JP7192590B2 - Electrode material manufacturing apparatus and electrode material manufacturing method - Google Patents

Description

The present disclosure relates to an electrode material manufacturing apparatus and an electrode material manufacturing method.

2. Description of the Related Art In recent years, electronic devices have been remarkably reduced in size and weight, and along with this, there is a growing demand for batteries used as power sources for driving such electronic devices to be smaller and lighter.
Non-aqueous electrolyte secondary batteries, typified by lithium ion secondary batteries, have been developed in order to satisfy such demands for miniaturization and weight reduction. Lithium ion capacitors are also known as power storage devices for applications that require high energy density characteristics and high output characteristics. Furthermore, sodium-ion batteries and capacitors using sodium, which is less expensive than lithium and abundant in resources, are also known.

In such batteries and capacitors, a process of pre-doping an electrode with an alkali metal (generally called pre-doping) is employed for various purposes. Various methods are known for pre-doping an electrode with an alkali metal. Pre-doping is performed by applying sonic vibration.

Japanese Patent No. 5760593

In the technique described in Patent Literature 1, after the pre-doping step, there is a risk that alkali metals (hereinafter referred to as residual alkali metals) remain in the aggregates without being doped with the active material. An object of one aspect of the present disclosure is to provide an electrode material manufacturing apparatus and an electrode material manufacturing method that can reduce the amount of residual alkali metal.

One aspect of the present disclosure is an electrode material manufacturing apparatus for manufacturing an electrode material including an active material doped with an alkali metal, the apparatus configured to inject the alkali metal into an assembly including at least the active material. an injection unit, a melting unit configured to melt the alkali metal in at least part of a path from the injection unit to the aggregate, kneading, stirring, and kneading the alkali metal and the aggregate. or a processing unit configured to mix.

By using the electrode material manufacturing apparatus according to one aspect of the present disclosure, it is possible to reduce the amount of residual alkali metal after kneading, stirring, or mixing the alkali metal and aggregate.
Another aspect of the present disclosure is a method of manufacturing an electrode material that includes an active material doped with an alkali metal, comprising: injecting the alkali metal into an aggregate containing at least the active material; The method for producing an electrode material includes melting, stirring, or mixing the alkali metal and the aggregate while the alkali metal is in a molten state in at least a part of the route to reach the aggregate.

By using the electrode material manufacturing method that is another aspect of the present disclosure, the amount of residual alkali metal after kneading, stirring, or mixing the alkali metal and aggregate can be reduced.

1 is an explanatory diagram showing a configuration of an electrode material manufacturing apparatus 1; FIG. 4 is an explanatory diagram showing a hand mixer 61 and a storage tank 9. FIG. 2 is a block diagram showing an electrical configuration of the electrode material manufacturing apparatus 1; FIG.

Exemplary embodiments of the present disclosure are described with reference to the drawings.
1. Configuration of Electrode Material Manufacturing Apparatus 1 The configuration of the electrode material manufacturing apparatus 1 will be described with reference to FIGS. 1 to 3. FIG. An electrode material manufacturing apparatus 1 manufactures an electrode material containing an active material doped with an alkali metal. Alkali metals, dopes, active materials, and electrode materials are described below.

As shown in FIG. 1, the electrode material manufacturing apparatus 1 includes a processing chamber 3, an injection unit 5, two heating gas injection units 6 and 7, a heater 8, a storage tank 9, and an alkali metal storage unit 11. , a heater 13 , a gas supply unit 15 and an exhaust unit 17 .

The processing chamber 3 is a hollow box-like member. The processing chamber 3 is made of an airtight material such as metal. The processing chamber 3 has an exhaust port 19 and a gas introduction port 21 .
The injection unit 5 is attached to the upper part of the processing chamber 3 . The injection unit 5 has a tubular basic form. The axial direction of the injection unit 5 is the vertical direction. The injection unit 5 comprises a first passageway 23 . The first passage 23 axially penetrates the injection unit 5 . An alkali metal supply port 25 is provided at the upper end of the first passage 23 . The lower end of the first passage 23 is used as an injection port 27 . The alkali metal supply port 25 is outside the processing chamber 3 . The injection port 27 is inside the processing chamber 3 .

