JP2010040190A - Method for manufacturing pole material slurry - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing pole material slurry used for manufacture of an electrode for improving output density, energy density, and cycle characteristics of an all-solid secondary battery. <P>SOLUTION: In the method for manufacturing pole material slurry, mixture solution is made up by mixing inorganic solid electrolyte, an active material, and a dispersant, the mixture solution is put in a stirring tub of a stirrer machine equipped with the cylindrical stirring tub 1 and rotating blades 11 with cylindrical parts 12 having a plurality of holes 12a formed with an interval S of 0.5 to 5 mm from an inner face of the stirring tub, the rotating blades are rotated at a peripheral speed of 15 to 60 m/sec at temperatures of -20 to 100°C, the mixture solution is retained in the stirring tub for 5 to 600 seconds, and is pressed onto the inner face of the stirring tub to be kept on stirring while it is spread in a thin-film cylindrical shape to obtain the slurry L. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an electrode material slurry that can be used for producing an electrode such as an all-solid secondary battery.

In recent years, with the widespread use of portable devices such as video cameras, mobile phones, and portable personal computers, the demand for secondary batteries has increased. In particular, a non-aqueous lithium ion secondary using a carbonaceous material (carbon-based material) as the negative electrode active material, LiMO ₂ (M = Ni, Co, etc.) as the positive electrode active material, and using an organic solvent as the electrolyte. Batteries have been developed and are attracting attention.

  An electrode of a non-aqueous secondary battery can be manufactured by applying a slurry in which an active material, a conductive agent, a binder, a solvent, etc. are mixed on a metal core to form an electrode material layer. . At this time, if the dispersion of the components in the electrode material layer is insufficient, there arises a problem that a secondary battery having excellent cycle characteristics cannot be obtained.

  Patent document 1 is disclosing the high-speed stirrer which has the outstanding stirring effect | action by the rotary blade with a good rotation balance. However, Patent Document 1 does not describe a method for producing a positive electrode / negative electrode slurry that enhances the performance of a secondary battery.

Patent Document 2 prepares a slurry by mixing a conductive agent composed of fibrous carbon, an active material, a binder, and a solvent, performs a stirring process using the stirrer of Patent Document 1, and turns the slurry into a metal core. The manufacturing method of the electrode for nonaqueous electrolyte secondary batteries which apply | coat and form a mixture layer is disclosed.
However, the invention of Patent Document 2 is a secondary battery intended for a non-aqueous electrolyte, and does not use a solid electrolyte. Conductive aids are limited to fibrous carbon. Even if a positive electrode / negative electrode slurry is prepared by the method of Patent Document 2 to produce an all solid Li secondary battery, the performance of the all solid Li secondary battery does not increase.

JP-A-11-347388 JP 2006-236658 A

  The objective of this invention is providing the manufacturing method of the electrode material slurry which can be used for manufacture of the electrode which improves the output density and energy density of an all-solid-state secondary battery, and improves a cycling characteristic in connection with it.

According to the present invention, the following method for producing an electrode slurry is provided.
1. An inorganic solid electrolyte, an active material, and a dispersion medium are mixed to prepare a mixed solution,
Stirring provided with a cylindrical stirring tank, and a rotary blade having a cylindrical portion in which a plurality of holes are formed in the stirring tank with an interval of 0.5 to 5 mm from the inner surface of the stirring tank. Put the mixed solution in the stirring tank of the machine,
The rotating blade is rotated at a peripheral speed of 15 to 60 m / sec at a temperature of −20 to 100 ° C., the mixed liquid is retained in the stirring tank for 5 to 600 seconds, and pressed against the inner surface of the stirring tank. A slurry is obtained by stirring while spreading into a thin-film cylinder.
Method for producing electrode material slurry.
2. The inorganic solid electrolyte is a sulfide-based solid electrolyte;
2. The method for producing an electrode slurry according to 1, wherein the active material is a negative electrode active material.
3. The method for producing an electrode material slurry according to 1 or 2, wherein the mixed solution further contains a conductive additive.
4). 4. The method for producing an electrode material slurry according to 3, wherein the amount of the conductive additive in the mixed solution is 0.1 to 6% by weight of the active material.
5). The conductive assistant is at least one selected from the group consisting of carbon black, acetylene black, ketjen black, thermal black, and fullerene, and the average particle diameter is 0.0001 to 10 μm according to 3 or 4. Method for producing electrode material slurry.
6). The pole material as described in any one of 3-5 whose content of the said conductive support agent and the said active material, and the said inorganic solid electrolyte in the said liquid mixture is 3: 7-9: 1 by weight ratio. A method for producing a slurry.
7). The manufacturing method of the electrode material slurry as described in any one of 1-6 whose solid content concentration of the said slurry is 25 to 80 weight%.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a novel electrode material slurry can be provided. The all-solid-state secondary battery using the electrode manufactured from the electrode material obtained by the method of the present invention has high output density and energy density, and is excellent in cycle characteristics.

