KR101592189B1 - Apparatus for Manufacturing Inorganic Compound and Method for Manufacturing Inorganic Compound by Using the Same - Google Patents

Abstract

The present invention relates to an apparatus for continuously producing an inorganic slurry by a hydrothermal method, comprising: a precursor liquid stream inlet including a precursor for producing water and an inorganic material; A reaction part in which the water contained in the flowed precursor liquid stream is converted into a supercritical state or a subcritical state under high temperature and high pressure conditions and the precursor for producing an inorganic material undergoes a hydrothermal reaction; And a discharge part for continuously discharging the inorganic slurry as a result of the hydrothermal reaction, wherein the clogging of the inlet part is suppressed, and a method for producing an inorganic compound using the same do.

Description

TECHNICAL FIELD The present invention relates to an apparatus for producing an inorganic compound and an inorganic compound using the inorganic compound,

The present invention relates to an apparatus for continuously producing an inorganic slurry by a hydrothermal method, comprising: a precursor liquid stream inlet including a precursor for producing water and an inorganic material; A reaction part in which the water contained in the introduced precursor liquid stream is converted into a supercritical state or a subcritical state under high temperature and high pressure conditions to cause hydrothermal reaction of the precursor for producing an inorganic material; And a discharge part for continuously discharging the inorganic slurry as a result of the hydrothermal reaction, wherein the clogging of the inlet part is suppressed, and a method for producing an inorganic compound using the same will be.

Inorganic compounds have been used as raw materials or end products in various fields, and have also been used as materials for electrode active materials in secondary batteries in which the amount of use is rapidly increasing recently.

A lithium secondary battery, which is a typical example of a secondary battery, generally uses a lithium transition metal oxide as a positive electrode active material, a carbonaceous material as a negative electrode active material, and a lithium hexafluorophosphate (LiPF ₆ ) solution using a carbonate solvent as an electrolyte. Lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ) and lithium manganese oxide having a spinel structure (LiMn ₂ O ₄ ) having a layered structure and the like are known as the positive electrode active material. However, Lithium oxide is the most.

However, since supply and demand of the main component cobalt is unstable and the cost of cobalt is high, a material in which cobalt is partially substituted with other transition metals such as Ni and Mn, or lithium manganese oxide having a spinel structure hardly containing cobalt, . A material which is structurally more stable even under a high voltage or a material which improves the stability by doping or coating another metal oxide with an existing cathode active material is also being developed.

The most widely known methods for producing a conventional cathode active material include a dry calcination method and a wet precipitation method. In the dry firing method, a transition metal oxide or hydroxide such as cobalt (Co), lithium carbonate or lithium hydroxide as a source of lithium are mixed in a dry state, and the mixture is calcined at a high temperature of 700 ° C to 1000 ° C for 5 hours to 48 hours, .

The dry sintering method has advantages in that it is easy to approach because it is a technique that has been widely used for producing metal oxides, but it is difficult to homogeneously mix the raw materials and thus it is difficult to obtain a single phase product, In the case of a multicomponent cathode active material made of a metal, it is difficult to homogeneously arrange two or more kinds of elements to an atomic level level. Further, even when a doping or substitution method is used for a specific metal component for improving the electrochemical performance, it is difficult for the specific metal component added in a small amount to be uniformly mixed. In addition, in the crushing and classifying process for obtaining particles of a desired size, There is also a problem that it occurs essentially.

Another conventional method for preparing the cathode active material is a wet precipitation method. In the wet precipitation method, a transition metal-containing salt such as cobalt (Co) is dissolved in water, and alkali is added to precipitate it as a transition metal hydroxide. Then, the precipitate is filtered and dried, and lithium carbonate or lithium hydroxide , Followed by calcination at a high temperature of 700 ° C to 1000 ° C for 1 hour to 48 hours to produce a cathode active material.

Although the wet precipitation method is known to be capable of easily obtaining a homogeneous mixture by coprecipitation of two or more transition metal elements, there is a problem that a long time is required for the precipitation reaction, and the process is complicated and waste acid is produced as a by-product. In addition, various methods such as a sol-gel method, a hydrothermal method, a spray pyrolysis method, and an ion exchange method have been proposed as a method for producing a cathode active material for a lithium secondary battery.

On the other hand, a method of producing an inorganic compound for a cathode active material by utilizing hydrothermal synthesis using high-temperature and high-pressure water is used in addition to the above methods.