The injection unit 5 further comprises a gas supply port 31 and a second passageway 29 . The gas supply port 31 opens on the side surface of the injection unit 5 and is outside the processing chamber 3 . The second passage 29 extends horizontally from the gas supply port 31 and merges with the first passage 23 .

The heating gas injection units 6 and 7 are attached to the upper part of the processing chamber 3, respectively. The heating gas injection units 6 and 7 are arranged so as to sandwich the injection unit 5 . The heating gas injection unit 6 has a tubular basic shape. The heated gas injection unit 6 comprises passages 33 . The passage 33 axially penetrates the heated gas injection unit 6 . The upper end of the passage 33 is used as a gas supply port 35 . A lower end of the passage 33 is used as a gas injection port 37 . A gas supply port 35 is located outside the processing chamber 3 . The gas injection port 37 is inside the processing chamber 3 . A direction D1 in which the gas injected from the gas injection port 37 travels intersects with a path 41, which will be described later. The heated gas injection unit 7 also has the same configuration as the heated gas injection unit 6 .

The heater 8 is attached to the outer peripheral surfaces of the heating gas injection units 6 and 7 . A heater 8 heats the heating gas injection units 6 and 7 .
The storage tank 9 is a tank with an upper opening. The containment vessel 9 can be arranged in the treatment chamber 3 . Also, the storage tank 9 can be taken out from the processing chamber 3 . The storage tank 9 can be arranged below the injection unit 5 . The storage tank 9 can store the assembly 39 . Aggregate 39 will be described later. A path from the injection port 27 to the assembly 39 housed in the storage tank 9 is hereinafter referred to as a path 41 .

The alkali metal storage unit 11 is outside the treatment chamber 3 and above the injection unit 5 . The alkali metal containing unit 11 is a hollow box-like member. The alkali metal containing unit 11 can contain the alkali metal 43 . The form of the alkali metal 43 is, for example, an ingot, powder, or the like. An outlet 45 is formed at the bottom of the alkali metal containing unit 11 . The outlet 45 communicates with the alkali metal supply port 25 through a pipe 46 . A gas supply port 12 is formed on the upper surface of the alkali metal storage unit 11 .

The heater 13 is attached to the outer peripheral surface of the alkali metal containing unit 11 . A heater 13 heats the alkali metal storage unit 11 .
The gas supply unit 15 includes a rare gas supply source 47, a first gas supply unit 49, a second gas supply unit 51, a third gas supply unit 53, a fourth gas supply unit 55, and a fifth gas supply unit. 56 and.

The rare gas supply source 47 supplies rare gas to each of the first gas supply unit 49, the second gas supply unit 51, the third gas supply unit 53, the fourth gas supply unit 55, and the fifth gas supply unit 56. . Examples of rare gases include argon and the like.

The first gas supply unit 49 supplies rare gas to the gas supply port 35 in the heating gas injection unit 6 . The second gas supply unit 51 supplies rare gas to the gas supply port 35 in the heating gas injection unit 7 . The third gas supply unit 53 supplies rare gas to the gas supply port 31 . The fourth gas supply unit 55 supplies rare gas to the gas inlet 21 . A fifth gas supply unit 56 supplies a rare gas to the gas supply port 12 .

The first gas supply unit 49, the second gas supply unit 51, the third gas supply unit 53, the fourth gas supply unit 55, and the fifth gas supply unit 56 each include a mass flow controller (hereinafter referred to as MFC) 57 and , and an open/close valve 59 . The MFC 57 is a flow regulator that regulates the flow rate of the noble gas.

The exhaust unit 17 decompresses the inside of the processing chamber 3 by exhausting air from the exhaust port 19 . Note that the heaters 8 and 13, the heating gas injection units 6 and 7, the first gas supply unit 49, and the second gas supply unit 51 correspond to the melting unit.

As shown in FIG. 2 , the electrode material manufacturing apparatus 1 has a hand mixer 61 . The hand mixer 61 has a grip portion 62 and a rotating portion 64 . The grip portion 62 is gripped by an operator. The rotating part 64 rotates. The contents 63 can be kneaded, stirred, or mixed by putting the rotating part 64 into the contents 63 of the storage tank 9 and rotating the rotating part 64 .

