JP2005247649A - Metallic chalcogen compound, method of manufacturing the same, electrode using the same and electrochemical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of synthesizing MnV<SB>2</SB>O<SB>6</SB>as same as the conventional one under atmospheric pressure though the synthesis of anhydrous MnV<SB>2</SB>O<SB>6</SB>having a brannerite type crystal structure in one pot conventionally requires to use a self hydrothermal method carried out in a tightly closed vessel under high pressure. <P>SOLUTION: When MnV<SB>2</SB>O<SB>6</SB>is obtained from V<SB>2</SB>O<SB>5</SB>and Mn(CH<SB>3</SB>COO)<SB>2</SB>in water medium, anhydrous MnV<SB>2</SB>O<SB>6</SB>is directly synthesized by feeding V<SB>2</SB>O<SB>5</SB>and Mn(CH<SB>3</SB>COO)<SB>2</SB>simultaneously or by feeding Mn(CH<SB>3</SB>COO)<SB>2</SB>after V<SB>2</SB>O<SB>5</SB>is fed. The anhydrous MnV<SB>2</SB>O<SB>6</SB>has a rectangular particle form. When the synthesis is not carried out by this way, bulky hydrate is obtained and not turned to the rectangular particle even if a heat treatment is carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a production method including a step of obtaining a solid metal element-containing chalcogen compound by chemical reaction in a solvent, and more specifically, by the production method, a primary battery, a secondary battery, an electric double layer capacitor, a large The present invention relates to a method for producing an electrode material for an electrochemical device such as a capacitor.

Electrode materials for electrochemical devices include noble metals such as Pt, passive metals such as Ni, Al,
Valve metals such as Ti and metal chalcogen compounds such as PbO ₂ , MnO ₂ , WO ₃ , V ₂ O ₅ , TiS ₂ and LiCoO ₂ are used. When a metal chalcogen compound is used as an electrode material for an electrochemical device, it accompanies an electrochemical reduction reaction in which group 1, group 2 elements such as protons, lithium ions, and magnesium ions are diffused, inserted, or occluded in the metal chalcogen compound. Since electrons can be received from the counter electrode through an external circuit, it is widely used for batteries and capacitors. Among batteries, lithium batteries using non-aqueous electrolytes have high energy density, and are expected to be used in various fields from small portable devices to large power storage power sources. Higher energy density is expected. In addition, the capacitor is expected to be used as an auxiliary power source for a hybrid car, a fuel cell car, and the like because a high output is obtained.

However, the synthesis of the metal chalcogen compound is usually performed at a high temperature such as several hundred degrees. For example, Patent Document 1 describes that a vanadium composite oxide typified by MnV ₂ O ₆ is used for a negative electrode of a battery. However, it is 1 at 800 ° C.
MnV ₂ O ₆ synthesized using a solid solution method including a step of baking for 2 hours (hereinafter referred to as “vanadium solid solution method”) has a problem of low electrochemical reversible capacity (347 mAh / g).
On the other hand, when the synthesis method described in Non-Patent Document 1 is used, a high reversible capacity of about 800 mAh / g is obtained. However, this synthesis method requires at least three stages of synthesis processes: (1) a step of making a gel of a raw material mixture using polyvinyl alcohol, (2) a preliminary firing and pre-grinding step, and (3) a main firing step. Therefore, there is a problem that the synthesis method is complicated and the manufacturing cost is increased.

On the other hand, in the non-patent document 2, the present inventors have used Mn (CH
A method for synthesizing an anhydrous vanadium complex oxide (MnV ₂ O ₆ ) having a brownelite structure by direct precipitation reaction between ₃ COO ₂ aqueous solution and V ₂ O ₅ was proposed. When this spontaneous hydrothermal synthesis method is used, there is an advantage that it can be manufactured at a temperature as low as 200 ° C. without requiring a large-scale apparatus. The powder obtained by this method has a relatively high crystallinity and has a strip-like uniform particle form, and an electrochemical device using this as an electrode has excellent electrochemical characteristics.

However, this synthesis method needs to be heated to 200 ° C. even at a relatively low temperature. Further, since it is necessary to use a pressure vessel because it is performed under high pressure conditions, it is dangerous and unsuitable for mass synthesis. Production costs were still high.