1, in the conventional hydrothermal synthesis apparatus, a liquid stream containing supercritical water, which has been converted through a heater, flows symmetrically from both sides of the reaction section 20, In one side direction, a precursor liquid stream containing a lithium precursor and a metal precursor is introduced, a hydrothermal reaction occurs in the reactor 20, and the inorganic slurry stream is discharged toward the other side of the reactor 20, Compounds are prepared.

However, it has been found by the inventors that when the precursor liquid or slurry stream is introduced into the reactor, the flow of the fluid is greatly resisted and the precursor liquid stream mixed in the pre-mixer M is introduced into the reactor 20 There is a problem that clogging phenomenon occurs in an inflow part.

That is, in the reactor 20, the precursor liquid stream is synthesized through a rapid heat exchange with the supercritical liquid stream, and this synthesis reaction begins to clog from the edge while occurring near the inlet.

As a result, the continuous operation time of the hydrothermal synthesis apparatus is only about one week, and there is a problem that labor and time are required for decomposing a clogged reactor and performing internal cleaning.

Therefore, there is a high need for a supercritical hydrothermal synthesis apparatus capable of greatly increasing process productivity and reducing investment cost by minimizing the clogging of the inlet port and increasing the continuous operation time.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments and have found that the water contained in the precursor liquid stream introduced into the reaction section of the hydrothermal synthesis apparatus undergoes supercritical or subcritical conditions under high temperature and high pressure conditions And that the clogging of the inlet portion can be suppressed when the precursor for converting inorganic materials causes the reaction, thereby completing the present invention.

Accordingly, the present invention provides an apparatus for continuously producing an inorganic slurry by a hydrothermal method, comprising: a precursor liquid stream inlet including a precursor for water and an inorganic material; A reaction part in which the water contained in the flowed precursor liquid stream is converted into a supercritical state or a subcritical state under high temperature and high pressure conditions and the precursor for producing an inorganic material undergoes a hydrothermal reaction; And a discharge unit for continuously discharging an inorganic slurry as a result of reaction after the hydrothermal reaction, wherein the clogging of the inlet portion is suppressed.

In the reaction part of the apparatus according to the present invention, water contained in the precursor liquid stream is converted into a supercritical or subcritical state under a predetermined high-temperature and high-pressure condition to cause a reaction of the precursor for producing an inorganic material. Problems can be solved fundamentally.

In the present invention, the high-temperature and high-pressure conditions can be arbitrarily set as long as they can produce sub-threshold coefficients similar to supercritical or supercritical temperature and pressure conditions.

However, it is possible to set the temperature of 100 to 800 DEG C and the pressure condition of 5 to 700 bar in consideration of the facility problem, the control problem of the reaction, and the like, specifically, the temperature of 200 to 700 DEG C and the pressure of 180 to 550 bar Can be set.

Similar results can be obtained by using the sub-coefficients even if the sub-coefficients are used.

The high-temperature conditions inside the apparatus can be formed by a heater, and the high-pressure condition can be formed by various kinds of pressure generators. Specifically, the heater may be included in the reaction part to form a high-temperature condition inside the reaction part.

In particular, the pressure generator is not limited in its type as long as it can form a high pressure in the hydrothermal synthesis apparatus, and may be located at various places outside or inside the apparatus, depending on the structure of the hydrothermal synthesis apparatus.

In one example, the pressure generator may be a pump and a back pressure regulator (BPR). Such a pump and a back pressure regulator (BPR) can be formed at the inlet and the outlet of the hydrothermal synthesis device, respectively, as shown in the following Example 2, thereby forming a high-pressure condition inside the device.

The reaction unit may further include a cooler. In particular, a cooler may be additionally provided between the precursor liquid stream and the reaction part and / or between the reaction part and the discharge part to prevent the heat from being transferred to the heater.

The position of the cooler may be arbitrarily set so as to prevent the heat from being transmitted to the heater, but specifically, it may be located at both ends of the heater based on the direction of the flow of the precursor liquid stream.

The inorganic material in the inorganic slurry is not particularly limited as long as it can be produced by the hydrothermal method. For example, Co ₂ O ₃ , Fe ₂ O ₃ , LiMn ₂ O ₄ , MO _x (M = Fe , Ni, Co, Mn and Al, x is a number satisfying electrical neutrality), MOOH (M is at least one selected from the group consisting of Fe, Ni, Co, Mn and Al) , a _a m _m x _x o _o s _s n _n f _f (a is Li, Na, K, Rb, Cs, be, Mg, Ca, at least one selected from the group consisting of Sr and Ba, and; m is a transition And may include at least one selected from the group consisting of B, Al, Ga and In, and X may be selected from the group consisting of P, As, Si, Ge, Se, Te and C O is oxygen, S is sulfur, N is nitrogen, F is fluorine, a, m, x, o, s, n and f are 0 or more and satisfy electrical neutrality .