The content 63 is a mixture of the assembly 39 and alkali metal injected from the injection unit 5 as described later. The electrode material manufacturing apparatus 1 may be provided with a stirring blade, a stirrer, etc. instead of the hand mixer 61 . The hand mixer 61, stirring blades, stirrers, etc. correspond to the processing unit.

FIG. 3 shows an electrical configuration of the electrode material manufacturing apparatus 1. As shown in FIG. The electrode material manufacturing apparatus 1 includes a control section 65 , an operation section 67 and a controlled object 69 .
The control unit 65 includes a microcomputer having a CPU 71 and a semiconductor memory such as RAM or ROM (hereinafter referred to as memory 73).

Each function of the control unit 65 is implemented by the CPU 71 executing a program stored in a non-transitional substantive recording medium. In this example, the memory 73 corresponds to a non-transitional substantive recording medium storing programs. Also, by executing this program, a method corresponding to the program is executed. Examples of the program include a program for executing the electrode manufacturing method described later.

The control unit 65 controls the controlled object 69 to execute an electrode material manufacturing method, which will be described later. Examples of controlled objects 69 include the MFCs 57 and opening/closing valves in each of the first gas supply unit 49, the second gas supply unit 51, the third gas supply unit 53, the fourth gas supply unit 55, and the fifth gas supply unit 56. 59. Further, the controlled object 69 includes, for example, the heater 8, the heater 13, and the exhaust unit 17 in each of the heating gas injection units 6 and 7. FIG.

An operation unit 67 receives an operator's operation. The operator's operation includes, for example, command input for operating the electrode material manufacturing apparatus 1 . The operation unit 67 includes, for example, a keyboard, touch panel, display, and the like.

2. Alkali Metals, Dopes, Active Materials, Electrode Materials, and Aggregates Examples of alkali metals include lithium and sodium. The doping of alkali metals is a general term for making alkali metals occluded, intercalated, inserted, supported, or alloyed in various states such as metals, ions, and compounds.

The active material is not particularly limited as long as it is an electrode active material applicable to an electricity storage device utilizing insertion/extraction of alkali metal ions. The active material may be a negative electrode active material or a positive electrode active material.

The negative electrode active material is not particularly limited. Examples of negative electrode active materials include carbon materials. Examples of carbon materials include graphite, graphitizable carbon, non-graphitizable carbon, and composite carbon materials in which graphite particles are coated with pitch or resin carbide. A specific example of the carbon material is the carbon material described in JP-A-2013-258392.

Examples of the negative electrode active material include materials containing metals, semimetals, and oxides thereof (hereinafter referred to as metal-containing materials). Examples of the metal or semimetal contained in the material containing metal include Si and Sn that can be alloyed with lithium. Specific examples of the metal-containing material include materials described in JP-A-2005-123175 and JP-A-2006-107795.

Examples of positive electrode active materials include transition metal oxides, sulfur-based active materials, and alkali metal-transition metal composite oxides. Examples of transition metal oxides include manganese oxide and vanadium oxide. Examples of sulfur-based active materials include elemental sulfur and metal sulfides. Examples of alkali metal-transition metal composite oxides include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, sodium cobalt oxide, sodium nickel oxide, sodium manganese oxide and the like.

Both the positive electrode active material and the negative electrode active material may be composed of a single substance, or may be composed of a mixture of two or more kinds of substances. The electrode material manufacturing method of the present disclosure is suitable for doping the negative electrode active material with an alkali metal, and is particularly suitable for the case where the negative electrode active material is a metal-containing material.

Electrode material is the material used to manufacture the electrode. The electrode material is, for example, the material of the electrode material layer formed on the surface of the current collector. The electrode material includes an active material doped with an alkali metal. The electrode material may further contain other components in addition to the alkali metal-doped active material. The electrode material includes, for example, aggregates described later. The electrode material may consist only of the aggregate, or may further contain other components in addition to the aggregate.

The assembly contains at least an active material. The assembly may be a mixture further containing other components in addition to the active material. Other components include, for example, solvents, electrolytic solutions, conductive aids, and the like.