On the other hand, as shown in Non-Patent Document 3, when a similar synthesis is performed under atmospheric pressure, for example, in an open system such as a beaker, there is a problem that a hydrate of MnV ₂ O ₆ is generated. It was. Although this hydrate of MnV ₂ O ₆ can be made into an anhydrate by heat treatment, the anhydrate obtained from the hydrate is greatly different from the anhydrate obtained by the above-mentioned spontaneous hydrothermal synthesis. In addition, the crystallinity is low and the particles are in the form of lumps, and the electrochemical characteristics when applied to an electrochemical device are also inferior.
Japanese Patent Publication No. 6-349491 KIM, SS. IKUTA, H .; WAKIHARA, M .; Synthesis and charac- terization of MnV2O6 as a high capacity nano material for a lithium secondary battery. Solid State Ionics. vol. 139, 2001, p. 57-65. Inagaki (INAGAKI, M.), Morishita (MORISHITA, T.), Hirano (HIRANO, M.), Gupta (GUPTA, V.), Nakajima (NAKAJIMA, T.), Synthesis of MnV2O6 under Autoidous Hydroids. Performance, Solid State Ionics, (Netherlands), 2003, 156, p. 275-282 LIAO, J. et al. -H. DREZEN, T .; LEROUUX, F .; GUYOMARD, D .; PIFFARD, Y .; : Synthesis, Structures and thermal analysis of MnV 2 O 6 .nH 2 O phases (n = 1, 2 and 4): Eur. J. et al. Solid State Inorg. Chem. : Vol. 33, no. 5, 1996, page 411-427.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing an anhydrate of a metal chalcogen compound by a simple method under mild conditions. Another object of the present invention is to provide a metal chalcogen compound produced thereby, an electrode using the same, and an electrochemical device.

The configuration and operational effects of the present invention are as follows. However, the mechanism of action probably includes estimation, and the success or failure of the mechanism of action does not limit the present invention.

The present inventors can synthesize a material similar to the anhydrous MnV ₂ O ₆ obtained by the self-hydrothermal method described in Non-Patent Document 2 under normal pressure (for example, an open system such as a beaker). If possible, we thought that the above-mentioned conventional problems could be solved at once. When the present inventors perform the reaction process described in Patent Document 2 in an open system such as a beaker, Mn (CH ₃ COO) ₂
Since V ₂ O ₅ is dissolved in water in an acidic aqueous solution in which is dissolved, it is assumed that a hydrate may be formed in the reaction process as shown in the following formula.
V ₂ O ₅ + H ₂ O → 2HVO ₃
2HVO ₃ + Mn (CH ₃ COO) ₂ → MnV ₂ O ₆ .nH ₂ O + 2CH ₃ COOH

Therefore, the present inventors have made it possible to react with Mn (CH ₃ COO) ₂ while suppressing dissolution of V ₂ O _{5 in} an aqueous solvent, whereby an anhydrate can be obtained without passing through a hydrate by the reaction process of the following formula. I thought it could be obtained directly.
V ₂ O ₅ + Mn (CH ₃ COO) ₂ → MnV ₂ O ₆ + (CH ₃ CO) ₂ O

Vanadium oxide hardly dissolves in neutral water and floats as colloidal particles.
The pH of the colloidal particle surface is about 4.5. Thus, the pH of the aqueous solution is 4.5
When it is further lowered, the solubility of vanadium oxide is greatly increased and completely dissolved to become an orange transparent solution. In order to achieve the above reaction, it is considered important to reduce the chance that V ₂ O ₅ comes into contact with the acidic aqueous solution.

According to the present invention, as described in claim 1, the inorganic compound X containing the metal element A having a property capable of being dissolved in a solvent to reduce the pH value, and the metal chalcogen containing the metal element B and soluble in an acidic solution A method for producing a metal chalcogen compound comprising a step of reacting a compound Y with a solvent in a solvent to obtain a solid metal chalcogen compound Z containing metal elements A and B, under atmospheric pressure release, and It is a method for producing a metal chalcogen compound, wherein the compound X and the compound Y are brought into contact with the solvent under temperature conditions for performing the reaction.