The precursors differ depending on the kind of the inorganic materials, and the usable precursors may be different even if the same inorganic material is produced. The selection of suitable precursors as required will be apparent to those skilled in the art. As a non-limiting example, cobalt nitrate (Co (NO ₃ ) ₃ ) or cobalt sulfate (Co ₂ (SO ₄ ) ₃ ) can be used as a precursor when preparing Co ₂ O ₃ .

The inorganic material is, specifically, Li _a M _b M _'c PO ₄ (M = Fe, Ni, and one or more selected from the group consisting of Co and Mn; M' in = Ca, Ti, S, C, and Mg A, b, and c are 0 or more and satisfy electrical neutrality), and in particular may be LiFePO ₄ .

LiFePO ₄ requires a precursor such as an iron precursor, a phosphorus precursor, and a lithium precursor, and these precursors can be appropriately selected and used as needed. For example, iron sulfide, phosphoric acid, lithium hydroxide and the like can be used as a precursor of LiFePO ₄ . More specifically, an aqueous solution prepared by mixing iron sulfate and phosphoric acid, and an aqueous solution obtained by mixing ammonia water and lithium hydroxide are preliminarily mixed and then introduced into the reaction part as a precursor liquid phase or slurry stream and reacted using high temperature and high pressure water to produce LiFePO ₄ Can be produced.

According to the inventors' findings, the material causing the clogging of the inlet portion in the conventional device may be? -Fe ₂ O ₃ . The mechanism by which? -Fe ₂ O ₃ is produced is shown in the following reaction formula 1.

Fe (OH) ₂ + 1 / 4O ₂ -> 1/2? -Fe ₂ O ₃ + H ₂ O (Scheme 1)

The Fe (OH) ₂ is known to be formed when the pH of the precursor is intermediate in the precipitation reaction. Fe (OH) ₂ is strongly adhered in the pipe, and heat is transferred from the front end of the hydrothermal synthesis reaction unit, and γ-Fe ₂ O ₃ can be produced by the reaction formula 1.

In the conventional apparatus, as described above, due to the occurrence of the clogging phenomenon, the relative amount of the supercritical liquid stream in the inorganic slurry stream is required in order to suppress it, so that the inorganic matter content is only about 1 wt%.

On the other hand, in the present invention, since such a problem can be solved, the content of the inorganic material in the inorganic slurry may be 1 to 5 wt%.

The above conditions are conditions for optimizing hydrothermal synthesis in the apparatus of the present invention, and may be changed according to various process conditions such as precursor, inorganic matter, production rate and the like.

In the present invention, the inlet direction of the precursor liquid stream and the discharge direction of the inorganic slurry stream may be located on a straight line.

Optionally, it may further comprise a pre-mixer for producing a precursor providing a precursor liquid stream. In such a pre-mixer for producing precursors, various kinds of precursors can be uniformly mixed.

The present invention also provides an inorganic slurry characterized by being manufactured using the hydrothermal synthesis apparatus.

The inorganic slurry can be used for various purposes depending on its kind. As one example, the inorganic slurry can be used as a cathode active material for a secondary battery. That is, the inorganic material obtained by drying the inorganic slurry can be used as a material for a cathode active material for a secondary battery.

A secondary battery using such an inorganic material as a cathode active material is composed of a cathode, a cathode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The anode may be prepared, for example, by applying a slurry prepared by mixing a cathode in a powder state with a solvent such as NMP, coating the cathode collector, followed by drying and rolling.

The positive electrode in the powder state is an inorganic material produced by using the apparatus as a positive electrode active material, and in addition, a conductive material, a binder, a filler, and the like may be optionally included.

The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component which assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the electrode, and is not particularly limited as long as it is a fibrous material without causing any chemical change in the battery. Examples of the filler include olefin-based polymerizers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The cathode current collector is generally made to have a thickness of 3 to 500 mu m. Such a positive electrode collector is not particularly limited as long as it has conductivity without causing chemical change to the battery, and may be formed on the surface of stainless steel, aluminum, nickel, titanium, sintered carbon or aluminum or stainless steel Carbon, nickel, titanium, silver, or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The negative electrode can be prepared, for example, by applying a slurry prepared by mixing a negative electrode in a powder state with a solvent such as NMP or water, and then drying and rolling the negative electrode current collector.