Solvents include, for example, solvents having alkali metal ion conductivity. As the solvent, an organic solvent is preferred, and an aprotic organic solvent is particularly preferred. Aprotic organic solvents include, for example, ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, tetrahydrofuran, dioxolane, methylene chloride, sulfolane, and the like. . The organic solvent may consist of a single component, or may be a mixed solvent of two or more components.

The electrolytic solution is a solution in which an alkali metal salt is dissolved in a solvent. Examples of the solvent contained in the electrolytic solution include the solvents described above. Alkali metal salts include, for example, lithium salts and sodium salts.

Phosphorus anions having a fluoro group such as PF ₆ ⁻ , PF ₃ (C ₂ F ₅ ) ₃ ⁻ , PF ₃ (CF ₃ ) ₃ ⁻ , etc.; BF ₄ ⁻ , BF Boron anions having a fluoro group or a cyano group such as ₂ (CF) ₂ ^- , BF ₃ (CF ₃ ) ^- , B(CN) ₄ ^- ; N(FSO ₂ ) ₂ ^- , N(CF ₃ SO ₂ ) ₂ ^- , sulfonylimide anions having a fluoro group such as N(C ₂ F ₅ SO ₂ ) ₂ ^— ; organic sulfonate anions having a fluoro group such as CF ₃ SO ₃ ^— . A single alkali metal salt may be dissolved in the solvent, or two or more alkali metal salts may be dissolved.

The electrolytic solution may further contain additives such as vinylene carbonate, vinylethylene carbonate, 1-fluoroethylene carbonate, 1-(trifluoromethyl)ethylene carbonate, succinic anhydride, maleic anhydride, propanesultone, diethylsulfone, etc. good.

The concentration of alkali metal ions in the electrolytic solution is preferably 0.1 mol/L or more, and more preferably within the range of 0.5 mol/L or more and 1.5 mol/L or less. When the concentration of alkali metal ions in the electrolytic solution is within this range, doping of the active material with the alkali metal proceeds efficiently.

Examples of conductive aids include carbon black, vapor-grown carbon fibers, metal powders other than alkali metals, and the like. The doping rate can be increased by including a conductive agent in the aggregate.

When the active material is a carbon material, the content of the active material in the aggregate is preferably 90% by mass or more with respect to all components excluding the solvent. When the active material is a metal-containing material, the content of the active material in the aggregate is preferably 50% by mass or more with respect to all components excluding the solvent. The content of the binder in the aggregate is usually 5% by mass or less, particularly preferably 1% by mass or less, relative to the active material, and most preferably the aggregate does not contain a binder.

The morphology of aggregates is amorphous. Amorphous means that the shape of the aggregate as a whole is variable. An amorphous aggregate containing an active material is not, for example, formed in the state of an electrode. Examples of forms of amorphous aggregates include powders, granular materials, slurries, and cakes. The aggregate, which is a powder or granular material, may consist of particles of an active material, or may further contain particles of other components in addition to particles of an active material. Particles of other components include, for example, particles of a conductive aid.

3. Electrode Material Manufacturing Method An electrode material manufacturing method can be implemented using the electrode material manufacturing apparatus 1 . As an electrode material manufacturing method, for example, there are the following first to third methods.

(3-1) First Method The aggregate 39 is stored in the storage tank 9 . Next, the storage tank 9 is installed in the processing chamber 3 . An alkali metal is contained in the alkali metal containing unit 11 . The alkali metal containing unit 11 is heated using the heater 13 to melt the alkali metal. By supplying rare gas to the gas supply port 12 by the fifth gas supply unit 56, the inside of the alkali metal storage unit 11 is pressurized. The molten alkali metal is sent from the alkali metal storage unit 11 to the injection unit 5 via the pipe 46 . A rare gas is supplied to the gas supply port 31 by the third gas supply unit 53 . As a result, the molten alkali metal is jetted from the jet port 27 . The injected alkali metal passes through path 41 and reaches assembly 39 . That is, the alkali metal is injected to the assembly 39 .