Here, the solvent is preferably water. The compound X and the compound Y are different substances. Metal element A and metal element B are different elements. Under atmospheric pressure release, for example, the reaction container is an open system such as a beaker, and the liquid level of the reaction solvent is physically connected to the atmosphere. A refluxer may be attached if necessary. The temperature at which the reaction is carried out is the temperature at which the reaction is to proceed in the process, and usually the temperature that the designer of the process considers to be the most suitable for proceeding with the reaction is selected. Is done. Needless to say, the temperature at which the reaction is carried out varies depending on the selection of compound X, compound Y or the reaction system thereof.

In the step of obtaining the anhydride of MnV ₂ O _{6 in} one step from V ₂ O ₅ and Mn (CH ₃ COO) ₂ which is the above example, the reaction temperature is preferably 60 ° C. or higher. The higher the reaction temperature, the higher the Mn
This is preferable because the time required to obtain an anhydride of V ₂ O ₆ can be shortened. In this respect, the temperature is more preferably 85 ° C or higher, and further preferably 95 ° C or higher. The time required to obtain the anhydride of MnV ₂ O ₆ takes about one week when the reaction temperature is 65 ° C., and three hours when the reaction temperature is 95 ° C. When the temperature is less than 60 ° C., V ₂ O ₅ and Mn (CH ₃ COO) ₂
Since the reaction rate with is not sufficient, the pH value of the solvent decreases due to the presence of Mn (CH ₃ COO) ₂ before the reaction proceeds sufficiently, and the possibility that the dissolution reaction of V ₂ O ₅ proceeds increases. There is a risk that the product contains a large amount of hydrate. For example, when the reaction temperature is 25 ° C., the product contains a large amount of hydrate. A product containing such a high amount of hydrate is 12
Although an anhydride can be obtained by heat treatment at 0 ° C. or higher, it is difficult to obtain an excellent electrochemical performance. The upper limit of the temperature at which the reaction is carried out is not particularly limited, but when a water solvent is used, although the boiling point is slightly increased, it is considered to be 110 ° C. or lower because it is under atmospheric pressure release. That is, in the above example, water of 60 ° C. or higher,
The compound X and the compound Y are brought into contact with a solvent. The method of contacting is not limited, but as an example of a specific embodiment, water is heated in a beaker, and when the temperature reaches 60 ° C. or higher, the compound X and the compound Y are heated in the beaker. Can be put in. Thereby, the anhydrous form of the solid metal chalcogen compound Z containing the metal elements A and B can be directly synthesized. Therefore, an anhydrous metal chalcogen compound can be obtained by a simple method under mild conditions.

Further, according to the present invention, as described in claim 2, the contact between the compound X and the solvent is performed after the contact between the compound Y and the solvent.

With such a configuration, the opportunity for the compound Y to contact the acidic aqueous solution of the compound X can be reduced. As an aspect in which the contact between the compound X and the solvent is performed after the contact between the compound Y and the solvent, a method in which each of the compound X and the compound Y is weighed and brought into contact with the solvent at the same time, a compound X And a method in which both are mixed, the mixture is brought into contact with the solvent, a method in which the compound X is introduced after the compound Y is introduced, and the like. Among them, a method is preferred in which compound Y is added while stirring the solvent, and after confirming that compound Y is sufficiently dispersed in the solvent, compound X is added therein.

Further, according to the present invention, the particle form of the compound Z is different from the particle form of the compound Y, as described in claim 3.

Taking the above reaction system as an example, an anhydride having a strip-like particle form can be obtained from V ₂ O ₅ having a massive particle form. In this case, without using the method of the present invention, for example, when manganese acetate powder is introduced and then V ₂ O ₅ powder is introduced, a hydrate having a massive particle form is obtained.

In the present invention, as described in claim 4, the metal element B contains V (vanadium).

In the present invention, the compound Z is a vanadium composite oxide having an AV ₂ O ₆ type brownene structure.

Further, according to the present invention, as described in claim 6, the metal element A includes Ca, Cd, Co,
It contains one or more selected from the group consisting of Ni, Mg, Mn, Zn and Cu.