In the method for producing an electrode slurry of the present invention, a solid electrolyte, an active material, and a dispersion medium are mixed to prepare a mixed solution, and the mixed solution is placed in a stirring tank of a stirrer and stirred.
The stirrer used in the present invention has a cylindrical stirring tank and a cylindrical part in which a plurality of holes are formed in the stirring tank with a space of 0.5 to 5 mm from the inner surface of the stirring tank. With rotating blades.
In the present invention, in such a stirrer, the rotating blade is rotated at a peripheral speed of 15 to 60 m / sec at a temperature of −20 to 100 ° C., and the mixed liquid is retained in the stirrer tank for 5 to 600 seconds. The mixed liquid is pressed against the inner surface of the stirring tank and stirred while expanding into a thin-film cylinder. In the present invention, aggregation of substances contained in the mixed solution can be crushed and dispersed in a short time.

  As the stirrer used in the present invention, for example, a high-speed stirrer described in Patent Document 1 can be used. This high-speed stirrer has a rotating shaft concentrically provided in a cylindrical stirring tank, a rotating blade having a slightly smaller diameter than that of the stirring tank is attached to the rotating shaft, and the liquid to be treated is placed on the inner surface of the stirring tank by the high-speed rotation of the rotating blade. Stir while spreading into a thin-film cylinder. The rotary blade includes a perforated cylindrical portion provided on the outer peripheral side of the cylindrical body through a large number of small holes in the radial direction. In this high-speed stirrer, the liquid to be treated is pressed against the inner surface of the agitation tank by high-speed rotation of the rotating blades to form a thin-film cylinder, and the cylindrical portion of the rotary blade moves in the thin-film cylindrical liquid to be treated. A large shearing force can be applied to the treatment liquid to loosen and disperse the aggregates of substances in the treatment liquid. Since this stirrer has no surface that collides with the liquid to be treated, there is little wear even when a liquid containing a solid component is processed, and metal components from metal parts such as rotating blades are mixed into the liquid mixture. There is little fear.

  In the stirrer used for this invention, the space | interval of a stirring tank and a rotary blade is 0.5-5 mm. If it is less than 0.5 mm, there is a possibility that the mixed solution will be clogged between the stirring tank and the rotary blade in a highly viscous mixed solution, and if the interval exceeds 5 mm, sufficient shear stress will not be applied to the mixed solution and stirring will be sufficient. I can't call. Preferably, it is 1.5-3 mm.

  The peripheral speed of the rotating wing is 15 to 60 m / sec. If it is less than 15 m / sec, it may not be sufficiently stirred, and if it exceeds 60 m / sec, the stress applied to the mixed solution is too large, and there is a risk of temperature rise and destruction of solid components. Preferably, it is 20-50 m / sec.

  The residence time of the mixed solution is 5 to 600 seconds. If the time is less than 5 seconds, the mixture may not be sufficiently stirred. If the time is longer than 600 seconds, the stress applied to the mixed solution is too large, so that the temperature may rise or the solid components may be destroyed. Preferably, it is 10 to 180 seconds.

  The stirring temperature is -20 to 100 ° C. If it is less than −20 ° C., the viscosity of the slurry is high and there is a possibility that the apparatus is burdened. If it exceeds 100 ° C., the dispersion medium may evaporate.

  Examples of the solid electrolyte used in the present invention include a sulfide-based solid electrolyte and an oxide-based solid electrolyte, and a sulfide-based solid electrolyte is preferable.