Simultaneously with injection of the alkali metal, the rare gas is supplied to the gas supply port 35 in the heating gas injection unit 6 by the first gas supply unit 49 . Also, the heater 8 heats the heating gas injection unit 6 . The rare gas is heated while passing through the passage 33 of the heating gas injection unit 6 and is injected from the gas injection port 37 in the direction D1.

Simultaneously with injection of the alkali metal, the second gas supply unit 51 supplies the rare gas to the gas supply port 35 of the heating gas injection unit 7 . Also, the heater 8 heats the heating gas injection unit 7 . The rare gas is heated while passing through the passage 33 of the heating gas injection unit 7 and is injected from the gas injection port 37 in the direction D1.

The rare gas injected from the heating gas injection units 6 and 7 heats the alkali metal on the path 41 .
In the first method, molten alkali metal is injected from injection port 27 . The alkali metal when reaching aggregate 39 may be in a molten state or in a solidified state.

As the temperature of the heater 13 and the heater 8 is increased, the state of the alkali metal when it reaches the assembly 39 is likely to be in a molten state.
The temperature of the rare gas injected from the heating gas injection units 6 and 7 is, for example, 150° C. or more and 300° C. or less on the path 41 . When the temperature of the rare gas is within this range, the alkali metal is likely to remain molten in path 41 . Next, the alkali metal and aggregates are kneaded, stirred, or mixed.

(3-2) Second Method The aggregate 39 is stored in the storage tank 9 . Next, the storage tank 9 is installed in the processing chamber 3 . Alkali metal powder is contained in the alkali metal containing unit 11 . By supplying rare gas to the gas supply port 12 by the fifth gas supply unit 56, the inside of the alkali metal storage unit 11 is pressurized. The alkali metal powder is sent from the alkali metal storage unit 11 to the injection unit 5 via the pipe 46 . A rare gas is supplied to the gas supply port 31 by the third gas supply unit 53 . As a result, alkali metal powder is injected from the injection port 27 . The injected alkali metal powder passes through the path 41 toward the assembly 39 .

Simultaneously with the ejection of the alkali metal powder, the rare gas is supplied to the gas supply port 35 in the heating gas ejection unit 6 by the first gas supply unit 49 . Also, the heater 8 heats the heating gas injection unit 6 . The rare gas is heated while passing through the passage 33 of the heating gas injection unit 6 and is injected from the gas injection port 37 in the direction D1.

Simultaneously with injection of the alkali metal, the second gas supply unit 51 supplies the rare gas to the gas supply port 35 of the heating gas injection unit 7 . Also, the heater 8 heats the heating gas injection unit 7 . The rare gas is heated while passing through the passage 33 of the heating gas injection unit 7 and is injected from the gas injection port 37 in the direction D1.

The rare gas injected from the heating gas injection units 6 and 7 heats the alkali metal powder on the path 41 . As a result, along the path 41, the alkali metal powder changes to a molten state.

The alkali metal when reaching aggregate 39 may be in a molten state or in a solidified state. As the temperature of the heater 8 is increased, the state of the alkali metal when it reaches the assembly 39 is likely to be in a molten state.

The temperature of the rare gas injected from the heating gas injection units 6 and 7 is, for example, 150° C. or more and 300° C. or less on the path 41 . When the temperature of the noble gas is within this range, the alkali metal powder in path 41 is likely to change into a molten state. Next, the alkali metal and aggregate are kneaded, stirred, or mixed.

(3-3) Third Method The third method is basically the same as the first method. However, in the third method, the heating gas injection units 6 and 7 do not inject the rare gas. In the third method, molten alkali metal is injected from injection port 27 . The alkali metal when reaching aggregate 39 may be in a molten state or in a solidified state.

The higher the temperature of the heater 13 and the heater 8, the more likely the state of the alkali group when it reaches the assembly 39 becomes the molten state.
4. Effects of the Electrode Material Manufacturing Apparatus 1 and the Electrode Material Manufacturing Method According to the electrode material manufacturing apparatus 1 and the electrode material manufacturing method, the amount of residual alkali metal after kneading, stirring, or mixing the aggregate and the alkali metal is reduced. can.

5. Examples (5-1) Production of Electrode Materials Electrode materials of Examples 1 to 4 and Comparative Example 1 were produced by the following method. In Examples 1 to 4, the electrode material manufacturing apparatus 1 was used.