By including at least one or more metal elements selected from the group consisting of Ca, Cd, Co, Ni, Mg, Mn, Zn and Cu as the metal element A, the metal chalcogen compound Z intended by the present invention can be obtained. Can be easily obtained. In particular, the compound Y is preferable when it contains V (vanadium) as a metal element.
₃ O ₈ , CaVO ₃ , Ca ₂ V ₂ O ₇ , CaV ₂ O ₆ , Ca ₃ V ₂ O ₈ , CdV ₃ O ₈ , CdVO ₃ , C
d ₂ V ₂ O ₇ , CdV ₂ O ₆ , Cd ₃ V ₂ O ₈ , CoV ₃ O ₈ , CoVO ₃ , Co ₂ V ₂ O ₇ , CoV ₂
O ₆ , Co ₃ V ₂ O ₈ , NiV ₃ O ₈ , NiVO ₃ , Ni ₂ V ₂ O ₇ , NiV ₂ O ₆ , Ni ₃ V ₂ O ₈ ,
MgV ₃ O ₈ , MgVO ₃ , Mg ₂ V ₂ O ₇ , MgV ₂ O ₆ , Mg ₃ V ₂ O ₈ , MnV ₃ O ₈ , MnV
O ₃ , Mn ₂ V ₂ O ₇ , MnV ₂ O ₆ , Mn ₃ V ₂ O ₈ , ZnV ₃ O ₈ , ZnVO ₃ , Zn ₂ V ₂ O ₇ ,
ZnV ₂ O ₆ , Zn ₃ V ₂ O ₈ , CuV ₃ O ₈ , CuVO ₃ , Cu ₂ V ₂ O ₇ , CuV ₂ O ₆ , Cu ₃ V
₂ O ₈ , Cu ₅ V ₂ O ₁₀ , Cu ₁₁ V ₆ O ₂₆ , Cu ₃ V ₅ O _4, etc. can be easily synthesized.

In addition to the metal element A, the compound X may contain other transition metals and typical metals such as Ca and Mg.

Moreover, this invention is a metal chalcogen compound obtained by the manufacturing method of an above described metal chalcogen compound.

Since such a metal chalcogen compound can be obtained by a simple method as described above, by using it as an electrode material of an electrochemical device, an electrochemical device having good performance can be provided at low cost.

Further, according to the present invention, as described in claim 8, the anhydrous product of the metal chalcogen compound Z is obtained without going through the hydrate of the metal chalcogen compound Z. It is a metal chalcogen compound.

Moreover, this invention is a metal chalcogen compound which has a strip-shaped particle | grain form, as described in Claim 9.

The strip-like particle form includes a needle-like or rod-like form. In addition, the particle | grain form said to this specification means the form of a primary particle. As will be described later in the examples, the short side of the strip shape is 10 to 10.
Since it is on the order of several tens of nanometers, the transmission electron microscope (TEM) is used to confirm the particle morphology.
Is preferred.

  Moreover, this invention is an electrode which has the said metal chalcogen compound.

  Moreover, this invention is an electrochemical device provided with the said electrode.

According to the present invention, a metal chalcogen compound anhydride can be obtained by a simple method.
Moreover, the electrode material for electrochemical devices excellent in electrochemical performance can be produced by a simple method.

The particle size of the inorganic compound X is not particularly limited, and when an ionic species generated by dissociation of the inorganic compound X in a solvent is used for the reaction, taking into account the dissolution rate of the inorganic compound X,
What is necessary is just to select a preferable particle size. Depending on the type of reaction, it is preferable that the ionic species generated by dissociation of the inorganic compound X is preferably provided at a high concentration in a short time, or conversely, it may be preferable to be provided gradually over a long time. It is considered that the supply rate of the ionic species as described above may be adjusted by adjusting the particle size of the inorganic compound X. Inorganic compound X
The particle size is preferably 0.1 μm or more and 500 μm or less.