As the sulfide-based electrolyte, for example, a sulfide-based electrolyte powder containing sulfur element, lithium element, and at least one element selected from the group consisting of boron, silicon, germanium, phosphorus, and aluminum can be used. The average particle size of the powder is preferably 0.01 to 100 μm.
Such sulfide electrolyte powder, a lithium sulfide, a compound represented by A _m S _n (A is selected from boron, silicon, germanium, a phosphorous or aluminum, m and n are each an integer from 1 to 10 Is obtained from.

Further, as the sulfide-based electrolyte, for example, a sulfide-based electrolyte powder containing sulfur element, lithium element, oxygen element, and at least one element selected from the group consisting of boron, silicon, germanium, phosphorus, and aluminum can be used. . The average particle size of the powder is preferably 0.01 to 100 μm.
Such sulfide electrolyte powder, lithium sulfide, a compound represented by A _m S _n (A is selected from boron, silicon, germanium, a phosphorous or aluminum, m and n are an integer from 1 to 10, respectively And a compound represented by Li _x M _y O _z (M is boron, silicon, germanium, sulfur, phosphorus, or aluminum, and x, y, and z are each an integer of 1 to 10). can get.

The oxide electrolyte that can be used in the present invention has high ionic conductivity by including a lithium ion conductive crystal, and can have sufficient conductivity to carry lithium ion migration in the electrode. Is.
Specifically, LiN, LISICON, La0.55Li0.35TiO ₃ having a perovskite structure, LiTi ₂ P ₃ O ₁₂ having a NASICON type structure, and the like are exemplified.
Among them, a particularly preferable lithium ion conductive crystal is Li _{1 + x + y} (Al, Ga) _x (Ti, Ge) _2−x Si _y P _3−y O ₁₂ (where 0 ≦ x ≦ 1, 0 ≦ y ≦ 1). ). This crystal has the advantages of high lithium ion conductivity, chemical stability and easy handling. Moreover, this crystal | crystallization can be precipitated as a crystal | crystallization in glass ceramics by heat-processing the glass of a specific composition.

The active material used in the present invention includes a positive electrode active material and a negative electrode active material.
A commercially available negative electrode active material can be used without particular limitation, and a carbon material, Sn metal, In metal, or the like can be suitably used. Specifically, natural graphite, various graphites, metal powder such as Sn, Si, Al, Sb, Zn, Bi, metal alloy powder such as Sn ₅ Cu ₆ , Sn ₂ Co, Sn ₂ Fe, other amorphous alloys and plating An alloy is mentioned. Although there is no restriction | limiting in particular regarding a particle size, A thing with an average particle diameter of several micrometers-80 micrometers can be used suitably.

A commercially available positive electrode active material can be used without particular limitation, and a composite oxide of lithium and a transition metal can be suitably used. Specifically, the following materials and similar materials having different composition ratios of the respective elements can be used, and LiCoO ₂ , LiNiCoO ₂ , LiNiO ₂ , LiNiMnCoO ₂ , LiFeMnO ₂ , Li ₂ PtO ₃ , LiMnNiO ₄ , LiMn ₂ Examples include O ₄ , LiNiMnO ₂ , LiNiVO ₄ , LiCrMnO ₄ , LiFePO ₄ , LiFe (SO ₄ ) ₃ , LiCoVO ₄ , LiCoPO ₄ , S, and the like. Although there is no restriction | limiting in particular regarding a particle size, The thing with an average particle diameter of several micrometers-15 micrometers can be used suitably.

  An electrode material is prepared by mixing an active material and a solid electrolyte. A suitable ratio of the active material is 30% to 90% by weight of the total weight of the active material and the solid electrolyte. More preferably, it is 40 weight%-80 weight%, More preferably, it is 50 weight%-80 weight%.

The dispersion medium used in the present invention preferably has a low reactivity with the electrode material, but if the electrode material surface is coated so that the electrode material and the dispersion medium do not react, the reaction with the electrode material It can be used even if it has high properties.
When a substance that easily reacts with moisture is contained in the mixed liquid, the influence of moisture in the air can be reduced by using a dehydrated dispersion medium.
Preferred dispersion media are hydrocarbon organic solvents such as toluene and xylene, and organic solvents such as ethers and carbonate compounds.

The method of preparing the electrode material mixture is a method of adding the electrode material while maintaining stirring to the mixture of the solid electrolyte and the dispersion medium, mixing the solid electrolyte and the dry powder of the electrode material in advance to form a mixture, and then a predetermined amount Any of a method of adding and stirring the material to the dispersion medium, a method of separately adding the pole material and the solid electrolyte to the dispersion medium, and the like may be used.
In the polar material mixture, the polar material is dispersed in the dispersion medium and is not dissolved in the dispersion medium.