(Example 1)
The aggregate 39 was stored in the storage tank 9 . The assembly 39 was obtained by adding 360 mg of an electrolytic solution to 360 mg of graphite powder vacuum-dried for 6 hours and stirring well. Graphite powder corresponds to the negative electrode active material. The 50% volume cumulative diameter D50 of the graphite powder was 20 μm. Then, the storage tank 9 was installed in the processing chamber 3 .

A lithium metal ingot was stored in the alkali metal storage unit 11 . The ingot diameter was 15 mm and the ingot mass was 10.8 g. The alkali metal containing unit 11 was heated using the heater 13 so that the temperature inside the alkali metal containing unit 11 was 200.degree. At this time, the lithium metal ingot melted.

By supplying rare gas to the gas supply port 12 from the fifth gas supply unit 56, the inside of the alkali metal storage unit 11 was pressurized at a pressure of 0.1 MPa. Lithium metal in a molten state was sent from the alkali metal storage unit 11 to the injection unit 5 via the pipe 46 . In addition, rare gas was supplied to the gas supply port 31 by the third gas supply unit 53 . As a result, lithium metal in a molten state was injected from the injection port 27 . The injected lithium metal passed through path 41 and reached assembly 39 .

Simultaneously with the injection of lithium metal, rare gas was supplied to the gas supply port 35 in the heating gas injection unit 6 by the first gas supply unit 49 . The pressure of the supplied rare gas was 0.3 MPa. In addition, the heater 8 heated the heating gas injection unit 6 . The rare gas was heated while passing through the passage 33 of the heating gas injection unit 6 and was injected from the gas injection port 37 in the direction D1.

Simultaneously with the injection of lithium metal, the rare gas was supplied to the gas supply port 35 of the heating gas injection unit 7 by the second gas supply unit 51 . The pressure of the supplied rare gas was 0.3 MPa. In addition, the heater 8 heated the heating gas injection unit 7 . The rare gas was heated while passing through the passage 33 of the heating gas injection unit 7 and was injected from the gas injection port 37 in the direction D1.

The rare gas injected from the heating gas injection units 6 and 7 heated lithium metal on the path 41 . The temperature of the rare gas injected from the heating gas injection units 6 and 7 was 200°C. The lithium metal injected from the injection unit 5 was in a molten state at least immediately after being injected from the injection unit 5 , became a mist, and was thermally sprayed onto the assembly 39 in the storage tank 9 .

Next, using a hand mixer 61, a step of kneading and mixing the assembly 39 and the lithium metal for 10 minutes at a rotation speed of 30 rpm was repeated six times to obtain a slurry. The slurry corresponds to the electrode material.

(Example 2)
A slurry was obtained basically in the same manner as in Example 1. However, in Example 2, no rare gas was injected from the heating gas injection units 6 and 7 . The lithium metal injected from the injection unit 5 is in a molten state at least immediately after being injected from the injection unit 5, becomes a wire with a diameter of 0.3 mm, and is thermally sprayed onto the assembly 39 in the storage tank 9. rice field.

(Example 3)
A slurry was obtained basically in the same manner as in Example 1. However, in Example 3, the pressure of the rare gas supplied to the gas supply port 35 in the heating gas injection units 6 and 7 was set to 0.15 MPa. The lithium metal injected from the injection unit 5 is in a molten state at least immediately after being injected from the injection unit 5, becomes granular with a particle size of 0.3 μm, and is thermally sprayed onto the assembly 39 in the storage tank 9. rice field.

(Example 4)
A slurry was obtained basically in the same manner as in Example 1. However, in Example 4, the alkali metal containing unit 11 contained lithium metal powder instead of the lithium metal ingot. The mass of lithium metal powder was 10.8 g. Moreover, in Example 4, the alkali metal storage unit 11 was not heated.

In Example 4, the lithium metal powder was sent from the alkali metal storage unit 11 to the injection unit 5 through the pipe 46 and then injected from the injection port 27 .
The rare gas injected from the heating gas injection units 6 and 7 heated the lithium metal powder on the path 41 . The temperature of the rare gas injected from the heating gas injection units 6 and 7 was 200°C. The lithium metal powder injected from the injection unit 5 is in a molten state at least in a part of the path 41, and further becomes granular with a particle size of 0.3 μm, and is thermally sprayed onto the assembly 39 in the storage tank 9. rice field.