When the particle size of the metal chalcogen compound Y is too small, the possibility of dissolution in a solvent increases, which is not preferable. When the particle size is too large, a solid phase reaction is caused to occur on the solid metal chalcogen compound Y particles. There is an increased risk that this reaction will not proceed sufficiently. For this reason, 1 μm or more 1
00 μm or less is preferable. Such a particle size is preferable also in this respect because it can be used as an electrode material for an electrochemical device without pulverization after completion of the reaction.

The production method of the present invention causes a solid phase reaction to occur on solid metal chalcogen compound Y particles. From this viewpoint, it is preferable to pay attention to the amount of the metal chalcogen compound Y to be present in the solvent. If the amount of the metal chalcogen compound Y to be present in the solvent is too small, the possibility that the metal chalcogen compound Y is dissolved in the solvent increases. In the step of obtaining the anhydride of MnV ₂ O ₆ from V ₂ O ₅ and Mn (CH ₃ COO) ₂ which is the above example in one step, the vanadium oxide (metal chalcogen compound Y) to be present in the solvent The amount is preferably 0.05 mol / liter or more. If it is 0.1 mol / liter or more, there is no possibility of melting even if the reaction temperature is low and the reaction rate is slow.

As an embodiment of the present invention, MnV ₂ O ₆ using V ₂ O ₅ and Mn (CH ₃ COO) ₂ as raw materials
The present invention will be described in more detail by taking as an example the case of applying to the reaction for obtaining

Anhydrous MnV ₂ O ₆ obtained by applying the production method of the present invention is about 3.5 V to ⁰ V (vs. Li / Li ⁺ ) with respect to the metal Li potential due to insertion of lithium ions. Since it changes in a potential range, an electrochemical device using this as an electrode can function as a battery. For example, Mn
A battery using V ₂ O ₆ as a positive electrode active material and using an electrode material (metal lithium, lithium alloy, carbonaceous material, etc.) exhibiting an operating potential lower than the above potential as a negative electrode active material can be configured. Also,
A battery using MnV ₂ O ₆ as a negative electrode active material and an electrode material exhibiting an operating potential higher than the above potential as a positive electrode active material can be configured. It is preferable to form a lithium battery using MnV ₂ O ₆ as the negative electrode active material because lithium metal is not deposited on the negative electrode, a discharge capacity is large, and a lithium battery excellent in charge / discharge cycle performance is obtained. Furthermore, it can also be used as an electrode material for capacitors with charge transfer. In that case, the metal chalcogen compound of the present invention can be used for both electrodes.

In applying MnV ₂ O ₆ of the present invention to an electrode for an electrochemical device, MnV ₂ O ₆ may contain Mo as required. Battery performance such as charge / discharge capacity and repeated charge / discharge cycle performance can be further improved by mixing and including Mo during the process of synthesizing MnV ₂ O ₆ or after synthesis. The amount of Mo to be included is 2 with respect to vanadium.
Equivalent or less, more preferably 0.1 equivalent or more and 1.5 equivalent or less. The vanadium composite oxide according to the present invention may have a single-phase structure or a multi-phase structure. In particular, by adding Mo, depending on the synthesis conditions and depending on the amount of Mo, a solid solution structure, Any phase structure can be employed, any of which is effective.

MnV ₂ O ₆ synthesized by the production method of the present invention may be further heat-treated and used in an electrochemical device. When the heat treatment is performed, the crystallinity of MnV ₂ O ₆ is improved. Although it does not specifically limit as said heat processing temperature, 400-600 degreeC is preferable. The atmosphere at the time of the heat treatment is not particularly limited, but air, a gas whose oxygen concentration is arbitrarily adjusted, an inert gas such as nitrogen or argon, or the like can be used. By setting the heat treatment temperature to 600 ° C. or less,
This is preferable in that the possibility of causing a reaction with the added solid material can be reduced.

As starting materials for synthesizing MnV ₂ O ₆ , it is preferable to use acetate containing element A and V ₂ O ₅ . Examples of the acetate containing the element A include calcium acetate, cobalt acetate, nickel acetate, magnesium acetate, manganese acetate, and zinc acetate. Among these, manganese acetate is inexpensive and it is particularly preferable that the obtained vanadium composite oxide is used for a battery since it can be excellent in electrochemical characteristics.