It is preferable that the mixed solution further contains a conductive additive.
The average particle size of the conductive assistant is preferably 0.0001 to 10 μm. If it is less than 0.0001 μm, the conductive path may not be formed because it re-aggregates. If it exceeds 10 μm, particles are sparsely present in the slurry when the conductive aid is evenly dispersed in the slurry. The conductive path is interrupted, and the electronic conductivity may be deteriorated. The average particle size is determined by SEM observation of the conductive additive, selecting a magnification at which about 300 particles can be confirmed in one field of view, observing eight fields at that magnification, picking up an arbitrary 500 specimens, and picking up a median diameter D50 Is the number average particle diameter obtained from the value.

  Examples of the conductive assistant include carbon black, acetylene black, ketjen black, thermal black, and fullerene. These may be used alone or in combination. By using a conductive additive that is fine and excellent in electron conductivity, an electron conduction path is formed, the output density and energy density of the lithium battery are improved, and the cycle characteristics are improved accordingly.

  In the mixed solution, the conductive assistant is preferably contained in an amount of 0.1 to 6% by weight of the active material. If the amount is less than 0.1% by weight, the electron conduction path cannot be sufficiently formed. If the amount exceeds 6% by weight, the ion conduction path may be inhibited. Preferably, it is 1 to 5% by weight.

  Moreover, it is preferable that the total amount of a conductive support agent and an active material, and an inorganic solid electrolyte are contained in a mixed liquid by the weight ratio of 3: 7-9: 1. If this ratio is not satisfied, the balance between electron conductivity and ion conductivity may be poor, and the characteristics may not be improved. Preferably, it is 5: 5 to 8: 2.

  The mixture of polar materials can also contain a binder, a lithium salt, and the like.

  The solid content concentration of the obtained electrode material slurry is preferably 25 to 80% by weight. If the amount is less than 25% by weight, it is difficult for sufficient shear stress to be applied to the slurry. Preferably, it is 30 to 50% by weight.

  Further, in the electrode material slurry, it is preferable that the lithium ion conductive binder is contained in an amount of 0.01 to 10% by weight based on the total solid content. If it is less than 0.01% by weight, the moldability is poor, and if it exceeds 10% by weight, the lithium ion conductivity of the binder is low relative to the lithium ion conductivity of the solid electrolyte, so the ionic conductivity in the slurry may be low. There is. More preferably, it is 1 to 7% by weight. The binder may be added when preparing the mixed solution, or may be added to the slurry after stirring.

  The electrode material slurry obtained by the above method can be applied onto a substrate by a known method to form an electrode (negative electrode / positive electrode) sheet. For example, the electrode sheet is prepared by sufficiently stirring the slurry, dropping it onto a current collector substrate, forming a film with a doctor blade, spin coating, screen printing, etc. .

  Alternatively, the dispersion medium in the slurry can be evaporated to a powder, and an electrode sheet can be prepared by vapor deposition or the like. An electrode can also be produced by a dry electrostatic coating method or the like.

  Examples of the positive electrode current collector sheet and the negative electrode current collector sheet include, for example, stainless steel, gold, platinum, zinc, nickel, tin, aluminum, molybdenum, niobium, tantalum, tungsten, titanium, and alloys thereof, and alloys thereof. , Foil, net, punched metal, expanded metal, etc. are used. In particular, an aluminum foil is preferable for the positive electrode current collector sheet, and an aluminum foil or a tin foil is preferable for the negative electrode current collector sheet in terms of current collection, workability, and cost.

The all solid state secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte layer sandwiched between the positive electrode and the negative electrode. The electrode sheet manufactured from the electrode material slurry obtained by the method of the present invention can be used as a negative electrode and / or a positive electrode of an all-solid secondary battery.
In the slurry obtained by the production method of the present invention, the active material, the solid electrolyte, and the dispersion medium are well mixed and uniformly dispersed, so that an electron conduction and ion conduction path is formed in the electrode produced from this, and the output of the battery The density and energy density are improved, and the cycle characteristics are also improved.

