1 (en) * | 1999-09-20 | 2005-04-26 | Sony Corporation | Secondary battery |
TW200723579A (en) | 2005-09-09 | 2007-06-16 | Kureha Corp | Negative electrode material for nonaqueous electrolyte secondary battery, process for producing the same, negative electrode and nonaqueous electrolyte secondary battery |
JP2009283344A (ja) * | 2008-05-23 | 2009-12-03 | Idemitsu Kosan Co Ltd | リチウム電池用負極合材、リチウム電池用負極、リチウム電池、装置およびリチウム電池用負極合材の製造方法 |
US20120156571A1 (en) * | 2010-01-15 | 2012-06-21 | Koji Kawamoto | Electrode for batteries, battery comprising the electrode, and method for producing the battery |
JP5682318B2 (ja) | 2011-01-12 | 2015-03-11 | トヨタ自動車株式会社 | 全固体電池 |
JP6021099B2 (ja) | 2012-04-02 | 2016-11-02 | 国立研究開発法人産業技術総合研究所 | 炭素−固体電解質複合体およびその製造方法 |
JP5858289B2 (ja) * | 2012-05-11 | 2016-02-10 | 株式会社豊田自動織機 | 二次電池用負極活物質、その製造方法、二次電池用負極、二次電池、及びSi−酸化物固体電解質複合体 |
JP6243103B2 (ja) * | 2012-06-29 | 2017-12-06 | 出光興産株式会社 | 正極合材 |
KR101700048B1 (ko) | 2012-09-06 | 2017-01-26 | 가부시끼가이샤 구레하 | 비수 전해질 2차 전지 음극용 탄소질 재료 및 이의 제조 방법 과 상기 탄소질 재료를 이용한 음극 및 비수 전해질 2차 전지 |
JPWO2014038494A1 (ja) * | 2012-09-06 | 2016-08-08 | 株式会社クレハ | 非水電解質二次電池負極用材料 |
-
2015
- 2015-03-31 WO PCT/JP2015/060075 patent/WO2015152215A1/ja active Application Filing
- 2015-03-31 JP JP2016511918A patent/JP6129407B2/ja active Active
- 2015-03-31 EP EP15773141.5A patent/EP3128583B1/en active Active
- 2015-03-31 KR KR1020167026970A patent/KR101758037B1/ko active IP Right Grant
- 2015-03-31 US US15/300,356 patent/US9947927B2/en active Active
- 2015-03-31 TW TW104110548A patent/TWI594484B/zh not_active IP Right Cessation
- 2015-03-31 CN CN201580017408.2A patent/CN106133954B/zh active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09330717A (ja) * | 1996-06-10 | 1997-12-22 | Hitachi Maxell Ltd | リチウムイオン二次電池 |
JPH10284089A (ja) * | 1997-04-03 | 1998-10-23 | Sony Corp | 非水溶媒系二次電池の電極用炭素質材料及びその製造方法、並びに非水溶媒系二次電池 |
JP2009200014A (ja) * | 2008-02-25 | 2009-09-03 | Sumitomo Bakelite Co Ltd | 二次電池用炭素材、二次電池用電極、および二次電池 |
WO2012099178A1 (ja) * | 2011-01-19 | 2012-07-26 | 住友電気工業株式会社 | 非水電解質電池 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3128583A4 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018179580A1 (ja) * | 2017-03-28 | 2018-10-04 | 株式会社村田製作所 | 全固体電池、電子機器、電子カード、ウェアラブル機器および電動車両 |
JPWO2018179580A1 (ja) * | 2017-03-28 | 2019-11-07 | 株式会社村田製作所 | 全固体電池、電子機器、電子カード、ウェアラブル機器および電動車両 |
WO2020116324A1 (ja) * | 2018-12-05 | 2020-06-11 | 昭和電工株式会社 | 全固体リチウムイオン電池および負極合剤 |
WO2020116323A1 (ja) * | 2018-12-05 | 2020-06-11 | 昭和電工株式会社 | 全固体リチウムイオン電池および負極合剤 |
WO2022092055A1 (ja) * | 2020-11-02 | 2022-05-05 | マクセル株式会社 | 全固体二次電池用負極および全固体二次電池 |
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EP3128583A4 (en) | 2017-02-08 |
US9947927B2 (en) | 2018-04-17 |
TW201603365A (zh) | 2016-01-16 |
CN106133954B (zh) | 2018-06-19 |
EP3128583A1 (en) | 2017-02-08 |
JP6129407B2 (ja) | 2017-05-17 |
KR101758037B1 (ko) | 2017-07-13 |
US20170141395A1 (en) | 2017-05-18 |
CN106133954A (zh) | 2016-11-16 |
EP3128583B1 (en) | 2019-03-13 |
KR20160118376A (ko) | 2016-10-11 |
JPWO2015152215A1 (ja) | 2017-04-13 |
TWI594484B (zh) | 2017-08-01 |
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