The cathode in the powder state may be a material commonly known in the art as a negative electrode active material, and may include components such as a conductive material, a binder, and a filler as described above, if necessary.

The negative electrode collector is generally made to have a thickness of 3 to 500 mu m. The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery. Examples of the negative electrode current collector include copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver or the like, aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

The separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

In the case of the liquid electrolyte, the lithium salt-containing non-aqueous electrolyte is composed of a non-aqueous organic solvent and a lithium salt, and other organic solid electrolytes, inorganic solid electrolytes, etc. may be used.

Examples of the non-aqueous organic solvent include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, A polymer containing an ionic dissociation group and the like may be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

For the purpose of improving the charge / discharge characteristics and the flame retardancy, the electrolytic solution is preferably mixed with an organic solvent such as pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, Benzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, . In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

Such a secondary battery includes a plurality of battery cells used as a power source for a middle- or large-sized device requiring high temperature stability, long cycle characteristics, and high rate characteristics, It can also be used as a unit battery in a middle- or large-sized battery module.

Examples of the medium and large-sized devices include a power tool which is powered by an electric motor and moves; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and the like; An electric motorcycle including an electric bike (E-bike) and an electric scooter (E-scooter); An electric golf cart, and the like, but the present invention is not limited thereto.

The present invention also provides a method for producing an inorganic slurry by hydrothermal synthesis, comprising the steps of flowing a precursor liquid stream containing water and a precursor for producing an inorganic material into a hydrothermal synthesis reaction unit;

Converting the water contained in the introduced precursor liquid stream into a supercritical state or a subcritical state under high temperature and high pressure conditions; And

And a step of continuously producing an inorganic slurry by a hydrothermal reaction in the hydrothermal synthesis reaction unit and suppressing clogging of the hydrothermal synthesis inlet portion.

Since the above-described production method can be carried out by the hydrothermal synthesis apparatus and the reaction conditions as described above, a detailed process is omitted.

This hydrothermal synthesis method can be applied not only to the inorganic materials known to be produced by the hydrothermal synthesis method but also to the inorganic materials which are difficult to efficiently produce by the conventional hydrothermal synthesis method due to the advantages described above.

As described above, in the case of using the hydrothermal synthesis apparatus of the present invention, the clogging of the inlet portion of the liquid stream can be minimized and the continuous operation time can be increased. Moreover, the reaction portion includes the cooler, It is possible to greatly increase the process productivity and reduce the investment cost.

1 is a schematic diagram of a hydrothermal synthesis apparatus according to the prior art;
2 is a schematic diagram of a hydrothermal synthesis apparatus according to one embodiment of the present invention.
3 is a schematic diagram of a hydrothermal synthesis apparatus according to another embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited by the scope of the present invention.

2 shows a schematic diagram of a method for producing inorganic particles using the hydrothermal synthesis apparatus according to one embodiment of the present invention.

Referring to FIG. 2, a lithium solution and a metal solution are mixed in a pre-mixer M ', and then introduced into a reaction part 200 through an inlet part 100. Such a mixture may be subjected to a hydrothermal synthesis reaction using a supernatant coefficient formed under high temperature and high pressure conditions inside the reaction part 200, and the product may be obtained through the discharge part 300.

Specifically, a lithium solution containing LiOH and water as a Li precursor and a FeSO₄, H₃PO₄ And a metal solution containing water are mixed in a pre-mixer (M ') to form a precursor liquid phase stream.

The precursor liquid phase stream containing such precursors for the production of water and minerals flows into the reaction section 200 through the inlet section 100. The inside of the hydrothermal synthesis unit forms a high pressure condition by a pump and a back pressure regulator (BPR), and a heater included in the reaction unit 200 can form a high temperature condition, Inside, the water contained in the precursor liquid stream is converted into a supercritical or subcritical state.

The high-temperature and high-pressure conditions can be arbitrarily set as long as they are capable of producing sub-threshold or supercritical temperature and pressure conditions. For example, a temperature of 100 to 800 ° C and a pressure of 5 to 700 bar Specifically, a temperature of 200 to 700 ° C and a pressure of 180 to 550 bar can be set.

Such supercritical or sublimation factors and precursors for the production of minerals may undergo hydrothermal reaction to produce an inorganic slurry, which is continuously discharged through outlet 300.

That is, the apparatus according to the present invention is characterized in that a precursor liquid stream containing water and a precursor for producing an inorganic material is introduced into the reaction part 200, and then the water is converted into a supercritical or subcritical state in the reaction part 200, The clogging of the inlet portion 100 is not observed as in the prior art because the precursor reacts hydrothermally.