When MnV ₂ O ₆ is used as an electrochemical device, particularly as a battery, charge transfer by oxidation / reduction of each element is used. For example, when applied to a lithium battery, the basic structure of the MnV ₂ O ₆ crystal changes due to the occlusion of lithium as each element is reduced, resulting in an amorphous state. Once amorphous, MnV ₂ O ₆ maintains an amorphous state by subsequent desorption and reinsertion of lithium ions. Therefore, when MnV ₂ O ₆ of the present invention is used in a battery system that utilizes insertion / extraction reactions of lithium ions, the vanadium composite oxide exhibits an amorphous crystal structure regardless of the charge / discharge depth.

The present invention will be described in more detail based on examples in which lithium batteries equipped with electrodes employing MnV ₂ O ₆ as a metal chalcogen compound are taken as examples, but the present invention is not limited to the examples unless it exceeds the gist of the invention. It is not limited.

(Example 1)
Manganese acetate Mn (CH ₃ COO) ₂ .4H ₂ O as an inorganic compound X (purity 99.0%
And 12.3 g (corresponding to compound X) and vanadium oxide V ₂ O ₅ (99.99%, high purity chemical, 200 mesh or less) as metal chalcogen compound Y
1 g (corresponding to compound Y) was fractionated. On the other hand, 100 ml of distilled water as a liquid solvent was placed in a round bottom flask (300 ml), and heated while slowly stirring with a magnetic stirrer. A reflux device was attached to the top of the flask. After confirming that the temperature reached 95 ° C., the separated vanadium oxide and manganese acetate were added simultaneously while vigorously stirring with a magnetic stirrer. Stirring was continued for 3 hours while maintaining the temperature at 95 ± 2 ° C., then the heating was stopped, the supernatant was removed by decantation, and the solution was filtered and washed several times with distilled water. Then, it dried at 60 degreeC and obtained the black brown powder. This is named Compound 1 of the present invention.

(Example 2)
Manganese acetate Mn (CH ₃ COO) ₂ .4H ₂ O as an inorganic compound X (purity 99.0%
, Manufactured by Nacalai Tesque) 12.3 g (corresponding to Compound X) and 9.1 g (corresponding to Compound Y) of vanadium oxide V ₂ O ₅ (99.99%, manufactured by High Purity Chemical Co.) as the metal chalcogen compound Y And were each sorted. Meanwhile, distilled water 1 as a liquid solvent in a round bottom flask (300 ml).
00 ml was added and heated with slow stirring with a magnetic stirrer. A reflux device was attached to the top of the flask. After confirming that the temperature reached 95 ° C., the magnetic stirrer was vigorously stirred and the separated vanadium oxide was added. After confirming that the vanadium oxide powder was sufficiently dispersed in water, manganese acetate that had been separated in the same manner was added. After stirring for 3 hours while maintaining the temperature at 95 ± 2 ° C.,
Heating was stopped, and the supernatant liquid was removed by decantation, followed by filtration and washing with distilled water several times.
Then, it dried at 60 degreeC and obtained the black brown powder. This is designated as Compound 2 of the present invention.

(Example 3)
Manganese acetate Mn (CH ₃ COO) ₂ .4H ₂ O as an inorganic compound X (purity 99.0%
And 12.3 g (corresponding to compound X) and vanadium oxide V ₂ O ₅ (99.99%, high purity chemical, 200 mesh or less) as metal chalcogen compound Y
1 g (corresponding to compound Y) was fractionated. On the other hand, 100 ml of distilled water as a liquid solvent was placed in a round bottom flask (300 ml), and heated while slowly stirring with a magnetic stirrer. A reflux device was attached to the top of the flask. After confirming that the temperature reached 95 ° C., the separated vanadium oxide and manganese acetate were added simultaneously while vigorously stirring with a magnetic stirrer. Stirring was continued for 168 hours while maintaining the temperature at 65 ± 2 ° C., then the heating was stopped, the supernatant liquid was removed by decantation, and the mixture was washed by filtration with distilled water several times. Then, it dried at 60 degreeC and obtained the black brown powder. This is designated as Compound 3 of the present invention.