(Comparative example 1)
A mixture was produced by mixing 360 mg of graphite powder vacuum-dried for 6 hours, 360 mg of electrolyte, and 10.8 mg of lithium metal flakes. Graphite powder corresponds to the negative electrode active material. The 50% volume cumulative diameter D50 of the graphite powder was 20 μm. The lithium metal piece is obtained by cutting a lithium metal plate having a thickness of 100 μm and a weight of 10.8 mg into four equal parts. The lithium metal pieces were arranged as evenly as possible in the mixture.

The mixture was put into a sample tube and kneaded and mixed using a hand mixer at a rotation speed of 30 rpm for 10 minutes. Further, the mixture was kneaded and mixed six times with a hand mixer to obtain a slurry.

Table 1 shows the manufacturing conditions of the electrode material in each example and each comparative example.

表１の「リチウム供給（溶射）」の列における「使用」とは、スラリーを製造するとき、電極材料製造装置１を使用してリチウム金属を噴射したことを意味する。表１の「リチウム供給（溶射）」の列における「未使用」とは、スラリーを製造するとき、電極材料製造装置１を使用しなかったことを意味する。

"Use" in the column "Lithium supply (thermal spraying)" in Table 1 means that lithium metal was sprayed using the electrode material manufacturing apparatus 1 when the slurry was manufactured. "Unused" in the "lithium supply (thermal spraying)" column in Table 1 means that the electrode material manufacturing apparatus 1 was not used when the slurry was manufactured.

"Molten" in the "lithium form" column of Table 1 means that the lithium metal was in a molten state immediately after being injected from the injection unit 5. "Powder" in the "lithium form" column of Table 1 means that the lithium metal was powder immediately after being injected from the injection unit 5 . The numerical values in the column of "heating gas blowing" in Table 1 mean the pressure of the rare gas supplied to the gas supply ports 35 of the heating gas injection units 6,7.

(5-2) Evaluation Method of Electrode Material The electrode materials of each example and each comparative example were evaluated as follows.
<OCV measurement>
A working electrode was prepared using the electrode material. Also, a counter electrode and a reference electrode made of lithium metal were prepared. A tripolar cell was assembled using a working electrode, a counter electrode, and a reference electrode. An electrolytic solution was injected into this three-electrode cell. The composition of the injected electrolytic solution was the same as the composition of the electrolytic solution used for producing the electrode material. Immediately after injection of the electrolyte, the potential of the working electrode relative to lithium metal was measured. The potential of the working electrode relative to lithium metal corresponds to OCV.
<Method for confirming the amount of residual Li>
A slurry was prepared by adding the same mass of dimethyl carbonate to the electrode material. The slurry was then suction filtered. Furthermore, the step of adding the same mass of dimethyl carbonate to the slurry after suction filtration and then performing suction filtration was repeated three times.

The obtained slurry was observed with an optical microscope at a magnification of 500 times. As a result of observation, it was confirmed that fine lithium pieces remained in the slurry. The tiny pieces of lithium correspond to the residual alkali metal.
Next, dimethyl carbonate was added to the resulting slurry. Next, using a magnetic stirrer, the slurry was stirred for 10 minutes at a rotational speed of 30 rpm. The slurry was then allowed to settle for 10 minutes. Next, a surface layer portion of the slurry was sampled using a poly dropper. The surface layer portion was a portion selectively containing lithium metal flakes floating on the surface of the slurry. The mass W2 of the lithium metal pieces contained in the sampled surface layer portion was measured. The ratio of W2 to the mass W1 of the lithium metal piece put into the production of the electrode material (hereinafter referred to as residual Li amount (%)) was calculated.
<Powder resistance measurement>
The powder resistance of the electrode material was measured using a powder resistance measurement system MCP-PD51 (Mitsubishi Kagaku Analytic Tech). A pressure of 0.02 MPa was applied to the electrode material when measuring the powder resistance. The thickness of the electrode material was 2 mm when a pressure of 0.02 MPa was applied.
<Volume resistance measurement of negative electrode>
A copper foil having a plurality of holes with a diameter of 10 μm and an aperture ratio of 40% was prepared. An electrode material was evenly placed on the surface of the copper foil in a circle with a diameter of 15 mm, and filtered under vacuum to prepare a negative electrode.