Production Example 1
[Production of lithium sulfide]
Lithium sulfide was produced according to the method of the first aspect (two-step method) in JP-A-7-330312. Specifically, N-methyl-2-pyrrolidone (NMP) 3326.4 g (33.6 mol) and lithium hydroxide 287.4 g (12 mol) were charged into a 10 liter autoclave equipped with a stirring blade, and 300 rpm, 130 The temperature was raised to ° C. After the temperature rise, hydrogen sulfide was blown into the liquid at a supply rate of 3 liters / minute for 2 hours. Subsequently, this reaction solution was heated under a nitrogen stream (200 cc / min), and the reacted lithium hydrosulfide was dehydrosulfurized to obtain lithium sulfide. As the temperature increased, water produced as a by-product due to the reaction between hydrogen sulfide and lithium hydroxide started to evaporate, but this water was condensed by the condenser and extracted out of the system. While water was distilled out of the system, the temperature of the reaction solution rose, but when the temperature reached 180 ° C., the temperature increase was stopped and the temperature was kept constant. The reaction was completed after the dehydrosulfurization reaction of lithium hydrosulfide (about 80 minutes) to obtain lithium sulfide.

[Purification of lithium sulfide]
After decanting NMP in the 500 mL slurry reaction solution (NMP-lithium sulfide slurry) obtained above, 100 ml of dehydrated NMP was added and stirred at 105 ° C. for about 1 hour. NMP was decanted at that temperature. Further, 100 mL of NMP was added, stirred at 105 ° C. for about 1 hour, NMP was decanted at that temperature, and the same operation was repeated a total of 4 times. After completion of the decantation, lithium sulfide was dried at 230 ° C. (temperature higher than the boiling point of NMP) under a nitrogen stream for 3 hours under normal pressure. The impurity content in the obtained lithium sulfide was measured. Incidentally, lithium sulfite _(Li 2 _SO 3), the content of each sulfur oxide lithium sulfate _(Li 2 SO ₄₎ and lithium thiosulfate _(Li 2 S2O _3), and N- methylamino acid lithium (NMAB) is Quantification was performed by ion chromatography. As a result, the total content of sulfur oxides was 0.13% by mass, and LMAB was 0.07% by mass.

Production Example 2
[Production of sulfide-based solid electrolytes]
Li ₂ S produced in Production Example 1 and P ₂ S ₅ (manufactured by Aldrich) were used as starting materials. 250 g of the mixture adjusted to a molar ratio of 70:30 was placed in a SUS container (capacity: 6.7 L) filled with zirconia balls, and 200 hours under a dry atmosphere at a dew point of −40 ° C. or lower and at room temperature. A mechanical milling treatment was performed by applying mechanical energy of 1 kJ / kg · s by a vibration mill to obtain a sulfide-based solid electrolyte powder of white yellow powder.
Powder X-ray diffraction measurement was performed on the obtained powder (CuKα: λ = 1.5418Å). From the obtained chart, it was confirmed that the peak of the raw material crystal disappeared completely, and this sulfide-based solid electrolyte powder was vitrified.
The obtained sulfide-based glass solid electrolyte powder (amorphous glass electrolyte) is sealed in an SUS tube in an argon atmosphere, subjected to a firing treatment at 300 ° C. for 2 hours, and a sulfide-based glass ceramic solid electrolyte (crystal) A vitrified glass electrolyte).

  The crystallized glass electrolyte produced above was subjected to powder X-ray diffraction measurement (CuKα: λ = 1.5418Å). The obtained crystallized glass electrolyte has 2θ = 17.8 ± 0.3 deg, 18.2 ± 0.3 deg, 19.8 ± 0.3 deg, 21.8 ± 0.3 deg, 23.8 ± 0.3 deg. 25.9 ± 0.3 deg, 29.5 ± 0.3 deg, 30.0 ± 0.3 deg.

Moreover, it confirmed that the crystallinity degree of the obtained crystallized glass electrolyte was 50% or more. The crystallinity, using JNM-CMXP302NMR apparatus (manufactured by JEOL Ltd.), to measure the solid ³¹ PNMR spectrum under the following conditions, the obtained solid ³¹ PNMR spectrum, is observed in 70~120ppm The resonance lines were separated into Gaussian curves using a non-linear least square method and calculated from the area ratio of each curve.