(Comparative Example 1)
Manganese acetate Mn (CH ₃ COO) ₂ .4H ₂ O (purity 99.0%, manufactured by Nacalai Tesque) 12.3 g (equivalent to compound X) and vanadium oxide V ₂ O ₅ (99.99%, high purity) 9.1 g (corresponding to Compound Y) was fractionated. On the other hand, round bottom flask (300
ml) was added 100 ml of distilled water as a liquid solvent, and the separated manganese acetate and vanadium oxide were added thereto, and the mixture was slowly stirred with a magnetic stirrer. A reflux device was attached to the top of the flask. If the stirring is continued for a while, the suspended liquid becomes transparent. Thereafter, the mixture was heated, and when the temperature reached 60 ° C. or higher, a brown precipitate began to float. Further, heating (90 ° C. or higher) and stirring were continued for 3 hours, then the heating was stopped, the supernatant liquid was removed by decantation, and the solution was filtered and washed several times with distilled water. Then, it dried at 60 degreeC and obtained the black brown powder. This is designated as Comparative Compound 1.

(Comparative Example 2)
Manganese acetate Mn (CH ₃ COO) ₂ .4H ₂ O (purity 99.0%, manufactured by Nacalai Tesque) and vanadium oxide V ₂ O ₅ (99.99%, manufactured by Kojun Chemical Co., Ltd.) V / Mn =
The aqueous solution was separated into 2 to obtain respective aqueous solutions. Next, both aqueous solutions were mixed at room temperature to adjust the mixed aqueous solution so that the metal ion concentration was 0.5 mol / l. At this time,
The pH value of the mixed aqueous solution was about 4. 18 ml of the mixed solution was sealed in a stainless steel 25 ml container whose surface was coated with polytetrafluoroethylene, and the container was placed at 10 rpm.
The sample was heated at a temperature of 200 ° C. for 10 hours while rotating at a rotation speed of. Next, the obtained precipitate was repeatedly washed with distilled water until the pH of the washing solution reached 7.0, and after separating the precipitate by centrifugation, the precipitate was dried in air at 65 ° C. This is designated as Comparative Compound 2.

About this invention compounds 1-3 and the comparison compounds 1 and 2, when measured by the powder X-ray-diffraction method using a CuK (alpha) ray, about this invention compounds 1-3 and the comparison compound 2, the anhydrous vanadium composite which can be assigned to a brownite structure It was confirmed that an oxide (MnV ₂ O ₆ ) was obtained. As an example, an X-ray diffraction pattern of the compound 3 of the present invention is shown in FIG. On the other hand, with respect to Comparative Compound 1, a hydrate of vanadium composite oxide that can be assigned to water-containing MnV ₂ O ₆ was obtained, and an anhydride could not be obtained directly.

Moreover, when this invention compounds 1-3 and the comparative compounds 1 and 2 observed the particle | grain form with the scanning electron microscope, the strip-like particle | grain form was observed about this invention compound 1-3 and the comparative compound 2. FIG. As an example, an observation image of the compound 2 of the present invention by a transmission electron microscope (TEM) is shown in FIG. The white bar shown at the bottom of the figure indicates that this length is 50 nanometers. From the figure, it can be seen that in the compound of the present invention, primary particles aggregate to form secondary particles, and the primary particles have a strip shape with a width of 10 to several tens of nanometers. On the other hand, the primary particles of the comparative compound 1 had a massive form. Further, when comparative compound 1 is heat-treated, anhydrous vanadium composite oxide (MnV ₂ O ₆₎ that can be assigned to the brownite structure.
)was gotten. However, the primary particle form remained agglomerated and did not become a strip-like primary particle form.

In Example 1 above, the reaction time was 3 hours, but a small amount of unreacted V ₂ O ₅ remains under these conditions. Although it is difficult to confirm the residual unreacted V ₂ O ₅ from the X-ray diffraction pattern of the product, a V ₂ O ₅ peak appears when the X-ray diffraction pattern of the heat-treated product (eg, 400 ° C. for 5 hours) is observed. This can be confirmed. If this unreacted V ₂ O ₅ remains, it can be solved by increasing the reaction time. When the reaction time was 72 hours under the conditions of Example 1, the product was heat-treated and the X-ray diffraction pattern was observed.
_{The 2} O ₅ peak is not observed.