The apparatus according to the present invention includes a cooler between the precursor liquid stream and the reaction part and between the reaction part and the discharge part to prevent heat from being diffused to the surroundings by a heater included in the reaction part 200 May be further included.

3 shows a schematic diagram of a method for producing inorganic particles using a hydrothermal synthesis apparatus according to another embodiment of the present invention.

Referring to FIG. 3, a lithium solution and a metal solution are introduced into a hydrothermal synthesis apparatus under a high pressure condition, mixed in a pre-mixer M ' As shown in FIG. Thereafter, in the reaction part 200, a hydrothermal synthesis reaction takes place under a high temperature condition formed by a heater, and the product can be obtained through the discharge part 300.

Compared with FIG. 2, the hydrothermal synthesis apparatus of FIG. 3 does not show the location of a pump and a back pressure regulator (BPR) to form a high pressure condition. That is, in FIG. 3, the pump and the BPR (back pressure regulator) are located outside the hydrothermal synthesis unit, and a high pressure condition can be formed inside the hydrothermal synthesis unit.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (16)

An apparatus for continuously producing an inorganic slurry by hydrothermal method,
A precursor liquid stream inlet comprising a precursor for the production of water and an inorganic material;
A reaction part in which the water contained in the flowed precursor liquid stream is converted into a supercritical state or a subcritical state under high temperature and high pressure conditions and the precursor for producing an inorganic material undergoes a hydrothermal reaction; And
A discharge unit for continuously discharging the resultant inorganic slurry after the hydrothermal reaction;
Wherein the clogging phenomenon of the inlet portion is suppressed by the structure including the inlet portion and the outlet portion. The hydrothermal synthesis apparatus according to claim 1, wherein the high-temperature and high-pressure conditions are a temperature of 100 to 800 ° C and a pressure of 5 to 700 bar. The hydrothermal synthesis apparatus according to claim 1, wherein the high-temperature and high-pressure conditions are a temperature of 200 to 700 ° C and a pressure of 180 to 550 bar. The hydrothermal synthesis apparatus according to claim 1, wherein a heater for forming the high-temperature condition is included in the reaction part. The hydrothermal synthesis apparatus according to claim 1, further comprising a pump and a back pressure regulator (BPR) for forming the high-pressure condition. The hydrothermal synthesis apparatus of claim 1, further comprising a cooler between the precursor liquid stream and the reacting section and / or between the reacting section and the outlet section. 7. The hydrothermal synthesis apparatus according to claim 6, wherein the coolers are located at both ends of the heater based on a direction of the flow of the precursor liquid stream. The method according to claim 1, wherein the inorganic material in the inorganic slurry is at least one selected from the group consisting of Co ₂ O ₃ , Fe ₂ O ₃ , LiMn ₂ O ₄ , MO _x (M = Fe, Ni, Co, , x is a number satisfying electric neutral), MOOH (m = Fe, Ni, Co, one or more selected from the group consisting of Mn and Al), a _a m _m x _x o _o S _s N _n F _f (a M is at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; M is at least one element selected from the group consisting of B, Al, X is at least one member selected from the group consisting of P, As, Si, Ge, Se, Te and C, O is oxygen, S is sulfur, N is nitrogen, F is fluorine, and a, m, x, o, s, n, and f are 0 or more and satisfy electrical neutrality). 9. The method according to claim 8, wherein the inorganic material is at least one selected from the group consisting of Li _a M _b M ' _c PO ₄ (M = Fe, Ni, Co, Mn; M' = Ca, Ti, S, A, b, and c are 0 or more and satisfy electrical neutrality). 10. The method of claim 9, wherein the inorganic material is a hydrothermal synthesis wherein a LiFePO _4. The hydrothermal synthesis apparatus of claim 1, wherein the inlet direction of the precursor liquid stream and the outlet direction of the inorganic slurry stream are in a straight line. The hydrothermal synthesis apparatus of claim 1, further comprising a pre-mixer for producing a precursor liquid stream. delete delete delete As a method for continuously producing an inorganic slurry by the hydrothermal method,
Introducing a precursor liquid stream containing water and a precursor for producing an inorganic material into a hydrothermal synthesis reaction unit;
Converting the water contained in the introduced precursor liquid stream into a supercritical state or a subcritical state under high temperature and high pressure conditions; And
A step of continuously producing an inorganic slurry by a hydrothermal reaction in a hydrothermal synthesis reaction unit;
Thereby preventing clogging of the hydrothermal synthesis inlet portion.

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