Measurement conditions of solid ³¹ P-NMR spectrum Observation nucleus: ³¹ P
Observation frequency: 121.339 MHz
Measurement temperature: Room temperature Measurement method: MAS method Pulse sequence: Single pulse 90 ° Pulse width: 4 μs
Magic angle rotation speed: 8600Hz
Wait time until the next pulse application after FID measurement: 100-2000s
(Set to be more than 5 times the maximum spin-lattice relaxation time)
Number of integrations: 64 times Chemical shifts were determined using (NH ₄ ) ₂ HPO ₄ (chemical shift 1.33 ppm) as an external reference.
In order to prevent deterioration due to moisture in the air during sample filling, the sample was filled into a hermetic sample tube in a dry box in which dry nitrogen was continuously flowed.

Example 1
FIG. 1 is a cross-sectional view showing a high-speed stirrer used for slurry stirring. Specifically, the trade name “TK Philmix” (manufactured by Primex Corporation) was used.

  As shown in FIG. 1, the stirrer is provided with a stirring tank 1 having a cylindrical inner surface, and an outer tank 2 is provided around the stirring tank 1. A cooling water chamber 3 is formed between the stirring tank 1 and the outer tank 2. Cooling water is supplied to the cooling water chamber 3 from the inflow pipe 4, absorbs frictional heat generated by stirring, and is discharged from an outflow pipe (not shown). Supply pipes 5 and 6 having valves 5 a and 6 a are connected to the bottom of the stirring tank 1. The supply pipes 5 and 6 can be used for supplying raw materials. In the case of batch production, a stopper can be introduced into the bottom of the stirring tank 1 for use.

  A weir plate 7 is placed on the top of the stirring tank 1, and an upper container 8 is mounted thereon. An outflow pipe 9 is connected to the upper container 8. The upper container 8 has a lid 8a and a cooling water chamber 8b, and is used when products are continuously produced. In this case, the weir plate 7 is replaced with one whose inner diameter is larger than that shown in the figure, and the raw material is continuously supplied from the supply pipes 5 and 6 so that the liquid after stirring continuously flows out over the weir plate 7. To be treated. The cooling water chamber 8b is connected to the water channel in parallel with the cooling water chamber 3.

  The rotating shaft 10 passes through the lid 8a in an airtight manner and is installed concentrically with the agitation tank 1. The rotating shaft 10 is driven to rotate at a high speed by a motor provided at the top. A rotating blade 11 is attached to the lower end of the rotating shaft 10.

  The rotary blade 11 has a cylindrical portion 12, and the cylindrical portion 12 is attached to the rotary shaft 10 by a boss 14 via an arm 13. A large number of holes 12 a are formed in the cylindrical portion 12. An appropriate number of communication holes 13 a is formed in the arm 13.

  FIG. 1 shows a state in which the liquid mixture L is put. The liquid mixture L is pressed in the circumferential direction by the high-speed rotation of the rotating blades 11 and rotates while being in close contact with the inner surface of the stirring tank 1 in a thin-film cylindrical shape by the centrifugal force generated by the rotation. The liquid mixture L is subjected to an agitation action due to a difference in speed between the surface thereof and the inner surface of the agitation tank 1, and the substances contained in the liquid mixture L are dispersed. The mixed liquid L flowing into the hole 12a receives a strong rotational force due to the rotation of the hole, flows into the gap S from the hole 12a, raises the pressure, and disturbs the flow of the mixed liquid L in the gap S. This promotes the stirring action.

A negative electrode mixture mixture was prepared using the solid electrolyte, graphite (active material), conductive additive, and toluene (dispersion medium) synthesized in Production Example 2. CGB manufactured by Nippon Graphite Industries Co., Ltd. was used as the graphite, and Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd. was used as the conductive assistant.
Denka black was added at 1% by weight with respect to CGB. Weighing was performed so that the weight ratio of the total amount of CGB and Denka Black to the solid electrolyte was 6: 4. Toluene was added in such an amount that the solid content concentration in the negative electrode mixture mixture was 45% by weight.

  The mixed liquid prepared as described above is filled in the stirring tank 1 shown in FIG. 1, and the rotating blade 11 is attached to the rotating shaft 10 so that the distance between the stirring tank 1 and the rotating blade 11 is 2 mm. The mixture was stirred for 180 seconds under the condition of a peripheral speed of 30 m / second. The temperature of the stirring tank 1 at this time was 25-35 degreeC.