The electrochemical properties of the present compounds 1 to 3 and comparative compounds 1 and 2 were measured. 0.50 g of each compound, 0.45 g of acetylene black and polytetrafluoroethylene powder 0
. 05 g was mixed, a small amount of toluene was added as a solvent, kneaded to make a paste, and repeatedly rolled with a roll to prepare a mixture sheet having a thickness of 100 μm. These mixture sheets are cut out to 2.25 cm ² and bonded to a nickel mesh with a terminal as a current collector,
An electrode was obtained. As the counter electrode, a lithium foil bonded to a nickel mesh with terminals was used. A microporous film made of polyethylene was sandwiched between the obtained electrode and the counter electrode to form a pole group. Electrode in which LiPF ₆ was dissolved to a concentration of 1 mol / l in a solution in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1 with this electrode group placed in an aluminum laminate bag with terminals extending from each electrode. After injecting the liquid, it was sealed by heat sealing to produce an electrochemical device.

Each electrochemical device was discharged at a current density of 10 mA / g up to 0 V and 10 m up to 3.7 V.
The battery was charged at a current density of A / g. As a result, no difference was observed in the charge / discharge behavior of the electrochemical devices using the present compounds 1 to 3 and comparative compound 2. However, no good charge / discharge behavior was observed for the electrochemical device using Comparative Compound 1.

From the above results, it was confirmed that the electrochemical characteristics equivalent to those synthesized using the self-hydrothermal method can be obtained even by using the production method of the present invention which can be performed relatively easily under the release of atmospheric pressure. .

According to the present invention, the reaction can be performed under mild conditions without using high pressure, and the electrochemical performance can be improved when used for an electrode for an electrochemical device without performing post-process such as heat treatment. Since an excellent metal chalcogen compound can be obtained, energy consumption for production can be suppressed.

In Example 3, the reaction temperature is 65 ° C. and the reaction time is about one week. However, this reaction condition is not unrealistic. Such a reaction condition that takes a long time at a moderate temperature has a high possibility of practical use in combination with, for example, the use of geothermal heat or the use of heat generated from a waste incineration facility.

It is an X-ray diffraction pattern of the metal chalcogen compound which concerns on an Example. It is a transmission electron microscope observation image of the metal chalcogen compound which concerns on an Example.

Claims (11)

A metal element obtained by reacting an inorganic compound X containing a metal element A having a property capable of reducing a pH value by dissolving in a solvent and a metal chalcogen compound Y containing a metal element B and dissolved in an acidic solution in the solvent. A method for producing a metal chalcogen compound comprising a step of obtaining an anhydrous product of a solid metal chalcogen compound Z containing A and B, wherein the compound X and the compound X and A method for producing a metal chalcogen compound, wherein the compound Y is brought into contact with the solvent. The method for producing a metal chalcogen compound according to claim 1, wherein the contact between the compound X and the solvent is performed after the contact between the compound Y and the solvent. The particle form of the compound Z is different from the particle form of the compound Y.
The manufacturing method of the metal chalcogen compound of description. The said metal compound B is a manufacturing method of the metal chalcogen compound in any one of Claims 1-3 containing V (vanadium). The compound Z is a manufacturing method of a metal chalcogen compound according to any one of claims 1 to 4 vanadium composite oxide having AV ₂ O ₆ type Burauneraito structure. The metal chalcogen compound according to any one of claims 1 to 5, wherein the metal compound A includes one or more selected from the group consisting of Ca, Cd, Co, Ni, Mg, Mn, Zn, and Cu. Production method. The metal chalcogen compound obtained by the manufacturing method of the metal chalcogen compound in any one of Claims 1-6. The metal chalcogen compound Z according to claim 7, wherein the anhydride of the metal chalcogen compound Z is obtained without going through the hydrate of the metal chalcogen compound Z. The metal chalcogen compound according to claim 7 or 8, which has a strip-like particle form. The electrode which has a metal chalcogen compound in any one of Claims 7-9. An electrochemical device comprising the electrode according to claim 10.