The volume resistance of the electrode material included in the negative electrode was measured using a powder resistance measurement system MCP-PD51 (Mitsubishi Kagaku Analytic Tech). A pressure of 0.02 MPa was applied to the electrode material when measuring the volume resistance. The thickness of the electrode material was 200 μm when a pressure of 0.02 MPa was applied.
(5-3) Evaluation Results of Electrode Materials Table 1 shows the evaluation results of the electrode materials of each example and each comparative example.

The residual Li amounts in Examples 1 to 4 were significantly smaller than the residual Li amount in Comparative Example 1.
6. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made.

(1) A function of one component in each of the above embodiments may be assigned to a plurality of components, or a function of a plurality of components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Also, at least part of the configuration of each of the above embodiments may be added, replaced, etc. with respect to the configuration of the other above embodiments.

(2) In addition to the electrode material manufacturing apparatus 1 described above, a non-transitional system such as a system having the electrode material manufacturing apparatus 1 as a component, a program for causing a computer to function as the control unit 65, a semiconductor memory storing this program, etc. The present disclosure can also be implemented in various forms such as a physical recording medium, an electricity storage device, and a method for manufacturing an electricity storage device.

DESCRIPTION OF SYMBOLS 1... Electrode material manufacturing apparatus 3... Processing chamber 5... Injection unit 6, 7... Heating gas injection unit 8... Heater 9... Storage tank 11... Alkali metal storage unit 12... Gas supply port 13... Heater 15 Gas supply unit 17 Exhaust unit 19 Exhaust port 21 Gas introduction port 23 First passage 25 Alkali metal supply port 27 Injection port 29 Second passage 31 Gas supply port 33 Passage 35 Gas supply port 37 Gas injection port 39 Aggregate 41 Path 43 Alkali metal 45 Outlet 46 Piping 47 Rare gas supply source 49 1st gas supply unit 51 2nd gas supply unit 53 3rd gas supply unit 55 4th gas supply unit 56 5th gas supply unit 57 MFC 59 Open/close valve 61 Hand mixer 62 Grasping part 63 Contents 64 Rotating part 65 Control part 67 Operation part 69 Control object 71 CPU 73 Memory

Claims (6)

An electrode material manufacturing apparatus for manufacturing an electrode material containing an active material doped with an alkali metal,
an injection unit configured to inject the alkali metal into an aggregate containing at least an active material;
a melting unit configured to bring the alkali metal into a molten state in at least a portion of the path from the injection unit to the assembly;
a processing unit configured to knead, stir, or mix the alkali metal and the aggregate;
Electrode material manufacturing apparatus. The electrode material manufacturing apparatus according to claim 1,
The melting unit is configured to melt the alkali metal in at least a part of the path by supplying a gas having a temperature of 150° C. or more and 300° C. or less to the path. . The electrode material manufacturing apparatus according to claim 1 or 2,
The electrode material manufacturing apparatus, wherein the injection unit is configured to inject the alkali metal in a molten state. The electrode material manufacturing apparatus according to claim 3,
further comprising an alkali metal containing unit configured to contain the alkali metal;
the melting unit is configured to melt the alkali metal contained in the alkali metal containing unit;
The electrode material manufacturing apparatus, wherein the injection unit is accommodated in the alkali metal accommodation unit and configured to inject the alkali metal in a molten state. The electrode material manufacturing apparatus according to any one of claims 1 to 4,
The electrode material manufacturing apparatus, wherein the melting unit melts the alkali metal when it reaches the assembly. An electrode material manufacturing method for manufacturing an electrode material containing an active material doped with an alkali metal,
injecting the alkali metal into an assembly containing at least an active material;
The alkali metal is in a molten state in at least a part of the route from being sprayed to reaching the aggregate,
A method for producing an electrode material, in which the alkali metal and the aggregate are kneaded, stirred, or mixed.

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