The obtained slurry was applied on an Al current collector and dried to prepare a negative electrode sheet.
The obtained negative electrode sheet was used as a negative electrode. The positive electrode was prepared by mixing the lithium composite oxide and the solid electrolyte obtained in Production Example 2 in a mortar at a weight ratio of 7: 3. As the electrolyte, the solid electrolyte obtained in Production Example 2 used for each electrode was used. A Ti foil was used as a current collector, laminated in the order of Ti foil / negative electrode / electrolyte / positive electrode / Ti foil, and compressed several times at 10 to 600 MPa to produce a lithium battery.

The charge / discharge measurement of the produced battery was performed under the conditions that the cut-off voltage was a lower limit of 1.0 V, an upper limit of 4.2 V, and the current density was 400 μA / cm ² .
As a result, the charge / discharge efficiency obtained from the ratio of the discharge capacity to the charge capacity was 90%.

Comparative Example 1
Instead of stirring the slurry using the stirrer shown in FIG. 1, a negative electrode sheet and a battery were produced in the same manner as in Example 1 except that the mixture was mixed in a planetary ball mill P-7 manufactured by Fritsch under a condition of 370 rpm for 2 hours. And evaluated. The charge / discharge efficiency was 75%.

Example 2
A negative electrode sheet and a battery were prepared and evaluated in the same manner as in Example 1 except that Denka Black was not added and the weight ratio of CGB to the solid electrolyte was 6: 4. The charge / discharge efficiency was 79%.

The electrode material slurry can be produced by the production method of the present invention, and the electrode can be produced from this slurry. This electrode can be used for an all-solid secondary battery such as a lithium battery.
All-solid-state secondary batteries are used in various portable electronic devices, especially notebook computers, notebook word processors, palmtop (pocket) computers, mobile phones, PHS, mobile faxes, mobile printers, headphone stereos, video cameras, and mobile TVs. , Portable CD, portable MD, electric shaving machine, electronic handrail, transceiver, electric tool, radio, tape recorder, digital camera, portable copying machine, portable game machine and the like. In addition, all-solid-state secondary batteries are electric vehicles, hybrid vehicles, vending machines, electric carts, load leveling power storage systems, household power storage devices, distributed power storage systems (built in stationary appliances), emergency power It can also be used for supply systems and the like.

It is sectional drawing of the high-speed stirrer used in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stirring tank 3,8b Cooling water chamber 5,6 Supply pipe 7 Dam plate 10 Rotating shaft 11 Rotating blade 12 Cylindrical part 12a Hole L Slurry S Gap t Film thickness

Claims (7)

An inorganic solid electrolyte, an active material, and a dispersion medium are mixed to prepare a mixed solution,
Stirring provided with a cylindrical stirring tank, and a rotary blade having a cylindrical portion in which a plurality of holes are formed in the stirring tank with an interval of 0.5 to 5 mm from the inner surface of the stirring tank. Put the mixed solution in the stirring tank of the machine,
The rotating blade is rotated at a peripheral speed of 15 to 60 m / sec at a temperature of −20 to 100 ° C., the mixed liquid is retained in the stirring tank for 5 to 600 seconds, and pressed against the inner surface of the stirring tank. A slurry is obtained by stirring while spreading into a thin-film cylinder.
Method for producing electrode material slurry. The inorganic solid electrolyte is a sulfide-based solid electrolyte;
The method for producing an electrode slurry according to claim 1, wherein the active material is a negative electrode active material.   The method for producing an electrode material slurry according to claim 1, wherein the mixed solution further contains a conductive additive.   The method for producing an electrode material slurry according to claim 3, wherein an amount of the conductive additive in the mixed solution is 0.1 to 6% by weight of the active material.   The conductive additive is at least one selected from the group consisting of carbon black, acetylene black, ketjen black, thermal black, and fullerene, and has an average particle size of 0.0001 to 10 μm. The manufacturing method of the electrode material slurry of description.   6. The content of the conductive auxiliary agent and the active material and the inorganic solid electrolyte in the mixed solution is 3: 7 to 9: 1 by weight ratio, according to claim 3. Method for producing electrode material slurry.   The method for producing an electrode material slurry according to any one of claims 1 to 6, wherein a solid content concentration of the slurry is 25 to 80 wt%.

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